Biomedical subjects
Publications and source records attributed to J S Kim.
Brugada syndrome is characterized by right bundle branch block, ST segment elevation in the precordial leads and sudden death caused by ventricular fibrillation. We present two successful anaesthetic management cases in patients with Brugada syndrome.
Explore the source record for details and available documents.
The technique of liver splitting offers an effective way of increasing the donor pool and decreasing pediatric waiting list mortality. A donor liver is divided in such a way that the left lateral liver graft can be transplanted into a small child and the right extended liver graft into an adult. This innovative technique did not harm the adult recipient pool. Because of its technical complexity and the initial poor results after split liver transplantation (SLT) this procedure has slowly gained acceptance in the Transplantation Community after its first introduction in 1988 (4). Small children with end stage liver disease suffered the most from the extreme shortage of cadaveric donor organs due to the difficulty of finding size-matched donors. The successful surgical development of SLT and a better donor and recipient selection have led to a reduction of the pediatric pretransplant mortality to nearly zero and to results comparable with those after whole organ transplantation (WLT). By splitting a donor organ into two 'full' hemi-grafts and providing a small adult ( < 60 kg) or a big child ( > 30 kg) with the full left graft and a medium-sized adult (60-80 kg) with the full right graft, a small-for-size situation for adolescents or adults can be avoided and the total number of available grafts can be increased. It is the goal to provide each recipient with its customized graft in the near future. However, splitting for two adults requires high technical skills and profound knowledge of the anatomic variations and should be performed in centers with large transplantation experience.
Explore the source record for details and available documents.
Recently, adaptivity was introduced to time-reversal mirror to steer the nulls, and referred to as an adaptive time-reversal mirror (ATRM) [J. S. Kim, H. C. Song, and W. A. Kuperman, J. Acoust. Soc. Am. 109, 1817-1825 (2001)]. In this study, ATRM is extended to simultaneous multiple focusing in an ocean waveguide. The multiple focusing is achieved by imposing a set of constraints in the formulation to find the weight vectors. The algorithm is applied to the long-range underwater acoustic communication to show, via simulation, that the simultaneous pulse compression at multiple receiving locations is achieved.
We performed nine metatarsal and three proximal phalangeal lengthenings in five patients with congenital brachymetatarsia of the first and one or two other metatarsal bones, by a one-stage combined shortening and lengthening procedure using intercalcary autogenous bone grafts from adjacent shortened metatarsal bones. Instead of the isolated lengthening of the first and the other metatarsal bones, we shortened the adjacent normal metatarsal and used the excised bone to lengthen the short toes, except for the great toe, to restore the normal parabola. One skin incision was used. All the operations were performed bilaterally and the patients were followed up for a mean period of 69.5 months (29 to 107). They all regained a nearly normal parabola and were satisfied with the cosmetic results. Our technique is straightforward and produces good cosmetic results. Satisfactory, bony union is achieved, morbidity is low, and no additional surgery is required for the removal of metal implants.
Biological ammonia-nitrogen removal utilizes two distinct processes, nitrification and denitrification. In nitrification, ammonia oxidizes to nitrite then to nitrate. In this study, elimination of nitrite oxidation to nitrate step was attempted in order to directly remove nitrite to nitrogen gas by denitrification. For this study the supernatant from an anaerobic digester was used as an ammonia source and a sequencing batch reactor (SBR) was employed. Emphasis was given to the evaluation of the operational factors affecting nitrite accumulation and the elucidation of kinetics for biological nitrification and denitrification. Accumulation of nitrite in the nitrification process was achieved by suppressing the growth of Nitrobacter, a nitrite oxidizer, by loading high concentration ammonia supernatant immediately after all ammonia in the previous loading was oxidized to nitrite. Nitrite oxidation was taking place as the solid retention time (SRT) was increased from 2.5 days to 3.0 days in a continuously aerated SBR mode with daily feeding. However, nitrite accumulation was achieved even at longer SRT of 5 days when the aeration and non-aeration periods were appropriately combined and the non-aeration period can be used for denitrification of the accumulated nitrite with a carbon source supplied.
