Surgery (St Vincent's) - Research Publications

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    Arthroplasty information on the internet
    Davaris, MT ; Dowsey, MM ; Bunzli, S ; Choong, PF (The British Editorial Society of Bone & Joint Surgery, 2020-04)
    Aims: Total joint replacement (TJR) is a high-cost, high-volume procedure that impacts patients’ quality of life. Informed decisions are important for patients facing TJR. The quality of information provided by websites regarding TJR is highly variable. We aimed to measure the quality of TJR information online. Methods: We identified 10,800 websites using 18 TJR-related keywords (conditions and procedures) across the Australian, French, German and Spanish Google search engines. We used the Health on the Net (HON) toolbar to evaluate the first 150 websites downloaded for every keyword in each language. The quality of information on websites was inspected, accounting for differences by language and tertiles. We also undertook an analysis of English websites to explore types of website providers. Results: ‘Total joint replacement’ had the most results returned (150 million websites), and 9% of websites are HON-accredited. Differences in information quality were seen across search terms (p < 0.001) and tertiles (p < 0.001), but not between languages (p = 0.226). A larger proportion of HON-accredited websites were seen from keywords in the condition and arthroplasty categories. The first tertile contained the highest number of HON-accredited websites for the majority of search terms. Government/educational bodies sponsored the majority of websites. Conclusion: Clinicians must consider the shortage of websites providing validated information, with disparities in both number and quality of websites for TJR conditions and procedures. As such, the challenge for clinicians is to lead the design of reliable, accurate and ethical orthopaedic websites online and direct patients to them. This stands to reward both parties greatly.
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    Gata-3 Negatively Regulates the Tumor-Initiating Capacity of Mammary Luminal Progenitor Cells and Targets the Putative Tumor Suppressor Caspase-14
    Asselin-Labat, M-L ; Sutherland, KD ; Vaillant, F ; Gyorki, DE ; Wu, D ; Holroyd, S ; Breslin, K ; Ward, T ; Shi, W ; Bath, ML ; Deb, S ; Fox, SB ; Smyth, GK ; Lindeman, GJ ; Visvader, JE (AMER SOC MICROBIOLOGY, 2011-11)
    The transcription factor Gata-3 is a definitive marker of luminal breast cancers and a key regulator of mammary morphogenesis. Here we have explored a role for Gata-3 in tumor initiation and the underlying cellular mechanisms using a mouse model of "luminal-like" cancer. Loss of a single Gata-3 allele markedly accelerated tumor progression in mice carrying the mouse mammary tumor virus promoter-driven polyomavirus middle T antigen (MMTV-PyMT mice), while overexpression of Gata-3 curtailed tumorigenesis. Through the identification of two distinct luminal progenitor cells in the mammary gland, we demonstrate that Gata-3 haplo-insufficiency increases the tumor-initiating capacity of these progenitors but not the stem cell-enriched population. Overexpression of a conditional Gata-3 transgene in the PyMT model promoted cellular differentiation and led to reduced tumor-initiating capacity as well as diminished angiogenesis. Transcript profiling studies identified caspase-14 as a novel downstream target of Gata-3, in keeping with its roles in differentiation and tumorigenesis. A strong association was evident between GATA-3 and caspase-14 expression in preinvasive ductal carcinoma in situ samples, where GATA-3 also displayed prognostic significance. Overall, these studies identify GATA-3 as an important regulator of tumor initiation through its ability to promote the differentiation of committed luminal progenitor cells.
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    AAV-mediated gene delivery of the calreticulin anti-angiogenic domain inhibits ocular neovascularization
    Tu, L ; Wang, J-H ; Barathi, VA ; Prea, SM ; He, Z ; Lee, JH ; Bender, J ; King, AE ; Logan, GJ ; Alexander, IE ; Bee, Y-S ; Tai, M-H ; Dusting, GJ ; Bui, BV ; Zhong, J ; Liu, G-S (SPRINGER, 2018-02)
    Ocular neovascularization is a common pathological feature in diabetic retinopathy and neovascular age-related macular degeneration that can lead to severe vision loss. We evaluated the therapeutic efficacy of a novel endogenous inhibitor of angiogenesis, the calreticulin anti-angiogenic domain (CAD180), and its functional 112-residue fragment, CAD-like peptide 112 (CAD112), delivered using a self-complementary adeno-associated virus serotype 2 (scAAV2) in rodent models of oxygen-induced retinopathy and laser-induced choroidal neovascularization. The expression of CAD180 and CAD112 was elevated in human umbilical vein endothelial cells transduced with scAAV2-CAD180 or scAAV2-CAD112, respectively, and both inhibited angiogenic activity in vitro. Intravitreal gene delivery of scAAV2-CAD180 or scAAV2-CAD112 significantly inhibited ischemia-induced retinal neovascularization in rat eyes (CAD180: 52.7% reduction; CAD112: 49.2% reduction) compared to scAAV2-mCherry, as measured in retinal flatmounts stained with isolectin B4. Moreover, the retinal structure and function were unaffected by scAAV2-CAD180 or scAAV2-CAD112, as measured by optical coherence tomography and electroretinography. Moreover, subretinal delivery of scAAV2-CAD180 or scAAV2-CAD112 significantly attenuated laser-induced choroidal neovascularization in mouse eyes compared to scAAV2-mCherry, as measured by fundus fluorescein angiography (CAD180: 62.4% reduction; CAD112: 57.5% reduction) and choroidal flatmounts (CAD180: 40.21% reduction; CAD112: 43.03% reduction). Gene delivery using scAAV2-CAD180 or scAAV2-CAD112 has significant potential as a therapeutic option for the management of ocular neovascularization.
