Development and differentiation of astrocytes and oligodendrocytes (OC) in the developing human fetal spinal cord (HFSC) have been investigated by the correlative analysis of light microscopic, EM, Golgi and immunocytochemical studies. The evidence is presented to suggest, (a) that radial glia are the first distinguishable neuroglial element among the cells within the ventricular zone, (b) that radial glia contains astrocyte-specific glial fibrillary acidic protein (GFAP), (c) that radial glia undergoes transformation into astroglial cells, (d) that "transitional forms" possessing the light and EM features of both astroglial and oligodendroglial cells appear just prior to the onset of myelination, and (e) the myelin-forming OC are most likely derived from radial glial cells, either directly or through intermediated astroglial forms.
Human ; In Vitro ; Microscopy, Electron ; Neuroglia/ultrastructure* ; Oligodendroglia/ultrastructure* ; Spinal Cord/embryology* ; Spinal Cord/ultrastructure

OBJECTIVEThe oligodendrocyte is a key cell component of brain white matter. It is important to understand the pathology of oligodendrocyte injury to better understand the mechanisms leading to white matter injury in the premature brain. This study investigated the ultrastructural changes of oligodendrocytes following ischemic brain injury in 3-day-old premature rats.

METHODSOne hundred and eight 3-day-old Sprague-Dawley (SD) premature rats were randomly divided into experimental and control groups. Ischemic brain injury was induced by ligation of bilateral carotid arteries. The control group underwent a sham operation without carotid ligation. At 6, 12 and 24 hrs after operation, 8 rats were randomly selected from surviving rats of both groups. The brain tissues were sampled for transmission electron microscopy.

RESULTSThe survival rate of the control and the experimental groups was 100% and 51%, respectively. At 6 hrs of ischemia, swollen oligodendrocytes were observed in all 8 experimental rats. Organelles, including mitochondria, endoplasmic reticulum, and the Golgi apparatus, were swollen and the number of organelles in all 8 rats decreased noticeably compared with control animals. The swollen and decreased mitochondria were the most frequent change. Vacuolated mitochondria were seen in one rat and degranulated rough endoplasmic reticulum was seen in another rat from the experimental group. At 12 hrs of ischemia, oligodendrocyte swelling and decreased number of organelles became more severe in the experimental group. The oligodendrocyte nuclear chromatin was unevenly distributed and karyopycnosis began to appear in experimental animals. At 24 hrs of ischemia, oligodendrocytes generally displayed karyopycnosis and karyolysis, and organelles disappeared in experimental animals.

CONCLUSIONSProgressive oligodendrocyte damage occurred in 3-day-old premature rats subjected to permanent cerebral ischemia. The organelles injury was observed at 6 hrs of ischemia and evolved to oligodendrocyte apoptosis at 24 hrs of ischemia.

Animals ; Animals, Newborn ; Body Weight ; Brain Ischemia ; pathology ; Female ; Male ; Microscopy, Electron, Scanning ; Oligodendroglia ; ultrastructure ; Rats ; Rats, Sprague-Dawley

UNLABELLEDOBJECTIVE To study the clinicopathologic features, radiologic findings, treatment modalities and prognosis of dysembryoplastic neuroepithelial tumor (DNT).

METHODSThe clinical features, histopathologic findings, immunohistochemistry and electron microscopy of 18 cases of DNT were analyzed. Results Among the 18 cases studied, 14 were males and 4 females. The age of these patients ranged from 3 to 46 (mean age = 22. 8 years). Partial seizure was the main presenting symptom in all patients. The history of epilepsy could be as long as 17 years. On magnetic resonance imaging (MRI) study, the tumor was hypodense on T1 and hyperdense on T2. There was neither edema nor mass effect. All but 2 cases were supratentorial and intracortical in location. Ten cases were treated by complete surgical excision and the remaining 8 tumors were partially excised. In the 14 patients with follow-up data available, 13 survived for 1.4 to 11 years after the operation (with more than 10 years survival observed in 2 patients). The average survival period was 5.5 years. None of the cases showed tumor recurrence after operation. Histologically, all tumors demonstrated a multinodular architecture and were intracortical in location, sometimes with extension into the white matter. The characteristic "glioneuronal constituent" was an essential feature for making the diagnosis of DNT. The tumor was formed by an admixture of oligodendrocyte-like cells, mature neurons and astrocytes, with obvious microcystic changes. These neurons were often dispersed singly in the mucoid matrix. In most cases, the foci of cortical dysplasia were found in adjacent areas. Immunohistochemical study demonstrated positivity for synaptophysin, neurofilament and S-100 protein in the neurons and some oligodendrocyte-like cells. The staining of glial fibrillary acidic protein in the oligodendrocyte-like cells was negative. Electron microscopy showed early neuronal, astrocytic and oligodendroglial differentiation of the oligodendrocyte-like cells.

