Publications by authors named "Hahm J"

Objectives: To promote the exchange of knowledge and standardization of medical procedures and medical systems in the Asia-Pacific region, we established a medical network with high-quality moving images over broadband Internet lines in February 2003.

Methods: Real-time teleconferences and live demonstrations with medical-quality videos, broadcast via the Digital Video Transport System, have been used to teach surgical techniques and other medical procedures across national borders. The Asia-Pacific Advanced Network (APAN) committee in August 2005 formally approved our proposal to establish a medical working group within APAN.

View Article and Find Full Text PDF

We describe a 47-year-old woman with severe coronary vasospasm induced by hyperthyroidism. The patient complained of anginal chest pain without specific characteristics of thyrotoxicosis. Coronary arteriography was performed and revealed 90% stenosis of both the left and right coronary os.

View Article and Find Full Text PDF

Understanding structural and functional changes of polymeric surface-bound proteins is extremely important as polymers play an increasingly significant role as arrays and substrates in proteomics applications. We carried out, for the first time, quantitative activity measurements of horseradish peroxidase (HRP) enzymes immobilized selectively on the polystyrene domains of microphase-separated polystyrene-block-polymethylmethacrylate ultrathin films. The specific enzymatic activity of HRP adsorbed on the diblock copolymer surface was evaluated and compared to that of HRP in free solution.

View Article and Find Full Text PDF

Background/aims: Diabetes is one of the risk factors of gallstone diseases. Many studies found a positive association between insulin and gallstones in individuals with diabetes. However, this association is unclear in non-diabetes.

View Article and Find Full Text PDF

We analyzed the in vivo tumor regression activity of high molecular mass poly-gamma-glutamate (gamma-PGA) from Bacillus subtilis sups. chungkookjang. C57BL/6 mice were orally administered 10-, 100-, or 2000-kDa gamma-PGA or beta-glucan (positive control), and antitumor immunity was examined.

View Article and Find Full Text PDF

Novel methods for affixing functional proteins on surfaces with high areal density have the potential to promote basic biological research as well as various bioarray applications. The use of polymeric templates under carefully balanced thermodynamic conditions enables spontaneous, self-assembled protein immobilization on surfaces with spatial control on the nanometer scale. To assess the full potential of such nanometer-scale protein platforms in biosensing applications, we report for the first time the biological activity of proteins on diblock copolymer platforms.

View Article and Find Full Text PDF

Background/aims: Telemedicine has opened the door to a wide range of learning experience and simultaneous feedback to doctors and students at various remote locations. However, there are limitations such as lack of approved international standards of ethics. The aim of our study was to establish a telemedical education system through the development of high quality images, using the digital transfer system on a high-speed network.

View Article and Find Full Text PDF

Various reports on the prevalence of gastroesophageal reflux disease (GERD) and uninvestigated dyspepsia have been conducted in Western countries. We sought to determine the frequency of GERD symptoms and uninvestigated dyspepsia in Korea. Telephone interviews were conducted with 1,044 individuals.

View Article and Find Full Text PDF

We investigated the importance and efficiency of active and passive exploration on the recognition of objects in a variety of virtual environments (VEs). In this study, 54 participants were randomly allocated into one of active and passive navigation conditions. Active navigation was performed by allowing participants to self-pace and control their own navigation, but passive navigation was conducted by forced navigation.

View Article and Find Full Text PDF

Aim: To examine the diagnostic yield of colorectal neoplasia at computed tomographic colonoscopy (CTC) as well as the feasibility of contrast enhanced CTC in patients with gastric cancer.

Methods: To examine the incidence of colon polyp we selected postoperative 188 gastric cancer patients, which we refer to as the 'colon polyp survey group'. To examine the feasibility of CTC for early detection of colon cancer or advanced colon adenoma, we selected 47 gastric cancer patients (M:F 29:18, mean age 53.

View Article and Find Full Text PDF

Novel methods for creating protein arrays with two-dimensional control can significantly enhance basic biological research as well as various bioarray applications. We demonstrate that the structural variety and chemical heterogeneity of self-assembled, hexagonal polystyrene-b-poly(vinylpyridine) micelles can be successfully exploited as templates for easy and rapid fabrication of functional protein arrays over a large scale. Spontaneous formation of such polymeric template-guided protein molecules yields high-density protein arrays that exhibit repeat spacings in a nanoscopic dimension.

View Article and Find Full Text PDF

The incidence of functional intussusception is extremely rare in adults. A 23-year-old woman, previously diagnosed with type 1 diabetes mellitus (DM), complained of colicky abdominal pain associated with vomiting of 1-day duration. Currant jelly stool was observed.

View Article and Find Full Text PDF

Background: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder in the West. But information on the prevalence of IBS in Asia is still lacking, especially in Korea. Therefore, the aims of the present study were to estimate the prevalence of IBS in the general population of Korea and also to investigate characteristics of IBS and health-care-seeking behavior of IBS patients.

