Search PubMed⌕ Search

Biomedical subjects

T K Kim

Publications and source records attributed to T K Kim.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Gastric adenoma with atypical appearance: findings on double-contrast barium study with histopathologic correlation.

BACKGROUND: To describe the radiologic findings of nonpolypoid gastric adenomas and to correlate them with pathologic findings. METHODS: During a 9-year period, we reviewed 49 pure gastric adenomas in 43 patients with positive radiologic findings. Of these adenomas, seven with atypical polypoid appearance were retrospectively included in the study. We reviewed these findings with double-contrast barium study and correlated them with the pathologic findings. RESULTS: Of seven nonpolypoid adenomas, four were depressed and three were flat at pathologic examination. All were diagnosed as early gastric carcinoma (five as type IIc, one as type IIb, one as type IIa + IIc) in upper gastrointestinal series. Three were located in the gastric angle, two in the lower body, and two in the antrum. Size ranged from 10 mm to approximately 25 mm (mean = 15 mm). Six lesions had nodular surface and five had convergency of the mucosal folds. A shallow depressed area was seen in six lesions. CONCLUSIONS: A considerable proportion of gastric adenomas presents as a depressed or flat lesion on double-contrast barium study because of histologic characteristics of decreased subjacent mucosa. Because the nonpolypoid adenoma has a greater potentional for malignancy, more precaution is needed during the follow-up of this uncommon lesion.

Adenoma↗
PubMedDate not supplied

Alteration of cell growth and morphology by overexpression of transforming growth factor beta type II receptor in human lung adenocarcinoma cells.

TGF-beta is a potent inhibitory regulator of cell growth, which is transduced through interaction between type I (RI) and type II (RII) receptors that form heteromeric kinase complexes. Abnormal expression of these receptors has been identified in several human epithelial cancers and has been shown to be highly associated with resistance to TGF-beta. In this study, we investigated the expression of RI and RII in 13 human non-small cell lung cancer cell lines (NSCLCs) and demonstrated decreased or loss of RII expression in five lung cancer cell lines, but not of RI. Of these cell lines, the role of RII in NCI-H358 adenocarcinoma, which lacks RII and is insensitive to TGF-beta, was investigated by transducing this cell line with a recombinant retrovirus expressing full-length TGF-beta RII. Stably transfected cells showed significant increase in RII mRNA and protein expression. These cells responded to exogenous TGF-beta1 with suppressed proliferation in a dose-dependent manner and G1 arrest accompanied by morphological change distinct from control cells. We also investigated whether overexpression of dominant-negative RII (dnRII) in NCI-H441 adenocarcinoma, which is sensitive but expresses low levels of RII, could block signaling through the receptor complex. The overexpression of this kinase-domain-truncated RII by expressing the retroviral dnRII construct led to loss of the ability to respond to TGF-beta1 and an exhibition of uncontrolled growth. These results suggest a close association between the loss of the expression of wild-type TGF-beta RII and carcinogenesis in human lung cancer cells.

Adenocarcinoma↗
PubMedDate not supplied

Transcatheter oily chemoembolization of the inferior phrenic artery in hepatocellular carcinoma: the safety and potential therapeutic role.

PURPOSE: To evaluate the efficacy and safety of transcatheter oily chemoembolization therapy (TOCE) via the inferior phrenic artery (IPA) in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty patients with HCC underwent a total of 82 procedures of TOCE of the IPA, as well as of the hepatic artery. In 16 patients, additional extrahepatic collaterals were depicted and were also embolized in 10 patients. TOCE was performed with an emulsion of iodized oil and doxorubicin hydrochloride, and gelatin sponge particle embolization was added in 32 patients. RESULTS: Initial response showed complete or partial remission of the tumor in 31 patients. The cumulative survival rates after combined TOCE of the hepatic artery, IPA, and other extrahepatic arteries were 89% (6 months), 78% (1 year), 46% (2 year), and 30% (3 year), when calculated from the time of IPA chemoembolization. Liver abscess and empyema developed in one case of combined IPA and multiple intercostal artery chemoembolization. There were no serious complications after IPA chemoembolization alone. CONCLUSION: TOCE of the IPA has a potential therapeutic role as a safe adjunct to TOCE of the hepatic artery in the management of HCC supplied by the IPA.