CONCLUSIONSDNT is a benign tumor (corresponding to WHO grade I) that can be cured by surgical excision, despite sometimes incomplete tumor removal. A correct diagnosis of this entity requires thorough understanding of the clinical, radiologic, histologic and immunohistochemical features.

Adolescent ; Adult ; Brain Neoplasms ; metabolism ; pathology ; surgery ; Cerebral Cortex ; pathology ; surgery ; Child ; Child, Preschool ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Neoplasms, Neuroepithelial ; metabolism ; pathology ; surgery ; Neurofilament Proteins ; metabolism ; Oligodendroglia ; pathology ; ultrastructure ; S100 Proteins ; metabolism ; Survival Rate ; Synaptophysin ; metabolism

OBJECTIVETo establish red-green dual-color fluorescence glioma model in nude mice and to explore its practical values.

METHODSCM-DiI-stained rat glioma C6 cells (C6-CM- DiI cells) expressing red fluorescence were inoculated into the brain of athymic nude mice expressing green fluorescence protein (NC-C57BL/6J-EGFP). Then the whole-body dual-color fluorescence imaging was detected dynamically. Finally whole brains of the tumor-bearing mice were removed and 5 µm thick serial frozen slices were made. Light microscopy, fluorescence microscopy and confocal laser scanning microscopy were performed to observe the transplanted tumor tissue structure and fluorescent cells.

RESULTSTumor mass with red fluorescence increased gradually under continuous in-vivo fluorescence imaging monitoring. Under the fluorescence microscope, cells with red, green and yellow fluorescence were observed in the frozen sections of transplanted tumor tissue and the mutual structural relationship among them could be defined. The tumor cells migration, implantation and cell fusion between transplanted tumor cells and host cells could be observed. It could be distinguished according to the fluorescence, that blood vessels of tumor-origin displayed red fluorescence, blood vessels of host-origin displayed green fluorescence and mosaic blood vessels appeared yellow fluorescence. It was depicted that host innate astrocytes and oligodendrocytes in the microenvironment at the tumor periphery could be activated and dedifferentiated into nestin-positive cells.

CONCLUSIONSIn contrast to traditional animal model, the dual-color fluorescence imaging of nude mouse models of glioma possesses enormous advantages in investigating tumor mass in-vivo fluorescence imaging, tumor cells migration and metastasis, tumor angiogenesis and reactive activation of host innate cells in the microenvironment at tumor periphery, thus, has highly practical application value.

Animals ; Astrocytes ; metabolism ; Brain Neoplasms ; blood supply ; metabolism ; pathology ; ultrastructure ; Carbocyanines ; metabolism ; Cell Fusion ; Cell Line, Tumor ; Cell Movement ; Disease Models, Animal ; Fluorescent Dyes ; metabolism ; Glioma ; blood supply ; metabolism ; pathology ; ultrastructure ; Green Fluorescent Proteins ; metabolism ; Luminescent Proteins ; metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Nude ; Microscopy, Confocal ; Microscopy, Fluorescence ; Neoplasm Transplantation ; Neovascularization, Pathologic ; Nestin ; metabolism ; Oligodendroglia ; metabolism ; Rats

OBJECTIVETo study the clinicopathologic features and radiologic findings of dysembryoplastic neuroepithelial tumor (DNT).

METHODSThe clinical presentations, radiologic findings, histologic features and immunophenotype of 9 cases of DNT were analyzed.

RESULTSThe age of patients ranged from 12 to 51 years (mean age = 32 years). Most presented with partial seizures, sometimes accompanied by transient aphasia, agraphia and decreased visual acuity. One case was asymptomatic and discovered incidentally during a routine check-up. All patients had no neurological deficit found on physical examination. All tumors were located in the supratentorial cerebral cortex. There was no peritumoral edema or space-occupying effect on radiologic examination. The tumors involved either frontal lobe (number = 4), temporal lobe (number = 4), frontoparietal lobe (number = 1) . Two cases showed cystic changes. Two histologic variants of DNT were recognized: simple (number = 3) and complex (number = 6). Simple variant was composed mainly of the glioneuronal element, accompanied by surrounding oligodendrocyte-like cells, and the complex variant contained a low-grade glioma component, in addition to the glioneuronal element and sometimes foci of cortical dysplasia.

CONCLUSIONSDNT is a benign tumor with excellent prognosis after surgical excision. Local recurrence is rare. Complex variant of DNT needs to be distinguished from other types of low-grade glioma.

Adolescent ; Adult ; Brain Neoplasms ; complications ; metabolism ; pathology ; surgery ; Cerebral Cortex ; metabolism ; pathology ; Child ; Child, Preschool ; Epilepsies, Partial ; etiology ; metabolism ; pathology ; surgery ; Female ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neuroectodermal Tumors, Primitive ; complications ; metabolism ; pathology ; surgery ; Neurofilament Proteins ; metabolism ; Oligodendroglia ; pathology ; ultrastructure ; S100 Proteins ; metabolism ; Survival Rate ; Synaptophysin ; metabolism