Toshio Ametani

Extracellular distribution of ruthenium red-positive substance in the cerebral cortex

Ruthenium red-positive materials in the extracellular spaces, including the basement lamina, of the rat brain were localized at the extraneous surface coat which arises from, or is closely attached to, the outer leaflet of the plasma membranes of neurons, astrocytes, oligodendrocytes, and endothelial cells. No regular structure or periodicity was detected in any regions of the extraneous coat other than flocculent, local variations in density and thickness and occasional irregular strands of the ruthenium red-marked substances. A diffuse distribution of the ruthenium red-marked substances was evident in the synaptic clefts. The intersynaptic ruthenium red-positive substances revealed striations or microvesicular profiles. Also, a characteristic feature was evident at an excitable cell membrane, such as dendritic and presynaptic plasma membranes. There the ruthenium red-positive materials were aligned along the inner and the outer leaflets of the plasma membranes, respectively, and sandwiched the clear intermediate layer of the unit membranes. The ruthenium redmarked materials around the myelinated nerve fibers were closely attached to the outermost intraperiod dense lines of the myelin lamellae.

Atypical cristae in mitochondria of human glioblastoma multiforme cells.

A conformation and structure of atypical cristae was seen in some enlarged mitochondria in human glioblastoma multiforme. In the transformation into atypical cristae, normal cristae were markedly decreased in number or absent, and instead, few of them elongated and straightened, becoming intensified in density. Two major forms were discernible in the atypical cristae: close junction type and septate desmosome type. In the close junction type, the apposed cristal unit membranes, about 60 A in thickness, appeared to be arranged in a closely parallel manner analogous to the formation of close junction between epithelial cells, and the intracristal space, about 70 A wide, was of an intermediate density. In the septate desmosome type, the apposed cristal unit membranes were separated by an intracristal space, about 70 A wide, where a series of oriented parallel lamellae or septa spanned at a regular interval of about 160 A from center to center, similar in feature to septate desmosomes. The individual parallel lamellae or septa were mostly composed of electron opaque bodies.

Sodium Localization in the Choroid Plexus

SummaryThe localization of sodium ion in the cat choroid plexus was studied by use of potassium pyroantimonate. The precipitates formed by the potassium pyroantimonate occur mostly on the plasma membrane in the epithelial cell and occasionally in the perivascular space. The precipitates in the epithelial cell are most numerous at the apical surface, particularly on the microvilli, and least in number at the basal and lateral surfaces. In the endothelial cell, the dense precipitates are situated on the plasma membrane as well as on the limiting membrane of the pinocytotic vesicle. Although the dense precipitates are sometimes situated on the external surface of the plasma membrane of the epithelial cell, most of them are localized on the internal surface of the plasma membrane. A similar localization of the precipitates is to be seen on the plasma membrane of the erythrocyte. When the cerebrospinal fluid/plasma ion ratio and potential gradients across the choroid plexus are considered, the precipitates on the plasma membrane would suggest a localization of sodium needed for the activation of ATPase.ZusammenfassungDie Lokalisation des Natriumions im Plexus chorioideus der Katze wurde mit Hilfe von Kaliumpyroantimonat untersucht. Die durch Kaliumpyroantimonat gebildeten Niederschläge treten meistens an der Plasmamembran in den Epithelzellen und gelegentlich im perivaskulären Raum auf. In den Epithelzellen kommen die Niederschläge am zahlreichsten an der apikalen Oberfläche vor, besonders an den Mikrovilli, am geringsten an den basalen und lateralen Oberflächen. In der Endothelzelle liegen die dichten Niederschläge an der Plasmamembran und an der Grenzmembran der Pinozytosebläschen. Einige der dichten Niederschläge befinden sich an der äußeren Oberfläche der Plasmamembran der Epithelzellen, die meisten aber an der inneren Oberfläche der Plasmamembran. Eine ähnliche Lokalisation der Niedersschläge wurde an der Plasmamembran des Erythrozyten festgestellt. Wenn man das Liquor Plasma-Ionenverhältnis und die Potentialgradienten am Plexus chorioideus in Betracht zieht, liegt es nahe, die nachgewiesene Lokalisation des Natriums auf eine Aktivierung von ATPase zu beziehen.

