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Biomedical subjects

S E Jung

Publications and source records attributed to S E Jung.

At least 19 recordsLinked to original sources
PubMed2004

Gallbladder wall thickening: MR imaging and pathologic correlation with emphasis on layered pattern.

The aim of this study was to correlate MR findings of gallbladder wall thickening with pathologic findings on the basis of the layered pattern and to evaluate the diagnostic value of MR imaging in gallbladder disease. We retrospectively evaluated the source images of HASTE sequences for MR cholangiography in 144 patients with gallbladder wall thickening. The layered pattern of thickened wall was classified into four patterns. Type 1 shows two layers with a thin hypointense inner layer and thick hyperintense outer layer. Type 2 has two layers of ill-defined margin. Type 3 shows multiple hyperintense cystic spaces in the wall. Type 4 shows diffuse nodular thickening without layering. MR findings of a layered pattern of thickened gallbladder were well correlated with histopathology. Chronic cholecystitis matched to type 1, acute cholecystitis corresponded to type 2, adenomyomatosis showed type 3, and the gallbladder carcinomas showed type 4. All four layered patterns were associated with PPV of 73% or greater, sensitivity of 92% or greater and specificity of 95% or greater. Our results indicate that MR findings of gallbladder wall thickening are characteristic in each entity and correlate well with pathologic findings. The classification of the layered pattern may be valuable for interpreting thickened gallbladder wall.

Adult↗
PubMed2001

Characteristic MR findings of cervical pregnancy.

The aim of this study was to define the characteristic MR findings of cervical pregnancy. Twelve patients with cervical pregnancy underwent MRI because of difficulty in the diagnosis by ultrasonography, human chorionic gonadotropin assessment, and other clinical evaluations. The assessment of MRI included size and location of the lesion, margin, MR signal intensity, rim of low-signal intensity, enhancement pattern, appearance of enhancing solid component, parametrial change, endometrial change, pelvic fluid collection, and ovarian change. All cases showed ill-marginated mass with very heterogeneous signal intensity on T2-weighted images, irregular internal high-signal intensities on T1-weighted images, a partial or circumferential rim of low-signal intensity, dense irregular peripheral enhancement and enhancing papillary solid components with accompanying tubular signal voids, and variably increased parametrial vascularities. This heterogeneous hemorrhagic mass with densely enhancing papillary solid components may be the typical MR finding for cervical pregnancy. J. Magn. Reson. Imaging 2001;13:918-922.

Adult↗
PubMed2001

Clinical characteristics and prognosis of patients with hepatoblastoma.

Hepatoblastoma is a rare pediatric malignancy that frequently appears in an advanced unresectable stage. Improved resectability and survival rate have been reported with the help of neoadjuvant chemotherapy. Between January 1987 and June 1995 a series of 20 patients were managed with a diagnosis of hepatoblastoma. The median age at diagnosis was 13 months (2 months to 7 years 10 months) with a male/female ratio of 13:7. Chemotherapy effectively reduced the tumor volume (with statistical significance: p = 0.008) and was able to convert seven of nine initially unresectable tumors (78%) to resectable ones. Altogether, 14 operations were done, 12 radical and 2 palliative, with or without adjuvant chemotherapy. The whole population was followed for a median duration of 33 months; and the median survival for the whole group was 26 months. The curative resection group displayed a 5-year survival rate of 61.1%, but none in the noncurative group survived more than 13 months (p = 0.0001). In the univariate analysis for prognostic factors, large tumor size at diagnosis and the absence of thrombocytopenia were associated with poor survival, but these differences were not statistically significant. Pure fetal histology was not associated with better prognosis. In this new era of neoadjuvant chemotherapy, the optimal management strategy for hepatoblastoma is still debated, with radical surgical resection at the earliest possible time being the final goal. For now an individualized approach appears to be the protocol of choice.

Chemotherapy, Adjuvant↗
PubMed2001

Lipoblastoma.

BACKGROUND/PURPOSE: Lipoblastoma is a rare benign mesenchymal tumor of embryonal fat that occurs almost exclusively in infants and children. This study was done to determine the clinical and pathologic characteristics of lipoblastoma. METHODS: Nine cases of pathologically proven lipoblastoma from 1979 to 1997 were reviewed. There were 6 boys and 3 girls ranging in age from 3 months to 29 months. RESULTS: A soft tissue mass was the chief complaint in 7 patients, abdominal distension in 1 patient with a retroperitoneal mass, and defecation difficulty in 1 patient with a perirectal mass. In 4 patients, tumors occurred on the back. Other tumor location includes the neck, scrotum, retroperitoneum, perirectal area, and buttock in 1 patient each. Lesions measured 2.3 to 19.5 cm. Complete excision was done in 8 patients. One perirectal tumor was removed by both the posterior sagittal approach and the intraabdominal approach but incompletely resected. Two tumors located on the back recurred with intraspinal extension 12 months and 18 months after resection. Second resection and second resection with laminectomy were done. Leg pain and urinary incontinence developed in 1 patient but improved on conservative treatment. CONCLUSIONS: Lipoblastoma is a benign neoplasm but can frequently recur (25%) in spite of complete excision. Lipoblastomas occurring on the back had a high recurrence rate (50%) and associated with intraspinal extension. J Pediatr Surg 36:905-907.

