Clinical School (Austin Health) - Research Publications
Now showing items 1-48 of 61
Relationship between urinary sodium-to-potassium ratio and ambulatory blood pressure in patients with diabetes mellitus
Previous studies investigating the relationship between sodium intake and blood pressure have mostly relied on dietary recall and clinic blood pressure measurement. In this cross-sectional study, we aimed to investigate the relationship between 24 hour urinary sodium and potassium excretion, and their ratio, with 24 hour ambulatory blood pressure parameters including nocturnal blood pressure dipping in patients with type 1 and 2 diabetes. We report that in 116 patients with diabetes, systolic blood pressure was significantly predicted by the time of day, age, the interaction between dipping status with time, and 24 hour urinary sodium-to-potassium ratio (R2 = 0.83) with a relative contribution of 53%, 21%, 20% and 6%, respectively. However, there was no interaction between urinary sodium-to-potassium ratio and dipping status.
Serum carbohydrate antigen 19-9 in pancreatic adenocarcinoma: a mini review for surgeons
The optimal management of oncological conditions is reflected by the careful interpretation of investigations for screening, diagnosis, staging, prognostication and surveillance. Serum tumour markers are examples of commonly requested tests in conjunction with other imaging and endoscopic tests that are used to help clinicians to stratify therapeutic decisions. Serum carbohydrate antigen 19-9 (CA19-9) is a key biomarker for pancreatic cancers. Although this biomarker is considered clinically useful and informative, clinicians are often challenged by the accurate interpretation of elevated serum CA19-9 levels. Recognizing the pitfalls of normal and abnormal serum CA19-9 concentrations will facilitate its appropriate use. In this review, we appraised the biomarker, serum CA19-9, and highlighted the clinical utility and limitations of serum CA19-9 in the investigation and management of pancreatic cancers.
Analysis of tenodesis techniques for treatment of scapholunate instability using the finite element method.
Chronic scapholunate ligament (SL) injury is a common disorder affecting the wrist. Despite advances in surgical techniques used to treat this injury, SL gap re-emergence may occur postoperatively. This paper presents an investigation into the performance of the Corella, schapolunate axis (SLAM), and modified Brunelli tenodesis (MBT) surgical reconstruction techniques used to treat scapholunate instability. Finite element (FE) models were used to undertake virtual surgery, and the resulting scapholunate (SL) gap and angle obtained using the 3 techniques were compared. The Corella technique was found to achieve the SL gap and angle closest to the intact (ligament) wrist, restoring SL gap and angle to within 5.6% and 0.6%, respectively. The MBT method resulted in an SL gap least close to the intact. The results of our study indicate that the contribution of volar scapholunate interosseous ligament to scapholunate stability could be important.
Temporal lobe epilepsy following maintenance electroconvulsive therapyElectrical kindling in the human brain?
Maintenance electroconvulsive therapy (ECT) is sometimes prescribed for refractory psychiatric conditions. We describe five patients who received maintenance ECT and developed florid temporal epileptiform abnormalities on electroencephalography (EEG) despite no history of epilepsy and normal neuroimaging. All patients had received regular ECT for at least 8 months. Three patients had clinical events consistent with epileptic seizures, and video-EEG monitoring captured electrographic seizures in two patients. After cessation of ECT the EEGs normalized in all patients, and no further clinical seizures occurred. Maintenance ECT may predispose to epilepsy with a seizure focus in the temporal lobe.
Sodium bicarbonate infusion in patients undergoing orthotopic liver transplantation: a single center randomized controlled pilot trial
BACKGROUND: Liver transplantation-associated acute kidney injury (AKI) carries significant morbidity and mortality. We hypothesized that sodium bicarbonate would reduce the incidence and/or severity of liver transplantation-associated AKI. METHODS: In this double-blinded pilot RCT, adult patients undergoing orthotopic liver transplantation were randomized to an infusion of either 8.4% sodium bicarbonate (0.5 mEq/kg/h for the first hour; 0.15 mEq/kg/h until completion of surgery); (n = 30) or 0.9% sodium chloride (n = 30). PRIMARY OUTCOME: AKI within the first 48 h post-operatively. RESULTS: There were no significant differences between the two treatment groups with regard to baseline characteristics, model for end-stage liver disease and acute physiology and chronic health evaluation (APACHE) II scores, and pre-transplantation renal function. Intra-operative factors were similar for duration of surgery, blood product requirements, crystalloid and colloid volumes infused and requirements for vasoactive therapy. Eleven patients (37%) in the bicarbonate group and 10 patients (33%) in the sodium chloride group developed a post-operative AKI (p = 0.79). Bicarbonate infusion attenuated the degree of immediate post-operative metabolic acidosis; however, this effect dissipated by 48 h. There were no significant differences in ventilation hours, ICU or hospital length of stay, or mortality. CONCLUSIONS: The intra-operative infusion of sodium bicarbonate did not decrease the incidence of AKI in patients following orthotopic liver transplantation.
The haemodynamic effects of intravenous paracetamol (acetaminophen) in healthy volunteers: a double-blind, randomized, triple crossover trial
AIM: The haemodynamic effects of intravenous paracetamol have not been systematically investigated. We compared the physiological effects of intravenous mannitol-containing paracetamol, and an equivalent dosage of mannitol, and normal saline 0.9% in healthy volunteers. METHODS: We performed a blinded, triple crossover, randomized trial of 24 adult healthy volunteers. Participants received i.v. paracetamol (1 g paracetamol +3.91 g mannitol 100 ml(-1) ), i.v. mannitol (3.91 g mannitol 100 ml(-1) ) and i.v. normal saline (100 ml). Composite primary end points were changes in mean arterial pressure (MAP), systolic blood pressure (SBP) and diastolic blood pressure (DBP) measured pre-infusion, during a 15 min infusion period and over a 45 min observation period. Systemic vascular resistance index (SVRI) and cardiac index were measured at the same time points. RESULTS: Infusion of paracetamol induced a transient yet significant decrease in blood pressures from pre-infusion values (MAP -1.85 mmHg, 95% CI -2.6, -1.1, SBP -0.54 mmHg, 95% CI -1.7, 0.6 and DBP -1.92 mmHg, 95% CI -2.6, -1.2, P < 0.0001), associated with a transient reduction in SVRI and an increase in cardiac index. Changes were observed, but to a lesser extent with normal saline (MAP -0.15 mmHg, SBP +1.44 mmHg, DBP --0.73 mmHg, P < 0.0001), but not with mannitol (MAP +1.47 mmHg, SBP +4.03 mmHg, DBP +0.48 mmHg, P < 0.0001). CONCLUSIONS: I.v. paracetamol caused a transient decrease in blood pressure immediately after infusion. These effects were not seen with mannitol or normal saline. The physiological mechanism was consistent with vasodilatation. This study provides plausible physiological data in a healthy volunteer setting, supporting transient changes in haemodynamic variables with i.v. paracetamol and justifies controlled studies in the peri-operative and critical care setting.
