To evaluate the differentiation status of smooth muscle in gastric stromal tumors which were negative for S-100 protein, immunohistochemistry using desmin, actin, myosin and vimentin was performed in 14 cases of gastric smooth muscle tumors. Ultrastructural Examination was also performed. For comparison a case of leiomyoma of the esophagus, a case of the sigmoid colon, 10 cases of the uterus were also examined. The results obtained were as follows. All gastric smooth muscle tumors showed vimentin-positivity. Six of 14 gastric smooth muscle tumors, (5 of 8 leiomyoma and 1 of 4 leiomyosarcoma) showed positivity for desmin, actin, and myosin(42.9%). All esophageal, colonic, and uterine leiomyomas showed diffuse positive reaction for desmin, actin, and myosin. Vimentin positivity was also noted in leiomyoma of the colon and uterus. Ultrastructurally, a few cells in the gastric stromal tumors had scattered microfilaments with dense bodies, subplasmalemmal dense plaques, and micropinocytic vesicles. However, most of the tumor cells did not have any of the ultrastructural features of smooth muscle differentiation. Leiomyomas of the esophagus and uterus showed many cytoplasmic microfilaments with dense bodies. These results suggest that most of the benign and malignant tumor cells of gastric stromal tumors have features of the undifferentiated cells, immunohistochemically as well as ultrastructurally, although a few cells have. It is speculated that most gastric stromal tumors may have lost their smooth muscle differentiation.

Saponin has been known to be a major antioxidant component in panax ginseng. Recent experimental study suggests that some antioxidant materials prevent Parkinson's disease caused by 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) in an animal model. The present study was performed to demonstrate the effect of ginseng saponins in the Parkinson's disease model induced by MPTP. To verify the effect of ginseng saponin on dopaminergic neurons in the mice brain, the tyrosine hydroxylase-immunoreactive (TH-ir) neurons were observed by immunohistochemical stain and immunoelectron microscopy (preembedding method). Also, in order to estimate the immunoreactivity of dopaminergic neuropils, they were quantified by image analysis. The number of TH-ir neurons of substantia nigra was significantly increased in the high-dose (0.46 mg/kg) ginseng saponin group compared with the MPTP injected group. The immunoreactivity of TH-ir neuropils in striatum was significantly increased in both high and low-dose (0.1 mg/kg) ginseng saponin groups compared with the MPTP injected group. In immunoelectron microscopic observation, TH-ir neurons of the control and both ginseng saponin injected group showed normal nuclei and well preserved cytoplasmic organelles. In the MPTP injected group, dying dopaminergic neurons showed destroyed nuclei and cytoplasmic organelles. These results suggest that ginseng saponin has a protective effect on the Parkinson's disease model induced by MPTP.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; Animals ; Brain ; Cytoplasm ; Dopaminergic Neurons* ; Mice* ; Microscopy, Immunoelectron ; Models, Animal ; Neurons ; Neuropil ; Organelles ; Panax* ; Parkinson Disease* ; Saponins* ; Substantia Nigra ; Tyrosine ; Tyrosine 3-Monooxygenase

The purpose of this study is to obtain the clinicopathological characteristics of replication error-positive (RER ) gastric adenocarcinoma in Korean, and to identify the significance of RER in adenoma stage of gastric carcinogenesis. Microsatellite instability was examined at D2S71, D2S119, D3S1067, D6S87, D11S905, DM, AR, VWF, HPRT, and BAT-26 loci. Frameshift mutation of BAX gene was analyzed in RER tumors. Normal and tumor DNA of 76 cases of gastric carcinoma and 25 cases of adenoma were examined. RER was found in 8 of 76 cases (10.5%), and it was more frequently found in adenocarcinoma of female (17.7%) than those of male (4.8%). The frequency of RER was not different between the histologic types, age of the patient, anatomical location of the carcinoma, and the stage. The RER found in adenoma suggests that RER contributes to the malignant transformation early in the adenoma stage of the gastric carcinogenesis. None of the RER tumors revealed frameshift mutation of the BAX gene.
Adenocarcinoma* ; Adenoma ; Carcinogenesis ; DNA ; Female ; Frameshift Mutation ; Humans ; Hypoxanthine Phosphoribosyltransferase ; Male ; Microsatellite Instability

BACKGROUND: While neurofibromas have generally been regarded as polyclonal hyperplastic lesions, it remains unclear whether the tumor is a true neoplasm or a hyperplastic lesion. METHODS: Determination of clonality by X chromosome inactivation pattern was investigated in twenty-one cases of neurofibroma employing enzyme digestion and PCR of the HUMARA gene. The histological, immunohistochemical, and ultrastructural characteristics of the tumors were also examined. RESULTS: Immunohistochemically, most of the tumor cells showed vimentin and S-100 protein positivity. Axons were demonstrated by neurofilament protein positivity and were seen mainly at the periphery and rarely in the central portion of the tumor. Ultrastructurally, the tumors were composed of a variety of cell types: perineurial cells, Schwann cells, fibroblasts, and axons. X chromosome inactivation analysis was completed on thirteen out of fifteen cases in which DNA was successfully extracted. Of thirteen neurofibromas that were heterozygous at the HUMARA loci, eleven showed a polyclonal pattern. The remaining two cases were considered as indeterminate for clonality because of unequal band intensity and failure to obtain the normal control DNA. CONCLUSION: The results from this study suggest that neurofibromas are polyclonal in origin and might be a neoplastic lesion comprising non-neoplastic cells among constituent components.
Axons ; Digestion ; DNA ; Fibroblasts ; Immunohistochemistry ; Neurofibroma* ; Polymerase Chain Reaction* ; S100 Proteins ; Schwann Cells ; Vimentin ; X Chromosome Inactivation

Distinction of hepatocellular carcinoma from benign entities such as focal nodular hyperplasia is important because failure of prompt diagnosis could result in a missed opportunity for curative resection. The differential deagnosis, especially among focal nodular hyperplasia and adenoma and even hepatocellualr carcinoma, may have difficult; and when using inly a single imaging method, the diagnosis is often equivocal. Therefore, a combination of imaging modalities is preferred. For focal nodular hyperplasia, the combination of computerized tomography (CT ), magnetic resonance imaging (MRI), and radionuclide scintigraphy showed a high sensitivity and specificity. But, histologic examination is required for the differential diagnos is of hepatic mass. We report a case of hepatocellular carcinoma without clinical evidence of malignancy or serum elevation of tumor marker, that mimicked the CT , MRI, and radionuclide scint igraphic appearance of focal nodular hyperplasia.
Adenoma ; Carcinoma, Hepatocellular* ; Diagnosis ; Focal Nodular Hyperplasia* ; Magnetic Resonance Imaging ; Radionuclide Imaging ; Sensitivity and Specificity