[Fornicate structure of blind saccular lymph vessel segments in the conjunctiva--scanning electron microscopy studies]. / Gewölbestruktur blindsackartiger Lymphgefässsegmente in der Konjunktiva--rasterelektronenmikroskopische Untersuchungen.

BACKGROUND: The accepted fundamental element of the initial lymphatic system is a tubular structure (lymphatic capillary), which is present either in the form of a finger-shaped blind-ending protuberance, or in the nature of a plexiform composite arrangement. We were able to demonstrate experimentally that the finger-shaped protuberances, which are known as "initial segments" are in fact temporary filling states. As the filling process continues, these vascular elements become intermediate segments, via which other parts of the vascular network take up the dye. To date there have been no investigations of the internal structure of these apparently blind-ending vessel segments. In this study, lymphographically represented "terminal segments" should be cut away for the purpose of examining the fornix by scanning electron microscopy. Is the internal surface of the fornix regular and unbroken, or are there fissure-like structures which could explain the observed filling processes? MATERIAL AND METHODS: In conjunctiva of bovine eyes (n = 80), interstitial double-contrast lymphography (Berlinblue solution/air) under a slit-lamp microscope was used specifically to search for finger-shaped terminal segments. The conjunctivae had previously been prepared by fixing in polymeric resins. A proportion (n = 21) of the specimens were amenable to examination under the scanning electron microscope. RESULTS: Notwithstanding the observed great variation in the shape of the lymphographically obtained blind-ending structures-in the form of terminations shaped variously like fingers, balloons, domes, pistons or pyramids, terminations with two humps, and terminations shaped like spear heads-scanning electron microscopy revealed within the fornices many relatively uniformly shaped structures in the form of fissures, configured with lips and saw-tooth edges, rather like zip fasteners. These findings are suggestive of preformed connections to neighbouring segments. This appears to be another element, in addition to the familiar flap-like structures, for controlling the circulation of lymph. Does the "initial part" of the lymphatic system now have to be redefined?

[Fine structure of conjunctival lymphatic vessel valves]. / Feinstruktur konjunktivaler Lymphgefässklappen.

BACKGROUND: Lymphatic valves are due to ensure a zentripetal flow of lymph. The majority of the authors regard these valves as bicuspid structures with joint insertion points of the downstream localized free valvular edges. Because of that valvular structure a retrograde flow of lymph is impossible. Observations of our own however demonstrated retrograde flow of fluid under physiological conditions. In the following paper the structure of conjunctival lymphatic valves should be investigated or rather those structures, which were regarded as valves hitherto. Are there segmental connections, which allow retrograde flow of lymph? Is a regulation of lymph flow possible without self-acting valves? MATERIALS AND METHODS: In the conjunctiva of bovine post-mortem eyes (n = 100) segmental connections of lymphatic vessels with a diameter of less than 1 mm were opened specifically under control of slit lamp microscope after having undertaken an interstitial double contrast lymphography (solution of Berliner Blue/air). Some of these preparations (n = 20) could be investigated further on with the scanning electron microscope. That procedure allowed to make the patterns of flow and vessels structures in the beginnings of the lymphatic system observed with the slit lamp microscope congruent with those structures shown by the scanning electron microscope. RESULTS: The following segmental connections could be demonstrated: 1. Lymphatic vessels, which flow like a pipe into the wall of another segment. 2. Laterally arranged oval connections with valve resembling an aperture. 3. Segments of lymphatic vessels arranged in a line, which flow into one another between two hump-shaped protrusions with bicuspid valvular structures. Also the existence of different connecting structures ("valves") in one segment ("gear segment") were observed. In bulbus-like segmental connections arranged one behind the other with two valvular leaflets it could be demonstrated by scanning electron microscopy, that the two leaflets were attached apart at the vessel wall. That divergence to the previous models of lymphatic valves means, that these valvular leaflets cannot work as self-acting valves and prevent retrograde flow. CONCLUSIONS: However according to the valveless model of Libau a directed regulation of flow is possible. Perhaps the valvular structures described above play an important part by the interaction between the endothelium of lymphatic vessels and the substances transported in the lymph. The variety of segmental connections, the network of vessels with different diameters, which seem to be connected by feed-back, demand a new way of looking at the initial lymph flow.

