Clinical School (Austin Health) - Research Publications

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    Advances in ureteroscopy
    Wetherell, DR ; Ling, D ; Ow, D ; Koonjbeharry, B ; Sliwinski, A ; Weerakoon, M ; Papa, N ; Lawrentschuk, N ; Bolton, DM (AME PUBLISHING COMPANY, 2014-09)
    Ureteroscopy (URS) is a procedure which has been constantly evolving since the development of first generation devices 40 years ago. Progress towards smaller and more sophisticated equipment has been particularly rapid in the last decade. We review the significant steps that have been made toward improving outcomes and limiting morbidity with this procedure which is central to the management of urolithiasis and other upper urinary tract pathology.
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    A multilingual evaluation of current health information on the Internet for the treatments of benign prostatic hyperplasia
    Chen, EC ; Manecksha, RP ; Abouassaly, R ; Bolton, DM ; Reich, O ; Lawrentschuk, N (ELSEVIER INC, 2014-12)
    PURPOSE: To compare the quality of current Internet information on benign prostatic hyperplasia (BPH) and its surgical and medical managements across four Western languages and a comparative analysis of website sponsors. BPH Internet information quality is particularly relevant in an era of expanding, minimally invasive and surgical therapies. However, no comprehensive analysis exists. METHODS: World Health Organization Health on the Net (HON) principles may be applied to websites using an automated toolbar function. Using a search engine (www.google.com), 9,000 websites were assessed using keywords related to BPH and its medical and surgical treatment in English, French, German, and Spanish. The first 150 websites in each language had HON principles measured whilst a further analysis of site sponsorship was undertaken. RESULTS: Very few BPH websites had greater than ten per cent HON accredited with significant differences (P<0.001) based on terms used for BPH, its medical and surgical management. Tertiles (thirds) of the first 150 websites returned differences in accredited websites (P<0.0001). English language had most accredited websites. Odds ratios for different terms returning accredited websites also were significantly different across terms (P<0.001). Websites were largely commercially sponsored. CONCLUSIONS: A lack of validation of most BPH sites should be appreciated with discrepancies in quality and number of websites across diseases, languages and also between medical and alternate terms. Physicians should participate in and encourage the development of informative, ethical and reliable health websites on the Internet and direct patients to them.
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    The impact of fluid intervention on complications and length of hospital stay after pancreaticoduodenectomy (Whipple's procedure)
    Weinberg, L ; Wong, D ; Karalapillai, D ; Pearce, B ; Tan, CO ; Tay, S ; Christophi, C ; McNicol, L ; Nikfarjam, M (BIOMED CENTRAL LTD, 2014-05-14)
    BACKGROUND: There is limited information on the impact on perioperative fluid intervention on complications and length of hospital stay following pancreaticoduodenectomy. Therefore, we conducted a detailed analysis of fluid intervention in patients undergoing pancreaticoduodenectomy at a university teaching hospital to test the hypothesis that a restrictive intravenous fluid regime and/or a neutral or negative cumulative fluid balance, would impact on perioperative complications and length of hospital stay. METHODS: We retrospectively obtained demographic, operative details, detailed fluid prescription, complications and outcomes data for 150 consecutive patients undergoing pancreaticoduodenectomy in a university teaching hospital. Prognostic predictors for length of hospital stay and complications were determined. RESULTS: One hundred and fifty consecutive patients undergoing pancreaticoduodenectomy were evaluated between 2006 and 2012. The majority of patients were, middle-aged, overweight and ASA class III. Postoperative complications were frequent and occurred in 86 patients (57%). The majority of complications were graded as Clavien-Dindo Class 2 and 3. Postoperative pancreatic fistula occurred in 13 patients (9%), and delayed gastric emptying occurred in 25 patients (17%). Other postoperative surgical complications included sepsis (22%), bile leak (4%), and postoperative bleeding (2%). Serious medical complications included pulmonary edema (6%), myocardial infarction (8%), cardiac arrhythmias (13%), respiratory failure (8%), and renal failure (7%). Patients with complications received a higher median volume of intravenous therapy and had higher cumulative positive fluid balances. Postoperative length of stay was significantly longer in patients with complications (median 25 days vs. 10 days; p < 0.001). After adjustment for covariates, a fluid balance of less than 1 litre on postoperative day 1 and surgeon caseloads were associated with the development of complications. CONCLUSIONS: In the context of pancreaticoduodenectomy, restrictive perioperative fluid intervention and negative cumulative fluid balance were associated with fewer complications and shorter length of hospital stay. These findings provide good opportunities to evaluate strategies aimed at improving perioperative care.
