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Biomedical subjects

K J Cho

Publications and source records attributed to K J Cho.

At least 55 records · Page 3Linked to original sources
PubMed1997

The dissected aorta: part III. Anatomy and radiologic diagnosis of branch-vessel compromise.

PURPOSE: To determine the anatomic, hemodynamic, and radiologic characteristics of branch-vessel compromise in patients with aortic dissection. MATERIALS AND METHODS: Sixty-two patients with aortic dissection were evaluated with aortography (n = 62), intravascular ultrasound (US) (n = 35), and manometry (n = 56). Branch-vessel compromise with ischemia was suspected in 40 of these patients. Radiologic and manometric findings were correlated with clinical findings of ischemia. Femoral artery pulse strength was correlated with access from the respective femoral artery to the true and false lumina of the dissected aorta. RESULTS: Twenty-six of 40 patients suspected of having ischemia had angiographic evidence of branch-vessel compromise, and intravascular US helped identify two types of branch-vessel compromise in them: static (dissection intersected and narrowed the vessel origin) and dynamic (dissection spared the vessel origin, but the dissection flap appeared to compress the true lumen at or above the origin and covered the origin). False-lumen pressure in classic dissections exceeded (n = 16) or equaled (n = 30) true-lumen pressure. Branch vessels that arose exclusively from the false lumen were well perfused. Findings of a dissection flap oriented concave toward the false lumen were 91% sensitive and 72% specific for a true-lumen pressure deficit. CONCLUSION: Intravascular US and manometric findings clarify the mechanisms of branch-vessel compromise after aortic dissection and provide a rational guide for percutaneous treatment.

Adolescent↗
PubMed1997

Suprahepatic caval anastomotic stenosis complicating orthotopic liver transplantation: treatment with percutaneous transluminal angioplasty, Wallstent placement, or both.

OBJECTIVE: Our objective was to evaluate, over a 5-year period, the nonsurgical treatment of three patients with suprahepatic caval anastomotic stenosis who had undergone orthotopic liver transplantation. CONCLUSION: Balloon angioplasty is a safe and effective method for treating chronic caval stenosis occurring in patients who have undergone orthotopic liver transplantation. Caval stenosis identified in the early postoperative period, especially when such stenosis is associated with caval torsion or kinking, may be effectively treated by stent placement.

Adult↗
PubMed1997

Mucoepidermoid carcinoma of the salivary gland--a clinico-pathologic and immunohistochemical study for c-erbB-2 oncoprotein.

Twenty-five cases of mucoepidermoid carcinoma of the salivary glands were studied with respect to clinico-pathologic features, prognostic factors, and c-erbB-2 oncoprotein expression. Fourteen cases were located in parotid glands, 2 in submandibular glands and 9 in minor salivary glands. Fourteen patients were confirmed to have local recurrences, 6 patients manifested systemic metastases, and 10 patients died of the disease. They were histologically graded as I in 5, II in 12 and III in 8 cases respectively, and the histologic grade was significantly correlated with disease-free interval and overall survival of the patients. c-erbB-2 overexpression was observed in 9 cases (36%), with a trend to be associated with the higher grade, but was not evaluated as a significant survival-related factor in this series. Larger size and major gland location of the tumors were correlated with more frequent regional lymph node metastases. The present study showed that c-erbB-2 overexpression was not uncommonly present in mucoepidermoid carcinoma of the salivary glands, especially of higher grade, and the histologic grade was the most important and handy prognostic indicator.

Adolescent↗
PubMed1996

Phylogenetic analysis of apiaceae subfamily apioideae using nucleotide sequences from the chloroplast rpoC1 intron.

Phylogenetic relationships among 25 members of Apiaceae (Umbelliferae) subfamily Apioideae, representing 7 of the 8 tribes and 8 of the 10 subtribes traditionally recognized in the subfamily, and 5 outgroups from Apiaceae subfamilies Hydrocotyloideae and Saniculoideae and allied families Araliaceae and Pittosporaceae have been inferred from nucleotide sequence variation in the intron of the chloroplast gene RNA polymerase C1 (rpoC1). Sequence divergence values in pairwise comparisons of unambiguous positions among all taxa ranged from 0 to 11.3% of nucleotides and averaged 3.8%. Trees derived from rpoC1 intron sequences estimated using maximum parsimony or maximum likelihood methods are of essentially similar topology, and indicate that (1) subfamily Apioideae, with Heteromorpha as its most basal element, is monophyletic and is a sister-group to Eryngium, the only representative examined of Apiaceae subfamily Saniculoideae, (2) Aralia (Araliaceae) arises from within a paraphyletic Apiaceae subfamily Hydrocotyloideae (represented by Centella and Hydrocotyle) and this clade is a sister-group to Apioideae+Saniculoideae, (3) there is a major phylogenetic division within Apioideae (excluding the basal Heteromorpha), with one clade comprising the genus Smyrnium and those taxa traditionally grouped in tribes Dauceae, Scandiceae, and Laserpitieae, and the other clade comprising all other examined taxa, and (4) relationships within each of these 2 major clades of Apioideae are largely equivocal owing to the low levels of nucleotide sequence divergence observed. Although rpoC1 intron sequences can provide valuable characters for addressing phylogenetic relationships among the outgroups and distantly related members of Apioideae, they have little power for resolving relationships among closely related taxa.

