The effect of donor graft type on survival after liver transplantation for hepatoblastoma in children.

BACKGROUND: Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatoblastoma (HBL). Although post-transplant outcomes have improved in the contemporary era, the impact of donor graft type on survival remains unclear. METHODS: Using the United Network for Organ Sharing database (02/2002-06/2021), demographics, clinical characteristics, and patient and graft survival were analyzed in children (<18 years) who underwent LT for HBL according to donor graft type. The Kaplan-Meier method, log-rank tests, and Cox regression modeling were used to evaluate the effect of whole, partial, and split deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT) on patient and graft survival. RESULTS: A total of 590 pediatric HBL LT recipients (344 whole graft DDLT; 62 partial graft DDLT; 139 split graft DDLT; 45 LDLT) were included. During 2012-2021 the proportion of LDLTs for HBL decreased to about 5% compared with about 11% during 2002-2011. No significant differences were identified by donor graft type in either patient survival (log-rank test, p = .45) or graft survival (log-rank test, p = .69). The results remained similar during the 2002-2011 era, while during the 2012-2021 era, split graft DDLT was associated with decreased graft loss risk versus whole graft DDLT (hazard ratio: 0.48, 95% confidence interval: 0.23-0.99, p = .046) without any other significant between-group differences. CONCLUSIONS: Utilizing non-whole liver grafts can increase access to LT in children with unresectable HBL while ensuring favorable outcomes. LDLT is underutilized in children with HBL in the United States, and efforts to explore LDLT options should be undertaken.

Access to Left Ventricular Assist Device: Travel Time Does Not Tell The Whole Story.

BACKGROUND: Negative health effects of traveling longer distances for surgical services have been reported. Given the high complexity of multidisciplinary care required for management of Left Ventricular Assist Device (LVAD) implantation, only 4 of 18 centers in our state perform these operations. Given the limited access we hypothesized increased travel time would adversely affect postoperative outcomes and 30-d mortality. METHODS: A statewide Society of Thoracic Surgeons database was queried to identify patients undergoing Heartmate II/III and HVAD implantation, and 725 patients were identified. Travel time was calculated by zip code. Patients were stratified into regional and distant groups by the upper quartile of travel time (1-h). Preoperative variables and outcomes were compared between the groups. Multivariate analysis was performed to evaluate the impact of travel time in risk-adjusted models of 30-d mortality. RESULTS: Median patient travel time to their LVAD center in our state is 32 min (mean 53 ± 65 min, 46 ± 71 miles). Patients in the distant group (n = 191) had lower median incomes, higher self-pay status, higher rates of medical comorbid disease. Despite these differences there was no difference between the groups in ICU and/or hospital length of stay, readmission, postoperative complications, or 30-d mortality. Multivariate regression demonstrated insurance status, age, and prior surgery predicted 30-d mortality, but not travel time. CONCLUSIONS: Despite only four centers in the state performing LVAD implantation, travel time was strongly associated with preoperative risk, and socioeconomic status but not postoperative outcomes or 30-d mortality. Therefore, increasing access should focus on insurance, and patient characteristics not travel time.

Sex-Based Differences Among Experimental Swine Abdominal Aortic aneurysms.

BACKGROUND: Female sex protects against abdominal aortic aneurysms (AAAs); however, the mechanisms behind these sex-based differences remain unknown. The purpose of this study was to explore the role of sex and sex hormones in AAA formation among swine. MATERIALS AND METHODS: Using a previous validated model, infrarenal AAA were surgically created in uncastrated male (n = 8), female (n = 5), and castrated male (n = 4) swine. Aortic dilation was measured on postoperative day 28 during the terminal procedure and compared to initial aortic diameter measured during the index procedure. Tissue was analyzed for immunohistochemistry, cytokine array, gelatin zymography, serum 17ß-estradiol, and testosterone assay. RESULTS: Uncastrated males had significantly larger maximal aortic dilation compared to castrated males (113.5% ± 11.4% versus 38.1% ± 4.5%, P = 0.0012). Females had significantly higher mean aortic dilation compared to castrated males (96.2% ± 7.5% versus 38.1% ± 4.5%, P = 0.0004). Aortic diameters between females and uncastrated males were not significantly different on day 28. Female swine had significantly higher concentrations of 17ß-estradiol compared with uncastrated males (1590 ± 873.3 ng/mL versus 95.2 ± 2.3 ng/mL, P = 0.047), with no significant difference between females and castrated males. Uncastrated male AAA demonstrated significantly more elastin degradation compared with female and castrated males (P = 0.01 and <0 .01, respectively). No differences existed for T-cells or smooth muscle cells between groups. Multiple proinflammatory cytokines were elevated within uncastrated male aortic walls compared to females and castrated males. CONCLUSIONS: Sex hormones, specifically 17ß-estradiol and testosterone, influence experimental swine AAA formation as demonstrated by increased aneurysm size, collagen turnover, and elastolysis in uncastrated males in processes reflective of human disease.