Predictors of Manuscript Rejection sYndrome (MiSeRY): a cohort study
OBJECTIVES: To assess whether specific factors predict the development of ManuScript Rejection sYndrome (MiSeRY) in academic physicians. DESIGN: Prospective pilot study; participants self-administered a questionnaire about full manuscript submissions (as first or senior author) rejected at least once during the past 5 years. SETTING: Single centre (tertiary institution). PARTICIPANTS: Eight academic physician-authors. MAIN OUTCOME MEASURES: Duration of grief. MiSeRY was pre-specified as prolonged grief (grief duration longer than the population median). RESULTS: Eight participants provided data on 32 manuscripts with a total of 93 rejections (median, two rejections per manuscript; interquartile range [IQR], 1-3 rejections per manuscript). Median age at rejection was 37 years (IQR, 33-45 years); 86% of 80 rejections involved male authors (86%), 56 of the authors providing data about these rejections were first authors (60%). The median journal impact factor was 5.9 (IQR, 5.2-17). In 48 cases of rejection (52%), pre-submission expectations of success had been high, and in 54 cases (58%) the manuscripts had been sent for external review. Median grief duration was 3 hours (IQR, 1-24 h). Multivariate analysis indicated that higher pre-submission expectation (adjusted odds ratio [aOR], 5.0; 95% CI, 1.5-18), first author status (aOR, 9.5; 95% CI, 1.1-77), and external review (aOR, 19.0; 95% CI 2.9-126) were independent predictors of MiSeRY. CONCLUSIONS: To help put authors out of their MiSeRY, journal editors could be more selective in the manuscripts they send for external review. Tempering pre-submission expectations and mastering the Coping and reLaxing Mechanisms (CaLM) of senior colleagues are important considerations for junior researchers.
Intra-operative cell salvage in urological surgery: a systematic review and meta-analysis of comparative studies
OBJECTIVE: To evaluate systematically the safety and efficacy of intra-operative cell salvage (ICS) in urology. METHODS: A search of Medline, Embase and Cochrane Library to August 2017 was performed using methods pre-published on PROSPERO. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. Eligible titles were comparative studies published in English that used ICS in urology. Primary outcomes were allogeneic transfusion rates (ATRs) and tumour recurrence. Secondary outcomes were complications and cost. RESULTS: Fourteen observational studies were identified, with a total of 4 536 patients. ICS was compared with no the blood conservation technique (seven studies), preoperative autologous donation (PAD; five studies) or both (two studies). Cohorts underwent open prostatectomy (11 studies), open cystectomy (two studies) or open partial nephrectomy (one study). Meta-analysis was possible only for ATRs within prostatectomy studies. In this setting, ICS reduced ATR compared with no the blood conservation technique (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.15-0.76) but not PAD (OR 0.76, 95% CI 0.39-1.31). In the non-prostatectomy setting, ATRs amongst patients who underwent ICS were significantly higher or similar in one and two studies, respectively. Tumour recurrence was found to be significantly less common (two studies), similar (eight studies) or not measured (four studies). All six studies reporting complications found no difference in their ICS cohorts. Regarding cost, one study from 1995 found ICS more expensive than PAD, while two more recent studies found ICS to be cheaper than no blood conservation technique. As a result of inter-study heterogeneity, meta-analyses were not possible for recurrence, complications or cost. CONCLUSION: Low-level evidence exists that, compared with other blood conservation techniques, ICS reduces ATR and cost while not affecting complications. It does not appear to increase tumour recurrence post-prostatectomy, although follow-up durations were short. Small study sizes and short follow-ups mean conclusions cannot be drawn with regard to recurrence after nephrectomy or cystectomy. Randomized trials with long-term follow-up evaluating ICS in urology are required.
Design considerations for an eHealth decision support tool in inflammatory bowel disease self-management
BACKGROUND: Electronic health (eHealth) decision support tools have the potential to: facilitate inflammatory bowel disease (IBD) self-management, reduce health care utilisation and alleviate the pressure on overburdened outpatient clinics. The purpose of this study was to explore the perspectives of key stakeholders on the potential use of a decision support tool for IBD patients. METHODS: A qualitative study using focus group methodology was conducted at a tertiary IBD centre in Melbourne, Australia in February 2015. Key stakeholders, including physicians, nurses and patients, were included in the study. Two independent reviewers undertook inductive coding and generated themes. RESULTS: In total, 31 participants were included in the study (including 16 males; 11 physicians; 6 nurses). An eHealth decision support tool was thought to be beneficial to facilitate IBD self-management. Four themes emerged: (i) Framework for the decision support tool - the tool should be an adjunct to current models of care and facilitate shared decision-making and patient engagement; (ii) Target population - stable patients with mild to moderate disease; (iii) Functionalities of the intervention - a web-based platform encompassing patient-reported outcomes, objective markers of disease and clinical algorithms based on international guidelines; and (iv) Design and Implementation - patients should be involved in the design. CONCLUSIONS: eHealth interventions are thought to be an important strategy to facilitate self-management for patients with IBD. A multi-stage iterative approach should be adopted in the design and implementation process of eHealth interventions. Patient perspectives need to be sought prior to and throughout the development of an eHealth decision support tools for IBD.
Radiotherapy-related complications presenting to a urology department: a more common problem than previously thought?
OBJECTIVE: To quantify the burden of the side effects of radiotherapy on a tertiary referral urology department. PATIENTS AND METHODS: A prospective study of all urology admissions to a public urology department at a tertiary hospital in a 6-month period was performed. Patients admitted with complications attributable to radiotherapy were included in the study. Data obtained included patient demographics, radiotherapy details, complication type and management required. RESULTS: A total of 1198 patients were admitted; 921 (77%) were elective and 277 (23%) were emergency admissions. Thirteen out of the 921 (1.4%) elective admissions and 20 out of the 277 (7.2%) emergency admissions were attributable to radiotherapy complications. Radiotherapy complications was the fourth most common reason for emergency admission, ahead of acute urinary retention. These 33 admissions were accounted for by 21 patients. A total of 39 separate complications attributable to radiotherapy were diagnosed, with some patients having multiple complications. The median (interquartile range) time to onset of complications was 4 (1-9) years. The surgical intervention rate was 67%. The commonest procedures were washout with/without clot evacuation or diathermy in theatre (15.8%) and urethral dilatation/bladder neck incision (15.8%). Two urinary diversions and two cystoprostatectomies plus urinary diversion were performed. CONCLUSION: Radiotherapy complications are consequential and account for a substantial proportion of a tertiary urology department's emergency workload. These complications generally occur years after radiotherapy and frequently require surgical intervention.
