E. van der Zypen

Ultrastructural localization of hyaluronan in myelin sheaths of the rat central and rat and human peripheral nervous systems using hyaluronan-binding protein-gold and link protein-gold

Neural tissue of central (rat spinal cord) and peripheral origin (rat sciatic nerve, nerve fascicles of rat skin and iris and of human conjunctiva) was processed by osmium tetroxide/microwave fixation and embedded in epoxy resin. Hyaluronan-binding proteins and link proteins coupled to 15-20-nm gold particles were used as markers in a one-step post-embedding procedure for identifying hyaluronan (hyaluronic acid) at the ultrastructural level. All myelin sheaths in both rat and human material were found to be intensely labelled. The specificity of the hyaluronan-binding probes was demonstrated by the total loss of labelling following treatment of sections with hyaluronidase or by preincubating either the probes with hyaluronan oligosaccharides or the sections with unlabelled hyaluronan-binding protein. The identified hyaluronan appears to be located extracellularly, but is precise role here remains to be elucidated.

Investigation of Development, Structure and Function of the Phrenicocolic and Duodenal Suspensory Ligaments

The development and structure of the duodenal suspensory ligament and the phrenicocolic ligament were studied in the human fetus, newborn and adult. The observations presented show that the superior retention band is transformed into the suspensory ligament of the duodenum. Within this ligament the muscle of Treitz develops. The inferior retention band atrophies. A new ligament, the phrenicocolic ligament, is formed in the fetal period of life. In this ligament, smooth muscle cells develop. The possible functions of the suspensory ligament of the duodenum and the phrenicocolic ligament are discussed.

Ultrastructural changes in adrenergic neurons following chemical sympathectomy.

The paper describes the ultrastructural changes of the sympathetic neurons following guanethidine administration in mice. The main characteristics changes, after prolonged administration (1-10 weeks) of guanethidine (Ismelin, Ciba-Geigy, Basel, Switzerland) at doses of 30-50 mg/kg/day i.p. and i.m. were: (1) Mitochondrial damages: swelling and deformation of the mitochondria, with disruption and dispersion of the cristae and condensation or dissolution of the matrix. Membranolysis of the outer and inner mitochondrial membranes. (2) Neural processes: swelling and disorganization of the internal architecture in the postganglionic axonal and dendritic synaptic varicosities. (3) Adrenergic vesicles: disappearance of the granular vesicles in the early stage of the experiment, increase of the coated vesicles in the later stage of treatment. The effect of guanethidine is specific for the postganglionic adrenergic neurons, but the observed destruction is not caused solely by guanethidine; other chemical substances induce the same or similar degeneration in the sympathetic ganglion.

Die Wirkung einer subtotalen Vagotomie auf den Plexus myentericus (Auerbach) verschiedener Darmabschnitte

The effect of a subtotal vagotomy on the function of the intramural nervous system of different parts of the intestinal tract is studied by means of quantitative measurements of the acetylcholinestera

Das Trigonum sternocostale und seine Beziehung zu den Blutgefässen der vorderen Bauchwand

Great divergences concerning the significance of the sternocostal triangle exist in the numerous, mainly German textbooks of the macroscopic anatomy. Some authors believe that it is a muscular fissure through which the internal thoracic artery passes; others are of the opinion that the superior epigastric artery passes through Larrey’s cleft. Our own investigations confirm the opinion of a minority of authors according to whom the sternocostal triangle does not have any relationship to any vessels at all. The transversus thoracis muscle and the transversus abdominis muscle form a continuous plate, which we have termed transversus trunci muscle. The internal thoracic artery and vein pass ventrally to this muscle plate. At the level of the 6th rib, the internal thoracic artery bifurcates into its two end-branches. The stronger end-branch, the superior epigastric artery runs downwards on top of the transversus trunci muscle and then becomes sandwiched between this plate and the rectus abdominis muscle at the level of the 7th rib.