Female Mice Exhibit Abdominal Aortic Aneurysm Protection in an Established Rupture Model.

BACKGROUND: Male gender is a well-established risk factor for abdominal aortic aneurysm (AAA), whereas estrogen is hypothesized to play a protective role. Although rupture rates are higher in women, these reasons remain unknown. In the present study, we sought to determine if female mice are protected from AAA rupture. MATERIALS AND METHODS: Apolipoprotein E-deficient male and female mice (aged 7 wk; n = 25 per group) were infused with angiotensin II (AngII; 2000 ng/kg/min) plus ß-aminopropionitrile (BAPN) in the drinking water for 28 d to test the effects of gender on AAA rupture. Separately, a second group of male apolipoprotein E-deficient mice underwent AngII infusion + BAPN while being fed high-fat phytoestrogen free or a high-fat phytoestrogen diet to assess effects of phytoestrogens on rupture. In a third group, female mice either underwent oophorectomy or sham operation 4 wk before infusion of AngII and BAPN to further test the effects of female hormones on AA rupture. Surviving mice abdominal aorta were collected for histology, cytokine array, and gelatin zymography on postoperative day 28. RESULTS: Female mice had decreased AAA rupture rates (16% versus 46%; P = 0.029). Female mice expressed fewer elastin breaks (P = 0.0079) and decreased smooth muscle cell degradation (P = 0.0057). Multiple cytokines were also decreased in the female group. Gelatin zymography demonstrated significantly decreased pro-matrix metalloproteinase 2 in female mice (P = 0.001). Male mice fed a high dose phytoestrogen diet failed to decrease AAA rupture. Female mice undergoing oophorectomy did not have accelerated aortic rupture. CONCLUSIONS: These data are the first to attempt to tease out hormonal effects on AAA rupture and the possible role of gender in rupture.

Preoperative beta blockade is associated with increased rates of 30-day major adverse cardiac events in critical limb ischemia patients undergoing infrainguinal revascularization.

OBJECTIVE: The association between beta blockers and cardiovascular or limb-related outcomes after revascularization for critical limb ischemia (CLI) remains unclear. The objective of this study was to assess the impact of preoperative beta blockade on 30-day major adverse cardiac events (MACEs) and major adverse limb events (MALEs) in patients undergoing infrainguinal revascularization for CLI. We hypothesized that rates of MALEs and MACEs will be higher in patients not receiving preoperative beta blockade. METHODS: The National Surgical Quality Improvement Program vascular targeted file for 2011 to 2014 identified patients receiving beta blockade and undergoing infrainguinal endovascular intervention and open bypass for CLI. Primary outcomes including 30-day MACE (stroke, myocardial infarction [MI], or death) and MALE (untreated loss of patency, reintervention, or amputation) were compared between patients taking and not taking preoperative beta blockers. Multivariate logistic regression identified independent predictors of MACEs and MALEs. RESULTS: A total of 11,785 revascularizations were performed for CLI during the study period (7408 bypasses vs 4377 endovascular interventions). Preoperative beta blockers were used by 7365 patients, including 4541 (61.7%) in the open bypass cohort and 2824 (64.5%) in the endovascular group (P < .01). MACEs and MI were significantly higher in patients with preoperative beta blockers (MACEs, 5.8% vs 3.4% [P < .0001]; MI, 3.1% vs 1.8% [P < .0001]). After controlling for cardiac risk factors, beta blockers independently predicted MACEs (odds ratio [OR], 1.27; P = .03) and MI (OR, 1.36; P = .03) but not stroke (OR, 1.17; P = .58) or 30-day mortality (OR, 1.22; P = .19). Beta-blocker use did not have an effect on MALEs (OR, 0.99; P = .88). CONCLUSIONS: In patients with CLI, preoperative beta blockade was an independent predictor of 30-day MI and MACEs after controlling for other cardiovascular risk factors. Beta blockers did not have an impact on short-term limb-related outcomes. The association between beta blockade and revascularization for CLI deserves further investigation.

