Myelin in the central nervous system as observed in experimentally induced edema in the rat.

The compact arrangement of cells in the normal white matter of the brain makes an analysis of cellular architecture difficult. To overcome this difficulty, cerebral edema was induced in rats by means of the unilateral intracerebral implantation of silver nitrate. Within 48 hr, the brains were fixed by perfusion with glutaraldehyde followed by immersion in Dalton's chrome-osmium. Sections of the callosal radiations were studied in the electron microscope. The untreated hemisphere appeared entirely unaltered, whereas in the edematous hemisphere the edema fluid separated individual cell processes and small groups of them. The myelin sheaths and their relationships to the axons appeared essentially unaltered. In this material, analysis of cellular architecture was relatively easy, and the widely held theory of spiral wrapping could be confirmed. In addition, several other aspects of the myelin and myelin-forming cell relationships became apparent in the edematous tissue. Most of these were later confirmed by extensive and careful study of the nonedematous tissue. These included the presence of occasional isolated cytoplasmic areas in myelin and the presence of two complete sheaths around a single axon. Other observations, such as the appearance of mitochondria and dense bodies within the outer loop and the separation of myelin lamellae, are apparently limited to the edematous tissue.

The effect of verapamil on pancreatic exocrine secretion.

This study set out to examine the effects of a Ca++ channel blocker, verapamil, on pancreatic exocrine secretion because of the known relationship between amylase secretion and intracellular Ca++. Pancreatic secretion was stimulated in dogs by infusing secretin and cholecystokinin. Verapamil was found to inhibit the secretion of amylase but to have no effect on lipase, trypsin, or total protein. There was no effect on the secretion of water and bicarbonate. To determine the possible physiologic significance of these findings, the pancreas was stimulated by a meat meal, and verapamil was found to inhibit amylase secretion again and in addition to inhibit the secretion of water and bicarbonate. The results suggest that verapamil has an inhibitory effect on amylase secretion by blocking the influx of Ca++ into the acinar cell and has an indirect effect leading to inhibition of water and bicarbonate secretion from the duct cells.

Cerebral glioblastomas can be cured!

In 1959, a 30-year-old man underwent the removal of a glioblastoma multiforme from the right parietal lobe of his brain. After the operation, he received x-ray therapy. He made a complete recovery. Today, over 25 years later, he is alive and well and is regularly employed full-time. If glioblastomas and other cerebral gliomas are removed completely, the patients can be cured of their tumors.

Intracerebellar "fibroma". Case report.

The authors report a unique case of intracerebellar fibroma; the tumor was well circumscribed and was treated by complete excision.

Vascular alterations in delayed radiation necrosis of the brain. An electron microscopical study.

A 51-year-old woman who had been given cobalt therapy for nasopharyngeal carcinoma was seen three years later with a mass in the left frontotemporal region of the brain. Biopsy specimen of the lesion showed the classic features of delayed radiation necrosis on light microscopy. In addition, several blood vessels showed endothelial cell proliferation. Transmission electron microscopical study demonstrated numerous alterations of the endothelial cell, such as intraluminal infoldings of the plasma membrane, an increased amount of cytoplasmic organelles, and the frequent occurrence of tubular bodies in addition to degenerative and reactive changes in the neuropil.

Variability of intracellular concentrations of basic fibroblast growth factor in cultured human gliomas.

BACKGROUND: Basic fibroblast growth factor (bFGF) is a small peptide with angiogenic and mitogenic properties that supports the growth and proliteration of human malignant glial tumors in vitro and in vivo in an autocrine fashion. The purpose of this study was to examine the potential relationship between intracellular bFGF concentrations and grade of glial malignancy using a monolayer cell culture system. MATERIALS AND METHODS: Samples from 13 histopathologically verified astrocytic brain tumors and two non-tumorous astrocyte specimens were grown in tissue culture and examined both early and late after explantation together with a bFGF-producing reference cell line. RESULTS: Elevated intracellular concentrations of bFGF were noted in the reference line as well as two of five other glioblastoma multiforme-derived cell cultules, three of five anaplastic glioma-derived cell cultures, and two of three astrocytoma-derived cell cultures. The cells derived from non-tumorous astrocyte specimens expressed low concentrations of bFGF. CONCLUSION: This study demonstrates that overlap exists between the grade ot glial malignancy and intracellular bFGF levels.

[The fine structure of ependymona (author's transl)].

The tumor cells form an unoriented mass rather than a layered structure. Most of the cells have no ependymal specialization, such as cilia, microtubular, etc. Instead, they assume a primitive undifferentiated appearance with large nuclei and abundant free ribosomes. Occasionally, however, certain cells tend to form a ring around a narrow lumen-like space within the mass. Such spaces are virtually filled with microvilli and, occasionally, even cilia arising form the surrounding cells. Elaborate desmosomes decorate the apposing surfaces of such cells and basal bodies are presented within the cytoplasm. In addition, the tumor cells often display glial filaments, glycogen granules and microtubules, similar to the cells comprising astrocytomas. As is well known, astrocytomas and ependymomas are often found mixed in the same tumor.

[The fine structure of epithelial cyst in the central nervous system (author's transl)].

The fine structure of three types of cysts within central nervous system, all with a single cell lining, has been examined. The first was in the subarachnoid space of the lumber cord and the lining cells included both ciliated and nonciliated secretory cells. It was considered to be of endodermal origin. The second type was a colloid cyst of the third ventricle and its fine structural features were almost identical to those of the first type. It was, therefore, likewise considered to be of endodermal origin. The third type was an intracerebral epithelial cyst in which the lining cells more closely resembled ependymal cells. The value of fine structural studies for the understanding of the pathogenesis of epithelial cysts within the central nervous system is discussed.