Hans Cain

Immunofluorescence microscopic demonstration of vimentin filaments in asteroid bodies of sarcoidosis

SummaryAsteroid bodies in multinucleate giant cells from sarcoid granulomas were investigated by immunofluorescence and electron microscopy. The following points have been established :1.Asteroid bodies are made up of individual components of the so-called cytoskeleton, predominantly vimentin filaments. Microtubules are involved in smaller amounts in the formation of the asteroid bodies.2.They arise within the area of the cytosphere. The body of the asteroid includes the centrioles while the arms of the asteroid usually extend into the Golgi area and occasionally up to the cell nuclei.3.Asteroid bodies result from aggregation of the flexible filamentous and microtubular systems of the centrosphere. The processes of aggregation probably result from local fluid shifts and sol-gel transformations.4.The stellate form of the aggregations is determined by the pre-existent radial arrangement of the elements of the cytosphere.5.The prevailing specific environment of the underlying granulomatous disease, together with the internal characteristics of the structure and function of the giant cells, in particular in states of exhaustion may play a part in their development.

Cellular aspects of granulomas.

We investigated granulomas of sarcoidosis and de Quervains thyroiditis of man as well as experimental granulomas of the rat-peritoneum. Though differing in their cellular composition, they show common features in their organisation. A central zone consisting predominantly of epithelioid cells, epithelioid cell equivalents and macrophages without phagosomes in contact with lymphocytes. An outer zone mainly consisting of large macrophages, rich in phagosomes, dark epithelioid cells, necrotic elements and newly immigrated cells. The outer zone is considered to be a functional transitional area. Many of the newly immigrated monocytes are often binucleate, which we consider to be due to disturbances in the spindle cleavage of mitosis following injury. Ordered multinucleate giant cells (Langhans type) are centrally organised under the influence of centrioles and cytoskeleton. They have one phagocytic pole, one large pluricorpuscular cytocentre and a nuclear pole. The ordered internal structure of these lightly stained giant cells indicates their functional activity. In contrast we consider the darkly stained giant cells to be exhausted elements possibly progressing to coagulative necrosis. Intercellular contacts in granulomas e.g. between macrophages are seen as interdigitations of microvilli with the formation of desmosome-similar junctions. We suppose them to be in part for exchange of information and fixation. Epithelioid cells are characterised by their prominent secretory apparatus as well as by a large centrosphere with radially diverging numerous Golgi dictyosomes. Microtubules, together with microfilaments, are significantly involved in transporting secretory granules towards the periphery of the cell. Degranulation also occurs in co-operation with the various components of the cytoskeleton. Disintegration of the membranes of epithelioid cells leading to necrosis may result from massive degranulation. We suppose the various subtypes of epithelioid cells described by other authors to be various stages of the same but not different types of epithelioid cells.

Vimentin filaments in peritoneal macrophages at various stages of differentiation and with altered function

SummaryComparative immunofluorescence microscopic, transmission and scanning electron microscopic investigations were carried out to study the arrangement and significance of vimentin filaments in monocytes, macrophages, epithelioid cell equivalents and multinucleate giant cells under various different functional conditions, and in the presence of functional disorders.Uncoated or sebum-coated coverslips were implanted in the peritoneal cavity of Wistar rats. Some of the animals received repeated i.p. injections of colchicine. Rats were killed at various times 1 to 14 days after initiation of the experiment. The number of macrophages, the degree of their activation, and the growth of cells on the coverslips was considerably greater on sebum-coated than on uncoated implants. Various characteristic vimentin distribution patterns were found dependent on the cell cycle, the form and volume of the cell, and on the degree of differentiation and maturity; they were also related to the type and intensity of cell function. These patterns were best developed in ordered multinucleate giant cells.Repeated administrations of colchicine resulted in a marked flattening of the cell body on the coverslips — which correlated with a considerable reduction in the number of vimentin filaments and of cytoplasmic processes — and also in the formation of circumscribed erect, tree-like protuberances. The “trunk” of these structures comprised closely bundled vimentin filaments, and the cell nucleus was located at its base. These morphologic changes, which were associated with a functional insufficiency, proved to be reversible.

