The effect of different metallic counterface materials and different surface treatments on the wear and friction of polyamide 66 and its composite in rolling-sliding contact

Original article can be found at: http://www.sciencedirect.com/science/journal/00431648 Copyright Elsevier B. V. DOI: 10.1016/S0043-1648(03)00054-1The effect of different metallic counterface materials and different surface treatments on the tribological behaviour of polymer and polymer composite under unlubricated, non-conformal and rolling-sliding contact has been investigated. The most widely used polymer materials - unreinforced polyamide 66 and its composite (RFL4036) – were tested. The metallic materials include aluminium, brass and steel and the surface treatments include Tufftride** treated (known as nitrocarbonising) and magnesium phosphate treated, etc. Tests were conducted over a range of slip ratios at a fixed load of 300 N, 1000 rpm rotational speed using a twin-disc test rig. The experimental results showed that the polyamide composite exhibited less friction and wear than the unreinforced polyamide 66 when running against steel and aluminium counterfaces. However, when tested against brass, polyamide 66 exhibited lower wear than the composite. The surface treatment of steel has a significant effect on the coefficient of friction and the wear rate, as well as on the tribological mechanism, of polyamide 66 composites. It has been observed that a thin film on the contact surface plays a dominant role in reducing the wear and friction of the composite and in suppressing the transverse cracks. This study clearly indicates that both the characteristics of the different counterface metallic materials and the surface treatment greatly control the wear behaviour of polyamide 66 and its composite.Peer reviewe

Active surveillance for favorable-risk prostate cancer: Is there a greater psychological impact than previously thought? A systematic, mixed studies literature review.

OBJECTIVE: Active surveillance (AS) allows men with favorable-risk prostate cancer to avoid or postpone active treatment and hence spares potential adverse effects for a significant proportion of these patients. Active surveillance may create an additional emotional burden for these patients. The aim of the review was to determine the psychological impact of AS to inform future study in this area and to provide recommendations for clinical practice. METHODS: Studies were identified through database searching from inception to September 2015. Quantitative or qualitative noninterventional studies published in English that assessed the psychological impact of AS were included. The Mixed Methods Appraisal Tool was used to assess methodological quality. RESULTS: Twenty-three papers were included (20 quantitative and 3 qualitative). Quantitatively, the majority of patients do not report psychological difficulties; however, when appropriateness of study design is considered, the conclusion that AS has minimal impact on well-being may not be accurate. This is due to small sample sizes, inappropriately timed baseline, and inappropriate/lack of comparison groups. In addition, a mismatch in outcome was noted between the outcome of quantitative and qualitative studies in uncertainty, with qualitative studies indicating a greater psychological impact. CONCLUSIONS: Because of methodological concerns, many quantitative studies may not provide a true account of the burden of AS. Further mixed-methods studies are necessary to address the limitations highlighted and to provide clarity on the impact of AS. Practitioners should be aware that despite findings of previous reviews, patients may require additional emotional support

Efficacy and Safety of Radium-223 Dichloride in Symptomatic Castration-resistant Prostate Cancer Patients With or Without Baseline Opioid Use From the Phase 3 ALSYMPCA Trial

Background: The phase 3 ALSYMPCA trial enrolled metastatic castration-resistant prostate cancer patients with or without baseline opioid use. Objective: To assess the efficacy and safety of radium-223 dichloride (radium-223) versus placebo in ALSYMPCA patients by baseline opioid use. Design, setting, and participants: Nine hundred and twenty one patients enrolled at 136 centers globally. Intervention: Radium-223 (50 kBq/kg, intravenous injection) every 4 wk for six cycles or matching placebo, each plus best standard of care. Outcome measurements and statistical analysis: Primary endpoint (overall survival [OS]), main secondary efficacy endpoints, and safety were evaluated by baseline opioid use. Additional analyses included time to first opioid use, time to first external beam radiation therapy for bone pain, and safety of concomitant external beam radiation therapy. Results and limitations: At baseline, 408 (44%) patients had no pain and no analgesic use or mild pain with nonopioid therapy (World Health Organization ladder pain score 0–1 [nonopioid subgroup]), and 513 (56%) had moderate pain with occasional opioids or severe pain with regular daily opioids (World Health Organization ladder pain score 2–3 [opioid subgroup]). Radium-223 significantly prolonged OS versus placebo in nonopioid (hazard ratio [HR] = 0.70; 95% confidence interval [CI]: 0.52–0.93; p = 0.013) and opioid (HR = 0.68; 95% CI: 0.54–0.86; p = 0.001) subgroups, and significantly reduced risk of symptomatic skeletal events versus placebo, regardless of baseline opioid use (nonopioid subgroup: HR = 0.56, 95% CI: 0.39– 0.82, p = 0.002; opioid subgroup: HR = 0.72, 95% CI: 0.53–0.98, p = 0.038). Time to first opioid use for bone pain was significantly delayed with radium-223 versus placebo (HR = 0.62, 95% CI: 0.46–0.85, p = 0.002). Adverse event incidences were similar between opioid subgroups. Conclusions: Radium-223 versus placebo significantly prolonged OS and reduced symptomatic skeletal event risk with a favorable safety profile in castration-resistant prostate cancer patients with symptomatic bone metastases, regardless of baseline opioid use. Patient summary: In this ALSYMPCA opioid subgroup analysis, baseline symptom levels did not appear to impact radium-223 dichloride efficacy or safet

