Corneal endothelial response to induced myopia in the chicken

Purpose: To investigate the role of corneal endothelial surface enlargement in the chicken myopia model in inducing corneal endothelial changes. Methods: Lid suture was performed on one eye of 1-day-old cockerels. Five chickens were killed at 1 week, and four chickens killed at each of 3 weeks, 6 weeks, and 10 weeks postnatal. The endothelial morphology was obtained by flat mounting the endothelial surface and the subsequent digitisation. Comparisons were undertaken between the control unsutured eye and the lid-sutured eye endothelium, and between the central endothelial areas compared to the peripheral endothelial areas in both the myopic and the normal corneas. Calculation of the contribution to the endothelial change by hypertrophy and mitosis were calculated using Bahn's formula. Results: Total endothelial surface area increased significantly over time in the myopic model compared to control eyes but the mean cell area of endothelial cells remained the same for both the enlarged myopic endothelial surface area and in the normal controls. Sampling from the central and the peripheral corneal endothelial surface also disclosed no difference. The mean cell area did increase steadily with age but was the same for both normal and myopic corneas. Conclusions: It would appear that there are equal contributions from hypertrophy and mitosis in the myopic group and the normal corneal group with a slightly increasing trend towards mitotic activity in the myopic corneal endothelial layer.

Intraorbital anatomy of the koala (Phascolarctos cinereus)

This is the first documented study of the anatomical details of the contents of the normal koala orbit, excluding the bulbus oculi. Baseline data were established which are necessary for understanding and treating ocular disease in the koala (Phascolarctos cinereus). The anatomy of the orbital contents of the koala were examined and described from animals that presented dead or were euthanized for humane reasons. Dissections of the orbital cavity were performed under magnification. Polymethyl methacrylate (PMMA) casts of the nasolacrimal system and the vascular supply of the orbit were also made in order to study these systems. The superficial lymphatic drainage of the conjunctival tissues was studied by subcutaneous injection of Evan's Blue into the palpebral conjunctiva of a freshly deceased animal, and by Microfil casts of the efferent lymphatics. In general, the orbital contents of the koala are consistent with those of other carnivorous polyprotodont and herbivorous diprotodont marsupials.

Controlled trial of hyperbaric oxygen treatment for alkali corneal burn in the rabbit

Purpose: To evaluate the efficacy of hyperbaric oxygen therapy in the treatment of alkali-induced corneal burns in an animal model. Methods: Twenty-four rabbits were randomized into a control group (n = 12) and hyperbaric oxygen treatment group (n = 12). After induction of anaesthesia, the alkali burn model was established by application of 1 N sodium hydroxide to one eye of each rabbit. The hyperbaric oxygen treatment group was treated each day for 21 days with hyperbaric oxygen at 2.4 Atmospheres Absolute (ATA) for 1 h. The eyes of the animals were examined daily for 2 weeks and then weekly until the end of the trial. The principal endpoint was that of perforation of the cornea at which time the animals were killed with a lethal dose of either intravenous or intraperitoneal barbiturate and the eyes immediately enucleated and fixed in 10% neutral buffered formalin. All animals in which complete healing took placed were also killed, the eyes removed, fixed and examined histologically. Photographs were taken of the rabbit's eyes at weekly intervals and the area of vascularization and epithelial defects in the hyperbaric and control groups were compared. Results: Equal numbers (seven) of the control and hyperbaric oxygen treated groups had perforated corneas and there was no statistical difference in the mean time to perforation (control 30.1 days; treated 30 days). There was also no statistical difference between the two groups with respect to epithelial defect size. Conclusion: Treatment with hyperbaric oxygen for 1 h daily for 21 days had no beneficial effect on alkali-induced corneal burns.

The medical zoologist - Ronald Vernon Southcott

Dr Ronald Vernon Southcott (1918–1998) was amongst the greatest of the Australian doctor-naturalists. His toxinological contributions included the description and naming of the box-jellyfish, Chironex fleckeri, the first definitive study (1950–1957) of the toxinology, taxonomy and biology of Australian scorpions; and the first observations in Australia of the introduced fiddleback spider, Loxosceles. His research into the medical effects of toxic fungi, poisonous plants and Australian insects was extensive. He was a founding member of the International Society on Toxinology and served on the Toxicon Editorial Board for more than 30 years. He also made extensive contributions to acarology, and to the taxonomy of mites, specifically the sub-families and genera of the Erythraeoidea. This prodigious output was achieved by one who, with the exception of war service (1942–1946), almost never travelled outside South Australia, was almost entirely self-funded and worked from his home laboratory. With Dr. P.D. Scott and C.J. Glover, he was also the authority on the fish of South Australia. Dr. Southcott was also a medical epidemiologist and senior medical administrator (1949–1978) with the Australian Commonwealth Department of Veterans’ Affairs. He served for 30 years as an Honorary Consultant in Toxicology to the Adelaide Children's Hospital. As a zoologist and botanist of astounding breadth, he worked indefatigably in a voluntary capacity for the South Australian Museum, of which he was Museum Board Chairman from 1974 to 1982. In the pantheon of the great doctor-naturalists who have worked in Australia, he stands with Robert Brown and Thomas Lane Bancroft.

Toxinology in Australia's colonial era: A chronology and perspective of human envenomation in 19th century Australia

The medical management of those envenomed by snakes, spiders and poisonous fish in Australia featured extensively in the writings 19th century doctors, expeditioners and anthropologists. Against the background of this introduced medical doctrine there already existed an extensive tradition of Aboriginal medical lore; techniques of heat treatment, suction, incision and the application of plant-derived pharmacological substances featured extensively in the management of envenomed victims. The application of a hair-string or grass-string ligature, suctioning of the bite-site and incision were practised in a variety of combinations. Such evolved independently of and pre-dated such practices, which were promoted extensively by immigrant European doctors in the late 19th century. Pacific scientific toxinology began in the 17th century with Don Diego de Prado y Tovar's 1606 account of ciguatera. By the end of the 19th century more than 30 papers and books had defined the natural history of Australian elapid poisoning. The medical management of snakebite in Australia was the focus of great controversy from 1860 to 1900. Dogmatic claims of the supposed antidote efficacy of intravenous ammonia by Professor G.B. Halford, and that of strychnine by Dr. Augustus Mueller, claimed mainstream medical attention. This era of potential iatrogenic disaster and dogma was brought to a conclusion by the objective experiments of Joseph Lauterer and Thomas Lane Bancroft in 1890 in Brisbane; and by those of C.J. Martin (from 1893) and Frank Tidswell (from 1898), both of Sydney. The modern era of Australian toxinology developed as a direct consequence of Calmette's discovery, in Paris in 1894, of immune serum, which was protective against snakebite. We review the key contributors and discoveries of toxinology in colonial Australia.