[Alfred Th. Leber (1881-1954): a pioneer in tropical ophthalmology. Missing in the South Seas--rediscovered in India]. / Alfred Th. Leber (1881-1954): Ein Pionier der Tropenophthalmologie. In der Südsee verschollen--in Indien wiederentdeckt.

In spite of the brief duration of German colonial rule during that period tropical medicine enjoyed a remarkable growth and development. This is the first account of the career of the pioneer of tropical ophthalmology, Alfred Theodor Leber (1881-1954); medical history had previously reported him missing in Java after the 1st world war. His career was greatly influenced by his uncle, Theodor Leber (1840-1917), the founder of experimental ophthalmology. Alfred Leber was the one who combined teaching and research in the subjects of ophthalmology and tropical medicine. During his first expedition as a private lecturer together with von Prowazek in Samoa (1910-1911), he discovered the involvement of the eye in filarial infections with Wuchereria bancrofti (Lebers fundus). In consideration of his extraordinary work he was appointed professor at the young age of 33. After his training at the eye clinic at Berlin University under von Michel he worked as senior physician with von Hippel in Göttingen. Both Ludwig Külz and the famous painter Emil Nolde joined him on his second expedition, to New Guinea, in 1913. During his expedition in summer 1914 World War I broke out. Leber could not return to Germany. He stayed in the neutral Dutch East Indies during these years. Favoured by the ravages of war, British and Australian authorities (Military Intelligence, War Office, Defence) succeeded in seizing some of Leber's research reports and kept them under lock and key. The "Leber-Külz medical demographic New Guinea expedition on behalf of the Reich's Colonial Office" was therefore known to the public only as "Emil Nolde's travels in the South Seas".(ABSTRACT TRUNCATED AT 250 WORDS)

[Saccular initial segments of the lymphatic vessel system]. / Zur Frage der kolbenförmigen Initialsegmente des Lymphgefässsystems.

It is commonly said that the lymphatic system begins "blindly" as saccular outpocketings. In order to examine these saccular outpocketings, 120 injections into the conjunctival lymphatics of 60 bovine postmortem eyes were carried out, measuring the level of injection pressure and simultaneously documenting the various filling stages photographically. 20 trials were selected for further analysis. We recorded low initial pressures when the tip of the needle was situated close to a larger lymphatic vessel and the coloured solution (1% aqueous Berliner Blue) as possibly applied intravascularly. Higher initial pressures were seen on positioning inside fine networks of vessels. Extremely high initial pressures without any visible filling of vessels but in the presence of simultaneously increasing depots of dye were probably caused by absent or insufficient connection between the tip of the needle and a vessel. During lymphography numerous coarser and finer, tube-like projections (saccular outpocketings) filled, from which further progression of the coloured solution could only be observed when higher injection pressures were applied. We were able to prove that such segments had connections to neighbouring vessels as well as forming plexus of their own. Based on our findings we have reason to doubt the existence of tube-like initial segments in the lymphatic system. Rather in the conjunctiva of the bovine eye this system has the structure of a fine network where tube-like segments can be demonstrated as temporary filling stages.

[Lymph drainage of the cornea, limbus and conjunctiva]. / Die Lymphdrainage von Cornea, Limbus und Conjunctiva.