Asteroid bodies: Derivatives of the cytosphere

SummaryAn electron microscopic study of asteroid bodies in granulomatous diseases of man, in particular in sarcoidosis and foreign body reactions, has led to the following conclusions.1.Asteroid cytoplasmic inclusions are composed of organic proteineous structures. The body and arms of the stars consist mainly of longitudinally orientated, partially helically wound, collagen free, microfilaments with a diameter of approximately 50 Å. Microtubules participate in their composition to a lesser degree. The filaments intertwine in various directions within the corpus of the stars.2.Deeply osmiophilic compact structures, considered to represent condensation forms of protein, are consistently present within the body of the stars. These structures are partially granular and partially ring-shaped; in the latter case, transverse sections of tubules are noted. Since it is disputed whether they constitute procentrioles or postcentrioles, they are best referred to as paracentrioles.3.The asteroid bodies are derivatives of the cytosphere, thus relating, in the broad sense, to the microfilamentous and microtubular apparatus of the cell.4.The asteroid bodies in multinucleated giant cells participate in the spatial compartmentalization of the cytoplasmic content and nuclei. The sphere, aided by the centrioles, induces the formation of the mitotic spindle and, in addition, functions as an organizing system of the cell.5.The light microscopical periastral clear zone does not correspond to a fluid space. Rather, it consists of closely packed accumulations of laminated and whorled myelin figures, which are derived from the degradation of lipoid substances.ZusammenfassungEigene elektronenmikroskopische Strukturanalysen von Asteroid-bodies in verschiedenen Granulomen des Menschen, besonders bei Morbus Boeck und Fremdkörper-Reaktionen, haben folgendes ergeben :1.Asteroide Zytoplasmainclusionen sind aus organischen Proteinstrukturen zusammengesetzt. Sternkörper und Sternarme bestehen hauptsächlich aus längsorientierten, z.T. spiralig gewundenen kollagenfreien Mikrofilamenten mit einem Durchmesser von ca. 50 Å. In geringerer Menge sind Mikrotubuli an ihrem Aufbau beteiligt. Im Corpus der Sterne durchflechten sich die Filamente in verschiedenen Richtungen.2.Im Stemcorpus finden sich regelmäßig kräftig osmiophile Verdichtungen, die wir für Kondensationsformen von Protein halten. Sie sind teils granulaartig, teils ringförmig und dann mit Tubulusquerschnitten versehen. Wir deuten diese Gebilde als Prozentriolen oder Postzentriolen und nennen sie daher Parazentriolen.3.Asteroide sind ein Derivat der Zytosphäre, sie gehören somit zum mikrofilamentären und mikrotubulären Apparat der Zelle im weiteren Sinne.4.Asteroid-bodies sind in mehrkernigen Riesenzellen an der räumlichen Gliederung des Zytoplasmainhaltes und der Kerne beteiligt. Die Sphäre bildet nicht nur mit Hilfe der Zentriolen die Teilungsspindel aus, sondern stellt grundsätzlich ein ordnendes System in der Zelle dar.5.Die lichtmikroskopische periastrale Aufhellung entspricht nicht einem Flüssigkeitsraum. Sie besteht vielmehr aus dichten Ansammlungen geschichteter, wirbeliger Myelinfiguren, die dem Abbau lipoider Substanzen entstammen.