Base Sequence↗
PubMed1996

Three-dimensional gadolinium-enhanced MR angiography of the thoracic aorta.

OBJECTIVE: Our objective was to evaluate image quality and preliminary clinical experience with three-dimensional gadolinium-enhanced MR angiography of the thoracic aorta. SUBJECTS AND METHODS: Ninety patients with suspected thoracic aorta pathology underwent 97 MR examinations at 1.5 T with a 4-min, three-dimensional spoiled gradient-echo techniques. Gadolinium infusion was timed for maximum arterial contrast during acquisition of the central portion of K-space. No ECG gating or breath-holding was used. All MR examinations were evaluated retrospectively for intravascular signal-to-noise ratio (SNR). In 30 of the 90 patients, results from surgery (n = 11), angiography (n = 12), or both (n = 7) were available. Four radiologists who were unaware of the angiographic or surgical findings assessed each of these 30 examinations for three types of pathology: dissection, coarctation, or aneurysm. The observers also assessed aortic branch vessel patency and vascular anomalies in the 19 patients who had angiographic correlation. RESULTS: Image quality (determined as SNR) was highest in the aortic arch, upper descending thoracic aorta, and upper abdominal aorta. We saw a small reduction in the SNR in the ascending aorta and lower descending thoracic aorta (p < .0001), attributable to cardiac and respiratory motion. Image quality was not affected by slow flow. MR imaging correctly diagnosed pathology in all 30 patients with angiographic or surgical correlation, including eight dissections, three coarctations, and 10 aneurysms. The type of the dissection was correctly determined in all eight patients. Stenoses of major branch vessel origins were detected with a sensitivity of 90% (95% bayesian confidence interval, 99-63%) and a specificity of 96% (95% bayesian confidence interval, 99-89%) in the 19 patients with angiographic correlation. Five vascular anomalies, including an aberrant right subclavian artery, a bovine arch, and three accessory renal arteries, were correctly identified. CONCLUSION: Three-dimensional gadolinium-enhanced MR angiography has the potential to accurately diagnose aortic dissection, coarctation, and aneurysm. It does not require ECG gating or breath-holding and thereby extends the diagnostic utility of MR imaging for the thoracic aorta.

Adolescent↗
PubMed1996

Mixed acinar-endocrine carcinoma of the pancreas--a case report.

A case of pancreatic carcinoma with both acinar and endocrine features is presented. The patient was a 52-year-old female presenting with jaundice of 3 weeks' duration. The tumor was a 6 x 6 cm-sized round solid mass in the head of pancreas, invading the superior mesenteric vein. Histologically, it was composed of monotonous ovoid cells with eosinophilic granular cytoplasm in solid nests and sheets with occasional acinar and glandular differentiation. Immunohistochemical study revealed coexpression of acinar and endocrine markers; amylase, chromogranin, neuron-specific enolase, glucagon, somatostatin, and gastrin in tumor cells. This is the first documented case of mixed acinar-endocrine carcinoma of the pancreas in Korea, and its amphicrine nature reflects a close histogenetic relationship between pancreatic exocrine and endocrine cells.

Biomarkers, Tumor↗
PubMed1996

Histiocytic necrotizing lymphadenitis. A clinico-pathologic study of 45 cases with in situ hybridization for Epstein-Barr virus and hepatitis B virus.

