Search Results - (Author, Cooperation:Y. I. Kim)

2015-06-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Bacterial Proteins/*chemistry/genetics/*metabolism ; *Circadian Rhythm ; Circadian Rhythm Signaling Peptides and Proteins/*chemistry/genetics/*metabolism ; Phosphorylation ; Protein Folding ; Protein Structure, Secondary ; Synechococcus/metabolism/*physiology

2012-10-02

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

AIDS Vaccines/*immunology ; Acquired Immunodeficiency Syndrome/*virology ; Animals ; CD8-Positive T-Lymphocytes/*immunology ; Disease Models, Animal ; Epitopes, T-Lymphocyte/immunology ; Female ; HIV-1/immunology ; HLA-B27 Antigen/immunology ; Humans ; Immunodominant Epitopes/immunology ; Macaca mulatta/immunology/virology ; Male ; SAIDS Vaccines/*immunology ; Simian Acquired Immunodeficiency Syndrome/immunology/*prevention & ; control/virology ; Simian Immunodeficiency Virus/growth & development/*immunology/pathogenicity ; Viral Load ; Viremia/immunology/prevention & control ; Virus Replication/*immunology

2018-08-07

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

2018-05-16

BMJ Publishing

2044-6055

Medicine

Open access, Smoking and tobacco

2018-11-16

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Materials Science

1365-2559

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

AimsTo clarify the relationship between the Epstein–Barr virus (EBV) and gastric carcinoma with lymphoid stroma (GCLS) in Koreans, and to characterize the EBV-positive GCLS.Methods and resultsEBV infection was examined using EBER in-situ hybridization and polymerase chain reaction in 45 cases of GCLS among Koreans, and in 292 consecutive cases of gastric carcinomas without lymphoid stroma (non-GCLS) as controls. EBV infection was found in 30 tumours (67%) of GCLS and 10 tumours (3.4%) of non-GCLS (P 〈 0.05). EBV-positive GCLS was more prevalent in males, poorly differentiated histological type and diffuse type in Lauren's classification, and tended to be located more in the middle third of the stomach than EBV-negative GCLS (P 〈 0.05). p53 overexpression was observed in 22% of GCLS (17% of EBV-positive GCLS and 33% of EBV-negative GCLS), and 34% of non-GCLS (EBV-positive GCLS vs. non-GCLS: P = 0.056). The survival of the patient with GCLS was not correlated with EBV infection or p53 immunoexpression (follow-up period: 11–97 months).ConclusionsGCLS in Koreans is strongly associated with EBV infection. The prognosis in GCLS is not dependent upon either the status of EBV infection or the status of p53 immunoexpression.

Electronic Resource

1365-2559

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Aims:  Gastric adenocarcinoma in young patients has been considered to differ in many ways from gastric carcinoma in older patients. This study was designed to determine the clinicopathological features and molecular mechanisms.Methods and results:  Based on 4123 patients of gastric cancer in Seoul National University Hospital, 135 patients (3.3%) were chosen by the age of 30 years or younger. Expression of E-cadherin, β-catenin, p53 and Epstein–Barr virus (EBV) was analysed using the tissue array method in formalin-fixed paraffin-embedded specimens and microsatellite instability (MSI) was determined. As a control, 320 cases of older patients were compared. Gastric adenocarcinoma of young patients revealed significant female predominance, type IV gross type, proximal location, diffuse type and frequent lymph node metastasis. In-situ hybridization for EBV showed higher positivity in young patients (9/78, 11.5%) than in older ones, but not statistically significant. In EBV+ cases, p53 over-expression was significantly higher in young patients than older patients (P 〈 0.05). Alteration of E-cadherin or β-catenin was significantly higher in younger patients than in older patients (P 〈 0.05). Overall survival was significantly poorer in younger patients than older ones. The frequency of MSI was rare (1.3%, P 〈 0.05) in young patients compared with older patients (9.3%).Conclusions:  These data indicate that gastric adenocarcinoma of young patients has a poor prognosis, possesses aggressive histopathological features, exhibits reduced expression of E-cadherin and β-catenin, and demonstrates lower MSI than tumours in older patients.