Transvitreal channel related to an intravitreal developmental anomaly

Description of an intravitreal glia particle connected to an atypical transvitreal channel, which was found incidentally during the autopsy of an unfixed sheep vitreous. The anomaly is interpreted as an avulsion of retinal tissue during prenatal development, resulting in a decreased density of the vitreous framework (transvitreal channel) above the retinal defect. In analogy to other observations of transvitreal channels, which occur at all sites where the inner retinal surface is altered, the analysis of the anomaly sustains the hypothesis that framework of the vitreous is formed by elements of the retinal surface. The cells within the particle were examined with electronmicroscopy. They show immature collagen fibrils between glia cells, which may be precursors of vitreous collagen, immigrating through intercellular lacunae into the vitreous. Es wird ein transvitrealer Kanal beschrieben im Zusammenhang mit einer Entwicklungsanomalie, die zufällig bei der Autopsie eines unfixierten Schafauges entdeckt wurde. Transvitreale Kanäle sind Zonen verminderter Dichte, die man über anatomisch besonders ausgezeichneten Arealen des Fundus findet (Papille, Macula, periphere Anomalien) oder an Stellen, an denen die Netzhautinnenfläche pathologisch verändert ist (Narben nach Entzündungen oder Eichtkoagulationen, äquatoriale Degenerationen etc.). Bei der hier beschriebenen Anomalie ist der transvitreale Kanal entstanden durch einen Retinaldefekt, der durch einen Ausriss von Retinalgewebe in einem frühen Entwicklungsstadium zustande kam. Die Form des Kanals ist dadurch erklärbar, daß über dem Retinaldefekt im Verlaufe des Wachstums kein Glaskörpergerüst mehr gebildet wurde. Dies ist ein Hinweis darauf, daß das Glaskörpergerüst von Elementen der Netzhautoberfläche produziert wird. Da man annehmen muß, daß der ausgerissene Partikel die Zellen enthält, die in der Lage sind, Glaskörper zu bilden, wurde er elektronenmikroskopisch untersucht. Der Partikel bestand ausschließlich aus Gliazellen mit ausgeprägten interzellulären Lacunen. In diesen wurde immatures Kollagen gefunden, welches Vorstadium von Glaskörperkollagen sein könnte, das durch die Zwischenräume in den Glaskörperraum geschleust wird. Diese Tatsache stützt die Hypothese, daß die Glaskörperfibrillen durch Gliazellen gebildet werden. Die nachgewiesenen Zellen hatten offensichtlich niedrige metabolische Bedürfnisse, zeigten sie doch mehrere Wochen nach Enukleation noch Zeichen der Vitalität.

Zur Ultrastruktur des Pterygium

13 pterygia from patients aged between 39 and 81 years are studied by electron microscopy. The pterygium is covered by a multilayered, highly differentiated cylindrocellular epithelium. Arrangement and height of the microvilli of the superficial epithelial cells differ from those of the conjunctival epithelium. Morphological signs of secretion and resorption are found. As a characteristic the basal epithelial cells of the pterygium are rich in metaplasmatic filaments. Tubular glands are localised underneath the covering epithelium; they may reach the deep substantia propria. Their walls consist of a single layer of cylindrical cells. A varying number of goblet-cells are embedded between them. The secretion by the epithelial formations of the pterygium is of the merocrine, holocrine and microapocrine type. Es gelangten 13 Pterygien von Patienten zwischen dem 39. und 81. Lebensjahr zur elektronenmikroskopischen Untersuchung. Das Pterygium ist von einem mehrschichtigen, hochdifferenzierten Zylinderepithel bedeckt. Die Oberflächenepithelzellen tragen einen Mikrovillibesatz, der in Anordnung und Höhe Unterschiede zum Conjunctivalepithel aufweist. Es finden sich morphologisch Anzeichen für Sekretions- und Resorptionsvorgänge. Der Reichtum der basalen Epithelzellen an metaplasmatischen Filamenten stellt ein besonderes Charakteristikum des Pterygialepithels dar. Vom Oberflächenepithel senken sich tubulöse Drüsenschläuche weit bis in das Stroma pterygii ein. Die Wand der Drüsenschläuche besteht aus einem einschichtigen Zylinderepithel, in das in wechselnder Menge Becherzellen eingelagert sind. Sekrete werden in Form einer merokrinen, holokrinen und mikroapokrinen Sekretion abgegeben.13 pterygia from patients aged between 39 and 81 years are studied by electron microscopy. The pterygium is covered by a multilayered, highly differentiated cylindrocellular epithelium. Arrangement and height of the microvilli of the superficial epithelial cells differ from those of the conjunctival epithelium. Morphological signs of secretion and resorption are found. As a characteristic the basal epithelial cells of the pterygium are rich in metaplasmatic filaments. Tubular glands are localised underneath the covering epithelium; they may reach the deep substantia propria. Their walls consist of a single layer of cylindrical cells. A varying number of goblet-cells are embedded between them. The secretion by the epithelial formations of the pterygium is of the merocrine, holocrine and microapocrine type.

Reparative Vorgänge an der Iris des pigmentierten Kaninchenauges nach Bestrahlung mit dem Argon-Laser