Forty-five cases of histiocytic necrotizing lymphadenitis (HNL) or Kikuchi-Fujimoto disease were reviewed clinico-pathologically and studied for Epstein-Barr virus (EBV) and hepatitis B virus (HBV) by in situ hybridization to assess their causative role. Histologically, the lymph nodes typically showed relatively well defined paracortical lesions composed of large atypical mononuclear cells, histiocytes, and karyorrhectic nuclear debris. Mild to moderate degree of coagulation type necrosis was present in 24 cases. Clinical features did not vary greatly from previously described female preponderance, young age onset, subacute cervical lymphadenopathy, and frequent leukopenia, except for a few cases with recurrent disease over 8-9 years. Serologic tests revealed EBV IgG antibody in one case, HBV surface antibody in 11 cases and HBV surface antigen in 2 cases. In situ hybridization was performed on 41 cases using internal repeat 1 fragment DNA and EBV-coded small RNA (EBER-1) for EBV, and pan-HBV DNA probe for HBV detection, and showed that all cases were negative for EBV or HBV genome. Our results suggest EBV or HBV may not have causative role in the pathogenesis of HNL.

Adolescent↗
PubMed1995

Transhepatic cardiac catheterization in children. Evaluation of efficacy and safety.

BACKGROUND: In some children with congenital heart disease, conventional venous access is unavailable for cardiac catheterization. This study investigates a novel transhepatic venous approach to cardiac catheterization in children and evaluates its efficacy and safety. METHODS AND RESULTS: Percutaneous transhepatic puncture was performed using a 22-gauge Chiba needle under fluoroscopic guidance. After wire exchanges were performed, a 5F to 8F sheath was positioned in the low right atrium and cardiac catheterization was performed. On completion of the catheterization, the sheath was withdrawn and a 3-mm steel coil was placed in the parenchymal tract between the hepatic vein and liver capsule. Liver enzyme studies were obtained before and after transhepatic catheterization, and an abdominal ultrasound was performed to evaluate the liver 24 hours after the procedure. Percutaneous transhepatic cardiac catheterization was performed successfully in 17 of 18 children in whom it was attempted. Patient age was 30 +/- 8 months (mean +/- SEM; range, 1 day to 9 years), weight was 10.5 +/- 1.5 kg (3.1 to 27.5 kg), and mean right atrial pressure was 10 +/- 1 mm Hg (5 to 19 mm Hg). Time from initial needle puncture to right atrial entry was 6.2 +/- 1.2 minutes. Diagnostic catheterization was performed successfully in all 17 children, and additional interventional procedures were performed in 5 children. The total catheterization time was 2.0 +/- 0.2 hours. Serum aspartate aminotransferase increased from 57 +/- 15 to 78 +/- 8 IU/L (P = .06), but alanine aminotransferase and gamma-glutamyl transpeptidase did not change. Ultrasound was performed 24 hours after transhepatic catheterization, and no evidence was found in any patient of hemorrhage or subcapsular hematoma. CONCLUSIONS: These data suggest that this novel transhepatic approach provides an effective and safe route for diagnostic and interventional cardiac catheterization in children.

Cardiac Catheterization↗
PubMed1995

Gadolinium-enhanced magnetic resonance angiography of abdominal aortic aneurysms.

PURPOSE: The objective of this study was to assess the usefulness of gadolinum-enhanced magnetic resonance angiography (MRA) for defining anatomic features relevant to performing aortic surgery for aneurysmal disease. METHODS: Anatomic data defined by MRA, including abdominal aortic aneurysm (AAA) size and character, as well as the status of the celiac, mesenteric, renal, and iliac arteries, were correlated with angiography, ultrasonography, computed tomography, or operative data in 43 patients. Five MRA sequences were obtained in an hour-long examination optimized for aortoiliac, splanchnic, and renal artery imaging at 1.5 T in a body coil. Four of the sequences were performed during or after infusion of gadolinium to improve image quality. RESULTS: MRA correctly defined the maximum aneurysm diameter, as well as its proximal and distal extent in all patients. MRA detected 33 of 35 significant stenoses among 153 splanchnic, renal, or iliac branches examined (sensitivity = 94% and specificity = 98%). MRA did not resolve the degree of aortic branch stenotic disease sufficiently to precisely grade its severity. MRA did not reliably define the status of the inferior mesenteric artery, lumbar arteries or internal iliac arteries. One ruptured AAA and one inflammatory AAA were correctly diagnosed by MRA. No patient had a contrast reaction or contrast-induced renal toxicity related to administration of gadolinium. CONCLUSION: Gadolinium-enhanced MRA of AAA provides appropriate, essential anatomic information for aortic reconstructive surgery in a 1-hour examination devoid of contrast-related renal toxicity or catheterization-related complications attending conventional arteriography.

