Surgery (RMH) - Research Publications
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ItemMitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary(BMC, 2008-07-28)BACKGROUND: Despite being one of the most studied families within the Carnivora, the phylogenetic relationships among the members of the bear family (Ursidae) have long remained unclear. Widely divergent topologies have been suggested based on various data sets and methods. RESULTS: We present a fully resolved phylogeny for ursids based on ten complete mitochondrial genome sequences from all eight living and two recently extinct bear species, the European cave bear (Ursus spelaeus) and the American giant short-faced bear (Arctodus simus). The mitogenomic data yield a well-resolved topology for ursids, with the sloth bear at the basal position within the genus Ursus. The sun bear is the sister taxon to both the American and Asian black bears, and this clade is the sister clade of cave bear, brown bear and polar bear confirming a recent study on bear mitochondrial genomes. CONCLUSION: Sequences from extinct bears represent the third and fourth Pleistocene species for which complete mitochondrial genomes have been sequenced. Moreover, the cave bear specimen demonstrates that mitogenomic studies can be applied to Pleistocene fossils that have not been preserved in permafrost, and therefore have a broad application within ancient DNA research. Molecular dating of the mtDNA divergence times suggests a rapid radiation of bears in both the Old and New Worlds around 5 million years ago, at the Miocene-Pliocene boundary. This coincides with major global changes, such as the Messinian crisis and the first opening of the Bering Strait, and suggests a global influence of such events on species radiations.
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ItemIn vitro sensitivity testing of minimally passaged and uncultured gliomas with TRAIL and/or chemotherapy drugs(NATURE PUBLISHING GROUP, 2008-07-15)TRAIL/Apo-2L has shown promise as an anti-glioma drug, based on investigations of TRAIL sensitivity in established glioma cell lines, but it is not known how accurately TRAIL signalling pathways of glioma cells in vivo are reproduced in these cell lines in vitro. To replicate as closely as possible the in vivo behaviour of malignant glioma cells, 17 early passage glioma cell lines and 5 freshly resected gliomas were exposed to TRAIL-based agents and/or chemotherapeutic drugs. Normal human hepatocytes and astrocytes and established glioma cell lines were also tested. Cross-linked TRAIL, but not soluble TRAIL, killed both normal cell types and cells from three tumours. Cells from only one glioma were killed by soluble TRAIL, although only inefficiently. High concentrations of cisplatin were lethal to glioma cells, hepatocytes and astrocytes. Isolated combinations of TRAIL and chemotherapy drugs were more toxic to particular gliomas than normal cells, but no combination was generally selective for glioma cells. This study highlights the widespread resistance of glioma cells to TRAIL-based agents, but suggests that a minority of high-grade glioma patients may benefit from particular combinations of TRAIL and chemotherapy drugs. In vitro sensitivity assays may help identify effective drug combinations for individual glioma patients.
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ItemNo Preview AvailableThe lymphatic anatomy of the breast and its implications for sentinel lymph node biopsy: A Human Cadaver Study(SPRINGER, 2008-03)BACKGROUND: Current understanding of the lymphatic system of the breast is derived mainly from the work of the anatomist Sappey in the 1850s, with many observations made during the development and introduction of breast lymphatic mapping and sentinel node biopsy contributing to our knowledge. METHODS: Twenty four breasts in 14 fresh human cadavers (5 male, 9 female) were studied. Lymph vessels were identified with hydrogen peroxide and injected with a lead oxide mixture and radiographed. The specimens were cross sectioned and radiographed to provide three dimensional images. Lymph (collecting) vessels were traced from the periphery to the first-tier lymph node. RESULTS: Lymph collecting vessels were found evenly spaced at the periphery of the anterior upper torso draining radially into the axillary lymph nodes. As they reached the breast some passed over and some through the breast parenchyma, as revealed in the cross-section studies. The pathways showed no significant difference between male and female specimens. We found also perforating lymph vessels that coursed beside the branches of the internal mammary vessels, draining into the ipsilateral internal mammary lymphatics. In some studies one sentinel node in the axilla drained almost the entire breast. In most more than one sentinel node was represented. CONCLUSION: These anatomical findings are discordant with our current knowledge based on previous studies and demand closer examination by clinicians. These anatomical studies may help explain the percentage of false-negative sentinel node biopsy studies and suggest the peritumoral injection site for accurate sentinel lymph node detection.