The reparative processes of the pigmented iris of the rabbit were analysed with ultrastructural methods. 1. Clearing of the damaged area by macrophages is the first step in the reparative processes. Clump cells are macrophages which are observed from the first day of the injury until the ninth week. 2. Repair of the anterior surface of the iris is largely finished after 32 days. 3. The repair of collagenous fibres reaches its maximum activity 32 days after irradiation. 4. The pigment epithelium has only an insignificant regeneration potential. 5. Irradiation of the iris by the argon-ion laser results in an atrophie, hyperpigmented scar. Clearing of the damaged area by macrophages is the first step in the reparative processes. Clump cells are macrophages which are observed from the first day of the injury until the ninth week. Repair of the anterior surface of the iris is largely finished after 32 days. The repair of collagenous fibres reaches its maximum activity 32 days after irradiation. The pigment epithelium has only an insignificant regeneration potential. Irradiation of the iris by the argon-ion laser results in an atrophie, hyperpigmented scar. The rapid regeneration of a lesion induced by the argon-ion laser in the rabbit iris casts doubt as to whether this method could be applied to the human eye with equal success. Die reparativen Vorgänge an der pigmentierten Kanincheniris nach Bestrahlung mit dem Argon-ion-laser wurden mit ultrastrukturellen Methoden untersucht. 1. Die reparativen Vorgänge beginnen mit einer Säuberung der Schadenszone durch Makrophagen. Zu den Makrophagen zählen die Klumpenzellen, die vom 1. Tag des Schadenscintritts bis Ende der 9. Woche nachgewiesen werden können. 2. Die Abdeckung der Schadenszone durch Mesothelzellen der Irisvorderfläche ist nach 32 Tagen weitgehend abgeschlossen. 3. Die Neubildung kollagener Bindegewebsfasern erreicht am 32. Tag nach der Bestrahlung ihre größte Aktivität. 4. Das Pigmentepithel zeigt eine nur geringe Regenerationspotenz. 5. Die Bestrahlung der Iris mit dem Argon-ion-laser führt zu einer atrophischen, hyperpigmentierten Vernarbung. Die reparativen Vorgänge beginnen mit einer Säuberung der Schadenszone durch Makrophagen. Zu den Makrophagen zählen die Klumpenzellen, die vom 1. Tag des Schadenscintritts bis Ende der 9. Woche nachgewiesen werden können. Die Abdeckung der Schadenszone durch Mesothelzellen der Irisvorderfläche ist nach 32 Tagen weitgehend abgeschlossen. Die Neubildung kollagener Bindegewebsfasern erreicht am 32. Tag nach der Bestrahlung ihre größte Aktivität. Das Pigmentepithel zeigt eine nur geringe Regenerationspotenz. Die Bestrahlung der Iris mit dem Argon-ion-laser führt zu einer atrophischen, hyperpigmentierten Vernarbung. Die schnelle Abheilung eines durch den Argon-ion-laser erzeugten Defektes an der pigmentierten Kanincheniris lassen diese Methode der Iridektomie auch am menschlichen Auge als Dauerlösung zweifelhaft erscheinen.The reparative processes of the pigmented iris of the rabbit were analysed with ultrastructural methods. 1. Clearing of the damaged area by macrophages is the first step in the reparative processes. Clump cells are macrophages which are observed from the first day of the injury until the ninth week. 2. Repair of the anterior surface of the iris is largely finished after 32 days. 3. The repair of collagenous fibres reaches its maximum activity 32 days after irradiation. 4. The pigment epithelium has only an insignificant regeneration potential. 5. Irradiation of the iris by the argon-ion laser results in an atrophic, hyperpigmented scar. The rapid regeneration of a lesion induced by the argon-ion laser in the rabbit iris casts doubt as to whether this method could be applied to the human eye with equal success.

Spontaneous and pharmacologically-modulated wound healing after Nd:YAG laser sclerostomy ab interno in rabbits.

The course of tissue repair evoked by Nd:YAG laser sclerostomy ab interno and the effect of mitomycin-C on same were investigated ultrastructurally in 15 rabbits. In ten of them, the dynamics of the spontaneous postoperative healing response (i.e. in the absence of medication) was analyzed at two-day intervals by light- and electron microscopy. In two, fibroblast activity was assessed autoradiographically. In the last three rabbits, the sclerostomy site was exposed transconjunctivally to mitomycin-C (0.5 mg/ml; 5 minutes) before surgery, and morphological analysis was done on postoperative days 6 and 12. Results. In the spontaneously healing group, blebs disappeared within five days of surgery. This corresponded to a massive invasion of macrophages and fibroblasts from the episclera and iris root. The sheath of coagulated tissue around the fistula appeared to act as a barrier to cell migration from the sclera itself at this stage. By days 8 to 12, the canal had become occluded by a network of cells and capillaries, and collagen fibrils in the coagulation sheath had undergone repolymerization. In the mitomycin-C group, large filtering blebs and patent, cell-free fistulas were observed over the entire period. Although applied transconjunctivally, the drug penetrated the whole scleral depth, as the iris root and ciliary body cell reaction was inhibited. Repolymerization of heat-damaged collagen was also hindered. The overall findings provide information on the sequence of repair events following laser sclerostomy. Local, non-invasive application of mitomycin-C delays the onset of this process, not only by inhibition of cell proliferation but also by suppressing the collagen recovery.

Radiation-Induced Developmental Abnormalities of the Brain Ventricles in the Golden Hamster

The dysontogenesis of the brain ventricle system of golden hamster fetuses was studied after X-ray irradiation of the mother at different stages of pregnancy. Groups of gravid hamsters were irradiated with a single dose (200 R) on either the 6th, 8th, 10th or 12th day of gestation. The fetuses were removed 1 day before birth. The most prominent finding in all stages of development was the dilatation of the brain ventricles. In addition to hydrocephalus, hematocephaly was also found in some cases. Furthermore, a widening of the central canal of the spinal cord with hemorrhagic content could sometimes be observed. Ependymal ectopies and subependymal rosettes occurred more frequently when irradiation was given in the late fetal period. The experimental findings demonstrate that after irradiation of the mother animal, malformation of the brain may be produced during the whole intrauterine period of development. The pattern and extent of malformation depend not only upon the dose of irradiation but also upon the stage of development at which irradiation was given.