Polygonal crystalline structures in human ependymoma cells

SummaryPolygonal crystalline structures were found in the lysosomes of human ependymoma cells, well demarcated from the granular matrix of the lysosomes. They were composed of a regular spacing at an interval of 150–160 Å of alternating dense and less dense layers, orientated along one to three axes and forming rectilinear, tetragonal, or hexagonal arrays.ZusammenfassungPolygonale kristalline Strukturen fanden sich in Lysosomen der Zellen eines menschlichen Ependymoms. Die von der granulären Matrix der Lysosomen gut abgegrenzten Strukturen waren aus regelrecht in Abständen von 150–160 Å angeordneten Formationen aufgebaut, in denen dichte und weniger dichte Schichten abwechselten. Diese waren in einer der drei Achsen angeordnet und bildeten rechteckige, tetragonale oder hexagonale Gebilde.

Ciliated human astrocytoma cells

SummaryCilia were found in a human astrocytoma. Most cilia in the astrocytoma showed an 8+1 pattern which possibly resulted from the displacement of one peripheral doublet of a 9+0 cilium into the middle of the cilium. The central fiber was often in an eccentric position. The delicate rootlet fibers radiated from the proximal portion of the basal body into the cytoplasm. The basal feet, conical in form, extended from the peripheral fibers of the basal body into the cytoplasm at approximately right angles to the longitudinal axis of the basal body, and were widest at their junction with the basal body. The core of the basal feet was of lesser density. The centrioles also demonstrated the fine rootlet fibers and the satellites similar in structure to the basal feet of the basal body. Some cilia in the astrocytoma demonstrated a two-centriole basal organization.ZusammenfassungIn einem menschlichen Astrocytom fanden sich Cilien. Sie zeigten meist ein Verteilungsmuster von 8+1, das möglicherweise aus der Verlagerung einer peripheren Faser eines 9+0 Cilium in die Cilienmitte entstand. Die Zentralfaser fand sich oft in exzentrischer Lage. Die zarten Wurzelfasern zeigten einen strahligen Verlauf vom proximalen Anteil des Basalkörpers in das Cytoplasma. Die konischen Basalfüße erstreckten sich von den peripheren Fasern des Basalkörpers in das Cytoplasma in annähernd rechtem Winkel zur Längsachse des Basalkörpers. Sie waren am weitesten an ihrer Vereinigung mit dem Basalkörper. Der Hof der Basalfüßchen zeigte geringere Dichte. Die Centriolen wiesen gleichfalls zarte Wurzelfasern und Satelliten auf, die strukturelle Ähnlichkeit mit den Basalfüßen des Basalkörpers zeigten. Einige Cilien in diesem Astrocytom wiesen eine Grundorganisation mit zwei Centriolen auf.

Nuclear structures of primary malignant lymphoma in the brain

Various classes of nuclear granules and inclusion bodies were observed in primary malignant lymphoma cells in the brain. In addition to the chromatin and the nucleoli, the perichromatin granules and the unusual dense granules were main granular structures. However, the most prominent features were clusters of interchromatin granules. The individual interchromatin granules were round or ovoid, sometimes filamentous in shape, and about 30 to 40 mμ in diameter. They were not extractable in enzyme digestion with pepsin, RNAase, or DNAase, and decreased markedly in electron density when both pepsin and RNAase were employed. It may be reasonably assumed that the interchromatin granules may be a complex of RNA and acidic proteins. Some nuclear bodies involved the interchromatin granules in formation. This study may suggest 2 possible processes of formation of nuclear bodies, which are derived (a) from the interchromatin substances or (b) from the inner nuclear membranes.