Adult↗
PubMedDate not supplied

Osmoprotective effect of glycine betaine on thrombopoietin production in hyperosmotic Chinese hamster ovary cell culture: clonal variations.

When 23 recombinant Chinese hamster ovary (rCHO) cell clones were cultivated in hyperosmolar medium resulting from NaCl addition (533 mOsm/kg), their specific thrombopoietin (TPO) productivity (q(TPO)) was increased. However, due to depressed cell growth at elevated osmolality, no enhancement in the maximum TPO titer was made in batch cultures of all 23 clones. To test the feasibility of using glycine betaine, known as a strong osmoprotective compound, for improved TPO production in hyperosmotic rCHO cell cultures, hyperosmotic batch cultures of 23 clones were performed in the presence of 15 mM glycine betaine. Glycine betaine was found to have a strong osmoprotective effect on all 23 clones. Inclusion of 15 mM glycine betaine in hyperosmolar medium enabled 22 clones to grow at 542 mOsm/kg, where most clones could not grow in the absence of glycine betaine, but at a cost of reduced q(TPO). However, the relative decrease in q(TPO) varied significantly among clones. Thus, efficacy of the simultaneous use of hyperosmotic pressure and glycine betaine as a means to improve foreign protein production was variable among clones. Six out of 23 clones displayed more than a 40% increase in the maximum TPO titer in the hyperosmolar medium containing glycine betaine, compared with that in the standard medium with a physiological osmolality. Taken together, the results obtained here emphasize the importance of selection of clones for the successful use of hyperosmotic pressure and glycine betaine as an economical means to improve TPO production.

Animals↗
PubMedDate not supplied

Intraperitoneal drop metastases from hepatocellular carcinoma: CT and angiographic findings.

UNLABELLED: Our goal was to describe the radiological manifestations of intraperitoneal drop metastases (IPDMs) from hepatocellular carcinoma (HCC). METHODS: Seven patients with clinically (n = 4) or pathologically (n = 3) proven IPDMs from HCC were retrospectively analyzed. Medical records, CT scans (n = 7), and angiographic findings (n = 5) were reviewed. RESULTS: On CT scans, all seven patients had single or multiple nodular masses in the liver. In six patients, the hepatic masses showed an exophytic growth. Single (n = 4) or multiple (n = 3) discrete omental masses, 3-10 cm in diameter, were also demonstrated in all patients. Intratumoral necrosis in the omental mass and engorgement of adjacent omental vessels were demonstrated in five and three patients, respectively. On angiography, the omental masses showed hypervascularity supplied by omental branches (n = 4) and superior mesenteric (n = 2) and inferior mesenteric (n = 1) artery and also showed prominent draining veins. CONCLUSION: The radiological manifestations of IPDM from HCC are single or multiple discrete hypervascular masses in the omentum. These are quite different from those of usually carcinomatosis peritonei.

Adult↗
PubMedDate not supplied

Nodular hepatocellular carcinoma: variation of tumor conspicuity on single-level dynamic scan and optimization of fixed delay times for two-phase helical CT.

PURPOSE: The purpose of this work was to determine the optimal delay times in two-phase helical CT for nodular hepatocellular carcinoma (HCC). METHOD: Twenty-four patients with nodular HCC (size 2.1-6.7 cm, mean 4.2 cm) were divided into three groups to undergo single-level dynamic CT with 150 ml of contrast material (iodine load of 45 g) at a rate of 3 ml/s. CT acquisition started 10, 30, or 60 s after the injection for each group, respectively, and lasted for 110 or 120 s. The optimal 20 s windows that allowed a tumor-to-liver contrast of >10 HU were determined in the pooled tumor-to-liver contrast curve. RESULTS: The determined temporal windows were 36-56 and 130-150 s, respectively. However, each window was not appropriate in seven (33%) and five (36%) patients because of the individual variations of the contrast curve. CONCLUSION: There is no optimal fixed delay time that is appropriate in all individual patients. The best delay times are 36 and at least 130 s with our injection protocol.