Adult↗
PubMed1995

Epithelial-myoepithelial carcinoma of salivary glands. A clinicopathologic, DNA flow cytometric, and immunohistochemical study of Ki-67 and HER-2/neu oncogene.

Thirty-one salivary gland epithelial-myoepithelial carcinomas from 26 patients were studied by DNA flow cytometry, and immunostaining for Ki-67 and HER-2/neu oncogene product. The results were correlated with clinicopathologic factors and patient outcome. The tumor most commonly involved the parotid gland, and mainly affected patients in their 6th to 8th decades. The clinical course was characterized by a high incidence of local recurrence (50%) and not infrequent distant metastasis (25%). None of the patients in this cohort died of disease. DNA content analysis revealed 21 neoplasms with DNA diploidy and 5 tumors with DNA aneuploidy; all aneuploid cases were near-diploid (hyperdiploidy) and showed low proliferative activity. All aneuploid and 60% of the diploid neoplasms developed recurrences and/or metastases. Immunohistochemical analysis of Ki-67 proliferation markers also showed low overall growth fractions. Interestingly, Ki-67 immunoreactivity was largely restricted to myoepithelial cells, suggesting a central role for this cell in the development of these tumors. HER-2/neu oncogene analysis failed to demonstrate overexpression in any of the tumors examined. This study indicates that epithelial-myoepithelial carcinoma is a low grade malignant neoplasm with a high propensity for recurrence. HER-2/neu oncogene and Ki-67 offer no additional advantages over current factors in the biologic evaluation of these neoplasms. DNA aneuploidy may allow for the identification of a subset of tumors that is more prone to recurrence and metastasis, but further studies with extended follow-up are needed.

Adolescent↗
PubMed1995

Associated injuries in patients with blunt chest trauma: detection by abdominal roentgenograms after aortography.

To determine the value of abdominal roentgenograms after aortography for detecting additional organ injuries, we retrospectively evaluated the abdominal and pelvic roentgenograms after aortography of 170 trauma patients who underwent arch aortography to detect aortic rupture. In 160 (94%) of 170 patients, the results of arch studies were normal. Ten (6%) of 170 patients had aortic rupture (8 patients) or rupture of a major vessel (2 patients). Thirty-one (18%) of 170 patients had associated injuries demonstrated by the roentgenograms taken after aortography, including pelvic or femoral fractures (13%), pelvic hematomas (5.8%), renal injuries (1.1%), and bladder ruptures (2.9%). We conclude that abdominal and pelvic pain roentgenograms should be part of a routine arch aortography performed for blunt chest trauma to detect additional organ injuries that frequently accompany injuries from motor vehicle crashes.

Abdominal Injuries↗
PubMed1995

Breath-hold gadolinium-enhanced MR angiography of the abdominal aorta and its major branches.

PURPOSE: To develop and evaluate a sequence for breath-hold three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography of the abdominal aorta. MATERIALS AND METHODS: In 63 patients, the abdominal aorta and its branches were imaged for 29, 43, or 58 seconds with breath holding. A fast spoiled gradient-echo sequence was used at 1.5 T during infusion of 42 mL of a gadolinium chelate. Correlation with conventional angiography was performed in 19 patients. MR image quality (signal-to-"total" noise ratio [S/N*]) with breath holding was compared with that with free breathing (104 patients). RESULTS: With breath-hold gadolinium-enhanced MR angiography, renal, celiac, and superior mesenteric artery occlusive disease was graded appropriately in 15 of 19 patients, and 10 of 11 accessory renal arteries were depicted correctly. Renal artery branches were visualized in 86 of 95 kidneys on breath-hold images compared with only 84 of 236 kidneys with free breathing (P < .001). Distal renal artery S/N* was 3.1 with breath holding and 2.1 with free breathing (P < .001). CONCLUSION: Breath holding statistically significantly improves three-dimensional gadolinium-enhanced MR angiography of the renal, celiac, and superior mesenteric arteries.

Adult↗
PubMed1995

Study of the lumbar curvature with various factors of pelvic inclination. Change of radiographic lumbar curvature according to hip joint flexion.

The objective of this study was to investigate the influence of the hip flexion upon parameters that are indicators of spinal mobility. These parameters include intervertebral disc angle and lumbar curvature by measurement of the radiography in twenty eight healthy men. The state of knowledge of how these parameters relate to lumbar mobility have resolved. The results of the parameters showed negligible changes in relation to the mobility of lumbar spine according to angle of hip flexion except at L4-L5 intervertebral disc angle and lumbar curvature (p < 0.05). This results of study confirms that hip joint movement therapy can be applied to these norms in patient management in supine position of for the stable spinal injuries in the upper lumbar region during early phase.