Electronic Resource

0921-4534

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0169-7439

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1432-2307

Key words Hepatoid adenocarcinoma ; AFP-producing gastric carcinoma ; Stomach ; Alpha-fetoprotein ; Metastasis

Springer Online Journal Archives 1860-2000

Medicine

Abstract  Hepatoid adenocarcinoma (HA) is a rare variant of adenocarcinoma of the stomach, which is clinically characterized by increased level of serum α-fetoprotein(AFP) and poor prognosis. Microscopic findings include both adenocarcinomatous and hepatoid elements. A case of gastric adenocarcinoma with focal hepatoid differentiation confined within the metastatic lymph nodes occurred in a 55-year-old woman, who developed an advanced gastric carcinoma composed entirely of a typical papillo-tubular adenocarcinoma. Metastatic tumors were present in 8 of 13 perigastric lymph nodes, and 3 of these showed medullary and trabecular tumour growth reminiscent of hepatocellular carcinoma with immunohistochemical positivity for AFP. Preoperative serum AFP was 630 ng/ml and dropped to 76 ng/ml 2 weeks after the operation. Microscopic and immunohistochemical studies on the entire primary tumour tissue failed to demonstrate a focus of hepatoid or an AFP-positive area. This suggests that elevation of serum AFP may be reflected by focal hepatoid differentiation only in the metastatic lymph nodes, requiring extensive evaluation of the metastatic tumour in regional lymph nodes in the case of AFP-producing gastric carcinoma.

Electronic Resource

1432-2307

Key words p53 Mutation ; Overexpression ; Dysplastic nodule ; Hepatocellular carcinoma

Springer Online Journal Archives 1860-2000

Medicine

Abstract  In hepatocarcinogenesis, both de novo and multistep pathways have been suggested and in the latter a dysplastic nodule is the proposed precancerous lesion. In this study, we tried to ascertain whether or not the p53 gene is altered in low-grade/high-grade dysplastic nodules (LDN/HDN) and to determine the role of p53 alteration in multistep hepatocarcinogenesis. Eight hepatocellular carcinomas (HCCs), 9 HDNs, 17 LDNs and 25 cirrhotic nodules (LCs) were examined by polymerase chain reaction-single strand conformation polymorphism/direct sequencing and immunohistochemical staining for p53. Four of the 8 HCCs (50%) revealed p53 overexpression and 2 (25%) had missense mutations. Four of the 9 HDNs (44%) showed weak and/or focal p53 overexpression but none had mutation in the exons examined. Neither p53 overexpression nor mutation was found in 17 LDNs and 25 LCs. These results suggest that p53 mutation might be an unusual event in precancerous lesions of multistep hepatocarcinogenesis (DN-HCC sequence) and may play a less crucial part than in colorectal carcinogenesis.

Electronic Resource

1432-0509

Liver, cholangiocarcinoama ; Liver, US studies ; Liver, CT studies

Springer Online Journal Archives 1860-2000

Medicine

Abstract A case of cystic peripheral cholangiocarcinoma is presented. Both sonography and computed tomography (CT) demonstrated a large intrahepatic cystic neoplasm containing an enhancing solid portion. Despite the very rare incidence of this tumor, we believe that cystic degeneration of peripheral cholangiocarcinoma should be considered with these radiologic findings.

Electronic Resource

1432-0509

Key words: Pancreas, ectopic—Stomach, diseases—Stomach, cysts—Stomach, CT.

