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C K Park

Publications and source records attributed to C K Park.

At least 19 recordsLinked to original sources
PubMed2006

Emerging invasive liver abscess caused by K1 serotype Klebsiella pneumoniae in Korea.

OBJECTIVES: The high incidence of invasive liver abscess caused by Klebsiella pneumoniae in Taiwan, contrasted with the rareness of this disease in Western countries, has aroused special interest. There have been few detailed reports from other Asian countries. To investigate a current epidemiology of K. pneumoniae liver abscess in Korea and to determine K serotype distribution in K. pneumoniae strains causing liver abscess, we performed a nationwide prospective study. METHODS: Community-acquired, culture-proven liver abscess cases were enrolled between 2004 and 2005. Etiologies and clinical features were analyzed. K. pneumoniae isolates were serotyped according to K antigen. Meta-analysis was done to determine the time trend of the etiologies of liver abscess in Korea. RESULTS: Out of 371 cases collected prospectively, 290 (78.2%) were caused by K. pneumoniae. Most K. pneumoniae liver abscesses were monomicrobial. Diabetes mellitus was the most common underlying disease (39.9%). Distant metastatic infections were frequently observed (8.7%). magA PCR revealed that 95 (59.4%) out of 160 K. pneumoniae isolates belonged to the K1 serotype. CONCLUSIONS: Our study indicates that K. pneumoniae has emerged as a major etiologic agent of liver abscess in Korea, and these emerging infections seem to be attributable to invasive K. pneumoniae strains with capsular K1 serotype.

Aged↗
PubMed2006

Effects of maturational age of recipient oocytes and activation conditions on the development of porcine fetal fibroblast nuclear transfer embryos.

This study was conducted to evaluate the nuclear remodeling patterns and the developmental potential of porcine fetal fibroblast nuclear transfer embryos (NTs) following the maturational age of recipient oocytes and activation conditions. Donor cells were transferred into the enucleated oocytes that were matured for 36 or 44h. Electrofused embryos were cultured in PZM-3 for 6 days without activation treatment (EF group). Some of these embryos were additionally activated by electric stimulus (ES; EF+ES group) or a combination of ES and DMAP (EF+ES+D group) before culture. The reconstituted embryos were fixed 2.5h after fusion to evaluate the nuclear remodeling patterns. The nuclear remodeling pattern of NTs reconstituted with 44 h-matured recipients showed a tendency to form a pronucleus-like structure, while that of NTs reconstituted with 36 h-matured recipients showed a tendency to undergo a premature chromosome condensation (PCC) and form one set of chromatin clump. In EF+ES+D group, blastocyst development was significantly increased regardless of maturational age of recipient oocytes (P<0.05). The result indicates that additional activation treatment is necessary to induce the activation of embryos reconstituted with 36 h-matured recipients, and treatment with the combination of electrical stimuli and DMAP could enhance the blastocyst formation rate of porcine NTs reconstituted with both 36 h- and 44 h-matured recipient oocytes.

Animals↗
PubMed2006

Effects of plasmin on sperm-oocyte interactions during in vitro fertilization in the pig.

The present study was undertaken to examine the effect of plasmin on sperm viability and sperm-oocyte interaction during in vitro fertilization in the pig. Porcine sperm, which were washed in Dulbecco's PBS were re-suspended and incubated in fertilization medium (mTBM; modified Tris-buffered medium) containing 0, 0.1, 1.0, 10.0 or 100.0ng/mL of plasmin. Sperm viability was not affected by plasmin treatment. Addition of plasmin in doses ranging from 0.1 to 100.0ng/mL for 2, 4 or 6h to washed boar sperm resulted in enhancement of acrosome reaction (AR) compared with untreated cells. The concentration of 0.1ng/mL plasmin (95+/-18 sperm/oocyte) had no effect on sperm binding, whereas 1.0ng/mL (123+/-21 sperm/oocyte), 10.0ng/mL (124+/-16 sperm/oocyte) and 100.0ng/mL (124+/-15 sperm/oocyte) of plasmin increased sperm binding compared with the control (83+/-15 sperm/oocyte). The zona pellucida solubility (zona dissolution time) was less in medium with 1.0ng/mL (123+/-24s), 10.0ng/mL (99+/-15s) or 100.0ng/mL (95+/-19s) plasmin compared with control (176+/-27s). When pig oocytes and sperm were co-incubated in various concentrations of plasmin for 6h, the penetration rate was greater in medium with 1.0ng/mL plasmin (77.5+/-3.1%) compared with the control. However, there were no differences in the polyspermic rates and mean number of sperm (MNS)/oocyte between the groups treated with plasmin and control. These results suggest that plasmin might play a role in events related to fertilization.