We consider, theoretically and experimentally, the effects of structural disorder, quantum fluctuations, and thermal fluctuations in the magnetic and transport properties of certain ferromagnetic alloys. We study the particular case of UCu2Si2-xGex. The low temperature resistivity, rho(T,x), exhibits Fermi liquid behavior as a function of temperature T for all values of x, which can be interpreted as a result of the magnetic scattering of the conduction electrons from the localized U spins. The residual resistivity, rho(0,x), follows the behavior of a disordered binary alloy. The observed nonmonotonic dependence of the Curie temperature, T(c)(x), with x can be explained within a model of localized spins interacting with an electronic bath. Our results clearly show that the Curie temperature of certain alloys can be enhanced due to the interplay between quantum and thermal fluctuations with disorder.
BACKGROUND: Tuberculosis has increased in parallel with the acquired immunodeficiency syndrome epidemic and the use of immunosuppressive therapy, and the growing incidence of extra-pulmonary tuberculosis, especially with intestinal involvement, reflects this trend. However, the duration of anti-tuberculous therapy has not been clarified in intestinal tuberculosis. AIM: To compare the efficacy of different treatment durations in tuberculous enterocolitis in terms of response and recurrence rates. METHODS: Forty patients with tuberculous enterocolitis were randomized prospectively: 22 patients into a 9-month and 18 into a 15-month group. Diagnosis was made either by colonoscopic findings of discrete ulcers and histopathological findings of caseating granuloma and/or acid-fast bacilli, or by clinical improvement after therapeutic trial. Patients were followed up with colonoscopy every other month until complete response or treatment completion, and then every 6 months for 1 year and annually. Complete response was defined as a resolution of symptoms and active tuberculosis by colonoscopy. RESULTS: Complete response was obtained in all patients in both groups. Two patients in the 9-month group and one in the 15-month group underwent operation due to intestinal obstruction and perianal fistula, respectively. No recurrence of active intestinal tuberculosis occurred during the follow-up period in either group. CONCLUSIONS: Tuberculous enterocolitis can be managed by 9-month chemotherapy without disease recurrence. Further investigations are needed in immunocompromised patients.
The purpose of this study was to investigate the dietary taurine intake and serum taurine levels of women on Jeju Island in Korea. Sixty six married women aged 43.5 +/- 7.1 volunteered for this study: 34 from the city area and 32 from two fishing-farming areas. Diet samples were collected from the participants; the samples included three meals (breakfast, lunch and supper), including snacks, drinks and whatever else the participants had eaten for 24 hours. Taurine levels in the diet and serum were determined as the dabsyl derivative by HPLC with a Rf-detector. The intake of taurine ranged from 8.4 to 767.6 mg/day and its mean value was 163.9 +/- 150.2 mg/day (mean +/- SD). There was a significant difference between the two groups: 114.9 +/- 78.7 for the women from the city area and 215.9 +/- 187.9 mg/day for the women from the fishing-farming areas (p<0.001). The taurine intake of the total diet, including all snacks and drinks, was 2300 +/- 584 g/day for the city area and 2342 +/- 528 g/day for the fishing-farming areas. The daily protein intake was 58.8 +/- 16.4 g for the women of the city area and 65.5 +/- 17.1 g for the women of the fishing-farming areas. There was a significant correlation between the intake of fish/shellfish and taurine (p=0.001) while there was no correlation between the intake of protein and taurine (p=0.057). The taurine levels in serum ranged from 68.6 to 261.6 micromol/L and the mean value was 169.7 +/- 41.5 micromol/L. There was no significant difference between the women from the city area and the women from the fishing-farming areas in serum taurine levels. The correlations of serum taurine levels with serum retinol levels (p=0.016) and alpha-tocopherol (p=0.014) levels were significant. These results suggest that taurine intake is dependent on the fish/shellfish intake and that taurine may play an important role in the retention of antioxidative nutrients.
The objective of this work was to provide a new, precise registration of the cortical mantle with a non-linear transformation. Image registration is broadly classified into two types, using intensity similarity and feature similarity. Whereas the former approach has merit in global brain matching, the latter provides a fast registration centred on a region of interest. The hybrid registration proposed in this paper was achieved using a Bayesian framework, which consisted of a likelihood model including intensity similarity and a prior model including feature information and a smoothing constraint. In this approach, each voxel was spatially transformed, so that the distance between corresponding features was shortened and also so that the intensity correlation was maximised. The result of the hybrid method clearly showed a good match of global brain (r = 0.930) by including intensity similarity. Moreover, this method compensated for the approximated sulcus of the feature-based method with intensity information, so that the geometric shape and thickness of the sulcus at the feature-defined region was likely to be registered. The accuracy in the feature-defined area was improved by 33.4% and 7.5% compared with feature-based and intensity-based methods, respectively.