Increased warm ischemia time during vessel harvest decreases the primary patency of cryopreserved conduits in patients undergoing lower extremity bypass.

OBJECTIVE: Autologous vein is the preferred conduit for lower extremity bypass. However, it is often unavailable because of prior harvest or inadequate for bypass owing to insufficient caliber. Cryopreserved cadaveric vessels can be used as conduits for lower extremity revascularization when autogenous vein is not available and the use of prosthetic grafts is not appropriate. Many studies have shown that donor characteristics influence clinical outcomes in solid organ transplantation, but little is known regarding their impact in vascular surgery. The purpose of this study was to examine the effects donor variables have on patients undergoing lower extremity bypass with cryopreserved vessels. METHODS: The tissue processing organization was queried for donor blood type, warm ischemia times (WITs), and serial numbers of cryopreserved vessels implanted at a single center from 2010 to 2016. The serial numbers were then matched with their respective patients using the institutional Clinical Data Repository and patient data were obtained from the Clinical Data Repository and chart review. Primary outcomes were primary patency of the bypass conduits and limb salvage. Time to loss of patency was evaluated using Kaplan-Meier methods and a Cox proportional hazards model determined risk-adjusted predictors of patency and limb salvage. RESULTS: Sixty patients underwent lower extremity bypass with 65 cryopreserved vessels (23 superficial femoral arteries, 41 saphenous veins, 1 femoral vein). Thirty-eight procedures were reoperations. There were 21 inflow, 44 outflow, and 44 infrainguinal procedures. Preexisting comorbidities did not differ significantly between those who lost patency and those who did not. The mean WIT among the entire cohort was 892.3 ± 389.1 minutes (range, 158.0-1434.0 minutes). The median follow-up was 394 days. Kaplan-Meier analysis demonstrated an overall 1-year primary patency rate of 51%. Primary patency at 1 year was 67% and 41% for inflow and outflow procedures, respectively, and did not differ significantly between the two groups (P = .15). Donor-to-recipient ABO incompatibility was not associated with loss of primary patency. The 1-year amputation-free survival was 74%. Primary patency significantly decreased with each hourly increase in WIT on risk-adjusted analysis (hazard ratio, 1.1; P = .02). CONCLUSIONS: Higher cryopreserved vessel WIT was associated with increased risk-adjusted loss of primary patency in this cohort. At 1 year, the overall primary patency was 51% and amputation-free survival was 74%. Vascular surgeons should be aware that WIT may affect outcomes for lower extremity bypass.

A novel swine model of abdominal aortic aneurysm.

OBJECTIVE: Few large-animal models exist for the study of aortic aneurysms. ß-Aminopropionitrile (BAPN) is a compound known to cause aortic aneurysms by inhibiting lysyl oxidase, a collagen cross-linking enzyme. It is hypothesized that BAPN plus aneurysm induction surgery would result in significant aneurysm formation in swine with biologic properties similar to human disease. METHODS: Initial experiments were performed in uncastrated male swine not treated with BAPN (surgery alone). Subsequently, uncastrated male swine were fed BAPN (0.15 g/kg) for 7 days before undergoing surgery; the infrarenal aorta was circumferentially dissected and measured, balloon dilated, and perfused with elastase (500 units) and type I collagenase (8000 units), with extraluminal elastase application. In the BAPN groups, daily BAPN feedings continued until swine harvest at postoperative days 7, 14, and 28. RESULTS: Swine undergoing surgery alone (n = 12) had significantly less dilation at 28 days compared with BAPN + surgery swine (51.9% ± 29.2% [0%-100%] vs 113.5% ± 30.2% [52.9%-146.2%]; P < .0003). Mean aortic dilation in animals undergoing treatment with surgery and BAPN was 86.9% ± 47.4% (range, 55.6%-157.1%), 105.4% ± 58.1% (50%-133.3%), and 113.5% ± 30.2% (52.9%-146.2%) at 7, 14, and 28 days, respectively. In the BAPN + surgery group, significant elastolysis was present at all time points, whereas aortic wall collagen content was not significantly different. Smooth muscle cells were significantly depleted at 14 and 28 days, and M1 macrophages were increased at 14 and 28 days (P < .05, all). Matrix metalloproteinase 2 was elevated at 7 days (P < .05). Multiple proinflammatory cytokines were elevated within the aortic wall of BAPN + surgery swine. CONCLUSIONS: BAPN plus surgery resulted in significantly larger aortic aneurysms than surgery alone and was critical to aneurysm formation in this novel swine model. Hallmarks of human disease, such as elastin fragmentation, smooth muscle cell depletion, macrophage infiltration, matrix metalloproteinase activation, and proinflammatory cytokine expression, were observed in BAPN-treated swine. This model better parallels many of the characteristics of human AAAs and may be suitable for prehuman drug trials.