Is there a Carcinoma in Situ of Gastric Mucosa

Carcinoma in situ, a precancerous lesion in the strict sense, was first recognized in stratified squamous epithelia. It is characterized by markedly atypical cells replacing the autochthonous epithelial cells without stromal invasion, the basement membrane being well preserved. Notwithstanding gradual transitions between carcinoma in situ on the one hand and dysplasias and invasive cancer on the other hand, its histological separation from the latter is feasible in the uterine portio. Its recognition has decisive therapeutic and prognostic implications, particularly in view of the frequently observed latent period between purely superficial spread and early invasive growth. In contrast difficulties are encountered in applying the concept of Carcinoma in situ to mucosal lesions of the stomach, though an analogous replacement stage has to be postulated, because the gastric and cervical mucous membranes differ fundamentally in their structural characteristics. The epithelial cells of the surface, pits and tubular glands do exhibit progressive atypia during cancerization. However, the single-layered epithelium offers far less distinctive criteria than the stratified squamous epithelium. Newly formed glandular complexes cannot be accepted as evidence for in situ growth. The latent period between purely superficial replacement by atypical cells and invasion appears to be considerably shorter in the stomach than in the portio, probably because the mechanical resistance of the loosely textured gastric lamina propria is small. In addition, stromal invasion may originate from any one epithelial cell in the gastric mucosa, whilst it is just the basal layer from which invasively growing cells may emanate in the uterine portio. The occurrence of dysplasia in the mucosa of the stomach does not justify a gastrectomy, according to our current experience, there being no intervention in gastric surgery equivalent to that of conization.

The cytoskeleton in activated and in functionally disordered cells of the macrophage system

In animal experiments, and for various granulomatous diseases of humans, components of the so-called cytoskeleton in cells of the macrophage system were investigated in the electron microscope and with the aid of indirect immunofluorescence microscopy using monospecific antibodies. In young monocytes and in non-activated or only slightly activated mononuclear phagocytes, predilection areas and characteristic patterns of arrangement were found: F-actin is observable, densely arranged, in particular, around the nucleus and below the cytomembrane; intermediate filaments of the vimentin type form a broad, intensely fluorescent wreath around the cell nucleus; microtubules radiate from the perinuclear centriole in all directions into the neighbouring cytoplasm, taking the form of a microaster. Modifications of this pattern of distribution begin in the pre-mitotic phase, and become highly evident in karyokinesis and cytokinesis. Increases in the cell function are associated with changes in the arrangement of the cytoskeleton of quite a different nature, in particular in the regions of the cytomembrane, the cytocentre, including the Golgi dictyosomes and neighbouring portions of the rough endoplasmic reticulum, at sites of endocytosis and exocytosis and polarization and orientation, and in conjunction with intracytoplasmic translocations after the fusion of macrophages to form multinucleate giant cells. We do not consider the findings described here to be a sort of more or less static compartimentalization phenomenon, but, rather, believe them to bear a causal relationship to the functional dynamism of highly activated and specially differentiated macrophages, epithelioid cell equivalents, epithelioid cells and giant cells. Moreover, they are suggestive of function-dependent, intimate interactions of the individual cytoskeletal components. The experimental, reversible disturbance by the use of colchicine leads in macrophages to a transient loss of structural and functional identity with drastic alterations of microtubules and vimentin filaments.

Ablagerungen Seltener Erden in der menschlichen Lunge und im Tierexperiment

Natural mixtures of rare earth metals, especially cerium, lanthanum, neodymium and praseodymium, are widely used in industry. The present investigations describe, firstly technics for the determination of cerit metals in histological sections and secondly tissue damage caused by these substances in man and experimental animals. 1. Deposits of rare earths could not be detected using routine or special staining technics. Their presence in the tissue was clearly demonstrated by electron microprobe and Debye-Scherrer roentgenographic technics. 2. The thorium content of the rare earth metals, which varies in different industrial preparations, is of special pathogenic significance. 3. Depending on the intensity and duration of exposure, pulmonary deposits of thorium-free cerit metals result in pathological reaction of varying degree with peribronchial and perivascular macrophage-rich granulomas and septal fibrosis. There is no progression after termination of exposure. The dust particles remain stored in the lungs. 4. Thorium-containing cerit metals cause pulmonary fibrosis, the evolution of which is independent of the duration of dust inhalation and progresses after termination of exposure. 5. Rare earth metals may constitute a component of dust found in the lungs of patients suffering from silicosis, as shown here in a stone cutter from the Schwarzwald region. Their occurance in nature is not as rare as is commonly assumed. Deposits of rare earths could not be detected using routine or special staining technics. Their presence in the tissue was clearly demonstrated by electron microprobe and Debye-Scherrer roentgenographic technics. The thorium content of the rare earth metals, which varies in different industrial preparations, is of special pathogenic significance. Depending on the intensity and duration of exposure, pulmonary deposits of thorium-free cerit metals result in pathological reaction of varying degree with peribronchial and perivascular macrophage-rich granulomas and septal fibrosis. There is no progression after termination of exposure. The dust particles remain stored in the lungs. Thorium-containing cerit metals cause pulmonary fibrosis, the evolution of which is independent of the duration of dust inhalation and progresses after termination of exposure. Rare earth metals may constitute a component of dust found in the lungs of patients suffering from silicosis, as shown here in a stone cutter from the Schwarzwald region. Their occurance in nature is not as rare as is commonly assumed.