Effect of QT interval prolongation on cardiac arrest following liver transplantation and derivation of a risk index
Liver transplantation (LT) has a 4-fold higher risk of periprocedural cardiac arrest and ventricular arrhythmias (CA/VAs) compared with other noncardiac surgeries. Prolongation of the corrected QT interval (QTc) is common in patients with liver cirrhosis. Whether it is associated with an increased risk of CA/VAs following LT is unclear. Rates of 30-day CA/VAs post-LT were assessed in consecutive adults undergoing LT between 2010 and 2017. Pretransplant QTc was measured by a cardiologist blinded to clinical outcomes. Among 408 patients included, CA/VAs occurred in 26 patients (6.4%). QTc was significantly longer in CA/VA patients (475 ± 34 vs 450 ± 34 ms, P < .001). Optimal QTc cut-off for prediction of CA/VAs was ≥480 ms. After adjustment, QTc ≥480 ms remained the strongest predictor for the occurrence of CA/VAs (odds ratio [OR] 5.2, 95% confidence interval [CI] 2.2-12.6). A point-based cardiac arrest risk index (CARI) was derived with the bootstrap method for yielding optimism-corrected coefficients (2 points: QTc ≥480, 1 point: Model for End-Stage Liver Disease [MELD] ≥30, 1 point: age ≥65, and 1 point: male). CARI score ≥3 demonstrated moderate discrimination (c-statistic 0.79, optimism-corrected c-statistic 0.77) with appropriate calibration. QTc ≥480 ms was associated with a 5-fold increase in the risk of CA/VAs. The CARI score may identify patients at higher risk of these events. Whether heightened perioperative cardiac surveillance, avoidance of QT prolonging medications, or beta blockers could mitigate the risk of CA/VAs in this population merits further study.
High Frequency, Low Background Rate Extrapleural Programmed Intermittent Bolus Ropivacaine Provides Superior Analgesia Compared with Continuous Infusion for Acute Pain Management Following Thoracic Surgery: A Retrospective Cohort Study.
Background: Thoracic surgery often results in severe postoperative pain. Regional analgesia via surgically placed extrapleural local anaesthetic (LA) and continuous infusion (CI) is an effective technique, however usually requires supplemental opioid to achieve satisfactory patient analgesia. We hypothesized that high frequency, low background rate extrapleural programmed intermittent boluses (PIB) of LA by could achieve superior patient analgesia and reduced oral morphine equivalent daily dosage (OMEDD) requirements for up to 3 days after thoracic surgery vs. CI. Methods: We retrospectively analysed data from 84 adult patients receiving extrapleural analgesia after thoracic surgery in a single tertiary teaching hospital. The primary outcome measure was the effect of PIB vs. CI on maximum daily 11-point numerical rating scale (NRS-11) ratings as determined by multivariate linear regression analysis, corrected for OMEDD use, total daily LA dose, surgery type, age, opioid type, and use of ketamine analgesia. Secondary outcome measures were the effect on OMEDD use, the effect of total 'rescue' LA boluses, and univariate analyses of the above outcomes and variables. Results: PIB on day 0, and a higher proportion of LA given as rescue boluses on day 1 were associated with reduced maximum NRS-11 ratings [standardized/ [unstandardized] beta coefficient -0.34/ [-0.92 NRS-11 if PIB] (P = 0.007); and -0.26/ [-0.029 NRS-11 per mg/kg extrapleural ropivacaine] (P = 0.03)], respectively. Only patient age was associated with reduced OMEDD use [day 0: -0.58/ [-4.4 OMEDDs per year of age] (P ≤ 0.005); day 1: -0.49/ [-3.56 OMEDDs per year of age] (P ≤ 0.005); day 2: -0.32/ [-1.9 OMEDDs per year of age] (P = 0.04)]. OMEDD use on day 2, however, was associated with slightly higher maximum NRS-11 ratings [+0.28/ +0.006 NRS-11 per mg OMEDD (P = 0.036)]. On univariate analysis, PIB patients achieved the largest difference in OMEDD use [-98 mg (95% CI -73 to -123 mg)] and NRS-11 ratings [-1.1 (-0.4 to -1.8)] against CI patients on day 3. Conclusions: Use of high frequency, low background rate PIB extrapleural LA after thoracic surgery appears to have a modest beneficial effect on acute pain, but not OMEDD use, over CI when adjusted for patient, surgical and other analgesic factors after thoracic surgery. Further work is required to elucidate the potential magnitude of effect that extrapleural LA given by PIB over CI can achieve.
Advances in ureteroscopy.
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.
A multilingual evaluation of current health information on the Internet for the treatments of benign prostatic hyperplasia.
(Elsevier BV, 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.
Clinical responses observed with imatinib or sorafenib in melanoma patients expressing mutations in KIT
(NATURE PUBLISHING GROUP, 2010-04-13)
BACKGROUND: Mutations in KIT are more frequent in specific melanoma subtypes, and response to KIT inhibition is likely to depend on the identified mutation. METHODS: A total of 32 patients with metastatic acral or mucosal melanoma were screened for mutations in KIT exons 11, 13 and 17. RESULTS: KIT mutations were found in 38% of mucosal and in 6% of acral melanomas. Three patients were treated with imatinib and one with sorafenib. All four patients responded to treatment, but three have since progressed within the brain. CONCLUSION: The observed clinical responses support further investigation of KIT inhibitors in metastatic melanoma, selected according to KIT mutation status.
Bench-to-bedside review: Inotropic drug therapy after adult cardiac surgery - a systematic literature review
Many adult patients require temporary inotropic support after cardiac surgery. We reviewed the literature systematically to establish, present and classify the evidence regarding choice of inotropic drugs. The available evidence, while limited in quality and scope, supports the following observations; although all beta-agonists can increase cardiac output, the best studied beta-agonist and the one with the most favourable side-effect profile appears to be dobutamine. Dobutamine and phosphodiesterase inhibitors (PDIs) are efficacious inotropic drugs for management of the low cardiac output syndrome. Dobutamine is associated with a greater incidence of tachycardia and tachyarrhythmias, whereas PDIs often require the administration of vasoconstrictors. Other catecholamines have no clear advantages over dobutamine. PDIs increase the likelihood of successful weaning from cardiopulmonary bypass as compared with placebo. There is insufficient evidence that inotropic drugs should be selected for their effects on regional perfusion. PDIs also increase flow through arterial grafts, reduce mean pulmonary artery pressure and improve right heart performance in pulmonary hypertension. Insufficient data exist to allow selection of a specific inotropic agent in preference over another in adult cardiac surgery patients. Multicentre randomized controlled trials focusing on clinical rather than physiological outcomes are needed.
An Investigation of the Basic Physics of Irrigation in Urology and the Role of Automated Pump Irrigation in Cystoscopy
(HINDAWI PUBLISHING CORPORATION, 2012-01-01)
OBJECTIVE: To investigate the effects of height, external pressure, and bladder fullness on the flow rate in continuous, non-continuous cystoscopy and the automated irrigation fluid pumping system (AIFPS). MATERIALS: Each experiment had two 2-litre 0.9% saline bags connected to a continuous, non-continuous cystoscope or AIFPS via irrigation tubing. Other equipment included height-adjustable drip poles, uroflowmetry devices, and model bladders. METHODS: In Experiment 1, saline bags were elevated to measure the increment in flow rate. In Experiment 2, saline bags were placed under external pressures to evaluate the effect on flow rate. In Experiment 3, flow rate changes in response to variable bladder fullness were measured. RESULTS: Elevating saline bags caused an increase in flow rates, however the increment slowed down beyond a height of 80 cm. Increase in external pressure on saline bags elevated flow rates, but inconsistently. A fuller bladder led to a decrease in flow rates. In all experiments, the AIFPS posted consistent flow rates. CONCLUSIONS: Traditional irrigation systems were susceptible to changes in height of irrigation solution, external pressure application, and bladder fullness thus creating inconsistent flow rates. The AIFPS produced consistent flow rates and was not affected by any of the factors investigated in the study.