Adult↗
PubMedDate not supplied

MRI in staging advanced gastric cancer: is it useful compared with spiral CT?

PURPOSE: During the last decade, rapid progress has been made in MR technology. Our objective was to evaluate the role of MRI in staging advanced gastric cancer (AGC; gastric cancer invading the muscularis propria) and to compare it with that of spiral CT. METHOD: We prospectively performed both MR and CT examinations on 26 patients with AGC proven by endoscopic biopsy. Contrast-enhanced CT and nonenhanced MRI with a 1.0 T scanner using FLASH, HASTE, and true-FISP sequences were obtained in each patient after injection of antiperistaltic drug and ingestion of 1 L of tap water. Fifty-two sets of CT and MR images were analyzed by two radiologists in consensus without any information from other images. T and N staging of AGC was determined according to the TNM classification. All patients underwent surgery within 1 week after both examinations. Diagnostic accuracy of each staging of AGC on CT or MRI was evaluated by comparison with the pathologic results. RESULTS: MRI was slightly superior to CT in T staging (81 vs. 73%, respectively; p < 0.05). Although MRI had a tendency to overstage the pathologic T2 cancer, positive predictability of T2 stage and sensitivity of T3 stage were high (100%, respectively). Regarding the N staging, CT was slightly superior to MRI (73 vs. 65%; p > 0.05). However, both CT and MRI demonstrated the tendency of understaging in N staging. CONCLUSION: Although MRI was superior to spiral CT in T staging, MRI cannot completely replace spiral CT in staging AGC because of its limitation in N staging.

Adult↗
PubMedDate not supplied

Factors influencing vascular and hepatic enhancement at CT: experimental study on injection protocol using a canine model.

PURPOSE: The purpose of this work was to evaluate the effects of contrast medium injection parameters on aortic, portal vein, and hepatic enhancement at spiral CT and to assess optimal injection protocol for hepatic CT. METHOD: Ten 15 kg dogs underwent single level dynamic CT through the hepatic hilum at 5 s intervals just after the injection of contrast medium for 3 min. With use of different volumes (1, 2, and 3 ml/kg), injection rates (0.5, 1, and 2 ml/s), and concentrations (150, 200, and 300 mg/ml), a total of 270 spiral CT scans were performed. In each scan, time-attenuation curves of aorta, portal vein, and liver were obtained. The degree of maximum contrast enhancement (Imax), time to maximum enhancement (Tmax), and time to equilibrium phase (Teq) for to each injection protocol were analyzed. RESULTS: Alterations in contrast material volume, injection rate, and concentration had significant impact on contrast enhancement of the liver. With increasing volume of contrast medium, Imax, Tmax, and Teq of aorta, portal vein, and liver increased (p < 0.005). With increasing rate of injection, on the other hand, Imax of aorta and liver increased (p < 0.05), but Tmax and Teq decreased (p < 0.005). Change of concentration of contrast medium had a significant effect on Imax of vessels (p < 0.05). CONCLUSION: Maximum contrast enhancement of liver and vessels was influenced mainly by injection volume of contrast medium and the time to peak enhancement by injection rate of contrast medium. Under given amounts of contrast medium, therefore, the strategy of increasing volume by dilution and faster injection might give better Imax values without penalty for the duration of an optimal temporal window (Tmax and Teq).

Animals↗
PubMedDate not supplied

Fat replacement with absence of acinar and ductal structure in the pancreatic body and tail.

