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Tae Yong Moon

Publications and source records attributed to Tae Yong Moon.

7 recordsLinked to original sources
PubMed2006

Gene expression in mixed type liposarcoma.

AIMS: Mixed type liposarcomas are rare. Here, we analysed the characteristics of an unusual case of mixed type liposarcoma, which consisted of a well-differentiated liposarcoma (WDL) and a pleomorphic liposarcoma (PL), with a special emphasis on molecular alterations. METHODS: Microscopic and immunohistochemical approaches were used to investigate this case of mixed type liposarcoma, and to identify molecular alterations in this tumour, gene expression was examined in PL, WDL, and normal adipose tissue (NA) samples using a 17,000 cDNA microarray. RESULTS: The tumour mass, 9 x 5 x 5 cm, was located in the left upper arm of a 76-year-old man. Grossly, the proximal portion of the tumour was composed of a yellowish fatty lesion, whereas the distal portion of the tumour was whitish and necrotic in nature. Histologically, the tumour was composed of two distinct components. The proximal component of the tumour was a WDL and the distal component was a PL. Immunohistochemically, S100 protein immunoreactivity highlighted lipoblasts in both tumour portions. The Ki-67 proliferation index was <1% in the WDL and 20% in the PL. MDM2 was positive in the WDL, but negative in the PL. p53 was negative in both areas. Numerous differentially expressed genes were found, which included genes coding for signal transduction, transcription, cell cycle, enzyme, structural protein, immune system and others. CONCLUSIONS: Our data demonstrate that multiple genes are differentially expressed in mixed type liposarcoma and suggest that these genes are associated with the differences in the morphological characteristics and pathogenesis of mixed type liposarcoma.

Adipose Tissue↗
PubMed2005

A model for research on the blood-brain barrier disruption induced by unsaturated fatty acid emulsion.

PURPOSE: The authors investigated whether fatty acid emulsion affects the blood-brain barrier (BBB), whether disrupted BBB is reversible, and whether the fatty acid emulsion technique may be a model for BBB research. MATERIALS AND METHODS: The fat emulsion was made with 0.05 mL of oleic acid or linoleic acid and 20 mL of normal saline. The internal carotid artery in 14 cats was infused with oleic acid emulsion (group 1) and with linoleic acid emulsion in 12 cats (group 2). Gd-enhanced T1-weighted (Gd-T1WI), diffusion-weighted (DWI), and additional apparent diffusion coefficient (ADC) map magnetic resonance imaging (MRI) was obtained at 1 hour, 1 and 4 days, and 1 week after infusion. MRI findings were evaluated qualitatively. Quantitatively, the signal intensity ratio (SIR) of the lesion to the contralateral hemisphere was measured on Gd-T1WIs. The SIRs were statistically analyzed using the student t test. The brain tissue was removed immediately for light and electron microscopy examination if the lesion showed no contrast enhancement and was isointense on DWIs and the ADC maps. RESULTS: The lesions appeared at 1 hour in both groups as contrast enhancement on Gd-T1WIs, as isointensity or mild hyperintensity on DWIs, and as isointensity on the ADC maps. On day 1, these MRI findings were decreased in group 1 and were not seen in group 2. At 1 hour, the SIRs of group 1 were significantly higher than those of group 2 (P = 0.016). On day 1, the SIRs of both groups approximated 1.0. Light microscopy findings revealed minor necrosis and demyelination in one cat from group 1 and in 3 cats from group 2. Electron microscopy examinations showed minimal findings in the cortical lesions in groups 1 and 2. CONCLUSIONS: Infusion of unsaturated fatty acid emulsion into the carotid artery of cats revealed vasogenic edema of the brain and reversible changes as depicted on MRI. This unsaturated fat emulsion technique may be used as a model for research on BBB disruption.

Animals↗
PubMed2005

Preliminary results of endovascular stent-assisted angioplasty for symptomatic middle cerebral artery stenosis.

BACKGROUND AND PURPOSE: Stent placement for intracranial atherosclerosis has become an alternative treatment technique; however, stent placement for middle cerebral artery (MCA) stenosis remains a technical and clinical challenge. Our purpose was to assess the feasibility, safety, and effectiveness of stent placement for MCA stenosis. METHODS: Between May 1998 and August 2003, we performed stent placement for MCA stenosis (more than 50%) in 17 patients and retrospectively analyzed the technical success rate, complications, and outcomes over 10 months. RESULTS: Stent placement was technically successful in 16 (94.1%) patients and failed in one patient (5.9%), because the stent did not reach the lesion due to carotid artery tortuousity. In 16 patients, postprocedural angiography showed restoration of the normal luminal diameter. Acute in-stent thromboses occurred in nine patients (56.3%) and was lysed with abciximab. The parent artery ruptured in two patients (12.5%): One died from massive subarachnoid hemorrhage, and the other patient received a second stent over the tear site. Stent jumping (distal migration at the time of balloon inflation) occurred in one patient (6.3%) and was solved by implanting a second stent. Periprocedural complications included subacute in-stent thrombosis (n = 1, 6.3%) and minor stroke (n=1, 6.3%); these were relieved with heparin therapy or local thrombolysis. Fifteen patients experienced symptomatic relief or were stable at follow-up. Angiographic follow-up (n=6) revealed no in-stent restenosis. CONCLUSION: Stent placement for symptomatic MCA stenosis was technically feasible and effective in alleviating symptoms and improving cerebral blood flow.