Acute Flaccid Paralysis: The New, The Old, and The Preventable
(OXFORD UNIV PRESS INC, 2016-12-01)
Acute flaccid paralysis (AFP) has a changing epidemiology with ongoing polio outbreaks and emerging causes such as nonpolio enteroviruses and West Nile virus (WNV). We report a case of AFP from the Horn of Africa that was initially classified as probable polio but subsequently found to be due to WNV.
The impact of fluid intervention on complications and length of hospital stay after pancreaticoduodenectomy (Whipple's procedure)
(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.
PD-L1 and Tumor Infiltrating Lymphocytes as Prognostic Markers in Resected NSCLC
(PUBLIC LIBRARY SCIENCE, 2016-04-22)
INTRODUCTION: Immune checkpoint inhibition has shifted treatment paradigms in non-small cell lung cancer (NSCLC). Conflicting results have been reported regarding the immune infiltrate and programmed death-ligand 1 (PD-L1) as a prognostic marker. We correlated the immune infiltrate and PD-L1 expression with clinicopathologic characteristics in a cohort of resected NSCLC. METHODS: A tissue microarray was constructed using triplicate cores from consecutive resected NSCLC. Immunohistochemistry was performed for CD8, FOXP3 and PD-L1. Strong PD-L1 expression was predefined as greater than 50% tumor cell positivity. Matched nodal samples were assessed for concordance of PD-L1 expression. RESULTS: Of 522 patients, 346 were node-negative (N0), 72 N1 and 109 N2; 265 were adenocarcinomas (AC), 182 squamous cell cancers (SCC) and 75 other. Strong PD-L1 expression was found in 24% cases. In the overall cohort, PD-L1 expression was not associated with survival. In patients with N2 disease, strong PD-L1 expression was associated with significantly improved disease-free (DFS) and overall survival (OS) in multivariate analysis (HR 0.49, 95%CI 0.36-0.94, p = 0.031; HR 0.46, 95%CI 0.26-0.80, p = 0.006). In this resected cohort only 5% harboured EGFR mutations, whereas 19% harboured KRAS and 23% other. KRAS mutated tumors were more likely to highly express PD-L1 compared to EGFR (22% vs 3%). A stromal CD8 infiltrate was associated with significantly improved DFS in SCC (HR 0.70, 95%CI 0.50-0.97, p = 0.034), but not AC, whereas FOXP3 was not prognostic. Matched nodal specimens (N = 53) were highly concordant for PD-L1 expression (89%). CONCLUSION: PD-L1 expression was not prognostic in the overall cohort. PD-L1 expression in primary tumor and matched nodal specimens were highly concordant. The observed survival benefit in N2 disease requires confirmation.
Nurse-Led Intervention to Improve Knowledge of Medications in Survivors of Stroke or Transient Ischemic Attack: A Cluster Randomized Controlled Trial
(FRONTIERS MEDIA SA, 2016-11-18)
INTRODUCTION: Limited evidence exists on effective interventions to improve knowledge of preventive medications in patients with chronic diseases, such as stroke. We investigated the effectiveness of a nurse-led intervention, where a component was to improve knowledge of prevention medications, in patients with stroke or transient ischemic attack (TIA). METHODS: Prospective sub-study of the Shared Team Approach between Nurses and Doctors for Improved Risk Factor Management, a randomized controlled trial of risk factor management. We recruited patients aged ≥18 years and hospitalized for stroke/TIA. The intervention comprised an individualized management program, involving nurse-led education, and management plan with medical specialist oversight. The outcome, participants' knowledge of secondary prevention medications at 12 months, was assessed using questionnaires. A score of ≥5 was considered as good knowledge. Effectiveness of the intervention on knowledge of medications was determined using logistic regression. RESULTS: Between May 2014 and January 2015, 142 consecutive participants from the main trial were included in this sub-study, 64 to usual care and 78 to the intervention (median age 68.9 years, 68% males, and 79% ischemic stroke). In multivariable analyses, we found no significant difference between intervention groups in knowledge of medications. Factors independently associated with good knowledge (score ≥5) at 12 months included higher socioeconomic position (OR 4.79, 95% CI 1.76, 13.07), greater functional ability (OR 1.69, 95% CI 1.17, 2.45), being married/living with a partner (OR 3.12, 95% CI 1.10, 8.87), and using instructions on pill bottle/package as an administration aid (OR 4.82, 95% CI 1.76, 13.22). Being aged ≥65 years was associated with poorer knowledge of medications (OR 0.24, 95% CI 0.08, 0.71), while knowledge was worse among those taking three medications (OR 0.15, 95% CI 0.03, 0.66) or ≥4 medications (OR 0.09, 95% CI 0.02, 0.44), when compared to participants taking fewer (≤2) prevention medications. CONCLUSION: There was no evidence that the nurse-led intervention was effective for improving knowledge of secondary prevention medications in patients with stroke/TIA at 12 months. However, older patients and those taking more medications should be particularly targeted for more intensive education. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN12688000166370).
Assessment of Liver Remnant Using ICG Clearance Intraoperatively during Vascular Exclusion: Early Experience with the ALIIVE Technique.
(Hindawi Limited, 2015)
Background. The most significant risk following major hepatectomy is postoperative liver insufficiency. Current preoperative assessment of the future liver remnant relies upon assumptions which may not be valid in the setting of advanced resection strategies. This paper reports the feasibility of the ALIIVE technique which assesses the liver remnant with ICG clearance intraoperatively during vascular exclusion. Methods. 10 patients undergoing planned major liver resection (hemihepatectomy or greater) were recruited. Routine preoperative assessment included CT and standardized volumetry. ICG clearance was measured noninvasively using a finger spectrophotometer at various time points including following parenchymal transection during inflow and outflow occlusion before vascular division, the ALIIVE step. Results. There were one case of mortality and three cases of posthepatectomy liver failure. The patient who died had the lowest ALIIVE ICG clearance (7.1%/min versus 14.4 ± 4.9). Routine preoperative CT and standardized volumetry did not predict outcome. Discussion/Conclusion. The novel ALIIVE technique is feasible and assesses actual future liver remnant function before the point of no return during major hepatectomy. This technique may be useful as a check step to offer a margin of safety to prevent posthepatectomy liver failure and death. Further confirmatory studies are required to determine a safety cutoff level.