Too Young to Undergo Temporal Artery Biopsy? Calciphylaxis-Related Anterior Ischemic Optic Neuropathy.

A 39-year-old male patient with end-stage renal failure presented with unexplained isolated unilateral anterior ischemic optic neuropathy, high sedimentation rate, and high CRP. Despite the relatively young age of the patient, an ipsilateral temporal artery biopsy was performed, disclosing calciphylaxis, a highly morbid condition associated with end-stage renal failure, which requires urgent, specific management.

Resolvin D1 decreases abdominal aortic aneurysm formation by inhibiting NETosis in a mouse model.

OBJECTIVE: Resolvins have been shown to attenuate inflammation, whereas NETosis, the process of neutrophils releasing neutrophil extracellular traps (NETs), produces increased inflammation. It is hypothesized that treatment of animals with resolvin D1 (RvD1) would reduce abdominal aortic aneurysm (AAA) formation by inhibiting NETosis. METHODS: Wild-type 8- to 12-week-old C57BL/6 male mice (n = 47) and apolipoprotein E-deficient (ApoE-/-) mice (n = 20) were used in two models to demonstrate the effects of RvD1 on AAA growth. In the topical elastase AAA model, wild-type mice were divided into three groups: a deactivated elastase control group, in which sham surgery was performed using deactivated elastase and mice were intravenously injected with phosphate-buffered saline (PBS) once a day until harvest; an elastase group, in which active elastase was used to induce AAA and mice were injected with PBS daily until harvest; and an RvD1-treated group, in which AAA was induced and mice were injected with RvD1 daily until harvest. In the angiotensin II (Ang II)-induced AAA model, ApoE-/- mice were fed a high-fat diet and implanted with osmotic infusion pumps containing Ang II (1000 ng/kg/min). The Ang II model was divided into two groups: an Ang II control group, in which Ang II was delivered and mice were injected with PBS daily until harvest; and an RvD1-treated group, in which Ang II was delivered and mice were injected with RvD1 daily until harvest. On postoperative day 3, day 14, or day 28, aortic and blood samples were collected for Western blot, histology, cytokine array, enzyme-linked immunosorbent assay, and gelatin zymography after aortic diameter measurement. RESULTS: The day 14 RvD1-treated group demonstrated 42% reduced AAA diameter compared with the elastase group (P < .001). On postoperative day 3, the RvD1-treated group showed decreased levels of NETosis markers citrullinated histone H3 (P = .04) and neutrophil elastase (P = .002) compared with the elastase group. Among important cytokines involved in AAA formation, interleukin (IL) 1ß was downregulated (P = .02) whereas IL-10, a protective cytokine, was upregulated (P = .01) in the RvD1-treated group. Active matrix metalloproteinase 2 also decreased in the RvD1-treated group (P = .03). The RvD1-treated group in the Ang II AAA model, a second model, demonstrated reduced AAA diameter compared with the Ang II control group on day 28 (P < .046). The RvD1-treated group showed decreased levels of citrullinated histone H3 on day 3 (P = .002). Cytokines interferon γ, IL-1ß, C-X-C motif chemokine ligand 10, monocyte chemotactic protein 1, and regulated on activation, normal T cell expressed and secreted (RANTES) were all decreased on day 28 (P < .05). CONCLUSIONS: RvD1-mediated inhibition of NETosis may represent a future medical treatment for the attenuation of AAA growth.