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    Review of the use of prophylactic drain tubes post-robotic radical prostatectomy: Dogma or decent practice?
    Nzenza, TC ; Ngweso, S ; Eapen, R ; Rajarubendra, N ; Bolton, D ; Murphy, D ; Lawrentschuk, N (WILEY, 2020-09)
    OBJECTIVE: To assess the necessity of routine prophylactic drain tube use following robot-assisted radical prostatectomy (RARP). METHOD: We performed a literature review using the Medline, Scopus, and Web of Science databases with no restriction of language from January 1900 to January 2020. The following terms we used in the literature search: prostatectomy, radical prostatectomy, robot assisted, drainage, and drain tube. RESULTS: We identified six studies that examined the use of routine prophylactic drain tubes following RARP. One of these studies was a randomized study that included 189 patients, with 97 in the pelvic drain (PD) arm and 92 in the no pelvic drain (ND) arm. This non-inferiority showed an early (90-day) complication rate of 17.4% in the ND arm versus 26.8% in the PD arm (P < .001). Another non-inferiority randomized control trial (RCT) showed a complication rate of 28.9% in the PD group versus 20.4% in the ND group (P = .254). Similarly, the other studies found no benefit of routine use of prophylactic drain tube after RARP. CONCLUSION: Drain tubes play a role during robotic-assisted radical prostatectomy, however, following a review of the current available literature, they can be safely omitted and we suggest that clinicians may be selective in their use.
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    Subinguinal orchiectomy-A minimally invasive approach to open surgery
    Anderson, E ; Pascoe, C ; Sathianathen, N ; Katz, D ; Murphy, D ; Lawrentschuk, N (WILEY, 2020-11)
    OBJECTIVES: To determine the rate of morbidity and assess the oncological outcomes for the subinguinal orchidectomy technique. BACKGROUND: Radical inguinal orchiectomy is the definitive management for a testicular mass suspicious for malignancy. The standard approach involves the division of the spermatic cord at the internal inguinal ring. In addition to the morbidity of a significant incision through skin and fascia, a known complication is damage to the nerves within the canal leading to local hypoesthesia or persistent inguinal and scrotal neuralgia. The subinguinal orchiectomy technique avoids opening the inguinal canal by excising the spermatic cord at the external inguinal ring. METHODS: Patient data from three urologists who routinely perform subinguinal orchiectomies for suspected testicular malignancy was collected. A retrospective analysis between March 2011 and March 2019 was undertaken evaluating demographic, clinical, and histological data points. Descriptive analysis of oncological and surgical outcomes of subinguinal orchiectomy for testicular mass was performed. Descriptive analysis of oncological and surgical outcomes of subinguinal orchiectomy for testicular mass was performed. RESULTS: About 42 orchiectomies performed via the subinguinal approach were identified. The median age was 38 years (range 22-72) and mean follow-up time was 18.4 months (range 0.59-61). Of the 38 patients with testicular cancer, histopathology showed 26 with pT1, 9 with pT2, and 3 with pT3 disease. Three patients had involvement of the cord, with one patient having a positive surgical margin secondary to venous invasion. No patients experienced neuropathic complications, hernia, or wound break down. CONCLUSION: These data suggest that subinguinal orchiectomy provides acceptable oncological outcomes, comparable to a traditional technique, and may decrease the risk of neuropathic injury and incisional/inguinal hernia. Further investigation with a larger, prospective series is required.
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    The delicate balance of melanoma immunotherapy
    Gyorki, DE ; Callahan, M ; Wolchok, JD ; Ariyan, CE (WILEY, 2013-08)
    The strategy of immune modulation for the treatment of cancer is being refined with the introduction of multiple new therapeutic agents into the clinic. Melanoma is a disease where many of these agents have demonstrated efficacy. The mechanisms of action of these agents exploit the counter-regulatory mechanisms of the immune response. However, these agents are also associated with immune-related adverse events (IRAEs), which represent tissue-specific inflammatory responses. These IRAEs highlight the delicate balance of immunologic homeostasis and, with some interventions, may occur more frequently in patients who sustain a therapeutic response. This review will discuss melanoma immunogenicity and immunotherapy. Furthermore, the spectrum and distinction between a reversible immune adverse event and autoimmunity will be highlighted.