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    Testosterone levels increase in association with recovery from acute fracture in men
    Cheung, AS ; Baqar, S ; Sia, R ; Hoermann, R ; Iuliano-Burns, S ; Vu, TDT ; Chiang, C ; Hamilton, EJ ; Gianatti, E ; Seeman, E ; Zajac, JD ; Grossmann, M (SPRINGER LONDON LTD, 2014-08)
    UNLABELLED: In this longitudinal case-control study, acute fracture was associated with low serum testosterone, which was transient in 43% of men. While assessment of gonadal status is part of the assessment of bone fragility, measurement of testosterone in the early period after fracture may overestimate the prevalence of androgen deficiency. INTRODUCTION: Measurement of circulating testosterone is recommended in the evaluation of bone fragility in men. Since acute illness can transiently decrease circulating testosterone, we quantified the association of acute fracture and serum testosterone levels. METHODS: A case-control study was conducted involving 240 men with a radiologically confirmed minimal trauma fracture presenting to a tertiary referral hospital and 89 age-matched men without a history of minimal trauma fracture serving as controls. Follow-up testosterone levels 6 months after baseline were available for 98 cases and 27 controls. Results were expressed as the median and interquartile (IQR) range. RESULTS: Compared to controls, cases had lower total testosterone [TT, 7.2 (3.5, 10.8) vs 13.6 (10.9, 17.1) nmol/L, p < 0.001]. The 143 cases treated as inpatients had lower testosterone levels than the 97 cases treated as outpatients [TT 4.7 (2.3, 8.1) vs 10.3 (7.5, 12.7) nmol/L, p < 0.001]. Group differences in calculated free testosterone (cFT) were comparable to the group differences in TT. At follow-up, in 98 cases, median TT increased from 6.5 nmol/L (3.2, 8.5) to 9.6 nmol/L (6.9, 12.0) p < 0.0001, and SHBG remained unchanged. Of cases with low testosterone, 43% with TT <10 nmol/L and/or cFT <230 pmol/L at presentation were reclassified as androgen sufficient at follow-up. TT was unchanged in the controls. CONCLUSIONS: Low testosterone levels in men presenting with an acute fracture may, at least in part, be due to an acute, fracture-associated, stress response. To avoid over diagnosis, evaluation for testosterone deficiency should be deferred until recovery from the acute event.
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    Hyperexpression of α-hemolysin explains enhanced virulence of sequence type 93 community-associated methicillin-resistant Staphylococcus aureus
    Chua, KYL ; Monk, IR ; Lin, Y-H ; Seemann, T ; Tuck, KL ; Porter, JL ; Stepnell, J ; Coombs, GW ; Davies, JK ; Stinear, TP ; Howden, BP (BMC, 2014-02-10)
    BACKGROUND: The community-associated methicillin-resistant S. aureus (CA-MRSA) ST93 clone is becoming dominant in Australia and is clinically highly virulent. In addition, sepsis and skin infection models demonstrate that ST93 CA-MRSA is the most virulent global clone of S. aureus tested to date. While the determinants of virulence have been studied in other clones of CA-MRSA, the basis for hypervirulence in ST93 CA-MRSA has not been defined. RESULTS: Here, using a geographically and temporally dispersed collection of ST93 isolates we demonstrate that the ST93 population hyperexpresses key CA-MRSA exotoxins, in particular α-hemolysin, in comparison to other global clones. Gene deletion and complementation studies, and virulence comparisons in a murine skin infection model, showed unequivocally that increased expression of α-hemolysin is the key staphylococcal virulence determinant for this clone. Genome sequencing and comparative genomics of strains with divergent exotoxin profiles demonstrated that, like other S. aureus clones, the quorum sensing agr system is the master regulator of toxin expression and virulence in ST93 CA-MRSA. However, we also identified a previously uncharacterized AraC/XylS family regulator (AryK) that potentiates toxin expression and virulence in S. aureus. CONCLUSIONS: These data demonstrate that hyperexpression of α-hemolysin mediates enhanced virulence in ST93 CA-MRSA, and additional control of exotoxin production, in particular α-hemolysin, mediated by regulatory systems other than agr have the potential to fine-tune virulence in CA-MRSA.