Air (n = 30), patent blue (n = 30), Berlin blue (n = 30), Berlin blue and air (n = 30), and Berlin blue and Mercox (n = 30) were injected into the corneas and conjunctivas of 150 enucleated cattle eyes. Using air for injection, so-called Bowman "corneal tubes" form in the cornea, which can easily be filled with pigment (patent blue, Berlin blue). In some cases (n = 3) the conjunctival lymphatics were filled with air during injection into the cornea. Besides the "corneal tubes", larger vessel-like structures can be demonstrated, which seem to be connected to corneal nerves. The significance of these structures as prelymphatics and their importance in the lymph drainage of the cornea are discussed. The injection of patent blue and Berlin blue into the limbus leads to the formation of a delicate network of arch-shaped lymphatics, from which larger lymphatics take their color. In the case of Berlin blue and Mercox, and Berlin blue and air injection, sections of lymphatic vessels in the shape of pointed arches form at the edges of the segments. It can be shown stereomicroscopically that these are not valves or invaginations, but only hump-shaped diverticula of the vessels. Annular constrictions of the lymphatic vessels were found, rather than bicuspid valves. The valveless pump mechanism described by Liebau is discussed as a possible means of lymph transport in the conjunctiva.

[Granular cell tumor of the orbits. Diagnosis and therapy]. / Der Granularzelltumor der Orbita. Diagnose und Therapie.

Report on two cases of tumours in the retroorbital space. The histological examination showed them to be granular cell myoblastomas (Abrikossoff), which in one case was bilateral. Tumours within the orbital space are rare. It is necessary in every case to make a biopsy to clarify the type of tumour because some of them are malignant. Computed tomography cannot differentiate between benign and malignant tumours in the orbita.

[Discovery of Loa ophthalmia by the French ship's surgeon François Guyot (1742-1816)]. / Die Entdeckung der Loa-Ophthalmie durch den französischen Schiffschirurgen François Guyot (1742-1816).

We are indebted to François Guyot (4. 10. 1742-13. 6. 1816) for the term "loa," designating a species of filaria, pathogenic in humans, which is common tropical West Africa. Biographical details about this French ship's surgeon are published here for the first time. On several slave-trading voyages between Africa and America, Guyot noticed that some of the negroes suffered from recurrent ophthalmia. He established that it was caused by a worm roaming around under the conjunctiva, and succeeded in extracting the parasite. In 26 May 1781 Guyot submitted a report on his findings to the "Académie Royale de Chirurgie" in Paris. This article discusses details of the report, which was hitherto believed lost.

Experimental studies on the spitting cobra ophthalmia (Naja nigricollis).

Experimental studies were conducted to investigate the clinical and morphological effects of various doses of Naja nigricollis venom (0.1-5.0 mg) on the eyes of rabbits. Our findings suggest that in the early stage of the ophthalmia caused by the spitting cobra, specific fractions of the venom are responsible for the nitrogen mustardlike effect. However, the further course seems to be determined by liberated inflammation mediators like prostaglandins and leukotrienes.

[Spitting cobra ophthalmia (Naja nigricollis)]. / Die Spei-Kobra-Ophthalmie (Naja nigricollis).

The spitting cobra (Naja nigricollis) can eject its venom into its adversary's eyes from a distance of several meters. This causes an immediate and painful conjunctival infection, followed by blepharospasm, corneal and conjunctival edema, and erosion. Corneal ulcer, in some cases with perforation, hypopyon and endophthalmitis are the results. The present paper reports on a 35-year-old patient from Hemkoa (South Upper Volta) whose eyes had been affected by the venom of a spitting cobra 5 years previously. The patient had meanwhile lost his sight as a result of bilateral sclerosing keratitis. The possible influence of the patient's basic disease (onchocerciasis) on the course of the sclerosing keratitis is discussed.

[Eye injuries in a large chemical factory]. / Augenverletzungen in einem chemischen Grossbetrieb.

In an investigation carried out in a large chemical factory it was found that the time lost as a result of eye lesions diminished by 50% between 1971 and 1981. The percentage of foreign employees involved in these accidents (19.5%) was almost the same as the proportion they represent of the total personnel. Accident rates were found to be lowest on Mondays and Wednesdays; peak accident times were in the late morning and early afternoon. Although there has been a considerable improvement in the availability of protective eyewear in recent years, it is still not worn often enough. In 60% of the eye accidents considered here protective goggles should have been worn.