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ItemImproving antibiotic prescribing for adults with community acquired pneumonia: Does a computerised decision support system achieve more than academic detailing alone? a time series analysis(BMC, 2008-07-31)BACKGROUND: The ideal method to encourage uptake of clinical guidelines in hospitals is not known. Several strategies have been suggested. This study evaluates the impact of academic detailing and a computerised decision support system (CDSS) on clinicians' prescribing behaviour for patients with community acquired pneumonia (CAP). METHODS: The management of all patients presenting to the emergency department over three successive time periods was evaluated; the baseline, academic detailing and CDSS periods. The rate of empiric antibiotic prescribing that was concordant with recommendations was studied over time comparing pre and post periods and using an interrupted time series analysis. RESULTS: The odds ratio for concordant therapy in the academic detailing period, after adjustment for age, illness severity and suspicion of aspiration, compared with the baseline period was OR = 2.79 [1.88, 4.14], p < 0.01, and for the computerised decision support period compared to the academic detailing period was OR = 1.99 [1.07, 3.69], p = 0.02. During the first months of the computerised decision support period an improvement in the appropriateness of antibiotic prescribing was demonstrated, which was greater than that expected to have occurred with time and academic detailing alone, based on predictions from a binary logistic model. CONCLUSION: Deployment of a computerised decision support system was associated with an early improvement in antibiotic prescribing practices which was greater than the changes seen with academic detailing. The sustainability of this intervention requires further evaluation.
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ItemSalvage robotic-assisted laparoscopic radical prostatectomy following failed primary high-intensity focussed ultrasound treatment for localised prostate cancer(SPRINGER LONDON LTD, 2008-09)We report the first case of salvage robotic-assisted laparoscopic radical prostatectomy (RALP) following failed primary high-intensity focussed ultrasound (HIFU) for localised carcinoma of the prostate. A 66-year-old male with a presenting prostate-specific antigen (PSA) of 5 ng/ml was diagnosed with T1c Gleason 3 + 4 prostate cancer. He underwent transurethral resection of the prostate and HIFU. His PSA dropped to 2.0 ng/ml and repeat biopsy revealed upgrading of his prostate cancer to Gleason 4 + 3. He was referred to us for a second opinion and, following discussion of his options, he underwent RALP. The total operative time was 159 min. There were no intra- or postoperative complications. He was discharged on postoperative day two and was fully continent 10 days following removal of his catheter. His PSA remained undetectable 6 months postoperatively. Salvage RALP was feasible in this case with good functional and short-term oncological outcomes for the patient.
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ItemHigh prostatic fascia release or standard nerve sparing? A viewpoint from the Royal Melbourne Hospital(SPRINGER LONDON LTD, 2008-09)Radical prostatectomy with preservation of the neurovascular bundles (NVB) is a treatment option for localised prostate cancer in selected patients. An interesting debate has developed about the precise technique used to preserve these nerves. The standard technique releases the NVB from the postero-lateral groove between the prostate and rectum. A new technique, dubbed the "veil of Aphrodite" technique, proposes a higher release of the lateral prostatic fascia on the presumption that cavernosal nerves exist in this area. We have reviewed the evidence for the anatomical basis of nerve-sparing radical prostatectomy, particularly with respect to the standard versus the "veil" technique of radical prostatectomy. Microdissections of the NVB in cadaveric specimens have confirmed the course of the cavernosal nerves in the postero-lateral groove between the prostate and rectum. Though studies have also demonstrated nerves higher in the lateral prostatic fascia, these are likely to innervate the prostate rather than the cavernosal tissues. Though excellent potency results have been reported for the "veil" technique from one institution, there is not sufficient anatomical evidence to support this technique over the standard technique of nerve-sparing radical prostatectomy.