SMARTphone-based, early cardiac REHABilitation in patients with acute coronary syndromes [SMART-REHAB Trial]: a randomized controlled trial protocol
BACKGROUND: There are well-documented treatment gaps in secondary prevention of coronary heart disease and no clear guidelines to assist early physical activity after acute coronary syndromes (ACS). Smartphone technology may provide an innovative platform to close these gaps. This paper describes the study design of a randomized controlled trial assessing whether a smartphone-based secondary prevention program can facilitate early physical activity and improve cardiovascular health in patients with ACS. METHODS: We have developed a multi-faceted, patient-centred smartphone-based secondary prevention program emphasizing early physical activity with a graduated walking program initiated on discharge from ACS admission. The program incorporates; physical activity tracking through the smartphone's accelerometer with interactive feedback and goal setting; a dynamic dashboard to review and optimize cardiovascular risk factors; educational messages delivered twice weekly; a photographic food diary; pharmacotherapy review; and support through a short message service. The primary endpoint of the trial is change in exercise capacity, as measured by the change in six-minute walk test distance at 8-weeks when compared to baseline. Secondary endpoints include improvements in cardiovascular risk factor status, psychological well-being and quality of life, medication adherence, uptake of cardiac rehabilitation and re-hospitalizations. DISCUSSION: This randomized controlled trial will use a smartphone-phone based secondary prevention program to emphasize early physical activity post-ACS. It will provide evidence regarding the feasibility and utility of this innovative platform in closing the treatment gaps in secondary prevention. TRIAL REGISTRATION: The trial was retrospectively registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) on April 4, 2016. The registration number is ACTRN12616000426482 .
An unusual presentation of carcinomatous meningitis
(OXFORD UNIV PRESS, 2016-08-01)
A 67-year old previously well male presented with a 1 week history of confusion on a background of 3 weeks of headache. Past history included two superficial melanomas excised 5 years ago. Treatment for meningoencephalitis was commenced based on lumbar puncture (LP) and non-contrast brain magnetic resonance imaging (MRI) results. Lack of a clinical response to antibiotics resulted in a second LP and contrast brain MRI which demonstrated hydrocephalus and leptomeningeal disease. Ongoing deterioration led to a whole-body computed tomographic and spinal MRI that showed widespread metastatic disease and extensive leptomeningeal involvement of the spinal cord. The diagnosis of metastatic melanoma with carcinomatous meningitis was made based on cytological analysis of cerebrospinal fluid. He died 2 weeks later in a palliative care facility. This case illustrates that the diagnosis of carcinomatous meningitis can be difficult to make as the heterogeneous nature of its presentation often delays the diagnosis.
Obesity-Related Chronic Kidney Disease-The Role of Lipid Metabolism
Obesity is an independent risk factor for chronic kidney disease (CKD). The mechanisms linking obesity and CKD include systemic changes such as high blood pressure and hyperglycemia, and intrarenal effects relating to lipid accumulation. Normal lipid metabolism is integral to renal physiology and disturbances of renal lipid and energy metabolism are increasingly being linked with kidney disease. AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) are important regulators of fatty acid oxidation, which is frequently abnormal in the kidney with CKD. A high fat diet reduces renal AMPK activity, thereby contributing to reduced fatty acid oxidation and energy imbalance, and treatments to activate AMPK are beneficial in animal models of obesity-related CKD. Studies have found that the specific cell types affected by excessive lipid accumulation are proximal tubular cells, podocytes, and mesangial cells. Targeting disturbances of renal energy metabolism is a promising approach to addressing the current epidemic of obesity-related kidney disease.
A Pathway Proteomic Profile of Ischemic Stroke Survivors Reveals Innate Immune Dysfunction in Association with Mild Symptoms of Depression - A Pilot Study
(FRONTIERS MEDIA SA, 2016-06-14)
Depression after stroke is a common occurrence, raising questions as to whether depression could be a long-term biological and immunological sequela of stroke. Early explanations for post-stroke depression (PSD) focused on the neuropsychological/psychosocial effects of stroke on mobility and quality of life. However, recent investigations have revealed imbalances of inflammatory cytokine levels in association with PSD, though to date, there is only one published proteomic pathway analysis testing this hypothesis. Thus, we examined the serum proteome of stroke patients (n = 44, mean age = 63.62 years) and correlated these with the Montgomery-Åsberg Depression Rating Scale (MADRS) scores at 3 months post-stroke. Overall, the patients presented with mild depression symptoms on the MADRS, M = 6.40 (SD = 7.42). A discovery approach utilizing label-free relative quantification was employed utilizing an LC-ESI-MS/MS coupled to a LTQ-Orbitrap Elite (Thermo-Scientific). Identified peptides were analyzed using the gene set enrichment approach on several different genomic databases that all indicated significant downregulation of the complement and coagulation systems with increasing MADRS scores. Complement and coagulation systems are traditionally thought to play a key role in the innate immune system and are established precursors to the adaptive immune system through pro-inflammatory cytokine signaling. Both systems are known to be globally affected after ischemic or hemorrhagic stroke. Thus, our results suggest that lowered complement expression in the periphery in conjunction with depressive symptoms post-stroke may be a biomarker for incomplete recovery of brain metabolic needs, homeostasis, and inflammation following ischemic stroke damage. Further proteomic investigations are now required to construct the temporal profile, leading from acute lesion damage to manifestation of depressive symptoms. Overall, the findings provide support for the involvement of inflammatory and immune mechanisms in PSD symptoms and further demonstrate the value and feasibility of the proteomic approach in stroke research.
Perioperative blood management programme reduces the use of allogenic blood transfusion in patients undergoing total hip and knee arthroplasty
BACKGROUND: Optimisation of blood management in total hip (THA) and knee arthroplasty (TKA) is associated with improved patient outcomes. This study aimed to establish the effectiveness of a perioperative blood management programme in improving postoperative haemoglobin (Hb) and reducing the rate of allogenic blood transfusion. METHODS: This retrospective before and after study involves 200 consecutive patients undergoing elective TKA and THA before (Usual Care group) and after (Intervention group) the introduction of a blood management programme in an Australian teaching hospital. Patients in the Intervention group underwent preoperative treatment for anaemia and received intraoperative tranexamic acid (15 mg/kg). The primary outcomes were to compare postoperative Hb levels and the rate of blood transfusion. Secondary outcomes included measurements of total amount of allogenic blood transfused, transfusion-related complications, postoperative complications, need for inpatient rehabilitation and duration of hospital stay. RESULTS: There were no differences between baseline characteristics between groups. The mean (SD) preoperative Hb was higher in the Intervention group compared to that in the Usual Care group: 138.7 (13.9) vs. 133.4 (13.9) g/L, p = 0.008, respectively. The postoperative day 1 Hb, lowest postoperative Hb and discharge Hb were all higher in the Intervention group (p < 0.001). Blood transfusion requirements were lower in the Intervention group compared to the Usual Care group (6 vs. 20 %, p = 0.003). There were no differences in any of the secondary outcomes measured. Patients who were anaemic preoperatively and who underwent Hb optimisation had higher Hb levels postoperatively (odds ratio 5.7; 95 % CI 1.3 to 26.5; p = 0.024). CONCLUSIONS: The introduction of a perioperative blood optimisation programme improved postoperative Hb levels and reduced the rate of allogenic blood transfusion.
The effects on coagulation of the reinfusion of unprocessed residual blood from the cardiopulmonary bypass.