Adult↗
PubMed2004

Effect of triolein emulsion on the blood-testis barrier in cats.

PURPOSE: Although the blood-testis barrier (BTB) is beneficial physiologically, it acts as an obstacle to chemotherapy. We wished to determine whether a triolein emulsion could alter the permeability of the BTB in cats. MATERIALS AND METHODS: An emulsion of 0.05-mL triolein in 20 mL of saline was infused into the abdominal aorta just proximal to the branching of the renal arteries of each of 15 cats (embolic group). As controls, 12 cats were each similarly infused with 20 mL of normal saline (control group). Pre and postcontrast MR images were obtained 30 minutes and 2 hours after embolization. The images were analyzed for the presence and degree of contrast enhancement (qualitative analysis), and the contrast enhancement ratios (CER) derived from one testis of each animal were compared and statistically analyzed by the mixed linear model (quantitative analysis). RESULTS: Contrast enhancement of the testis was observed in both groups at both time points, but it was more prominent in the embolic group. The CERs in the embolic group (0.63 at 30 minutes, 0.42 at 2 hours) were significantly higher than in the control group (0.36 at 30 minutes, 0.28 at 2 hours; P = 0.0001). In each group, the CERs at 2 hours were significantly lower than those at 30 minutes (P = 0.006). CONCLUSION: Intra-arterial infusion of triolein emulsion increased the permeability of the BTB. This result may be useful in future studies of BTB disruptions caused by fat emulsions.

Animals↗
PubMed2003

Magnetic resonance imaging and histologic findings of experimental cerebral fat embolism.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine whether cerebral fat embolism demonstrated reversible or irreversible findings in magnetic resonance (MR) imaging over time and to compare the features in MR images with histologic findings in a cat model. MATERIALS AND METHODS: MR images were obtained serially at 2 hours, 1 and 4 days, and 1, 2, and 3 weeks after embolization with 0.05 mL of triolein into the internal carotid artery in 19 cats. Any abnormal signal intensity and change in the signal intensity were evaluated on T2-weighted images, T1-weighted images, diffusion-weighted images (DWIs; including apparent diffusion coefficient [ADC] maps), and gadolinium-enhanced T1-weighted images (Gd-T1WI) over time. After MR imaging at 3 weeks, brain tissue was obtained and evaluated for light microscopic (LM) examination using hematoxylin-eosin and Luxol fast blue staining. For electron microscopic examination, the specimens were obtained at the cortex. The histologic and MR findings were compared. RESULTS: The embolization lesions showed hyperintensity on T2-weighted images, hyperintensity, or isointensity on DWIs, hypointensity, or isointensity on ADC maps and contrast enhancement on Gd-T1WIs at 2 hours. The T2-weighted hyperintensity extended to the white matter at day 1 and decreased thereafter. Contrast enhancement decreased continuously from day 1, and hyperintensity on DWI decreased after day 4. Hypointensity on ADC maps became less prominent after day 4. By week 3, most lesions had reverted to a normal appearance on MR images and were correlated with LM findings. However, small focal lesions remained in the gray matter of 8 cats and in the white matter of 3 cats on MR images, and this correlated with the cystic changes on LM findings. Electron microscopic examination of the cortical lesions that reverted to normal at week 3 in MR images showed that most of these lesions appeared normal but showed sporadic intracapillary fat vacuoles and disruption of the endothelial walls. CONCLUSIONS: The embolized lesions of the hyperacute stage were of 2 types: type 1 lesions, showing hyperintensity on DWIs and hypointensity on ADC maps, have irreversible sequelae, such as cystic changes; whereas type 2 lesions, showing isointensity or mild hyperintensity on DWIs and ADC maps, reverted to a normal appearance in the subacute stage.

Animals↗
PubMed2002

Experimental cerebral fat embolism: embolic effects of triolein and oleic acid depicted by MR imaging and electron microscopy.

BACKGROUND AND PURPOSE: In fat embolism, free fatty acid is more toxic than neutral fat in terms of tissue damage. We evaluated the hyperacute embolic effects of triolein and oleic acid in cat brains by using MR imaging and electron microscopy. METHODS: T2-weighted imaging, diffusion-weighted imaging, and contrast-enhanced T1-weighted imaging were performed in cat brains after the injection of triolein (group 1, n = 8) or oleic acid (group 2, n = 10) into the internal carotid artery. MR images were quantitatively assessed by comparing the signal intensity ratios of the lesions with their counterparts on T2-weighted images, apparent diffusion coefficient (ADC) maps, and contrast-enhanced T1-weighted images. Electron microscopic findings in group 1 were compared with those in group 2. RESULTS: Qualitatively, MR images revealed two types of lesions. Type 1 lesions were hyperintense on diffusion-weighted images and hypointense on ADC maps. Type 2 lesions were isointense or mildly hyperintense on diffusion-weighted images and isointense on ADC maps. Quantitatively, the signal intensity ratios of type 1 lesions in group 2 specimens were significantly higher on T2-weighted images (P =.013)/(P =.027) and lower on ADC maps compared with those of group 1. Electron microscopy of type 1 lesions in both groups revealed more prominent widening of the perivascular space and swelling of the neural cells in group 2, in contrast to notable endothelial defects in group 1. CONCLUSION: MR and electron microscopic data on cerebral fat embolism induced by either triolein or oleic acid revealed characteristics suggestive of both vasogenic and cytotoxic edema in the hyperacute stage. Tissue damage appeared more severe in the oleic acid group than in the triolein group.

Animals↗