Acrosome Reaction↗
PubMed2006

Endoscopic submucosal resection with double ligation technique for treatment of small rectal carcinoid tumors.

BACKGROUND AND STUDY AIMS: It is difficult to achieve complete endoscopic resection of rectal carcinoid tumors without any procedure-related complications. In this study, we evaluated the efficacy and safety of endoscopic submucosal resection with double ligation (ESMR-DL) for the treatment of small rectal carcinoid tumors. PATIENTS AND METHODS: Eleven rectal carcinoid tumors (in 11 patients) were resected by ESMR-DL between November 2001 and April 2004, using a conventional single-channel endoscope with an attached band-ligator device. The lesion was aspirated into the ligator device and an elastic band was placed around the base; a detachable snare was then used to ligate the stalk below the elastic band; and snare resection was performed above the elastic band. The resected specimens were examined with respect to size, histological atypia, depth of invasion, and the histological appearance of the resection margins. RESULTS: All the lesions were excised completely without any complications. There was no tumor invasion beyond the submucosal layer and there was no evidence of atypia in any of the specimens. Tumor diameter varied from 2.0 mm to 10.0 mm (average 6.2 mm). None of the 11 specimens showed histopathological evidence of tumor involvement at the resection margins. There were no immediate or late complications (bleeding or perforation) after ESMR-DL. There was no local recurrence and there were no distant metastases in any patients during the mean follow-up period of 18 months. CONCLUSION: Endoscopic submucosal resection with double ligation is a useful and safe method for the treatment of small rectal carcinoid tumors.

Carcinoid Tumor↗
PubMed2006

Hepatic intra-arterial injection of 3-bromopyruvate in rabbit VX2 tumor.

PURPOSE: To evaluate the antitumoral effects of an intra-arterial injection of 3-bromopyruvate (3-BrPA) on liver VX2 tumor in rabbits. MATERIAL AND METHODS: Twenty rabbits with surgically implanted liver VX2 tumors were used. The rabbits were divided into three groups: a control, a saline, and a 3-BrPA group. Four rabbits were not treated at all, and they served as the control group. The saline group (n = 6) received only intra-arterial saline injection. The 3-BrPA group (n = 10) received an intra-arterial injection of 3-bromopyruvate through the hepatic artery. The delivered amounts of 3-bromopyruvate were as follows: 25 ml of 0.5 mM in six rabbits, 25 ml of 1.0 mM in two rabbits, and 25 ml of 2.0 mM in two rabbits. Four days after intra-arterial injection, the rabbits were sacrificed and histopathologic analysis of the explanted livers was performed with comparison of the tumor necrosis ratio (a percentage of the necrotic area versus the entire tumorous area) in each group. RESULTS: The mean tumor necrosis ratio was 12.5+/-4.2%, 44.8+/-24.7%, and 49.4+/-14.3% in the control, saline, and 3-BrPA groups, respectively. Between the control and the saline group, and between the control and the 3-BrPA group the mean tumor necrosis ratio appeared to be significantly different (P<0.05). However, there was no statistical difference in the mean tumor necrosis ratio between the saline and the 3-BrPA group (P = 0.416). CONCLUSION: A single session of intra-arterial injection of 3-BrPA showed no better results in terms of tumor necrosis than that of saline injection in a rabbit VX2 tumor model.