Der juxtaglomeruläre Apparat der Niere bei maligner Hypertonie und terminaler Niereninsuffizienz

SummaryFour patients with malignant hypertension and terminal renal insufficiency were subjected to bilateral nephrectomy, since hypertension neither was to be controlled by diminishing of sodium and plasma volume in hemodialysis nor by antihypertensive medication. After nephrectomy the blood pressure significantly decreased.Micromorphological findings and juxtaglomerular granulation index show a strong hyperplasia, hypertrophy and hypergranulation of the vascular part of the juxtaglomerular apparatus. The abundant presence of cytoplasmic organelles which are responsible for secretion, and the appearance of granules in different stages of maturation represent a truede novo synthesis of secretion material. The release of secretion and its effect upon the vascular system can be concluded from the highly elevated blood pressure before nephrectomy and from its decrease after nephrectomy.The cause of increased production of renin in malignant hypertension is not clear. Intrarenal regulations certainly are disturbed by the strong morphological alterations of vessels and nephrons. They can be followed by a dissociation of intrarenal control mechanisms, possibly combined with an uninhibited production of renin. Extrarenal stimulations of humoral or nerval nature may play a primordial role in releasing malignant hypertension.ZusammenfassungVier Patienten mit maligner Hypertonie und terminaler Niereninsuffizienz wurden beidseitig nephrektomiert, da der Hochdruck weder durch Salz- und Volumenentzug bei chronischer Hämodialyse, noch medikamentös unter Kontrolle zu bringen war. Nach der Nephrektomie sank der Blutdruck rasch und signifikant und ließ sich nun auch durch Natrium- und Wasserentzug korrigieren.Die mikromorphologischen Befunde an den entfernten Nieren und die Bestimmung des juxtaglomerulären Granulationsindex ergaben eine starke Hyperplasie, Hypertrophie und Hypergranulierung der juxtaglomerulären Gefäßpole. Die reichliche Bereitstellung von Cytoplasmastrukturen, die der Sekretherstellung dienen, und das Auftreten verschiedener Reifungsstadien von Granula in den Zellen der Vasa afferentia sprechen für eine echt vermehrte Neubildung von Sekretmaterial. Die Freisetzung des Sekretes aus den Zellen und seine Wirkung am Gefäßsystem können aus dem stark erhöhten Blutdruck vor Nephrektomie und dem deutlichen Absinken der Werte nach Entfernung der Nieren geschlossen werden.Die Ursache der ungehemmten Produktion von Renin, das bei der malignen Hypertonie eine Schlüsselstellung einnimmt, ist nicht bekannt. Intrarenale Regulationen sind bei den schweren morphologischen Veränderungen der Gefäße und der nachgeschalteten Nephrone sicher gestört und können eine Loslösung der Reninproduktion aus dem Reglerkreis zur Folge haben. Möglicherweise spielen extrarenale Stimulationen humoraler oder nervaler Art in der Auslösung der malignen Hypertorie eine übergeordnete Rolle.