Uros Roessmann

Immunohistochemical localization of glial fibrillary acidic protein in human glial neoplasms

The presence and distribution of glial fibrillary acidic protein in fixed, paraffin embedded tissue were studied in 85 human intracranial neoplasms, using the peroxidase‐anti‐peroxidase method. In some cases, indirect immunofluorescence of frozen sections was used as well. In normal tissue, only the cell processes and perikarya of fibrous astrocytes were stained. Immunostaining was also observed in the following glial neoplasms: astrocytomas (all varieties), astroblastoma, subependymal giant cell astrocytoma, subependymoma, glioblastoma multiforme and ependymoma. The astrocytic elements of mixed gliomas and of medulloblastomas undergoing glial differentiation were likewise strongly stained. In contrast, oligodendrogliomas, meningiomas, pituitary adenomas, sarcomas, lymphomas and metastatic carcinomas were negative. Either a perikaryal or a diffuse fibrillary staining pattern was observed. Combination of the two patterns occasionally occurred. The perikaryal staining was prominent in gemistocytic astrocytomas and in astroblastomas. A distinct negative correlation existed between the degree of anaplasia and the intensity of immunostaining.

Glial fibrillary acidic protein (GFAP) in ependymal cells during development. An immunocytochemical study

Human ependymal cells show positive immunostaining for glial fibrillary acidic protein (GFAP) at one stage of the fetal development. The reaction seems to coincide with maturation of the epithelial layer and development of cilia. Two types of reactive cells are present: epithelial and tanycytes. The GFAP-positive reaction in both these cells is transient, appearing at different times and with different patterns in the various regions of the ventricular system. In order to explain the presence of detectable GFAP in developing ependymal cells and its absence in mature cells, it is proposed that either the synthesis of detectable amounts of GFAP occurs only at a stage of ependymal cell maturation, or that the intermediate filaments assembled in developing ependymal cell are antigenically distinct form those of the mature cells. The present findings indicate that tanycytes are not an immature from of ependymal cells but that they develop parallel to the epithelial cells. The role of the tanycytes remains obscure, but it is suggested that they are not related to radial glia.

The Presence of Glial Fibrillary Acidic Protein in the Human Pituitary Gland

The presence of glial fibrillary acidic protein (GFAP) was studied in human pituitary glands with the peroxidase-antiperoxidase (PAP) method. Positive reaction was observed in cells and processes of the neurohypophysis, in occasional cells lining the Rathkes cysts of the pars intermedia, and in scattered star-shaped cells and small follicles of the pars distalis. GFAP immunoreactivity was sparse and variable in amount from case to case. An increase in GFAP-immunoreactivity was observed as a reaction to injury. GFAP-positive cells were seen within and around pituitary adenomas regardless of their secretory cell type. Evidence is presented to indicate that these cells do not contain conventional pituitary hormones. It is postulated that the GFAP-positive cells of the pars distalis are nonsecretory elements, identical to the folliculostellate cells. They may become visible by immunostaining following increased synthesis of GFAP. The latter may be a response to cell injury or metabolic changes in adjacent secretory elements. A similar reaction in pituicytes may explain the appearance of immunoreactive GFAP in the neural lobe. The presence of GFAP in the adenohypophysis suggests that some of their cells are neuroectodermal in origin

Neuronal and astrocytic differentiation in human neuroepithelial neoplasms: An immunohistochemical study

Neuroepithelial neoplasms of childhood were examined immunohistochemically using antibodies against a neurofilament polypcptide and glial fibrillary acidic protein. Ninety-one cases, including 11 controls, were examined. Positively reacting cells, indicating neuronal and glial differentiation, were found in 59 of the 80 tumors. The study supports a neuroepithelial origin for medulloblastomas, central neuroblastomas, and primitive neuroectoder-mal tumors of childhood. The results also indicate that only a small number of the tumor cells differentiate along either neuronal or glial cell lines.

Massive intracerebellar hemorrhage in low-birth-weight infants.

The clinical and pathologic observations of massive intracerebellar hemorrhage (destruction of at least one-third of cerebellar tissue) are described in six low-birth-weight infants. In all infants, severe progressive apnea associated with a falling hematocrit were the prominent clinical features. Four infants were asphyxiated at birth. Some degree of cerebellar hemorrhage (macroscopic or microscopic) was observed in 21% of 157 newborn brains examined at autopsy. The cause of massive intracerebellar hemorrhage is unknown, but may result from deforming pressures on the skull secondary to perinatal trauma. A close follow-up of cerebellar function in low-birth-weight infants is important.

Metastatic lesions in the sella turcica and pituitary gland

The sella turcica with adjacent osseous tissues was examined histologically in 60 cases of carcinoma which came to postmortem examination in the course of one year. Forty‐nine of the specimens were also examined by roentgenography. Sixteen contained metastatic lesions, 9 of which originated from the breast. Statistical analysis showed that the incidence of sellar metastases was significantly higher for carcinoma of the breast than for all other neoplasms. Involvement of the sella was positively correlated with other skeletal metastases. X‐ray examination was found to be a relatively insensitive method for detecting metastatic lesions in the sella.

Astrocytes in the developing human brain. An immunohistochemical study.

SummaryPatterns of appearance and maturation of astrocytes, as demonstrated by the immunohistochemical detection of glial fibrillary acidic protein (GFAP), were studied in fetal and mature neonatal brains. Mature astrocytes were present throughout much of the normal central nervous system at 15 weeks of gestation, but they varied in density in different parts. Glioneogenesis continued throughout the fetal and postnatal ages. Marginal glia were conspicuous with strong reaction and probably constituted a distinct subpopulation of glia. There was no temporal relationship between astrocytic proliferation and “myelination gliosis”. Radial glia and Bergmann fibers in normal brains did not react to GFAP antiserum.

Pathological reaction of astrocytes in perinatal brain injury. Immunohistochemical study.

SummaryAstrocytic reaction to various types of pre-and perinatal damage in the brain was studied using the immunohistochemical method for glial fibrillary acidic protein. The reactive gliosis could be detected as early as 20 weeks gestation. Reactive proliferation of the astrocytes could be seen already at 4 days after the insult. In addition to reacting to focal lesions, the astrocytes also proliferated diffusely throughout the white matter. The diffuse proliferation is the most significant finding in the evaluation of the perinatal damage, in both the acute state and in the long-term survivors.

Thrombosis Of the middle cerebral artery associated with birth trauma

After birth trauma, an infant had middle cerebral artery thrombosis, proved at autopsy. Unusual forces exerted on the head and neck at the time of attempted high forceps delivery damaged the inner layers of the right middle cerebral artery, which led to thrombosis and infarction.

Respiratory distress and Arnold‐Chiari malformation

Fourteen children with Arnold-Chiari malformation had history of respiratory distress, apnea, vocal cord paralysis or inability to swallow. Postmortem examination in 12 disclosed vascular lesions in the tegmentum of the medulla oblongata. The length of survival of these children was markedly shorter than of those without such history and anatomic findings. It is suggested that the malformation results in changes in the vascular supply of the herniated portion of the brainstem. Stretching of the arteries may result in irreversible damage to the brainstem with subsequent life-threatening disturbance of respiratory function.