In silico predicted transcriptional regulatory control of steroidogenesis in spawning female fathead minnows (Pimephales promelas).

Oocyte development and maturation (or oogenesis) in spawning female fish is mediated by interrelated transcriptional regulatory and steroidogenesis networks. This study integrates a transcriptional regulatory network (TRN) model of steroidogenic enzyme gene expressions with a flux balance analysis (FBA) model of steroidogenesis. The two models were functionally related. Output from the TRN model (as magnitude gene expression simulated using extreme pathway (ExPa) analysis) was used to re-constrain linear inequality bounds for reactions in the FBA model. This allowed TRN model predictions to impact the steroidogenesis FBA model. These two interrelated models were tested as follows: First, in silico targeted steroidogenic enzyme gene activations in the TRN model showed high co-regulation (67-83%) for genes involved with oocyte growth and development (cyp11a1, cyp17-17,20-lyase, 3ß-HSD and cyp19a1a). Whereas, no or low co-regulation corresponded with genes concertedly involved with oocyte final maturation prior to spawning (cyp17-17α-hydroxylase (0%) and 20ß-HSD (33%)). Analysis (using FBA) of accompanying steroidogenesis fluxes showed high overlap for enzymes involved with oocyte growth and development versus those involved with final maturation and spawning. Second, the TRN model was parameterized with in vivo changes in the presence/absence of transcription factors (TFs) during oogenesis in female fathead minnows (Pimephales promelas). Oogenesis stages studied included: PreVitellogenic-Vitellogenic, Vitellogenic-Mature, Mature-Ovulated and Ovulated-Atretic stages. Predictions of TRN genes active during oogenesis showed overall elevated expressions for most genes during early oocyte development (PreVitellogenic-Vitellogenic, Vitellogenic-Mature) and post-ovulation (Ovulated-Atretic). Whereas ovulation (Mature-Ovulated) showed highest expression for cyp17-17α-hydroxylase only. FBA showed steroid hormone productions to also follow trends concomitant with steroidogenic enzyme gene expressions. General trends predicted by in silico modeling were similar to those observed in vivo. The integrated computational framework presented was capable of mechanistically representing aspects of reproductive function in fish. This approach can be extended to study reproductive effects under exposure to adverse environmental or anthropogenic stressors.

Equal treatment: no evidence of gender inequity in osteoporosis management in a coordinator-based fragility fracture screening program.

We evaluated gender imbalance in osteoporosis management in a provincial coordinator-based fracture prevention program and found no difference by gender in treatment of high-risk fragility fracture patients. This establishes that a systemic approach with interventions for all fragility fracture patients can eliminate the gender inequity that is often observed. INRODUCTION: The purpose of this study was to evaluate an Ontario-based fracture prevention program for its ability to address the well-documented gender imbalance in osteoporosis (OP) management, by incorporating its integrated fracture risk assessments within a needs-based evaluation of equity. METHODS: Fragility fracture patients (≥ 50 years) who were treatment naïve at screening and completed follow-up within 6 months of screening were studied. Patients who underwent bone mineral density (BMD) testing done in the year prior to their current fracture were excluded. All participants had BMD testing conducted through the Ontario OP Strategy Fracture Screening and Prevention program, thus providing us with fracture risk assessment data. Our primary study outcome was treatment initiation at follow-up within 6 months of screening. Gender differences were compared using Fisher's exact test, at p < 0.05. RESULTS: After adjusting for subsequent fracture risk, study participants did not show a statistically significant gender difference in pharmacotherapy initiation at follow-up (p > 0.05). 68.4% of women and 66.2% of men at high risk were treated within 6 months of screening. CONCLUSION: Needs-based analyses show no difference by gender in treatment of high-risk fragility fracture patients. An intensive coordinator-based fracture prevention model adopted in Ontario, Canada was not associated with gender inequity in OP treatment of fragility fracture patients after fracture risk adjustment.

Canine urothelial carcinoma: genomically aberrant and comparatively relevant.