Animals↗
PubMed2005

Regulation of prostaglandin synthesis by interleukin-1alpha in bovine endometrium during the estrous cycle.

Interleukin (IL)-1 has been suggested to participate in regulation of many reproductive functions. To investigate the possible role of IL-1alpha as a local regulator in bovine endometrium, we determined the effects of IL-1alpha on prostaglandin (PG) E2 and PGF(2alpha) output by the bovine endometrium at different stages of the estrous cycle. The expressions of IL-1alpha and IL-1 receptor type 1 (IL-1RT1) mRNA in bovine endometrium were also studied. Bovine uteri were classified into six stages (estrus: day 0; early luteal: days 2-3; developing luteal: days 5-6; mid luteal: days 8-12; late luteal: days 15-17; and follicular: days 19-21). After 1h of pre-incubation, endometrial tissues (20-30mg) were exposed to 0 or 10ng/ml IL-1alpha for 4h. IL-1alpha significantly stimulated PGE2 output throughout the luteal stages, with the highest response during the mid luteal stage, while it did not stimulate PGE2 output during the estrus and the follicular stage. On the other hand, IL-1alpha significantly enhanced PGF(2alpha) output throughout the estrous cycle except in the endometrium from the mid luteal stage, with the highest response at the follicular stage (P<0.001). The treatment of endometrial tissue with IL-1alpha resulted in an increase of the PGE2:PGF(2alpha) ratio at the mid luteal stage, and in a decrease during the late luteal and follicular stages of the estrous cycle. A semiquantitative reverse transcription-polymerase chain reaction revealed that IL-1alpha and IL-1RT1 mRNA are expressed in the endometrium throughout the estrous cycle. IL-1alpha mRNA expression was greater in the early luteal stage than in the estrus, late luteal, and follicular stages (P<0.05). IL-1RT1 mRNA was greater in the late luteal stage than in the other stages (P<0.05). The overall results suggest that IL-1alpha is produced in bovine endometrium throughout the estrous cycle, and plays some roles not only in maintenance of CL, but also in luteolysis by regulating the local PGE2:PGF(2alpha) ratio in bovine endometrium during the estrous cycle.

Animals↗
PubMed2005

Molecular characterization and chromosomal mapping of porcine adipose differentiation-related protein (ADRP).

ADRP plays an important role in regulating lipid storage in various cells. We investigated the ADRP gene as a candidate gene for intramuscular fat deposition and marbling traits in pigs. A full-length transcript of porcine ADRP was cloned by RT-PCR and RACE. The porcine ADRP cDNA (1848 bp) contains a 1377-bp open reading frame, encoding a deduced protein of 459 amino acids, which has amino acid sequence identities of 89, 89, 82 and 81% with cattle, human, mouse and rat ADRP genes respectively. The genomic structure and sequence of the porcine ADRP were also analysed using a BAC clone of a Korean native pig. Pig ADRP comprises eight exons spanning approximately 13 kb and is located on chromosome 1 q2.3-q2.7 between microsatellite markers SW2185 and SW974. Several sequence variations were detected from nine different pig breeds. The biological role of this gene and the mapping localization indicated that the porcine ADRP is a possible candidate gene for fat deposition and marbling traits.

Adipose Tissue↗
PubMed2005

CT halo sign: the spectrum of pulmonary diseases.

The CT halo sign indicates ground glass attenuation surrounding a pulmonary nodule on CT. Although it was initially proposed as an early, specific finding of invasive pulmonary aspergillosis, it can be caused by many other pathological conditions such as infection, neoplastic and inflammatory diseases. The halo of ground glass attenuation pathologically represents pulmonary haemorrhage, tumour infiltration, or non-haemorrhagic inflammatory processes. Although non-specific, this sign is important because the clinical setting and associated radiological features may give a clue to the differential diagnosis. In this review, we demonstrate the spectrum of pulmonary diseases showing the "CT halo sign" on thin-section CT and discuss their radiological and clinical features.

Adult↗
PubMed2005

Plasmon resonance methods in GPCR signaling and other membrane events.