Amyloidosis is a disease characterized by the deposition of fibrillar protein amyloid of beta-structure in organs or tissues. It is usually classified as either a primary disease or secondary to a co-existent condition, such as rheumatoid arthritis, tuberculosis, or neoplasm (particularly multiple myeloma or renal cell carcinoma). Amyloid protein deposition can be seen in a variety of organs though it occurs with higher frequency in the gastrointestinal tract, kidney, and heart. Amyloidosis can have a wide spectrum of manifestations in nearly every abdominal organ. Some of these, for example, multiple cystic submucosal masses of the stomach, amyloidosis of the gallbladder, and dirty soft tissue infiltration of the subcutaneous fat, have not yet been covered in the radiological literature. The combination of various imaging techniques and the identification of characteristic computed tomography (CT) hepatic features may help in the differentiation of amyloidosis from other infiltrative diseases; however, confirmative diagnosis can usually only be achieved by tissue biopsy.
Using the chequerboard titration method, the activity in combination of beta-lactams, fluoroquinolones and aminoglycosides was investigated against 24 Pseudomonas aeruginosa isolates resistant to these antibiotics. Synergy was detected with one or more antimicrobial combinations against 15 of 24 (63%) isolates and partial synergy was detected with one or more combinations against all 24 isolates. No antagonism was seen with any combination. Ceftazidime and cefepime with aztreonam, amikacin and isepamicin showed synergy or partial synergy against 12-20 (50-80%) isolates. Imipenem and meropenem with amikacin and isepamicin showed synergy or partial synergy against eight to 12 (33-50%) isolates. The results of this study indicate that against P. aeruginosa, synergy may occur between beta-lactams, fluoroquinolones and aminoglycosides although the strains are resistant to the individual antibiotics.
BACKGROUND: Helicobacter pylori infection elicits persistent neutrophil infiltration in gastric mucosa. The expression of cyclooxygenase (COX)-2 and inhibition of apoptosis in the neutrophils could contribute to the pathogenesis of H. pylori infection. Rebamipide, a mucosal protective and ulcer-healing drug, has been known to inhibit neutrophil activation. AIM: To evaluate the effect of rebamipide on the neutrophils activated by H. pylori water-soluble proteins. METHODS: After neutrophils were stimulated with H. pylori water extract (HPWE) or pre-treated with rebamipide, the expression of COX-2 mRNA and protein was assessed by quantitative RT-PCR and Western blotting, respectively. Prostaglandin (PG) E2 synthesis was determined by radioimmunoassay. Neutrophil apoptosis was evaluated by cytosolic oligonucleosome-bound DNA ELISA and caspase-3 activity was measured by the detection of p-nitroanilide after cleavage from labelled substrate. RESULTS: Stimulation with HPWE up-regulated COX-2 expression and PGE2 secretion, and inhibited neutrophil apoptosis. Rebamipide suppressed PGE2 secretion from neutrophils dose-dependently. Rebamipide, however, did not affect neutrophil apoptosis and caspase-3 activity. CONCLUSIONS: Rebamipide effectively suppressed PGE2 secretion from neutrophils activated by H. pylori water-soluble proteins. This is another possible mechanism of gastric mucosal protection by rebamipide.
A scientific basis for the evaluation of the risk to public health arising from excessive dietary intake of nitrate in Korea is provided. The nitrate () and nitrite () contents of various vegetables (Chinese cabbage, radish, lettuce, spinach, soybean sprouts, onion, pumpkin, green onion, cucumber, potato, carrot, garlic, green pepper, cabbage and Allium tuberosum Roth known as Crown daisy) are reported. Six hundred samples of 15 vegetables cultivated during different seasons were analysed for nitrate and nitrite by ion chromatography and ultraviolet spectrophotometry, respectively. No significant variance in nitrate levels was found for most vegetables cultivated during the summer and winter harvests. The mean nitrates level was higher in A. tuberosum Roth (5150 mg kg(-1)) and spinach (4259 mg kg(-1)), intermediate in radish (1878 mg kg(-1)) and Chinese cabbage (1740 mg kg(-1)), and lower in onion (23 mg kg(-1)), soybean sprouts (56 mg kg(-1)) and green pepper (76 mg kg(-1)) compared with those in other vegetables. The average nitrite contents in various vegetables were about 0.6 mg kg(-1), and the values were not significantly different among most vegetables. It was observed that nitrate contents in vegetables varied depending on the type of vegetables and were similar to those in vegetables grown in other countries. From the results of our studies and other information from foreign sources, it can be concluded that it is not necessary to establish limits of nitrates contents of vegetables cultivated in Korea due to the co-presence of beneficial elements such as ascorbic acid and alpha-tocopherol which are known to inhibit the formation of nitrosamine.