We report an unusual case of fat replacement of the pancreatic body and tail. Findings on contrast-enhanced computed tomography and ERCP could be confused with dorsal pancreas agenesis. Histopathologic examination of the resected specimen revealed massive fat replacement with complete absence of the acinar and ductal tissue and scattered islets of Langerhans.

Adipose Tissue↗
PubMedDate not supplied

Castleman disease of the abdomen: imaging spectrum and clinicopathologic correlations.

PURPOSE: The purpose of this work was to define the imaging spectrum of Castleman disease of the abdomen and to correlate the results with clinicopathologic findings. METHOD: Seventeen patients (male/female 7:10; mean age 35.6 years) with pathologically proved Castleman disease in the abdomen were included in this study. Radiologic findings (CT, n =17; US, n =10; MR, n =1) were retrospectively reviewed by two readers and were correlated with clinical and pathologic findings. RESULTS: Subjects were divided into those with localized (n = 11) and disseminated (n = 6) disease. In localized disease, the pathologic subtypes were hyaline vascular type in eight and plasma cell type in three. Radiologic studies showed a single large mass in six and a single dominant mass with small satellite nodules in five. Central low attenuation was seen in two cases, and calcification was seen in three cases. Regional lymphadenopathy was found in five cases. In disseminated disease, there were three hyaline vascular types and three plasma cell types. Radiologic findings included diffuse lymphadenopathy (n = 6), hepatosplenomegaly (n = 5), ascites (n = 3), and thickening of the retroperitoneal fascia (n = 3). Disseminated disease revealed symptoms and abnormal laboratory findings (anemia, hypoalbuminemia, elevated erythrocyte sedimentation rate/C-reactive protein, etc.) more frequently than localized disease and showed poor prognosis. CONCLUSION: There are two distinctive types of radiologic manifestations in Castleman disease of the abdomen: localized and disseminated. The localized type usually shows single or multiple discrete masses, and the disseminated type frequently shows nonspecific organomegaly and lymphadenopathy.

Abdomen↗
PubMedDate not supplied

Evaluation of tracheobronchial disease with helical CT with multiplanar and three-dimensional reconstruction: correlation with bronchoscopy.

The advantage of volumetric computed tomography in the thorax is the possibility of acquiring both multiplanar and three-dimensional (3D) images, thus enabling precise diagnosis and evaluation of extent of disease involving the airways. Multiplanar and 3D images appear to be useful for global understanding of the status of the tracheobronchial tree, particularly for evaluation of focal stenosis of the airways. Such images seem to be especially useful in evaluating the longitudinal extent of airway lesions, thus providing valuable information for preparing a road map for bronchoscopy, for surgical planning, and for follow-up of treatment response. However, multiplanar and 3D images do not appear to be useful in lesion detection or evaluation of transaxial extension. Multiplanar and 3D images also seem to be helpful in demonstrating whether a lesion is endobronchial, submucosal, or peribronchial. The quality of such images appears to be excellent or good in almost all patients.

Adult↗
PubMedDate not supplied

Hilar cholangiocarcinoma: thin-section spiral CT findings with cholangiographic correlation.

Hilar cholangiocarcinoma, a highly lethal tumor, is difficult to diagnose with conventional computed tomography (CT) because of its small size. Spiral CT allows more effective evaluation of these small lesions and better demonstrates the status of the hepatic arterial or portal venous circulation. Among 27 patients with hilar cholangiocarcinoma (infiltrative in 21, exophytic in two, polypoid in one, diffuse in three), thin-section spiral CT allowed identification of each tumor as an area of focal wall thickening that obliterated the lumen. Seventeen of the infiltrative tumors (81%) showed high attenuation. Identification of the level of biliary obstruction was possible in 63% of the patients (17 of 27). The level of obstruction was underestimated in six patients and overestimated in four. Spiral CT is a valuable method for diagnosis of hilar cholangiocarcinoma; however, spiral CT is less accurate in evaluation of intraductal tumor extent because of the limited z-axis resolution.