Child, Preschool↗
PubMed2001

The findings of ruptured hepatocellular carcinoma on helical CT.

To evaluate the helical CT findings of ruptured hepatocellular carcinoma (HCC), 12 patients with ruptured HCC were reviewed with regard to the tumour's location, size and contour protrusion, the appearance of the mass, the enhancement pattern, multiplicity and secondary changes. All ruptured tumours were located at the periphery of the liver and had a protruding contour. The maximum diameter of tumours ranged from 2 cm to 16 cm. Discontinuity of the hepatic surface was seen in 11 cases. In eight cases, CT images during the arterial phase showed a non-enhancing low attenuating lesion with focal discontinuity and peripheral rim enhancement. Seven cases showed separation of tumour content from the peripheral enhancing rim and intraperitoneal rupture of tumour content into the perihepatic space. Because of the similar appearance to an enucleated orbital globe with remaining sclera, this was termed the "enucleation sign". As well as ruptured masses, 10 cases with non-ruptured masses also showed a non-enhancing low attenuating pattern. Seven cases showed a haematoma with high attenuation around the ruptured mass. The peripheral location, protruding contour, discontinuity of the hepatic surface and surrounding haematoma are helpful signs in the diagnosis of ruptured HCC. The "enucleation sign" may be a characteristic finding in ruptured HCC.

Adult↗
PubMed1999

Utility of the resistance index ratio in differentiating obstructive from nonobstructive hydronephrosis in children.

PURPOSE: We assessed the utility of the resistance index ratio (RIR) in distinguishing between obstructive and nonobstructive upper urinary tract dilatation in children. METHODS: Twenty-three children (7 days-14 years old) with unilateral dilated collecting systems and a contralateral normal kidney were prospectively evaluated by duplex Doppler sonography. We measured the resistance index (RI) of the intrarenal arteries and calculated the RIR. Ninety-six normal kidneys in 48 controls were also evaluated. RESULTS: Twelve kidneys were proved to be obstructed at the ureteropelvic junction, and 11 were found by renal scintigraphy with furosemide and/or by surgery to have nonobstructive dilatation. The mean RIR differed significantly between the obstructed and dilated nonobstructed kidneys (1.16+/-0.04 versus 1.04+/-0.04, respectively; p < 0.01). After surgical correction of ureteropelvic junction obstruction, the obstructed kidneys showed significant drops in the RIR (1.18+/-0.03 to 1.07+/-0.03, p < 0.01). The RIR showed no statistically significant relationship with age (r = -0.268, p > 0.01); however, the RI declined with increasing age (r= -0.414, p < 0.01). An RIR cut-off value of > or = 1.10 provided a good discriminatory level, resulting in a sensitivity of 92%, a specificity of 97%, a positive predictive value of 85%, and a negative predictive value of 97%. CONCLUSIONS: An RIR cut-off value of > or = 1.10 appears to be an effective parameter for evaluation and follow-up of unilateral obstructive hydronephrosis in children.

Adolescent↗
PubMed1999

Solid and papillary epithelial neoplasm of the pancreas in children.

Solid and papillary epithelial neoplasm of the pancreas is an uncommon low-grade malignant tumor found predominantly in young females. In this paper, the authors report the tumor's clinical characteristics and the results of surgery in six children. Six cases of solid and papillary epithelial neoplasm of the pancreas pathologically verified at Seoul National University Children's Hospital between 1985 and 1997 were retrospectively analyzed. Four were girls and two were boys, and their mean age at surgery was 11.2 years (range 8-13 years). All patients presented with an abdominal mass and tumor ranging in size from 6.5 x 6.0 cm to 10.5 x 8.0 cm. Five were located in the head and one in the tail of the pancreas; exploration showed that no case involved local invasion or metastasis. All patients underwent complete resection, which involved five pancreaticoduodenectomies and one distal pancreatectomy. No patient died during surgery, and after a mean follow-up period of 5.5 years (range 1.5-12.5 years) all were alive with no recurrences. We believe that the malignancy of this tumor is low grade and that the prognosis is good. For a neoplasm arising anywhere in the pancreas, complete resection is the treatment of choice. Solid and papillary epithelial neoplasm of the pancreas of children shows less female preponderance in children than in adults.

