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?

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 (Berlin-blue 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 Nothwithstanding 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?

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 now possible without self-acting valves?Materials and methods In the conjunctiva of bovine postmortem eyes (n = 100) segmental connections of lymphatic vessels with a diameter of less than 1 mm were opened specificly 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 flowConclusions 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.

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)

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.

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.

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.

12 Kleinnager (Mastomys natalensis und Meriones persicus) wurden mit L3-Larven von Litomosoides carinii oder Dipetalonema viteae infiziert. Als Ausdruck der gelungenen Infektion fanden sich ca. 80 Tage p. i. Mikrofilariendichten (L1-Larven) im peripheren Blut zwischen 48 und 69 × 103 pro ml Blut. Die Tiere wurden seziert und die Augen (Kornea, Iris, Ziliarkörper, Bulbuswand, Sehnervenstumpf mit Papille) sowie weitere Organe (Haut, Gehirn, Leber, Herz- und Skelettmuskulatur, Niere, Zwerchfell, Lunge) elektronenmikroskopisch untersucht. 8 der 12 infizierten Kleinnager, die für diese Filarien spezifische Wirte darstellen, wurden vor der Sektion kurzfristig mit den Filariziden Diaethylcarbamazin und Metrifonat behandelt. Elektronenmikroskopisch konnten wir bei den unbehandelten Tieren Mikrofilarien in den Gefäßen der hinteren Augenabschnitte (Chorioidea und Retina) nachweisen. Unter Therapie konnten im Auge keine Wurmlarven nachgewiesen werden. In den Blutkapillaren und im Interstitium anderer Organe fanden sich jedoch degenerierte Mikrofilarien. Außerdem beobachteten wir einzelne Larven intrazellulär (Leber, Muskulatur). Diese Mikrofilarien weisen im Vergleich zu den extrazellulären deutlich weniger Läsionen auf. Möglicherweise entziehen sie sich so der Filarizid-Einwirkung. Unbekannt ist bisher, ob ähnliche Phänomene bei humanpathogenen Filarien auftreten.

Conjunctival lymphographies in patients infected with Onchocerca volvulus in Liberia showed normal or only slightly dilated lymphatics. The light-microscopical studies of conjunctival specimens revealed microfilariae predominantly in edematous dilated interstitial channels. Microfilariae in lymphatics and interstitial channels without endothelium of the conjunctivae were demonstrated by scanning and transmission electron microscopy. No signs of inflammatory cellular reaction were found in the vicinity of the parasites. In conclusion, the dilatation of lymphatics and interstitial channels as well as the pathways along which the microfilarial penetrated the cornea and the anterior segments of the eye are discussed.

Hyalinosis cutis et mucosae is a rare, probably autosomal-recessively inherited disease, which begins in the first weeks of life with a remarkable hoarseness due to deposits of hyaline material in the larynx. Later on alterations of the mucous membranes and the skin are involved. Etiology and pathogenesis are unknown. An effective treatment does not exist. We present a Turkish family whose 4 children show the typical picture of hyalinosis cutis et mucosae. The skin alterations at the mother's eyelids, however, cannot be submitted to the lipoid proteinosis Urbach-Wiethe with certainty. The occurrence of hyalinosis cutis et mucosae in the 4 children makes the hitherto presumed autosomal-recessive heredity of the disease questionable.

Twelve rodents (Mastomys natalensis and Meriones persicus) were infected, with L3 larvae of Litomosoides carinii and Dipetalonema viteae. Eighty days after infection the number of microfilariae (L1 larvae) was determined by smears from the peripheral venous blood. It was found that there were 48 and 69 X 10(3) microfilariae per ml blood. The hosts were killed and the eyes (conjunctiva, cornea, uvea, posterior part of the globe, optic nerve) as well as other organs (skin, brain, liver, heart and skeletal muscles, kidney, diaphragm and lung) were embedded for electron microscopic studies. Eight of the infected rodents, which are the specific hosts for these filariae, had been treated before the dissection with metrifonate (3 X 100 mg/kg) or diethylcarbamazine (3 X 250 mg/kg). These dosages led to the disappearance of microfilariae from the peripheral venous blood. In untreated controls microfilariae were found in the vessels of the chorioidea and retina, whereas after therapy there was no trace of these larvae in the eye. However, in the capillaries and in the interstitial space of other organs numerous degenerating microfilariae were observed. Furthermore, some larvae were seen intracellularly in liver and muscles. These intracellular stages had fewer or even no lesions compared to the extracellular ones, suggesting that they might escape the activity of the drugs. It is unknown whether similar phenomena occur in worms pathogenic to man. These laboratory models using the filariae of rodents (D. viteae with unsheathed and L. carinii with sheathed microfilariae) are very helpful for studying the pathogenic effects in eyes caused by microfilariae which circulate in the blood stream (Loa, Wuchereria).(ABSTRACT TRUNCATED AT 250 WORDS)

In experiments in the dog, it is possible to demon­ strate the lymph drainage system of the conjunctiva and lids as far as the jugular trunk by means of in­ direct administration of the water-soluble contrast medium lotasul and application of a pressure band­ age. Quicker opacification of the cervical lymph nodes can be achieved by simultaneous indirect lymphography (SIL) which also includes the chin region.

For the first time the lymphatic pathways of the conjunctiva and the eyelids of dogs could be presented in vivo with the water-soluble X-ray contrast medium iotasul. By means of indirect application the lymph flow could be demonstrated up to the truncus jugularis. Because of the simultaneous infusion of the contrast medium at different points the lymphography of the face- and neck-region is considerably facilitated.