Springer Online Journal Archives 1860-2000

Medicine

Abstract Background: The purpose of this study was to characterize the computed tomographic (CT) findings of heterotopic pancreas of the stomach. Methods: CT scans of six surgically proven cases of heterotopic pancreas of the stomach were reviewed. Three were dynamic spiral CT scans, with both arterial dominant and late phase scans. In other three, both unenhanced and contrast-enhanced scans were obtained by using conventional techniques. Particular attention was given to the enhancement of the heterotopic pancreas. Pathologic and surgical findings were correlated with CT findings. Results: The locations were in the gastric antrum in five cases and in the mid-body in one. Size ranged from 1 cm to 3 cm (mean = 2.1 cm). Three cases showed homogeneous, strong enhancement similar to the pancreas and consisted mainly of pancreatic acini with the same histologic features as the normal pancreas. Two cases showed poor enhancement and consisted mainly of ducts and hypertrophied muscle; pancreatic acini were a minor component. In one case appearing as a cystic lesion on CT, a pseudocyst was found with many ducts and some nests of pancreatic acini. Conclusions: Heterotopic pancreas of the stomach showed a diverse spectrum of CT findings. Good understanding of these CT findings may be helpful in making a correct diagnosis.

Electronic Resource

1432-0509

Key words: Liver CT—Bile duct neoplasm—Peripheral cholangiocarcinoma—Cystic tumor of liver—Bile duct neoplasm, ERCP.

Springer Online Journal Archives 1860-2000

Medicine

Abstract The computed tomographic (CT) appearance of a case of intraductal mucosal-spreading mucin-producing peripheral cholangiocarcinoma of the liver is described in a patient presenting with acute pericardial tamponade due to rupture of the cystically dilated left intrahepatic ducts by mucin hypersecretion. CT showed cystic and tubular dilatation of the intrahepatic ducts of the left and caudate lobes, but there was no grossly visible tumor mass. Pathology showed a single layer of tall columnar tumor cells with short intraluminal papillary projections lining each bile duct; the ducts were markedly dilated because of excessive mucin secretion. There was no gross tumor mass in the bile ducts. The tumor spread diffusely and contiguously along the intrahepatic bile ducts, with minimal invasion to the bile duct wall. To our knowledge, there has been no report about mucosal-spreading peripheral cholangiocarcinoma of the liver.

Electronic Resource

1432-0509

Liver, neoplasms ; Sonography ; Angiography ; Computed tomography ; Oily contrast media

Springer Online Journal Archives 1860-2000

Medicine

Abstract To evaluate the characteristics of combined hepatocellular and cholangiocarcinoma of the liver by imaging techniques, six patients (five male and one female), aged 46–60 years, with proved combined tumors were selected for this study from the review of 500 resected specimens of liver tumors. Images obtained from sonography, computed tomography (CT), angiography, and CT after intraarterial injection of iodized oil (iodized-oil CT) were retrospectively reviewed and correlated with the appearance of pathologic specimens. Sonographic findings were round or ovoid hypoechoic masses with central hyperechoic area (target appearance) in all patients. On CT scans, tumors were relatively well-defined low- and/or iso-attenuation masses in all patients. Angiography showed hypovascular masses in five patients. In one patient, the tumor appeared as a hypovascular mass with a central hypervascular area. On iodized-oil CT scans, all patients showed partial retention of iodized oil in tumors. Echogenicity in tumors at sonography or attenuation in tumors at CT could not be correlated with histologic difference in tumors at pathologic specimens. However, the hypervascular area at angiography and the compact retention areas of iodized oil at iodized-oil CT corresponded to portions of hepatocellular carcinoma within the combined tumor. On the basis of our results, imaging features, including target appearance at sonography, hypovascular mass with central hypervascular portions at angiography, and partial retention of iodized oil in tumors at iodized-oil CT, might be helpful in making accurate diagnosis of these rare tumors.

Electronic Resource

1573-4811

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Electronic Resource

1432-1424

Small-cell lung cancer cells ; Voltagegated sodium channels ; Action potentials ; Lambert-Eaton syndrome ; Paraneoplastic neurological disorders