Adolescent↗
PubMed1999

Effect of protease inhibitor on ischemia-reperfusion injury to rat liver.

Liver failure due to ischemia-reperfusion injury, believed to be closely related to the generation of oxygen-free radicals, is a serious problem during liver surgery. Gabexate mesilate, a synthetic protease inhibitor, suppresses the extracellular release of oxygen-free radicals in the microvascular endothelium. To determine its effects on ischemia-reperfusion injury to the liver, we performed experiments with rats. We divided the animals into two ischemia-reperfusion groups: an experimental group, which underwent ischemic injury for 30 minutes, along with the infusion of gabexate mesilate, and a control group, which underwent injury only. Each group was then divided into four subgroups: ischemic injury only and 60-, 120-, and 180-minute reperfusion injury. The test parameters were tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) in serum and superoxide dismutase (SOD), catalase, and malondialdehyde (MDA) in liver and lung tissues. The experimental group had a significantly higher liver SOD and catalase levels and a significantly lower level of liver and lung MDA than the control groups. TNFalpha levels in the experimental groups were significantly lower during the early phase, but a comparison of IL-6 levels between the two groups yielded no differences. Levels of lung catalase and SOD were not significantly different between the two groups. We concluded that protease inhibitor suppressed liver ischemia-reperfusion injury, and that it was due to an increase of antioxidant or suppression of oxygen-free radicals. The roles of TNFalpha and IL-6 in liver reperfusion injury were not clear, though TNFalpha might have had an effect during the early phase. With liver ischemia-reperfusion injury, the mechanism of lung involvement might be different from that of liver involvement.

Animals↗
PubMed1999

Diffuse and focal adenomyosis: MR imaging findings.

Adenomyosis is a common gynecologic disorder that affects women during their menstrual life. Preoperative magnetic resonance (MR) images obtained in 45 patients with pathologically proved adenomyosis who underwent hysterectomy were retrospectively reviewed. Diffuse adenomyosis was seen in 30 cases (66.7%) and focal adenomyosis in 15 cases (33.3%). On T2-weighted MR images, diffuse adenomyosis usually manifested as diffuse thickening of the endometrial-myometrial junctional zone (7-37 mm; mean, 16 mm) with homogeneous low signal intensity. T2-weighted MR images were superior to contrast material-enhanced T1-weighted images in the evaluation of junctional zone thickening. High-signal-intensity foci were observed on T2-weighted images only in nine cases and on both T1- and T2-weighted images in three cases. Focal adenomyosis manifested on both T2-weighted and contrast-enhanced T1-weighted MR images as a localized, low-signal-intensity round or oval mass with a diameter of 2-7 cm (mean, 3.8 cm). All but one of the focal lesions had ill-defined margins. High-signal-intensity foci were noted in all cases of focal adenomyosis, either on T2-weighted images only (four cases) or on both T1- and T2-weighted images (11 cases). MR imaging is useful in diagnosing adenomyosis, differentiating adenomyosis from uterine myoma, and planning appropriate treatment.

Adenomyoma↗
PubMed1999

MR findings in ovarian granulocytic sarcoma.

Granulocytic sarcoma (chloroma) is a mass of malignant myeloid precursor cells in an extramedullary location. The female genital tract, including the ovary, may be the first site for clinical manifestation of granulocytic sarcoma. The MR findings are reported in a case of ovarian granulocytic sarcoma which preceded acute myelogenous leukaemia. Granulocytic sarcoma shows a mixed cystic and solid adnexal mass with intermediate signal intensity on T1 weighted images and hypointensity on T2 weighted images.

Child↗
PubMed1999

Lovastatin-induced proliferation inhibition and apoptosis in C6 glial cells.

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase is the rate-limiting enzyme in cholesterol biosynthesis. HMG-CoA reductase converts HMG-CoA to mevalonate, which is then converted into cholesterol or various isoprenoids through multiple enzymatic steps. In this study, we examined the cytotoxic effects of lovastatin, an HMG-CoA reductase inhibitor, in C6 glial cells. Lovastatin at concentrations higher than 10 microM suppressed cell proliferation and induced cell death, which were prevented completely by mevalonate (300 microM). The data from lactate dehydrogenase assay and fluorescence microscopic assay using Hoechst 33342 and propidium iodide showed that mevalonate at a concentration of 100 microM could prevent lovastatin-induced cell death, whereas it could not prevent lovastatin-induced inhibition of cell proliferation. These data suggest that the lovastatin-induced interruption of cell cycle transition was not sufficient to induce cell death in C6 glial cells. In the presence of lovastatin at concentrations higher than 10 microM, DNA laddering, the typical finding of apoptosis, was identified. Lovastatin-induced apoptosis was prevented by mevalonate (100 microM). Both cycloheximide (0.5 microgram/ml) and actinomycin D (0.1 microgram/ml) prevented lovastatin-induced DNA laddering. In this study, we demonstrated that the cytotoxic effects of lovastatin fall into two categories: suppression of cell growth and induction of apoptosis in C6 glial cells.