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    Glucagon-like peptide 1 and peptide YY are in separate storage organelles in enteroendocrine cells
    Cho, H-J ; Robinson, ES ; Rivera, LR ; McMillan, PJ ; Testro, A ; Nikfarjam, M ; Bravo, DM ; Furness, JB (SPRINGER, 2014-07)
    A sub-group of enteroendocrine cells (L cells) release gastrointestinal hormones, GLP-1 and PYY, which have different but overlapping physiological effects, in response to intraluminal nutrients. Whilst their release profiles are not identical, how the plasma levels of these two hormones are differentially regulated is not well understood. We investigate the possibility that GLP-1 and PYY are in separate storage vesicles. In this study, the subcellular location of GLP-1 and PYY storage organelles is investigated using double-labelling immunohistochemistry, super resolution microscopy and high-resolution confocal microscopy. In all species tested, human, pig, rat and mouse, most cytoplasmic stores that exhibited GLP-1 or PYY immunofluorescence were distinct from each other. The volume occupancy, determined by 3D analysis, overlapped by only about 10∼20 %. At the lower resolution achieved by conventional confocal microscopy, there was also evidence of GLP-1 and PYY being in separate storage compartments but, in subcellular regions where there were many storage vesicles, separate storage could not be resolved. The results indicate that different storage vesicles in L cells contain predominantly GLP-1 or predominantly PYY. Whether GLP-1 and PYY storage vesicles are selectively mobilised and their products are selectively released needs to be determined.
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    A variant of KCC2 from patients with febrile seizures impairs neuronal Cl- extrusion and dendritic spine formation
    Puskarjov, M ; Seja, P ; Heron, SE ; Williams, TC ; Ahmad, F ; Iona, X ; Oliver, KL ; Grinton, BE ; Vutskits, L ; Scheffer, IE ; Petrou, S ; Blaesse, P ; Dibbens, LM ; Berkovic, SF ; Kaila, K (WILEY-BLACKWELL, 2014-06)
    Genetic variation in SLC12A5 which encodes KCC2, the neuron-specific cation-chloride cotransporter that is essential for hyperpolarizing GABAergic signaling and formation of cortical dendritic spines, has not been reported in human disease. Screening of SLC12A5 revealed a co-segregating variant (KCC2-R952H) in an Australian family with febrile seizures. We show that KCC2-R952H reduces neuronal Cl(-) extrusion and has a compromised ability to induce dendritic spines in vivo and in vitro. Biochemical analyses indicate a reduced surface expression of KCC2-R952H which likely contributes to the functional deficits. Our data suggest that KCC2-R952H is a bona fide susceptibility variant for febrile seizures.
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    Does variation in NIPA2 contribute to genetic generalized epilepsy?
    Hildebrand, MS ; Damiano, JA ; Mullen, SA ; Bellows, ST ; Scheffer, IE ; Berkovic, SF (SPRINGER, 2014-05)
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    The genetic basis of music ability
    Tan, YT ; McPherson, GE ; Peretz, I ; Berkovic, SF ; Wilson, SJ (FRONTIERS MEDIA SA, 2014-06-27)
    Music is an integral part of the cultural heritage of all known human societies, with the capacity for music perception and production present in most people. Researchers generally agree that both genetic and environmental factors contribute to the broader realization of music ability, with the degree of music aptitude varying, not only from individual to individual, but across various components of music ability within the same individual. While environmental factors influencing music development and expertise have been well investigated in the psychological and music literature, the interrogation of possible genetic influences has not progressed at the same rate. Recent advances in genetic research offer fertile ground for exploring the genetic basis of music ability. This paper begins with a brief overview of behavioral and molecular genetic approaches commonly used in human genetic analyses, and then critically reviews the key findings of genetic investigations of the components of music ability. Some promising and converging findings have emerged, with several loci on chromosome 4 implicated in singing and music perception, and certain loci on chromosome 8q implicated in absolute pitch and music perception. The gene AVPR1A on chromosome 12q has also been implicated in music perception, music memory, and music listening, whereas SLC6A4 on chromosome 17q has been associated with music memory and choir participation. Replication of these results in alternate populations and with larger samples is warranted to confirm the findings. Through increased research efforts, a clearer picture of the genetic mechanisms underpinning music ability will hopefully emerge.