Urothelial carcinoma (UC), also referred to as transitional cell carcinoma (TCC), is the most common bladder malignancy in both human and canine populations. In human UC, numerous studies have demonstrated the prevalence of chromosomal imbalances. Although the histopathology of the disease is similar in both species, studies evaluating the genomic profile of canine UC are lacking, limiting the discovery of key comparative molecular markers associated with driving UC pathogenesis. In the present study, we evaluated 31 primary canine UC biopsies by oligonucleotide array comparative genomic hybridization (oaCGH). Results highlighted the presence of three highly recurrent numerical aberrations: gain of dog chromosome (CFA) 13 and 36 and loss of CFA 19. Regional gains of CFA 13 and 36 were present in 97 % and 84 % of cases, respectively, and losses on CFA 19 were present in 77 % of cases. Fluorescence in situ hybridization (FISH), using targeted bacterial artificial chromosome (BAC) clones and custom Agilent SureFISH probes, was performed to detect and quantify these regions in paraffin-embedded biopsy sections and urine-derived urothelial cells. The data indicate that these three aberrations are potentially diagnostic of UC. Comparison of our canine oaCGH data with that of 285 human cases identified a series of shared copy number aberrations. Using an informatics approach to interrogate the frequency of copy number aberrations across both species, we identified those that had the highest joint probability of association with UC. The most significant joint region contained the gene PABPC1, which should be considered further for its role in UC progression. In addition, cross-species filtering of genome-wide copy number data highlighted several genes as high-profile candidates for further analysis, including CDKN2A, S100A8/9, and LRP1B. We propose that these common aberrations are indicative of an evolutionarily conserved mechanism of pathogenesis and harbor genes key to urothelial neoplasia, warranting investigation for diagnostic, prognostic, and therapeutic applications.

Thymofibrolipoma in a labrador retriever.

While thymomas are uncommon but well-known mediastinal masses, collagen-rich variants are exceedingly rare. Thymofibrolipoma and sclerosing thymoma tumor variants have been recently recognized in medical pathology, and thymofibrolipoma has been only rarely reported in dogs. A cranial thoracic mass was identified in a 6-year-old Labrador Retriever that was characterized by robust collagenous stroma dissected by thin cords of cytokeratin-positive neoplastic epithelial cells and bordered by mildly pleomorphic epithelial cells with occasional lymphocytic aggregates and rare Hassall corpuscles. To the authors' knowledge, this is only the second report of thymofibrolipoma in veterinary medicine and the first to describe a variant with a mitotically active and relatively pleomorphic, adjacent thymic epithelial population.

Subtotal cholecystectomy with omental pedicle plug for the challenging gallbladder: A case report and review of the literature.

If patient anatomy or disease does not allow for a traditional or partial cholecystectomy, an omental pedicle plug may be a viable option to limit the risk of postoperative uncontrolled bile leak from the cystic duct and to control patient symptoms.

Optimising the hygiene of a liquid feeding system to improve the quality of liquid feed for pigs.

Poor feeding system hygiene may contribute to uncontrolled spontaneous fermentation in liquid pig feed and its associated undesirable effects. This study aimed to determine the effects of an intensive sanitisation programme in a grow-finisher liquid feeding system by monitoring microbiological and physico-chemical parameters of liquid feed and microbial colonisation of the feeding system surfaces. The sanitisation programme involved a combination of physical and chemical cleaning between batches of grow-finisher pigs, combined with nightly rinsing of the system with an organic acid blend. Improved hygiene of the internal surfaces of the mixing tank and feed pipeline, particularly until week 5 post-cleaning, was evidenced by reduced counts of lactic acid bacteria, total aerobes, Enterobacteriaceae, yeasts and moulds and decreased adenosine triphosphate concentrations. Enterobacteriaceae and moulds remained undetectable on pipeline surfaces for 10 weeks. Scanning electron microscopy of the feed pipelines confirmed these findings. Conversely, the impact on liquid feed microbiology was minimal and short-lived. However, acetic acid, ethanol and biogenic amine concentrations decreased in the feed post-cleaning and no gross energy losses were observed. Therefore, by controlling surface microbial communities on liquid feeding systems via implementation of the sanitisation programme developed in the current study, on-farm liquid feed quality should be improved.