The existence of surface guided electromagnetic waves has been theoretically predicted from Maxwell's equations and investigated during the first decades of the 20th century. However, it is only since the late 1960's that they have attracted the interest of surface physicists and earned the moniker of "surface plasmon". With the advent of commercially available instruments and well established theories, the technique has been used to study a wide variety of biochemical and biotechnological phenomena. Spectral response of the resonance condition serves as a sensitive indicator of the optical properties of thin films immobilized within a wavelength of the surface. This enhanced surface sensitivity has provided a boon to the surface sciences, and fosters collaboration between surface chemistry, physics and the ongoing biological and biotechnological revolution. Since then, techniques based on surface plasmons such as Surface Plasmon Resonance (SPR), SPR Imaging, Plasmon Waveguide Resonance (PWR) and others, have been increasingly used to determine the affinity and kinetics of a wide variety of real time molecular interactions such as protein-protein, lipid-protein and ligand-protein, without the need for a molecular tag or label. The physical-chemical methodologies used to immobilize membranes at the surface of these optical devices are reviewed, pointing out advantages and limitations of each method. The paper serves to summarize both historical and more recent developments of these technologies for investigating structure-function aspects of these molecular interactions, and regulation of specific events in signal transduction by G-protein coupled receptors (GPCRs).

Cell Membrane↗
PubMed2004

Patterns of failure in gastric carcinoma after D2 gastrectomy and chemoradiotherapy: a radiation oncologist's view.

The risk of locoregional recurrence in resected gastric adenocarcinoma is high, but the benefit of adjuvant treatment remains controversial. In particular, after extended lymph node dissection, the role of radiotherapy is questionable. Since 1995, we started a clinical protocol of adjuvant chemoradiotherapy after D2 gastrectomy and analysed the patterns of failure for 291 patients. Adjuvant chemotherapy consisted of five cycles of fluorouracil and leucovorin, and concurrent radiotherapy was given with 4500 cGy from the second cycle of chemotherapy. With a median follow-up of 48 months, 114 patients (39%) showed any type of failure, and the local and regional failures were seen in 7% (20 out of 291) and 12% (35 out of 291), respectively. When the recurrent site was analysed with respect to the radiation field, in-field recurrence was 16% and represented 35% of all recurrences. Our results suggest that adjuvant chemoradiotherapy has a potential effect on reducing locoregional recurrence. Moreover, low locoregional recurrence rates could give a clue as to which subset of patients could be helped by radiotherapy after D2 gastrectomy. However, in order to draw a conclusion on the role of adjuvant radiotherapy, a randomised study is needed.

Adenocarcinoma↗
PubMed2004

Pulmonary preservation effect of nitroglycerine in isolated rat lung reperfusion model.

PURPOSE: Though nitric oxide has many favorable protective effects on donor lungs, it may also have cytotoxic side effects. In this regard, we investigated whether administration of nitroglycerine, a nitric oxide donor, could minimize ischemia-reperfusion injury in an isolated rat lung reperfusion model. MATERIALS AND METHODS: Thirty-five Sprague-Dawley rats were used for this experiment. The nitroglycerine (NTG) group (n = 18) received the drug intravenously and the 17 control group hosts were treated with the same amount of normal saline. The heart-lung block was retrieved, weighed, and maintained in University of Wisconsin solution for 24 hours at 10 degrees C. Reperfusion was performed using human blood diluted in Krebs-Hensleit solution for 60 minutes. Peak inspiratory pressure, pulmonary artery pressure, and blood gas analysis were performed. After 60 minutes of reperfusion, the amount of protein in bronchoalveolar lavage (BAL) fluid and the myeloperoxidase (MPO) activity in the lung were measured. RESULTS: There were no major statistical differences between the two groups in peak inspiratory pressure and pulmonary artery pressure, but the NTG group maintained lower pulmonary artery pressure during the whole period of reperfusion. Oxygen tension in the NTG group was significantly higher, whereas there were no differences in carbon dioxide tension, BAL fluid, protein, or MPO activity. CONCLUSION: Administration of NTG before donor lung preservation resulted in better lung protection, a possible strategy for clinical application.