Adult↗
PubMed1994

Extended evaluation of the titanium Greenfield vena caval filter.

PURPOSE: The purpose of this study was to evaluate the long-term safety and efficacy of the titanium Greenfield filter-modified hook for prevention of pulmonary embolism. METHODS: We conducted a prospective study in 173 patients from four institutions who underwent clinical examination, abdominal radiography, and duplex ultrasound examinations of the vena cava and lower extremities. If indicated by protocol or clinical presentation, computed tomography scans, pulmonary angiograms, or venacavograms were obtained. RESULTS: The most common procedural event was filter limb asymmetry (10%), which had no clinical significance. A variety of other minor procedural events occurred in another 10% of cases. Early follow-up (< 6 months) was completed in 149 patients, and long-term evaluation was completed in 113 (> 12 months). Deaths in 24 patients were from nonembolic causes in all but one. There were four suspected or confirmed recurrent pulmonary emboli, for an incidence of 3.5% (four of 113), with one death (0.9%). Four patients had inferior vena cava occlusion at early follow-up and at long-term evaluation, only one remained occluded (1%). Insertion site venous thrombosis was seen in only two patients (2%). CONCLUSION: The titanium Greenfield filter provides protection comparable to the standard stainless steel Greenfield filter after 1 year with a low incidence of recurrent pulmonary embolism (3.5%) and a high caval patency rate (99%).

Cohort Studies↗
PubMed1994

Outcome analysis of 42 cases of renal angiomyolipoma.

Angiomyolipomas were found in 42 kidneys in 23 female and 8 male patients at our medical center. Angiomyolipoma was diagnosed by computerized tomography (CT) alone in 55% of the cases, and by a combination of ultrasound and CT in 36%. Nine of 11 patients with bilateral angiomyolipoma had associated tuberous sclerosis. Treatment consisted of observation in 22 patients, selective arterial embolization in 6, partial nephrectomy in 6 and nephrectomy in 8. A total of 17 patients who were observed had tumors smaller than 4 cm. and 4 h had angiomyolipoma of 4 to 10 cm. With a mean followup of 3.8 years, no observation patient had subsequent renal hemorrhage and only 1 (tumor larger than 10 cm.) had radiographic progression. Despite progression, the latter patient remained asymptomatic for 18 years. Selective arterial embolization (3 tumors 4 to 10 cm. and 3 larger than 10 cm.) resulted in preservation of renal function at a mean of 1 year. All patients treated with partial nephrectomy (6 tumors 4 to 10 cm.) maintained stable renal function without recurrence during a mean 4.7-year followup. Similarly, all individuals who underwent nephrectomy (4 tumors smaller than 4 cm., 3 tumors 4 to 10 cm. and 1 tumor larger than 10 cm.) have stable renal function. We recommend renal conservation for patients with renal angiomyolipoma using a strategy of observation for small asymptomatic tumors, partial nephrectomy for moderate size tumors and selective arterial embolization of large tumors not amenable to partial nephrectomy.

Adolescent↗
PubMed1994

Safety and toxicity of catheter gene delivery to the pulmonary vasculature in a patient with metastatic melanoma.

One approach to gene therapy for human cancer is transcatheter injection of DNA liposomes into tumor masses. To determine the feasibility of selective delivery of recombinant genes by a catheter to the pulmonary vasculature in humans, a patient with melanoma received two treatments of HLA-B7 plasmid DNA complexed to cationic liposomes into a right posterior basal pulmonary artery associated with a mass lesion. The treatments were well tolerated. No adverse respiratory, cardiac, immunologic, or other organ toxicities were detected. The delivery of recombinant genes by catheter may be a useful modality to treat human malignancy and other diseases.

Adenocarcinoma↗
PubMed1994

Lichen planus and lichenoid lesions of the oral cavity.

Lichen planus is a mucocutaneous disease of unknown cause that has its principal clinical manifestations in the skin and mucosa of the oral cavity. The natural history of the cutaneous form is one of spontaneous resolution over time, while oral lichen planus pursues a much more chronic course with a low order of resolution. Oral lichen planus must be distinguished from lichenoid lesions, including lichenoid dysplasia. Malignant change in oral lichen planus is rare and is prompted by carcinogenic cofactors. There is no increased risk of development of carcinoma in cutaneous lichen planus.

Carcinoma, Squamous Cell↗