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract Sodium channels of human small-cell lung cancer (SCLC) cells were examined with whole-cell and single-channel patch clamp methods. In the tumor cells from SCLC cell line NCI-H146, the majority of the voltage-gated Na+ channels are only weakly tetrodotoxin (TTX)-sensitive (K d =215 mm). With the membrane potential maintained at −60 to −80 mV, these cells produced all-or-nothing action potentials in response to depolarizing current injection (〉20 pA). Similar all-ornothing spikes were also observed with anodal break excitation. Removal of external Ca2+ did not affect the action potential production, whereas 5 μm TTX or substitution of Na+ with choline abolished it. Action potentials elicited in the Ca2+-free condition were reversibly blocked by 4 mm MnCl2 due to the Mn2+-induced inhibition of voltage-dependent sodium currents (I Na). Therefore, Na+ channels, not Ca2+ channels, underlie the excitability of SCLC cells. Whole-cell I Na was maximal with step-depolarizing stimulations to 0 mV, and reversed at +45.2 mV, in accord with the predicted Nernst equilibrium potential for a Na+-selective channel. I Na evoked by depolarizing test potentials (−60 to +40 mV) exhibited a transient time course and activation/ inactivation kinetics typical of neuronal excitable membranes; the plot of the Hodgkin-Huxley parameters, m∞ and h∞, also revealed biophysical similarity between SCLC and neuronal Na+ channels. The single channel current amplitude, as measured with the inside-out patch configuration, was 1.0 pA at −20 mV with a slope conductance of 12.1 pS. The autoantibodies implicated in the Lambert-Eaton myasthenic syndrome (LES), which are known to inhibit I Ca and I Na in bovine adrenal chromaffin cells, also significantly inhibited I Na in SCLC cells. These results indicate that (i) action potentials in human SCLC cells result from the regenerative increase in voltage-gated Na+ channel conductance; (ii) fundamental characteristics of SCLC Na+ channels are the same as the classical sodium channels found in a variety of excitable cells; and (iii) in some LES patients, SCLC Na+ channels are an additional target of the pathological IgG present in the patients' sera.

Electronic Resource

1573-4811

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Electronic Resource

1573-482X

Springer Online Journal Archives 1860-2000

Electrical Engineering, Measurement and Control Technology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract The effects of La content and rapid thermal annealing (RTA) on the capacitance (C–V) and leakage current (J–E) properties of the PLT films were investigated. The films were deposited on Pt/Ti/SiO2/Si substrates at 480 °C by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR PECVD). The La doped films showed slim P–E hysteresis curves and almost no frequency dependency of permittivity. As the La content increased beyond 11%, Pb was excessively incorporated into the PLT film, resulting in non-stoichiometric compositions with (Pb+La)/Ti〉1, degraded crystallinity and decreased capacitance. After RTA at 700 °C, C–V curves became symmetric and leakage current characteristics were improved, but the crystallinity and the ferroelectricity of the films were not so much improved although the film became stoichiometric. The leakage current of the films was controlled by Schottky conduction except for the low electric field region where the trap current of mobile charges or hopping conduction appeared to be dominant. In order to explain the RTA dependence of the C–V shift and the polarity dependence of the J–E characteristics of the PLT films, a physical model was suggested, based on the surface states and Pb vacancies, which affects the width of the space charge region and the height of the Schottky barrier. © 1998 Kluwer Academic Publishers

Electronic Resource

1741-2765

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract The problem of using measured modal parameters to detect and locate damage in structures made of fiberreinforced composites is investigated. Recent work in this area using modal sensitivity equations is used in conjunction with internal-state variable constitutive theory to derive a set of damage-detection equations which are used to predict, from changes in measured modal parameters, the current value of the internal-state variables in each finite element. The value of the internal-state variable determines the extent of damage at a given location. Numerical examples involving damaged composite beams are used to demonstrate the capability of the theory to predict the exact location and the severity of damage. To provide experimental evidence to support the theory, mechanical and modal tests are performed on a [0,903] s laminated composite beam in the undamaged state and in three additional states of progressive damage. At each stage of damage, edge replications are taken to determine the crack density along the length of the beam. The predicted values of the internal-state variables, obtained from the modalsensitivity equations using measured modal information, are compared with the values of the internal-state variables obtained from crack-density measurements along the length of the beam. Good agreement between the predicted and the measured values is found.

Electronic Resource