Which intravenous bronchodilators are being administered to children presenting with acute severe wheeze in the UK and Ireland?

During a prospective 10-week assessment period, 3238 children aged 1-16 years presented with acute wheeze to Paediatric Emergency Research in the UK and Ireland centres. 110 (3.3%) received intravenous bronchodilators. Intravenous magnesium sulfate (MgSO4) was used in 67 (60.9%), salbutamol in 61 (55.5%) and aminophylline in 52 (47.3%) of cases. In 35 cases (31.8%), two drugs were used together, and in 18 cases (16.4%), all three drugs were administered. When used sequentially the most common order was salbutamol, then MgSO4, then aminophylline. Overall, 30 different intravenous treatment regimens were used varying in drugs, dose, rate and duration

Observed high incidence of prostatic calculi with the potential to act as natural fiducials for prostate image guided radiotherapy

Purpose: This study aims to quantify the incidence and distribution of prostatic calculi in a population of prostate radiotherapy patients and assess their potential role in prostate image guided radiotherapy (IGRT). Methods & materials: A retrospective analysis of trans-rectal ultrasound (TRUS), computed tomography (CT) planning and treatment verification cone beam CT (CBCT) scans from radical prostate radiotherapy patients (external beam and brachytherapy) between 2012 and 2014 was undertaken by a single experienced observer. An internationally validated schema from the Prostate Imaging Reporting and Data system (PIRADS) was used to map the location of calculi. The association of calculi with patient and disease characteristics was explored. Data was analysed using SPSS (IBM version 22.0) using descriptive statistical methods and logistic binary regression analysis. Results: 389 scan sets from 254 patients were included in the analysis. The overall incidence of calculi was 85% (n = 218) of which 79% (n = 201) were intra-prostatic calculi. The mean number of intra-prostatic calculi was 2 (range 1–10) and the mean size of calculi was 3.7 mm (range 0.5–15 mm). Calculi were most frequently observed in the posterior of the mid-gland (PI-RADs 3p, 9p) and posterior of the apex (PI-RADs 5p, 11p). 99% (n = 135) of CT planning scans with a corresponding CBCT had calculi in the same PIRADs location and all calculi were visible at the last fraction. There was no statistically significant association of calculi and N stage, M stage or Gleason score. Conclusions: A significant proportion of prostate radiotherapy patients have prostatic calculi detectable on pre radiotherapy imaging. Calculi observed on CT were also detectable on CBCT in 99% of cases and remain visible at the end of treatment. These findings add to the growing evidence base supporting the potential of calculi as an alternative to fiducial markers to aid prostate IGRT. Keywords: Prostate, Calculi, Incidence, IGR

Remote conditioning or erythropoietin before surgery primes kidneys to clear ischemia-reperfusion-damaged cells: a renoprotective mechanism?