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    Electrical probing of cortical excitability in patients with epilepsy
    Freestone, DR ; Kuhlmann, L ; Grayden, DB ; Burkitt, AN ; Lai, A ; Nelson, TS ; Vogrin, S ; Murphy, M ; D'Souza, W ; Badawy, R ; Nesic, D ; Cook, MJ (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2011-12)
    Standard methods for seizure prediction involve passive monitoring of intracranial electroencephalography (iEEG) in order to track the 'state' of the brain. This paper introduces a new method for measuring cortical excitability using an electrical probing stimulus. Electrical probing enables feature extraction in a more robust and controlled manner compared to passively tracking features of iEEG signals. The probing stimuli consist of 100 bi-phasic pulses, delivered every 10 min. Features representing neural excitability are estimated from the iEEG responses to the stimuli. These features include the amplitude of the electrically evoked potential, the mean phase variance (univariate), and the phase-locking value (bivariate). In one patient, it is shown how the features vary over time in relation to the sleep-wake cycle and an epileptic seizure. For a second patient, it is demonstrated how the features vary with the rate of interictal discharges. In addition, the spatial pattern of increases and decreases in phase synchrony is explored when comparing periods of low and high interictal discharge rates, or sleep and awake states. The results demonstrate a proof-of-principle for the method to be applied in a seizure anticipation framework. This article is part of a Supplemental Special Issue entitled The Future of Automated Seizure Detection and Prediction.
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    Tight Junction Protein Claudin-2 Promotes Self-Renewal of Human Colorectal Cancer Stem-like Cells
    Paquet-Fifield, S ; Koh, SL ; Cheng, L ; Beyit, LM ; Shembrey, C ; Molck, C ; Behrenbruch, C ; Papin, M ; Gironella, M ; Guelfi, S ; Nasr, R ; Grillet, F ; Prudhomme, M ; Bourgaux, J-F ; Castells, A ; Pascussi, J-M ; Heriot, AG ; Puisieux, A ; Davis, MJ ; Pannequin, J ; Hill, AF ; Sloan, EK ; Hollande, F (American Association for Cancer Research, 2018-06-01)
    Posttreatment recurrence of colorectal cancer, the third most lethal cancer worldwide, is often driven by a subpopulation of cancer stem cells (CSC). The tight junction (TJ) protein claudin-2 is overexpressed in human colorectal cancer, where it enhances cell proliferation, colony formation, and chemoresistance in vitro. While several of these biological processes are features of the CSC phenotype, a role for claudin-2 in the regulation of these has not been identified. Here, we report that elevated claudin-2 expression in stage II/III colorectal tumors is associated with poor recurrence-free survival following 5-fluorouracil–based chemotherapy, an outcome in which CSCs play an instrumental role. In patient-derived organoids, primary cells, and cell lines, claudin-2 promoted colorectal cancer self-renewal in vitro and in multiple mouse xenograft models. Claudin-2 enhanced self-renewal of ALDHHigh CSCs and increased their proportion in colorectal cancer cell populations, limiting their differentiation and promoting the phenotypic transition of non-CSCs toward the ALDHHigh phenotype. Next-generation sequencing in ALDHHigh cells revealed that claudin-2 regulated expression of nine miRNAs known to control stem cell signaling. Among these, miR-222-3p was instrumental for the regulation of self-renewal by claudin-2, and enhancement of this self-renewal required activation of YAP, most likely upstream from miR-222-3p. Taken together, our results indicate that overexpression of claudin-2 promotes self-renewal within colorectal cancer stem-like cells, suggesting a potential role for this protein as a therapeutic target in colorectal cancer.
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    Laminin 521 enhances self-renewal via STAT3 activation and promotes tumor progression in colorectal cancer
    Qin, Y ; Shembrey, C ; Smith, J ; Paquet-Fifield, S ; Behrenbruch, C ; Beyit, LM ; Thomson, BNJ ; Heriot, AG ; Cao, Y ; Hollande, F (ELSEVIER IRELAND LTD, 2020-04-28)
    Remodeling of basement membrane proteins contributes to tumor progression towards the metastatic stage. One of these proteins, laminin 521 (LN521), sustains embryonic and induced pluripotent stem cell self-renewal, but its putative role in cancer is poorly described. In the present study we found that LN521 promotes colorectal cancer (CRC) cell self-renewal and invasion. siRNA-mediated knockdown of endogenously-produced laminin alpha 5, as well as treatment with neutralizing antibodies against integrin α3β1 and α6β1, were able to reverse the effect of LN521 on self-renewal. Exposure of CRC cells to LN521 enhanced STAT3 phosphorylation, and incubation with STAT3 inhibitors Napabucasin and Stattic was sufficient to block the LN521-driven self-renewal increase. Robust expression of laminin alpha 5 was detected in 7/10 liver metastases tissue sections collected from CRC patients as well as in mouse liver metastasis xenografts, in most cases within areas expressing metastasis cancer stem cell markers such as c-KIT and CD44v6. Finally, retrospective analysis of multiple CRC datasets highlighted the significant association between high LN521 mRNA expression and poor clinical outcome in colorectal cancer patients. Collectively our results indicate that high Laminin 521 expression is a frequent feature of metastatic dissemination in CRC and that it promotes cell invasion and self-renewal, the latter through engagement of integrin isoforms and activation of STAT3 signaling.