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Biomedical subjects

H W Jung

Publications and source records attributed to H W Jung.

7 recordsLinked to original sources
PubMed1992

Intraventricular neurocytoma: clinicopathological analysis of seven cases.

A retrospective analysis of seven patients with intraventricular neurocytoma is presented. Patient age at diagnosis ranged from 15 to 38 years (mean 24.6 years) and the male:female ratio was 6:1. Raised intracranial pressure due to hydrocephalus was the main cause of the clinical manifestations. An isodense mass with multiple intratumoral cysts and homogeneous contrast enhancement was the characteristic computerized tomography finding. The lesions commonly involved the lateral ventricle with or without extension to the third ventricle. Cerebral angiography showed homogeneous vascular staining in five patients. Magnetic resonance images revealed a mass isointense with the cerebral cortex on both T1- and T2-weighted images. Gadolinium-diethylenetriaminepenta-acetic acid-enhanced images showed homogeneous enhancement. Total removal of the tumor was possible in four patients. Pathologically, six cases were initially diagnosed as oligodendroglioma and the remaining case as ependymoma. However, immunohistochemical studies demonstrated strong positivity for neuron-specific enolase in all seven cases and for synaptophysin in five cases. On electron microscopy, three cases showed well-defined neurosecretory granules and 10-nm microtubules in their cytoplasm and cytoplasmic processes. One patient developed a recurrent tumor 18 months after surgery. The remaining six patients are free of recurrent tumors at 2 to 62 months after surgery. It is suggested that neurocytoma must be included in the differential diagnosis of intraventricular lesions, and that electron microscopic and immunohistochemical studies should be undertaken.

Adolescent↗
PubMed1992

Malignant triton tumor of the acoustic nerve. Case report.

The authors present the clinical, radiological, pathological features, and autopsy findings of a patient with malignant triton tumor of the acoustic nerve, which probably arose from a pre-existing acoustic schwannoma. The term "malignant triton tumor" is applied to malignant schwannomas with rhabdomyoblastic differentiation. A cerebellopontine angle tumor with spinal drop metastasis occurred in this patient 10 months after near-total removal of the original tumor.

Female↗
PubMed1991

A three-dimensional micro-organ culture system optimized for in vitro growth of human malignant brain tumors.

A brain tumor is composed not only of tumor cells, but also of normal glial, mesenchymal, endothelial, and microglial cells, as well as lymphocytes and macrophages. Therefore, homogeneous cultures of tumor cells, currently used for chemosensitivity testing, do not accurately model in situ tumors. We have developed an in vitro growth assay for brain tumors that includes normal host cells and is potentially useful for studies of chemotherapy and biological response modifiers. Human glioblastoma xenografts (U251-MG) were resected from mice, minced, and explanted into agarose-coated culture wells. After 5 to 7 days, microtumors emerged as expanding spheroids, which grew most efficiently in minimum essential medium supplemented with 20% fetal calf serum, 90% of which was replaced on alternate days. The growth rate and bromodeoxyuridine labeling index were similar in the microtumors and the xenografts, and light microscopy revealed highly cellular, pleomorphic tumors with high mitotic activity in both. Immunohistochemical studies also demonstrated the persistence of macrophages in both xenografts and microtumors. Microtumors treated for 2 hours with 75 mumol/L 1,3-bis-(2-chloroethyl)-1-nitrosourea showed a growth delay of 1.5 days; no effects were observed after treatment with lower doses. This in vitro system for brain tumor culture may provide a useful technique for the study of new therapies as an alternative to in vivo xenograft studies using immunodeficient animals.

Animals↗
PubMed1989

Separation of amino- and acetylamino-polycyclic aromatic hydrocarbons by reversed- and normal-phase high-performance liquid chromatography.

In the field of chemical carcinogenesis, amino- and acetylamino-polycyclic aromatic hydrocarbons (PAHs) are among the most studied compounds. Many of these compounds have recently been detected in the environment. Presently, knowledge permitting predictions of the high-performance liquid chromatographic (HPLC) retention order of amino- and acetylamino-PAHs, particularly among their geometric isomers is lacking. In order to obtain a better understanding of the separation of these types of compounds, we have studied the separation of a series of structurally related amino- and acetylamino-PAHs derived from naphthalene, phenanthrene, anthracene, pyrene, benz[a]anthracene, benzo[a]pyrene, and benzo[e]pyrene by using reversed-phase and normal-phase HPLC columns of different types (monomeric, polymeric, and chiral stationary phase). The results indicate: (i) Pirkle-type chiral stationary phase columns and the Zorbax SIL column can efficiently separate both the amino-PAHs and acetylamino-PAHs; (ii) in general, there was no correlation between retention time and molecular size; (iii) when acetylamino-PAHs were separated on the monomeric Zorbax ODS column, the isomer with the acetylamino group located at the carbon position of higher electron density has a shorter retention time; and (iv) separation of the parent PAHs was better than that of the amino-PAHs and acetylamino-PAHs. Our results thus may provide useful information for the analysis of amino-PAHs, particularly for distinguishing the geometric isomers of environmental samples.

Amines↗
PubMed1988

Acute cerebral infarction and changes of regional cerebral blow flow (rCBF) following experimental middle cerebral artery (MCA) occlusion.

An unanaesthetized cat model of acute focal cerebral ischaemia has been established by the technique of transorbital snare ligature for middle cerebral artery (MCA) occlusion. The model was used to investigate the patterns of changes of regional cerebral blood flow (rCBF) for up to 16 h following MCA occlusion by the hydrogen clearance technique and to explore the correlation among changes of rCBF, neurological deficits, and pathological changes. The animals were divided into 2 groups according to the size of infarct which was identified by 2% triphenyl tetrazolium chloride (TTC) solution stain. Infarct larger than 10% of coronal section surface of ipsilateral hemisphere was found in 18 cats (Group A), and a smaller infarct was found in the remaining 7 cats (Group B). Between these 2 groups, there was a statistically significant difference in the average rCBF value of the ipsilateral MCA territory. The increasing grade of contralateral paralysis correlated well with the decreasing rCBF in the ipsilateral MCA territory, and the increasing grade of cerebral hemispheric swelling was directly proportional to the increasing grade of paralysis. Three patterns of changes of rCBF were observed: persistent severe ischaemia (15 cats, Group A); persistent mild to moderate ischaemia (7 cats, Group B); and immediate severe ischaemia followed by early post-ischaemic hyperaemia and death (3 cats, Group A). During the initial stage of ischaemia, a significant decrease in rCBF of the contralateral hemisphere was observed in both groups, however, in Group A rCBF gradually increased to preocclusion level, while Group B presented a further decrease in rCBF suggesting the occurrence of interhemispheric diaschisis. Thus, Group B appeared to take advantage of diaschisis during the late phase of infarct development, as well as the substantial collateral flow from the surrounding anterior and posterior cerebral artery territories.

Animals↗