AIM: To evaluate the compatibility of poloxamer hydrogel as a material for an injectable intraocular lens, in vivo and in vitro. METHODS: The appropriate concentration of poloxamer hydrogel was determined for injection by examining the transparency and gelling temperature of this material, assessing the lens capsule refilling technique, and studying the postoperative findings in a rabbit model. RESULTS: Poloxamer hydrogel showed excellent transparency and 25% was identified as an appropriate concentration for the lens refilling material. The authors developed a technique for injecting the material in vivo and obtained excellent short term results. CONCLUSIONS: Poloxamer hydrogel was identified as an appropriate material for direct lens refilling, and the developed injection technique produced excellent short term results.
INTRODUCTION: T-PLS (Twin-Pulse Life Support) is the first commercial pulsatile ECLS (Extra Corporeal Life Support) device (1). The dual sac structure of T-PLS can effectively reduce high membrane oxygenator inlet pressure and hemolysis. To verify both the use of T-PLS for ECLS and the advantages of T-PLS, we tested various models. METHOD AND RESULTS: In the partial CPB (cardio pulmonary bypass) model (swine), T-PLS (N = 6), and Biopump (N = 2), a single pulsatile pump (N = 2), were compared. In the case of single pulsatile flow, during pump systole, pressure increased to 700 - 800 mmHg at the inlet port of the membrane oxygenator. fHb, a hemolysis measurement value, was about 80 mg/dL at 3 hours. On the contrary, because of T-PLS's dual sac system, the pressure of T-PLS had a maximum value of about 250 mmHg and fHb was similar to that of the commercial centrifugal pumps. In the total CPB model (bovine, N = 6), the heart was stopped via cardioplegia (Kcl). T-PLS flow was maintained at 3.0-4.5 L/min. T-PLS functioned like a natural heart, having a pulse pressure of 26-43 mmHg and a pulse rate of 40-60 bpm (beats per minute). In the emergency case model (canine, N = 6), T-PLS was started 10 minutes after cardiac arrest from electronic shock. In spite of cardiac arrest for a period of 40 minutes, the heart was recovered after defibrillation. In the ARDS (Acute Respiratory Distress Syndrome) model (canine, N = 6), minimal ventilator parameters were set: tidal volume 130 ml, respiration rate = bpm, FiO2 = 10%. Three hours after starting T-PLS, PO2 of the carotid artery blood (after 2 hours: 195 +/- 89.4; after 3 hours: 258 +/- 99.3 mmHg) was above half the value of the femoral artery but was within normal range. CONCLUSION: It is suggested that a portable pulsatile ECLS like T-PLS may be used as a CPB device and as an alternative CPR (cardiopulmonary resuscitation) device in the case of cardiac arrest. Due to the pulsatile flow, oxygenated blood is delivered to the patient without overloading the ARDS patients heart.
The structural similarity of eugenol with capsaicin suggests that these two agents may share molecular mechanisms to produce their effects. We investigated the effects of eugenol in comparison with those of capsaicin using whole-cell patch clamp and Fura-2-based calcium-imaging techniques in a heterologous expression system and with sensory neurons. In vanilloid receptor 1 (VR1)-expressing human embryonic kidney (HEK) 293 cells and trigeminal ganglion (TG) neurons, eugenol activated inward currents, whereas capsazepine, a competitive VR antagonist, and ruthenium red (RR), a functional VR antagonist, completely blocked eugenol-induced inward currents. Moreover, eugenol caused elevation of [Ca(2+)](i), and this was completely abolished by both capsazepine and ruthenium red in VR1-expressing HEK 293 cells and TG neurons. Our results provide strong evidence that eugenol produces its effects, at least in part, via VR1 expressed by the sensory nerve endings in the teeth.