Sodium localization in the adult brain

SummaryGrossly visible precipitates were formed when 2% solution of potassium pyroantimonate was added to 0.01 M acetic acid, 0.1 N hydrochloric acid, or some divalent cation solutions. Localization of sodium ion in the brain of rat and cat was, therefore, studied by use of potassium pyroantimonate buffered with s-collidin. The sodium precipitates were observed mainly on the plasma membranes of neuron, astrocyte, endothelial and perivascular cells as well as erythrocyte. In the neuron, the precipitates were most numerous on the plasma membranes of terminal boutons and dendrites, particularly synapses. The dense precipitates were less in number on the plasma membranes of astrocyte, endothelial and perivascular cells than of neuron. In addition, there was some evidence of the dense precipitates localized in the extracellular space. All of the sodium precipitates shown on the plasma membranes in the brain were situated on the internal surface of the plasma membranes. Similar localization of the sodium ion was evident on the plasma membrane of the erythrocyte. The site of the sodium precipitates on the plasma membranes was discussed in relation to the distribution of Na+-K+ stimulated ATPase.ZusammenfassungBei Zugabe von 2% Kalium-Pyroantimonat zu 0,01 M Essigsäure, 0,1 N Salzsäure oder verschiedenen bivalenten Kationenlösungen werden deutlich erkennbare Präcipitate gebildet. Die Lokalisation von Na+-Ionen im Gehirn von Ratten und Katzen wurde daher mittels Kalium-Pyroantimonat gepuffert mit S-Collodin untersucht. Die Na+-Niederschläge wurden vorwiegend an den Plasmamembranen der Neuronen, Astrocyten, Endothel- und perivasculären Zellen sowie in Erythrocyten beobachtet. In den Neuronen waren die Niederschläge gehäuft an den Plasmamembranen der Endknöpfchen und Dendriten, vorwiegend an Synapsen. Dichte Präcipitate waren an den Plasmamembranen der Astrocyten, Endothel- und perivasculären Zellen weniger häufig als am Neuron. Ferner ergaben sich Hinweise für dichte Präcipitate im extracellulären Raum. Alle an den Plasmamembranen in Gehirn nachgewiesenen Na+-Niederschläge lagen an der inneren Membranoberfläche. Ähnliche Lokalisation zeigten sie an der Plasmamembran des Erythrocyten. Der Sitz der Na+-Präcipitate an den Plasmamembranen wird in bezug auf die Verteilung der Na+-K+-aktivierten ATPase diskutiert.

Nuclear periphery of human glioma and meningioma cells.

SummaryThe nuclear periphery of 10 glioblastomas multiforme, 5 astrocytomas, 2 ependymomas, 2 medulloblastomas, and 3 meningiomas, were examined with the electron micro-scope. All tumors exhibited the marginal heterochromatin granules forming a dense beaded row and running parallel to the inner nuclear membrane. The marginal heterochromatin granules in all tumors were sometimes not in contact with the inner nuclear membrane, and seemed to be separated from the inner nuclear membrane by a moderately dense layer, about 70 Å thick. The inner side of this layer was irregular in contour, because of the presence of the spherical heterochromatin granules.In certain glioblastoma multiforme and astrocytoma as well as fibroblastic meningioma, the fibrous lamina or the nuclear limiting zone was obviously found between the inner nuclear membrane and the marginal heterochromatin granules. It was similar in density as the nucleoplasm in the glioblastoma multiforme as well as the astrocytoma and homogeneously dense in the fibroblastic meningioma. The inner side of this nuclear peripheral zone exhibited some indentation, because of the protrusion of the marginal heterochromatin granules into the nuclear limiting zone, and did not possess its own delimiting membrane to keep the nuclear chromatin separated from the substance of the nuclear limiting zone. The fibrous lamina or the nuclear limiting zone in the fibroblastic meningioma appeared interrupted or greatly attenuated and poorly defined on the inner side of the nuclear pore, and often seemed to continue unchanged across the nuclear pore.In the E.M. examination of brain tumors, there was a variation in thickness and appearance of the nuclear limiting zone within the same type of cells, and the nuclear limiting zone was often absent.

Membranous stacks in human glioblastoma multiforme.

SummaryCurious, characteristic stacks of membranes were found, mainly in the perinuclear cytoplasm of the cells of some human glioblastomas multiforme. The membranes were arranged either in concentric rings or extended haphazardly in several directions. They consisted of closely apposed cisternae, the outermost membranes of which were studded sparsely with ribosomes. The interspaces, formed by the close apposition of adjacent cisternae, were about 160–180 A in width and of intermediate density.The nuclear envelopes of a small percentage of glioblastoma multiforme cells projected in a complicated fashion into the cytoplasm to form unusual layered structures. The surface of each projection consisted of a membrane continuous with the outer nuclear membrane. A laminated dense zone about 160–180 A wide, sandwiched between the two spaces, was continuous with the nucleoplasm at the point of origin of the projection. Consequently, the stacks of membranes were similar in appearance with the projected nuclear envelope.

Rosenthalsche Fasern im Gollschen Kern

SummaryIn addition to axonal spheroids (axonal dystrophy) a few of Rosenthals fibers were found in the Golls nucleus in cases between aged 49 and 90 years.