Acute kidney injury is common, serious with no specific treatment. Ischemia-reperfusion is a common cause of acute kidney injury (AKI). Clinical trials suggest that preoperative erythropoietin (EPO) or remote ischemic preconditioning may have a renoprotective effect. Using a porcine model of warm ischemia-reperfusion-induced AKI (40-min bilateral cross-clamping of renal arteries, 48-h reperfusion), we examined the renoprotective efficacy of EPO (1,000 iu/kg iv.) or remote ischemic preconditioning (3 cycles, 5-min inflation/deflation to 200 mmHg of a hindlimb sphygmomanometer cuff). Ischemia-reperfusion induced significant kidney injury at 24 and 48 h (χ(2), 1 degree of freedom, >10 for 6/7 histopathological features). At 2 h, a panel of biomarkers including plasma creatinine, neutrophil gelatinase-associated lipocalin, and IL-1β, and urinary albumin:creatinine could be used to predict histopathological injury. Ischemia-reperfusion increased cell proliferation and apoptosis in the renal cortex but, for pretreated groups, the apoptotic cells were predominantly intratubular rather than interstitial. At 48-h reperfusion, plasma IL-1β and the number of subcapsular cells in G2-M arrest were reduced after preoperative EPO, but not after remote ischemic preconditioning. These data suggest an intrarenal mechanism acting within cortical cells that may underpin a renoprotective function for preoperative EPO and, to a limited extent, remote ischemic preconditioning. Despite equivocal longer-term outcomes in clinical studies investigating EPO as a renoprotective agent in AKI, optimal clinical dosing and administration have not been established. Our data suggest further clinical studies on the potential renoprotective effect of EPO and remote ischemic preconditioning are justified

Synovial sepsis of unknown origin in the adult Thoroughbred racehorse

Background: Synovial sepsis of unknown origin is a rare cause of lameness in the adult horse, and a haematogenous pathogenesis has been proposed in previous cases. Objectives: To describe the features and outcome of synovial sepsis of unknown origin in adult Thoroughbred racehorses. Study design: Retrospective case series. Methods: Hospital records for admissions between 2005 and 2015 were reviewed to identify adult horses diagnosed with synovial sepsis of unknown origin. Presentation, clinicopathological, microbiological and diagnostic imaging findings were recorded. Treatment methods, surgical findings, complications and long-term outcome were evaluated. Results: Eleven cases were identified over the study period. Diagnosis was established from clinical examination and clinicopathologic findings, which were comparable to other aetiologies of synovial sepsis. Affected structures included synovial joints, tendon sheaths and bursae. Concurrent osteochondritis dissecans or articular cartilage lesions were evident during arthroscopic surgery in three cases. Significant intrasynovial haemorrhage was not identified. Microbial culture of synovial fluid or synovial biopsy was positive in 6/11 of cases, with all isolates being Gram-positive cocci. Of the 6 positive microbial cultures, all isolates demonstrated in vitro sensitivity to a cephalosporin antimicrobial agent. A concurrent remote wound was present in a single case. No other potential origins of bacteraemia were identified. Treatment methods included endoscopic surgery, standing multineedle lavage, intravenous regional limb perfusion, intrasynovial medication and/or systemic antimicrobial administration. All horses survived to hospital discharge. For the 6/11 cases that raced following synovial sepsis, the median period for return to racing was 221 days. Main limitations: A small study population, which was retrospectively reviewed. Conclusions: Synovial sepsis of unknown origin is rare in the adult Thoroughbred racehorse and can affect a range of synovial structures. A concurrent potential source of bacteraemia is rarely identified. With appropriate management, the prognosis to return to racing is fair

Remote effects of acute kidney injury in a porcine model

Background: Acute Kidney Injury (AKI) is a common and serious disease with no specific treatment. An episode of AKI may affect organs distant to the kidney, further increasing the morbidity associated with AKI. The mechanism of organ cross-talk after AKI is unclear. The renal and immune systems of pigs and humans are alike. Using a preclinical animal (porcine) model, we test the hypothesis that early effects of AKI on distant organs is by immune cell infiltration leading to inflammatory cytokine production, extravasation and edema. Study Design: In 29 pigs exposed to either sham-surgery or renal ischemia-reperfusion (control, n=12; AKI, n=17) we assessed remote organ (liver, lung, brain) effects in the short-(from 2 to 48h reperfusion) and longer-term (5 weeks later) using immunofluorescence (for leucocyte infiltration, apoptosis), a cytokine array, tissue elemental analysis (electrolytes), blood hematology and chemistry (e.g. liver enzymes) and PCR (for inflammatory markers). Results: AKI elicited significant, short-term (~24h) increments in enzymes indicative of acute liver damage (e.g. AST:ALT ratio; P=0.02) and influenced tissue biochemistry in some remote organs (e.g. lung tissue [Ca++] increased; P=0.04). These effects largely resolved after 48h and no further histopathology, edema, apoptosis or immune cell infiltration was noted in liver, lung or hippocampus in the short- and longer-term. Conclusions: AKI has subtle biochemical effects on remote organs in the short-term including a transient increment in markers of acute liver damage. These effects resolved by 48h and no further remote organ histopathology, apoptosis, edema or immune cell infiltration was noted