(Springer Science and Business Media LLC, 2016-02-03)
BACKGROUND: Autologous blood transfusion is a common technique in cardiac surgery to directly re-infuse residual blood from the cardiopulmonary bypass (CPB) circuit to the patient. The objective of this study was to evaluate the effects of reinfusion of unprocessed residual pump blood on the coagulation system after separation from the CPB circuit and reversal of systemic heparin with protamine. MEASUREMENTS AND MAIN RESULTS: After ethics approval, 40 participants undergoing cardiac surgery were recruited in a prospective single center cohort study. Changes in coagulation were assessed with standard plasma based laboratory assays and thromboelastography. After the reinfusion of unprocessed residual pump blood there were decreases in the mean aPTT (effect size 6 s; SD: 6.05; p < 0.0001) and thrombin time (effect size 4.08 s; SD: 9.7; p = 0.01). There were no significant changes in PT, INR and D-dimer. Post reinfusion there were increases in fibrinogen, hemoglobin and platelet counts. There were improvements in the R-time (effect size 9.1 s; SD: 16.9; p = 0.0023), K-time (effect size 1.5 s; SD: 3.6 s; p = 0.0017), alpha angle (6.9°; SD: 15.8; p = 0.012), and maximum amplitude (3.0 mm; SD: 5.6, p = 0.002) on thromboelastography. CONCLUSION: The reinfusion of unprocessed residual CPB blood resulted in no deleterious effects on the coagulation system measured by both the common laboratory plasma based measurements of coagulation and thromboelastography.
Evolution of ischemic damage and behavioural deficit over 6 months after MCAo in the rat: Selecting the optimal outcomes and statistical power for multi-centre preclinical trials
(PUBLIC LIBRARY SCIENCE, 2017-02-09)
Key disparities between the timing and methods of assessment in animal stroke studies and clinical trial may be part of the reason for the failure to translate promising findings. This study investigates the development of ischemic damage after thread occlusion MCAo in the rat, using histological and behavioural outcomes. Using the adhesive removal test we investigate the longevity of behavioural deficit after ischemic stroke in rats, and examine the practicality of using such measures as the primary outcome for future studies. Ischemic stroke was induced in 132 Spontaneously Hypertensive Rats which were assessed for behavioural and histological deficits at 1, 3, 7, 14, 21, 28 days, 12 and 24 weeks (n>11 per timepoint). The basic behavioural score confirmed induction of stroke, with deficits specific to stroke animals. Within 7 days, these deficits resolved in 50% of animals. The adhesive removal test revealed contralateral neglect for up to 6 months following stroke. Sample size calculations to facilitate the use of this test as the primary experimental outcome resulted in cohort sizes much larger than are the norm for experimental studies. Histological damage progressed from a necrotic infarct to a hypercellular area that cleared to leave a fluid filled cavity. Whilst absolute volume of damage changed over time, when corrected for changes in hemispheric volume, an equivalent area of damage was lost at all timepoints. Using behavioural measures at chronic timepoints presents significant challenges to the basic science community in terms of the large number of animals required and the practicalities associated with this. Multicentre preclinical randomised controlled trials as advocated by the MultiPART consortium may be the only practical way to deal with this issue.
Germline BRCA2 mutations drive prostate cancers with distinct evolutionary trajectories
(NATURE PUBLISHING GROUP, 2017-01-09)
Germline mutations in the BRCA2 tumour suppressor are associated with both an increased lifetime risk of developing prostate cancer (PCa) and increased risk of aggressive disease. To understand this aggression, here we profile the genomes and methylomes of localized PCa from 14 carriers of deleterious germline BRCA2 mutations (BRCA2-mutant PCa). We show that BRCA2-mutant PCa harbour increased genomic instability and a mutational profile that more closely resembles metastastic than localized disease. BRCA2-mutant PCa shows genomic and epigenomic dysregulation of the MED12L/MED12 axis, which is frequently dysregulated in metastatic castration-resistant prostate cancer (mCRPC). This dysregulation is enriched in BRCA2-mutant PCa harbouring intraductal carcinoma (IDC). Microdissection and sequencing of IDC and juxtaposed adjacent non-IDC invasive carcinoma in 10 patients demonstrates a common ancestor to both histopathologies. Overall we show that localized castration-sensitive BRCA2-mutant tumours are uniquely aggressive, due to de novo aberration in genes usually associated with metastatic disease, justifying aggressive initial treatment.
Efficacy of Smartphone-Based Secondary Preventive Strategies in Coronary Artery Disease.
(SAGE Publications, 2020)
Background: Cardiac rehabilitation programs provide a comprehensive framework for the institution of secondary preventive measures. Smartphone technology can provide a platform for the delivery of such programs and is a promising alternative to hospital-based services. However, there is limited evidence to date supporting this approach. Accordingly, we performed a systematic review and meta-analysis examining smartphone-based secondary prevention programs to traditional cardiac rehabilitation in patients with established coronary artery disease to ascertain the feasibility and effectiveness of these interventions. Methods: A systematic search of PubMed, MEDLINE, EMBASE, and the Cochrane Library was conducted. A meta-analysis was performed using a random-effects model with the outcomes of interest being 6-minute walk test (6MWT) distance, systolic blood pressure, low-density lipoprotein (LDL) cholesterol, and body mass index (BMI). Results: A total of 8 studies with 1120 patients across 5 countries were included in the quantitative analysis. Follow-up ranged from 6 weeks to 12 months. Five studies examined all patients post acute coronary syndrome, 2 studies examined only patients undergoing percutaneous coronary intervention, and 1 study examined all patients with a diagnosis of coronary artery disease, independent of intervention. Exercise capacity, as measured by the 6MWT, was significantly greater in the smartphone group (20.10 meters, 95% confidence interval [CI] 7.44-33.97; P < .001; I 2 = 45.58). There was no significant difference in BMI reduction, systolic blood pressure, or LDL cholesterol levels between groups (P value for all > .05). Conclusion: Publicly available smartphone-based cardiac rehabilitation programs are a convenient and easily disseminated intervention which show merit in exercise promotion in patients with established coronary artery disease. Further research is required to establish the clinical significance of recent findings favoring their use.
Salmonella typhimurium: a rare cause of mesh-related infection
(OXFORD UNIV PRESS, 2017-10-01)
The use of mesh in the management of abdominal wall hernias has significantly reduced the incidences of hernia recurrences. The placement of synthetic meshes to reinforce the abdominal wall is not without caveats. Synthetic meshes are associated with a risk of infection. Common causative microorganisms for mesh-related infection range from a diversity of gram positive, gram negative and anaerobic bacteria. However, non-typhoidal Salmonella spp. mesh-related infection remains poorly described in the literature. In this case, we report the management of an immunocompromised patient who developed Salmonella typhimurium mesh-related infection that was complicated by abscess formation.
Zinc ion dyshomeostasis increases resistance of prostate cancer cells to oxidative stress via upregulation of HIF1α.