Anticholesteremic Agents↗
PubMed1999

Purification and properties of Thermus filiformis DNA polymerase expressed in Escherichia coli.

The gene encoding Thermus filiformis (Tfi) DNA polymerase was expressed under the control of the tac promoter on a high-copy plasmid, pJR, in Escherichia coli. The Tfi DNA polymerase was purified by using heat treatment and DEAE-Sephacel column chromatography. The purified enzyme had a molecular mass of 92 kDa, as estimated by SDS/PAGE. The optimum pH and temperature of the enzyme were 8.4-9.0 and 70-72.5 degrees C respectively. The half-life of the enzyme at 94 degrees C was approx. 40 min. The enzyme was activated by the bivalent cations, Mg(2+) and Mn(2+), and was inhibited by EDTA. The optimal Mg(2+) concentration of the enzyme was 4 mM. The optimal conditions for the PCR reaction were slightly different from those for the enzyme activity except for the optimal Mg(2+) concentration. Low concentrations of KCl had no effect on either the enzymic activity or the PCR amplification. The result of the PCR experiment with the enzyme indicates that Tfi DNA polymerase might be useful in DNA amplification.

Base Sequence↗
PubMed1998

Benign solitary fibrous tumour of the pre-sacral space: MRI findings.

Benign solitary fibrous tumour, a rare mesenchymal tumour of adults, usually arises from the pleura. Only a few cases have been reported in the retroperitoneum and, to our knowledge, there has been no report of its imaging features. We describe the MRI features of benign solitary fibrous tumour arising from the pre-sacral space.

Humans↗
PubMed1997

Cloning and analysis of the DNA polymerase-encoding gene from Thermus filiformis.

The gene encoding Thermus filiformis (Tfi) DNA polymerase was cloned and its nucleotide sequence was determined. The primary structure of Tfi DNA polymerase was deduced from its nucleotide sequence. Tfi DNA polymerase is comprised of 833 amino acid residues and its molecular mass was determined to be 93,890 Da. The deduced amino acid sequence of Tfi DNA polymerase showed a high sequence homology to E. coli DNA polymerase I-like DNA polymerases: 78.5% homology to Taq DNA polymerase, 78.4% to Tca DNA polymerase, and 41.8% to E. coli DNA polymerase I. An extremely high sequence identity was observed in the region containing polymerase activity. The G + C content of the coding region for the Tfi DNA polymerase gene was 68.5%, which was higher than that of the chromosomal DNA (65%). The G + C contents in the first, second, and third positions of the codons used were 71.8%, 40.9%, and 92.7% respectively. Codon usage in Tfi DNA polymerase was heavily biased towards the use of G + C in the third position. Rare codons with U or A as the third base were sometimes used to avoid using GA(A/T) TC and TCGA sequences, as they are recognition sites for the restriction endonucleases TfiI and TaqI.

Amino Acids↗
PubMed1997

Currarino triad: anorectal malformation, sacral bony abnormality, and presacral mass--a review of 11 cases.

Currarino et al, in 1981, described an association of a congenital anorectal stenosis, or another type of low anorectal malformation, an anterior sacral defect, and presacral mass. Eleven patients with this anomaly were treated at the Department of Pediatric Surgery, Seoul National University Children's Hospital from 1984 to 1995. Among these patients, low-type imperforate anus (IA) was seen in three cases and anorectal stenosis was present in eight cases. Presacral masses included seven teratomas, two meningoceles, one dermoid cyst, and one enteric cyst with dermoid cyst. All had a deformed sacrum. Among the eight with anorectal stenoses, posterior sagittal anorectoplasty (PSARP) with diverting colostomy was performed in seven cases, and repeated rectal dilatation was performed in one case. Among the three low-type IA, anoplasty was performed in two cases and PSARP was performed in one case. Although PSARP is a safe and satisfactory method facilitating the excision of the presacral mass, in meningoceles the repair should be performed before correction of anorectal malformation because of the risk of meningitis that can occur when surgeries are done simultaneously. In two cases, untethering of a tethered spinal cord was performed. All patients are continent. Because the incidence of Currarino triad is high when there is an anorectal stenosis (38% in the present series), the Currarino triad should be suspected in anorectal stenosis. Magnetic resonance imaging is a preferred diagnostic method because the incidence of association of tethered cord in this triad is high (18% in the present series).

Anal Canal↗