Adult↗
PubMedDate not supplied

Unusual gastric tumors: radiologic-pathologic correlation.

The overlap of radiologic findings in many gastric tumors makes differentiation difficult. However, some unusual gastric tumors have characteristic radiologic features that may suggest a specific diagnosis. At barium study, lipomas typically manifest as a smooth submucosal mass or an ulcerated lesion with a "bull's-eye" appearance that is indistinguishable from other mesenchymal tumors. At computed tomography (CT), lipomas usually manifest as well-circumscribed submucosal masses with fat attenuation. At radiology, glomus tumors appear as smooth submucosal masses with or without ulceration and may contain tiny flecks of calcification. These tumors frequently demonstrate strong enhancement on early-phase contrast material-enhanced images. At barium study, lymphangiomas may appear as smooth intramural masses that are indistinguishable from other mesenchymal tumors. At CT, they manifest as non-enhancing extramucosal masses with homogeneous low attenuation. Diffuse lesions in Brunner gland hamartoma manifest as multiple small nodules, producing a characteristic "cobblestone" appearance. Lymphomas may have typical imaging features (eg, more pronounced and homogeneous mural thickening) that can help differentiate them from adenocarcinoma. In addition, adenocarcinomas may demonstrate unusual findings such as transpyloric spread, unusually large polyps, or intratumoral calcifications. Familiarity with these radiologic features of gastric tumors can help ensure correct diagnosis and proper management.

Adenocarcinoma↗
PubMedDate not supplied

The anatomic relationship of the brachial plexus and axillary artery to the glenoid. Implications for anterior shoulder surgery.

Iatrogenic brachial plexus injury is an uncommon but potentially severe complication of shoulder reconstruction for instability that involves dissection near the subscapularis muscle and potentially near the brachial plexus. We examined the relationship of the brachial plexus to the glenoid and the subscapularis muscle and evaluated the proximity of retractors used in anterior shoulder surgical procedures to the brachial plexus. Eight fresh-frozen cadaveric shoulders were exposed by a deltopectoral approach. The subscapularis muscle was split in the middle and dissected to reveal the capsule beneath it. The capsule was split at midline, and a Steinmann pin was placed in the equator of the glenoid rim under direct visualization. The distance from the glenoid rim to the brachial plexus was measured with calipers with the arm in 0 degrees, 60 degrees, and 90 degrees of abduction. The brachial plexus and axillary artery were within 2 cm of the glenoid rim, with the brachial plexus as close as 5 mm in some cases. There was no statistically significant change in the distance from the glenoid rim to the musculocutaneous nerve, axillary artery, medial cord, or posterior cord with the arm in various degrees of abduction. Retractors placed superficial to the subscapularis muscle or used along the scapular neck make contact with the brachial plexus in all positions tested.

Aged↗
PubMedDate not supplied

Hepatic hemangiomas: spectrum of US appearances on gray-scale, power Doppler, and contrast-enhanced US.

Because US plays a key role in the initial evaluation of hepatic hemangiomas, knowledge of the entire spectrum of US appearances of these tumors is important. Most hemangiomas have a distinctive US appearance, and even with those with atypical appearances on conventional gray-scale US, specific diagnoses can be made using pulse-inversion harmonic US with contrast agents. In this essay, we review the spectrum of US appearances of hepatic hemangiomas on conventional gray-scale, power Doppler, and pulse-inversion harmonic US with contrast agents.

Adult↗
PubMedDate not supplied

Biliary ascariasis: MR cholangiography findings in two cases.

We describe the imaging features of two cases of biliary ascariasis. Ultrasonography and CT showed no specific abnormal findings, but MR cholangiography clearly demonstrated an intraductal linear filling defect that led to the correct diagnosis. MR cholangiography is thus a useful technique for the diagnosis of biliary ascariasis.

Adult↗