(Impact Journals, 2018-02-02)
Zinc ions (Zn2+) are known to influence cell survival and proliferation. However the homeostatic regulation of Zn2+ and their role in prostate cancer (PC) progression is poorly understood. Therefore the subcellular distribution and uptake of Zn2+ in PC cells were investigated. Inductively coupled plasma mass spectroscopy and fluorescent microscopy with the Zn2+-specific fluorescent probe FluoZin-3 were used to quantify total and free Zn2+, respectively, in the normal prostate epithelial cell line (PNT1A) and three human PC cell lines (PC3, DU145 and LNCaP). The effects of Zn2+ treatment on proliferation and survival were measured in vitro using MTT assays and in vivo using mouse xenografts. The ability of Zn2+ to protect against oxidative stress via a HIF1α-dependent mechanism was investigated using a HIF1α knock-down PC3 model. Our results demonstrate that the total Zn2+ concentration in normal PNT1A and PC cells is similar, but PC3 cells contain significantly higher free Zn2+ than PNT1A cells (p < 0.01). PNT1A cells can survive better in the presence of high concentrations of Zn2+ than PC3 cells. Exposure to 10 µM Zn2+ over 72 hours significantly reduces PC3 cell proliferation in vitro but not in vivo. Zn2+ increases PC3 cell survival up to 2.3-fold under oxidative stress, and this protective effect is not seen in PNT1A cells or in a HIF1α-KD PC3 cell model. A state of Zn2+ dyshomeostasis exists in PC. HIF1α is an integral component of a Zn2+-dependent protective mechanism present in PC3 cells. This pathway may be clinically significant through its contribution to castrate-resistant PC survival.
Translating genomics into practice for real-time surveillance and response to carbapenemase-producing Enterobacteriaceae: evidence from a complex multi-institutional KPC outbreak
(PEERJ INC, 2018-01-03)
Background: Until recently, Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae were rarely identified in Australia. Following an increase in the number of incident cases across the state of Victoria, we undertook a real-time combined genomic and epidemiological investigation. The scope of this study included identifying risk factors and routes of transmission, and investigating the utility of genomics to enhance traditional field epidemiology for informing management of established widespread outbreaks. Methods: All KPC-producing Enterobacteriaceae isolates referred to the state reference laboratory from 2012 onwards were included. Whole-genome sequencing was performed in parallel with a detailed descriptive epidemiological investigation of each case, using Illumina sequencing on each isolate. This was complemented with PacBio long-read sequencing on selected isolates to establish high-quality reference sequences and interrogate characteristics of KPC-encoding plasmids. Results: Initial investigations indicated that the outbreak was widespread, with 86 KPC-producing Enterobacteriaceae isolates (K. pneumoniae 92%) identified from 35 different locations across metropolitan and rural Victoria between 2012 and 2015. Initial combined analyses of the epidemiological and genomic data resolved the outbreak into distinct nosocomial transmission networks, and identified healthcare facilities at the epicentre of KPC transmission. New cases were assigned to transmission networks in real-time, allowing focussed infection control efforts. PacBio sequencing confirmed a secondary transmission network arising from inter-species plasmid transmission. Insights from Bayesian transmission inference and analyses of within-host diversity informed the development of state-wide public health and infection control guidelines, including interventions such as an intensive approach to screening contacts following new case detection to minimise unrecognised colonisation. Conclusion: A real-time combined epidemiological and genomic investigation proved critical to identifying and defining multiple transmission networks of KPC Enterobacteriaceae, while data from either investigation alone were inconclusive. The investigation was fundamental to informing infection control measures in real-time and the development of state-wide public health guidelines on carbapenemase-producing Enterobacteriaceae surveillance and management.
Prospective Whole-Genome Sequencing Enhances National Surveillance of Listeria monocytogenes
(AMER SOC MICROBIOLOGY, 2016-02-01)
Whole-genome sequencing (WGS) has emerged as a powerful tool for comparing bacterial isolates in outbreak detection and investigation. Here we demonstrate that WGS performed prospectively for national epidemiologic surveillance of Listeria monocytogenes has the capacity to be superior to our current approaches using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), multilocus variable-number tandem-repeat analysis (MLVA), binary typing, and serotyping. Initially 423 L. monocytogenes isolates underwent WGS, and comparisons uncovered a diverse genetic population structure derived from three distinct lineages. MLST, binary typing, and serotyping results inferred in silico from the WGS data were highly concordant (>99%) with laboratory typing performed in parallel. However, WGS was able to identify distinct nested clusters within groups of isolates that were otherwise indistinguishable using our current typing methods. Routine WGS was then used for prospective epidemiologic surveillance on a further 97 L. monocytogenes isolates over a 12-month period, which provided a greater level of discrimination than that of conventional typing for inferring linkage to point source outbreaks. A risk-based alert system based on WGS similarity was used to inform epidemiologists required to act on the data. Our experience shows that WGS can be adopted for prospective L. monocytogenes surveillance and investigated for other pathogens relevant to public health.
Testosterone levels increase in association with recovery from acute fracture in men
(SPRINGER LONDON LTD, 2014-08-01)
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.
Current role of salvage robotic-assisted laparoscopic prostatectomy.
(Springer Science and Business Media LLC, 2013-06)
OBJECTIVES: Salvage Robotic-Assisted Laparoscopic Prostatectomy (sRALP) is a treatment option for biochemical recurrence (BCR) in prostate cancer. It is a new and presently uncommonly performed procedure, which may be technically challenging. We aim to summarise the current literature regarding sRALP with specific reference to patient selection, complications and peri-operative functional and oncological outcomes. METHODS: A comprehensive and critical review of all peer-reviewed publications regarding sRALP. RESULTS: Within the body of literature, we identified six low-volume case-series studies analysing outcomes of sRALP. Overall, peri-operative outcomes were encouraging with low complication rates and estimated blood loss (EBL) equivocal to open and laparoscopic salvage radical prostatectomy (sRP). Long-term follow-up for functional and oncological outcomes was limited. From the limited follow-up data, the current sRALP studies show similar BCR compared to large-volume open sRP series. Potency outcomes were poor post-sRALP. CONCLUSIONS: Salvage Robotic-Assisted Laparoscopic Prostatectomy is a technically feasible operation with a low risk of significant associated complications. Robotic technology can aid the surgeon in salvage prostatectomy. Data on functional and oncological outcomes lack long-term information but initial results are encouraging. Larger series with longer follow-up periods are necessary to draw significant conclusions about the efficacy of sRALP.
Hyperexpression of alpha-hemolysin explains enhanced virulence of sequence type 93 community-associated methicillin-resistant Staphylococcus aureus
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.
