51 research outputs found
Low-dose stereotactic radiosurgery is inadequate for medically intractable mesial temporal lobe epilepsy: a case report
AbstractThe successful surgical treatment of medically refractory epilepsy is based on one of three different principles: (1) elimination of the epileptic focus, (2) interruption of the pathways of neural propagation, and (3) increasing the seizure threshold through cerebral lesions or electrical stimulation. Temporal lobe epilepsy, being the most common focal epilepsy, may ultimately require temporal lobectomy. This is a case report of a 36-year-old male with drug-resistant right mesial temporal lobe epilepsy who failed to obtain seizure control after stereotactic radiosurgery to the seizure focus. Complex-partial seizures occurred 6–7 times monthly, and consisted of a loss of awareness followed by involuntary movements of the right arm. EEG/CC TV monitoring indicated a right mesial temporal lobe focus, which was corroborated by decreased uptake in the right temporal lobe by FDG-PET and by MRI findings of right hippocampal sclerosis. Stereotactic radiosurgery was performed with a 4MV linac, utilizing three isocenters with collimator sizes of 10, 10, and 7 mm respectively. A dose of 1500 cGy (max dose 2535 cGy) was delivered in a single fraction to the patient’s right amygdala and hippocampus. There were no acute complications. Following radiosurgery the patient’s seizures were improved in both frequency and intensity for approximately 3 months. Antiepileptic medications were continued. Thereafter, seizures increased in both frequency and intensity, occurring 10–20 times monthly. At 1 year post radiosurgery, standard right temporal lobectomy including amygdalohippocampectomy was performed with subsequent resolution of complex-partial seizures. Histopathology of the resected temporal lobe revealed hippocampal cell loss and fibrillary astrocytosis, consistent with hippocampal sclerosis. No radiation-induced histopathologic changes were seen. We conclude that low-dose radiosurgery doses temporarily changed the intensity and character of seizure activity, but actually increased seizure activity long-term. If radiosurgery is to be an effective alternative to temporal lobectomy for medically intractable temporal lobe epilepsy, higher radiosurgery doses will be required. The toxicity and efficacy of higher-dose radiosurgery is currently under investigation
Serapias lingua L.(tongue orchid): naturalised in the Adelaide Hills, South Australia - caveat cultivator?
The European tongue orchid (Serapias lingua) is reported as naturalised from a site at Ironbank in the Adelaide Hills, South Australia where plants have now been observed sporadically over at least a 13 year period. Despite the removal of all visible plants in 1997, there was subsequent re-establishment, with 23 plants again removed in 2010. Although the colony is small, the reappearance of plants after their presumed eradication, combined with evidence of limited seed set indicates that ongoing monitoring of the site is required to prevent further reoccurrence. This also suggests that the disposal of unwanted cultivated Serapias material should be done with care to prevent further escapes.J. Conran, E. Maciunas and K. Maciunashttp://www.adelaide.edu.au/imer/docs/imer-annual-report-2011.pd
Miocene Astelia (Asparagales: Asteliaceae) macrofossils from southern New Zealand
The discovery of Early Miocene Asteliaceae fossils at Foulden Maar in southern New Zealand provided a good opportunity to assess the usefulness of cuticular information for identifying members in this family. On the basis of cuticular morphology, the Foulden specimens are assigned to Astelia Banks & Sol. ex R.Br. and described as a new species, A. antiquua Maciunas et al. They are shown to have some affinities with A. alpina, A. linearis and also an apparently unnamed Astelia taxon from southern Westland, New Zealand. Although cuticular characteristics alone were of help in identifying individual species, the addition of gross morphological characters facilitated the differentiation between Asteliaceae genera, greatly improving the phylogenetic placement of the fossil. On the basis of analysis of the combined data, Astelia and Collospermum formed a clade and were sister to a Milligania and Neoastelia clade, albeit with most branches showing little overall bootstrap support.Elizabeth Maciunas, John G. Conran, Jennifer M. Bannister, Rosemary Paull and Daphne E. Le
Evolution of the eucalypts - an interpretation from the macrofossil record
Eucalypts have influenced the fire ecology of the Australian landscape more than any other plant group. They are the iconic plant taxon in the Australian vegetation today, but their origin, early evolution and migration remain poorly understood, mostly because of a remarkably sparse and underworked fossil record. However, a recent major macrofossil find in southern South America, coupled with increasing sophistication of molecular phylogenetic and palynological research allow for a more comprehensive summary of the likely early history of this group of genera. It is likely that the origin was close to the Cretaceous–Paleogene boundary, somewhere in the Weddellian Biogeographic Province (which includes southern South America, western Antarctica and south-eastern Australia), in an area with high natural fire frequency. Evidence for the early record of eucalypts in Australia and their eventual spread across the continent, leading to their current dominance of the Australian plant biomass is growing and is consistent with a drying climate and increasing fire frequency following a very wet period during the Paleogene. The causes of the extinction of eucalypts from South America and probably New Zealand are considered, but remain obscure.Robert S. Hill, Yelarney K. Beer, Kathryn E. Hill, Elizabeth Maciunas, Myall A. Tarran and Carmine C. Wainma
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