View Article and Find Full Text PDF

Biliary complication occurs in 6-34% of all liver transplant patients. Although bile leaks and strictures are relatively common, other biliary complications such as T-tube leak, choledocholithiasis, and biliary cast syndrome can also be observed. The biliary cast syndrome describes the presence of casts causing obstruction with its resultant sequelae of biliary infection, hepatocyte damage secondary to bile stasis and ductal damage, all contributing to cholangiopathy.

View Article and Find Full Text PDF

Hyperglycemic hyperosmolar state (HHS) is an acute complication mostly occurring in elderly type 2 diabetes mellitus (DM). Thyrotoxicosis causes dramatic increase of glycogen degradation and/or gluconeogenesis and enhances breakdown of triglycerides. Thus, in general, it augments glucose intolerance in diabetic patients.

View Article and Find Full Text PDF

In Crohn's disease, neurologic complications such as cerebrovascular accident, headache, peripheral neuropathy have been reported sporadically. The pathogenesis of these neurologic complications is still unknown and controversial. We experienced a 22-year-old man, with Crohn's disease accompanied by optic neuritis.

View Article and Find Full Text PDF

Most studies of bowel habits have been conducted in Western countries. This study was conducted to estimate the epidemiology of constipation and the discrepancy between self-reported constipation and bowel habits in Koreans. Telephone interviews regarding bowel habits were conducted with a total of 1029 individuals in Korea, 15 years of age or older.

View Article and Find Full Text PDF

CyberKnife is an image-guided robotic system designed for stereotactic radiosurgery. It uses the combination of robotics and image guidance to deliver concentrated and accurate beams of radiation to intracranial and extracranial targets. Although the frameless nature of the CyberKnife allows tumors in the chest and abdomen to be treated as well, complications associated with CyberKnife treatment have not been established yet due to its short clinical experience.

View Article and Find Full Text PDF

Here we report the case of a 20-year-old female patient previously diagnosed with Hashimoto's thyroiditis and overt hypothyroidism, and who had been taking synthetic thyroxine (100 microg/day) for eight months. She experienced intermittent dizziness and generalized weakness, and was diagnosed as having severe autoimmune hemolytic anemia (AIHA). We prescribed prednisolone treatment and continued synthetic thyroxine administration.

View Article and Find Full Text PDF

Fluorescence detection is currently one of the most widely used methods in the areas of basic biological research, biotechnology, cellular imaging, medical testing, and drug discovery. Using model protein and nucleic acid systems, we demonstrate that engineered nanoscale zinc oxide structures can significantly enhance the detection capability of biomolecular fluorescence. Without any chemical or biological amplification processes, nanoscale zinc oxide platforms enabled increased fluorescence detection of these biomolecules when compared to other commonly used substrates such as glass, quartz, polymer, and silicon.

View Article and Find Full Text PDF

Crohn's disease is a condition of chronic inflammation potentially involving any location of the alimentary tract from mouth to anus. Numerous extraintestinal manifestations can also be present. Urologic complications of inflammatory bowel disease are seen in up to 25% of patients, but renal parenchymal disease has been rarely reported.

View Article and Find Full Text PDF

The peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear receptor highly expressed in the colon and playing an anti-inflammatory role through inhibition of the NF-kappaB pathway. Toll-like receptor 4 (TLR4) has been known to mediate LPS-induced cellular signaling through activation of NF-kappaB pathway in intestinal epithelial cells. The aims of this study were to evaluate attenuation of inflammation by PPARgamma in intestinal epithelial cells and to study the possible relation between PPARgamma and TLR4.

View Article and Find Full Text PDF

We investigated the in vitro antibiotic activity of the 19-amino acid antimicrobial peptide HP (2-20), derived from the N-terminus of Helicobacter pylori Ribosomal Protein L1 (RPL1), against antibiotic susceptible and resistant pathogens from a patient with gallstones. HP (2-20) was active against antibiotic-susceptible and antibiotic-resistant clinical isolates of pathogens from a patient with gallstones, but this peptide showed no hemolytic activity against normal human erythrocytes. HP (2-20) acted synergistically with ciprofloxacin against pathogenic bacteria.

View Article and Find Full Text PDF

Percutaneous liver biopsy is well established for the diagnosis and follow-up of many liver diseases. Although it is rather safe, major complications, such as bleeding into the peritoneal or thoracic cavity, hemobilia, enteric perforation and intrahepatic hematoma, have been reported related to the procedure. Recently, incidence of such major complications has been decreased since the introduction of ultrasonography-guided liver biopsy.

View Article and Find Full Text PDF

We developed a straightforward method to produce hexagonal ZnO nanorods and microrods using a novel biocatalyst, Magnetospirillum magnetotacticum. ZnO nanorods were synthesized homogeneously on growth substrates when the bacterial catalysts were deposited uniformly on substrates whereas ZnO microrods were formed when the catalysts were introduced to selective areas of growth substrates using microcontact printing. X-ray diffraction measurements reveal that these ZnO structures exhibit Wurtzite structures with preferential growth along [0001] direction.

View Article and Find Full Text PDF