Renal Structure in Normoalbuminuric and Albuminuric Patients With Type 2 Diabetes and Impaired Renal Function
(AMER DIABETES ASSOC, 2013-11-01)
OBJECTIVE: The structural basis of normoalbuminuric renal insufficiency in patients with type 2 diabetes remains to be elucidated. We compared renal biopsy findings in patients with type 2 diabetes and estimated glomerular filtration rate (eGFR) and measured GFR of <60 mL/min/1.73 m2, associated with either normo-, micro-, or macroalbuminuria. RESEARCH DESIGN AND METHODS: In patients with normo- (n = 8) or microalbuminuria (n = 6), renal biopsies were performed according to a research protocol. In patients with macroalbuminuria (n = 17), biopsies were performed according to clinical indication. Findings were categorized according to the Fioretto classification: category 1 (C1), normal/near normal; category 2 (C2), typical diabetic nephropathy (DN) with predominantly glomerular changes; and category 3 (C3), atypical with disproportionately severe interstitial/tubular/vascular damage and with no/mild diabetic glomerular changes. RESULTS: In our study population (mean eGFR 35 mL/min/1.73 m2), typical glomerular changes (C2) of DN were observed in 22 of 23 subjects with micro- or macroalbuminuria compared with 3 of 8 subjects with normoalbuminuria (P = 0.002). By contrast, predominantly interstitial or vascular changes (C3) were seen in only 1 of 23 subjects with micro- or macroalbuminuria compared with 3 of 8 normoalbuminuric subjects (P = 0.08). Mesangial area increased progressively from normal controls to patients with type 2 diabetes and normo-, micro-, and macroalbuminuria. Varying degrees of arteriosclerosis, although not necessarily the predominant pattern, were seen in seven of eight subjects with normoalbuminuria. CONCLUSIONS: Typical renal structural changes of DN were observed in patients with type 2 diabetes and elevated albuminuria. By contrast, in normoalbuminuric renal insufficiency, these changes were seen less frequently, likely reflecting greater contributions from aging, hypertension, and arteriosclerosis.
Glucagon-like peptide 1 and peptide YY are in separate storage organelles in enteroendocrine cells
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.
A New Machine Learning Framework for Understanding the Link Between Cannabis Use and First-Episode Psychosis.
Lately, several studies started to investigate the existence of links between cannabis use and psychotic disorders. This work proposes a refined Machine Learning framework for understanding the links between cannabis use and 1st episode psychosis. The novel framework concerns extracting predictive patterns from clinical data using optimised and post-processed models based on Gaussian Processes, Support Vector Machines, and Neural Networks algorithms. The cannabis use attributes' predictive power is investigated, and we demonstrate statistically and with ROC analysis that their presence in the dataset enhances the prediction performance of the models with respect to models built on data without these specific attributes.
A correction for sample overlap in genome-wide association studies in a polygenic pleiotropy-informed framework
BACKGROUND: There is considerable evidence that many complex traits have a partially shared genetic basis, termed pleiotropy. It is therefore useful to consider integrating genome-wide association study (GWAS) data across several traits, usually at the summary statistic level. A major practical challenge arises when these GWAS have overlapping subjects. This is particularly an issue when estimating pleiotropy using methods that condition the significance of one trait on the signficance of a second, such as the covariate-modulated false discovery rate (cmfdr). RESULTS: We propose a method for correcting for sample overlap at the summary statistic level. We quantify the expected amount of spurious correlation between the summary statistics from two GWAS due to sample overlap, and use this estimated correlation in a simple linear correction that adjusts the joint distribution of test statistics from the two GWAS. The correction is appropriate for GWAS with case-control or quantitative outcomes. Our simulations and data example show that without correcting for sample overlap, the cmfdr is not properly controlled, leading to an excessive number of false discoveries and an excessive false discovery proportion. Our correction for sample overlap is effective in that it restores proper control of the false discovery rate, at very little loss in power. CONCLUSIONS: With our proposed correction, it is possible to integrate GWAS summary statistics with overlapping samples in a statistical framework that is dependent on the joint distribution of the two GWAS.
Lactation is associated with greater maternal bone size and bone strength later in life
(SPRINGER LONDON LTD, 2012-07-01)
SUMMARY: The association between lactation and bone size and strength was studied in 145 women 16 to 20 years after their last parturition. Longer cumulative duration of lactation was associated with larger bone size and strength later in life. INTRODUCTION: Pregnancy and lactation have no permanent negative effect on maternal bone mineral density but may positively affect bone structure in the long term. We hypothesized that long lactation promotes periosteal bone apposition and hence increasing maternal bone strength. METHODS: Body composition, bone area, bone mineral content, and areal bone mineral density of whole body and left proximal femur were assessed using DXA, and cross-sectional area and volumetric bone mineral density of the left tibia shaft were measured by pQCT in 145 women (mean age 48 years, range 36-60 years) 16 to 20 years after their last parturition. Hip (HSI) and tibia strength indexes (TBSI) were calculated. Medical history and lifestyle factors including breastfeeding patterns and durations were collected via a self-administered questionnaire. Weight change during each pregnancy was collected from personal maternity tracking records. RESULTS: Sixteen to 20 years after the last parturition, women who had breastfed in total more than 33 months in their life, regardless of the number of children, had greater bone strength estimates of the hip (HSI = 1.92 vs. 1.61) and the tibia (TBSI = 5,507 vs. 4,705) owing to their greater bone size than mothers who had breastfed less than 12 months (p < 0.05 for all). The differences in bone strength estimates were independent of body height and weight, menopause status, use of hormone replacement therapy, and present leisure time physical activity level. CONCLUSION: Breastfeeding is beneficial to maternal bone strength in the long run.
Innovations in cardiac surgery: techniques and applications of 3D printing
(Future Medicine, 2018)
Aim: The 3D printing is a developing technology which has begun to flourish in felds where the ability to visualize complex anatomy in novel ways can aid interventions. This paper reviews the literature on 3D printing in cardiac surgery. Methods: We performed a literature search in three databases using appropriate search terms to capture publications pertaining to 3D printing in cardiac surgery. Results: Our search demonstrated a paucity of literature in this area, with 27 relevant publications identified since 1980. The majority of articles pertained to the utility of 3D printing in presurgical planning, but its application in other areas was largely unexplored. Conclusion: There is enormous potential for growth of 3D printing in cardiac surgery, which can drastically change the way, we practice medicine.
A variant of KCC2 from patients with febrile seizures impairs neuronal Cl- extrusion and dendritic spine formation
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.
From ideas to long-term studies: 3D printing clinical trials review
(SPRINGER HEIDELBERG, 2018-09-01)
PURPOSE: Although high costs are often cited as the main limitation of 3D printing (3DP) in the medical field, current lack of clinical evidence is asserting itself as an impost as the field begins to mature. The aim is to review clinical trials in the field of 3DP, an area of research which has grown dramatically in recent years. METHODS: We surveyed clinical trials registered in 15 primary registries worldwide, including ClinicalTrials.gov. All trials which utilized 3DP in a clinical setting were included in this review. Our search was performed on December 15, 2017. Data regarding the purpose of the study, inclusion criteria, number of patients enrolled, primary outcomes, centers, start and estimated completion dates were extracted. RESULTS: A total of 92 clinical trials with [Formula: see text]252 patients matched the criteria and were included in the study. A total of 42 (45.65%) studies cited China as their location. Only 10 trials were multicenter and 2 were registered as international. The discipline that most commonly utilized 3DP was Orthopedic Surgery, with 25 (27.17%) registered trials. At the time of data extraction, 17 (18.48%) clinical trials were complete. CONCLUSIONS: After several years of case reports, feasibility studies and technical reports in the field, larger-scale studies are beginning to emerge. There are almost no international register entries. Although there are new emerging areas of study in disciplines that may benefit from 3DP, it is likely to remain limited to very specific applications.