Animals↗
PubMed2004

Comparison of canine single and sequential bilateral lung transplant model for lung preservation study.

The purpose of this study was to compare canine sequential bilateral lung transplantation (SBLT) with left single lung transplant (LSLT) models. After 24 hours of lung preservation with low potassium/dextran glucose (LPDG) solution, seven SBLT procedures were performed using mongrel dogs. The comparative group including nine cases of LSLT. After completion of each transplant, the dogs were maintained on a ventilator for 3 hours. Thereafter serial hemodynamics were evaluated with recipients with chest X-ray, computed tomography, and lung perfusion scan checked at 2 hours after transplantation. Pathological evaluations were also performed. Five of seven SBLT successfully completed the whole assessment, all LSLT survived. In SBLT, pulmonary arterial pressure and pulmonary vascular resistance were significantly elevated, but recovered 3 hours after reperfusion. The ultrastructural aspects of alveolae and pulmonary artery endothelium showed a reversible mild injury 24 hours after lung preservation and reperfusion. The present study suggests that the canine SBLT model using LPDG solution provides an excellent preservation effect and is more physiological as the dog is completely dependent on the function of the transplanted lung.

Animals↗
PubMed2004

Ultrastructural evaluation of the protective effect of nitroglycerin in preservation-reperfusion injury of rat lungs.

AIM OF STUDY: Nitric oxide (NO) has been reported as a favorable protective supplement in donor lung preservation, but related ultrastructural studies are rare in the literature. This study was performed to assess the ultrastructural changes and to evaluate the protective effect of NO as donor nitroglycerin (NTG) treatment of ischemia-reperfusion injury in rat lungs. MATERIALS AND METHODS: Fifteen Sprague-Dawley rats weighing 300 to 350 g were used in this study. The NTG group (n = 5) used intravenous administration followed by mixture in the University of Wisconsin (UW) solution. For the non-NTG group (n = 5), we injected the same amount of normal saline intravenously followed by admixture in the UW solution. The heart-lung blocks were removed, weighed, and kept in UW solution for 24 hours at 10 degrees C. Reperfusion using human blood diluted in Krebs-Hensleit solution was done for 60 minutes. For the control group (n = 5), we injected the same amount of normal saline intravenously, and removed the lungs with no preservation and reperfusion procedures. RESULTS: The non-NTG group showed multiple patchy areas of alveolar collapse with marked swelling and destruction of type I epithelial cells, loss of type II cell surfactant granules, endothelial swelling and papillary projection, interstitial edema, and alveolar macrophages with active phagocytosis of the destroyed materials. The NTG group showed similar ultrastructural changes, but in a lesser severity compared with the non-NTG group. CONCLUSION: Administration of the NTG reduced the ischemia-reperfusion injury in the rat donor lungs. Ultrastructural examination was an effective tool to evaluate the protective effect of NTG in ischemia-reperfusion procedures of donor lungs.

Animals↗
PubMed2004

Dysplastic nodules in liver cirrhosis: detection with triple phase helical dynamic CT.

The purpose of this study was to determine the sensitivity of triple phase helical dynamic CT for detecting dysplastic nodules in patients with liver cirrhosis. 76 dysplastic nodules were confirmed by histopathological examination of the liver specimens after surgical resection in 21 patients or after explantation of the whole liver in 20 patients. Triple phase helical dynamic CT including arterial, portal venous and delayed phases was performed as a pre-operative evaluation for hepatocellular carcinoma. Two readers retrospectively evaluated the images. The presence of dysplastic nodules was determined by one-to-one correlation of the CT images and the pathological results in terms of the anatomical location and size of each nodule. Helical dynamic triple phase CT depicted eight of 76 dysplastic nodules (10%): five of 35 high grade dysplastic nodules (14%) and three of 41 low grade dysplastic nodules (7%). Triple phase helical dynamic CT is insensitive for detection of dysplastic nodules in cirrhotic livers.

Adult↗