A disposable sticky electrode for the detection of commercial silver NPs in seawater.

The ability to perform efficient and affordable field detection and quantification of nanoparticles in aquatic environmental systems remains a significant technical challenge. Recently we reported a proof of concept of using 'sticky' electrodes for the detection of silver nanoparticles (Tschulik et al 2013 Nanotechnology 29 295502). Now a disposable electrode for detection and quantification of commercial Ag nanoparticles in natural seawater is presented. A disposable screen printed electrode is modified with cysteine and characterized by sticking and stripping experiments, with silver nanoparticle immobilization on the electrode surface and subsequent oxidative stripping, yielding a quantitative determination of the amount of Ag nanoparticles adhering to the electrode surface. The modified electrode was applied to natural seawater to mimic field-based environmental monitoring of Ag NPs present in seawater. The results demonstrated that commercial Ag NPs in natural seawater can be immobilized, enriched and quantified within short time period using the disposable electrodes without any need for elaborate experiments.

Electrochemical detection of commercial silver nanoparticles: identification, sizing and detection in environmental media.

The electrochemistry of silver nanoparticles contained in a consumer product has been studied. The redox properties of silver particles in a commercially available disinfectant cleaning spray were investigated via cyclic voltammetry before particle-impact voltammetry was used to detect single particles in both a typical aqueous electrolyte and authentic seawater media. We show that particle-impact voltammetry is a promising method for the detection of nanoparticles that have leached into the environment from consumer products, which is an important development for the determination of risks associated with the incorporation of nanotechnology into everyday products.

Using research feedback loops to implement a disability case study with Aboriginal and Torres Strait Islander communities and service providers in regional and remote Australia.

While there is a well-developed body of literature in the health field that describes processes to implement research, there is a dearth of similar literature in the disability field of research involving complex conditions. Moreover, the development of meaningful and sustainable knowledge translation is now a standard component of the research process. Knowledge users, including community members, service providers, and policy makers now call for evidence-led meaningful activities to occur rapidly. In response, this article presents a case study that explores the needs and priorities of Aboriginal and Torres Strait Islander women in Australia who have experienced a traumatic brain injury due to family violence. Drawing on the work of Indigenous disability scholars such as Gilroy, Avery and others, this article describes the practical and conceptual methods used to transform research to respond to the realities of community concerns and priorities, cultural considerations and complex safety factors. This article offers a unique perspective on how to increase research relevance to knowledge users and enhance the quality of data collection while also overcoming prolonged delays of knowledge translation that can result from the research-production process.

Artificial intelligence tool detection of intravenous contrast enhancement using spleen attenuation.

PURPOSE: To assess the ability of an automated AI tool to detect intravenous contrast material (IVCM) in abdominal CT examinations using spleen attenuation. METHODS: A previously validated automated AI tool measuring the attenuation of the spleen was deployed on a sample of 32,994 adult (age ≥ 18) patients (mean age, 61.9 ± 14.7 years; 13,869 men, 19,125 women) undergoing 65,449 supine position CT examinations (41,020 with and 24,429 without IVCM by DICOM header) from January 1, 2000 to December 31, 2021. After exclusions, receiver operating characteristic (ROC) curve analysis was performed to determine the optimal threshold for binary classification of IVCM status (non-contrast vs IVCM enhanced), which was then applied to the sample. Discordant examinations (i.e., IVCM status determined by AI tool did not match DICOM header) were manually reviewed to establish ground truth. Repeat ROC curve and contingency table analysis were performed to assess AI tool performance. RESULTS: ROC analysis of the initial study sample of 61,783 CT examinations yielded AUC of 0.970 with Youden index suggesting an optimal spleen attenuation threshold of 65 Hounsfield units (HU). Manual review of 2094 discordant CT examinations revealed discordance due to DICOM header error in 1278 (61.0%) and AI tool misclassification in 410 (19.6%), with 406 (9.4%) meeting exclusion criteria. Analysis of 61,377 CT examinations in the final study sample yielded AUC of 0.999 with accuracy of 99.3% at the 65 HU threshold. Error rate for DICOM header information was 2.1% (1278/61,377) versus 0.7% (410/61,377) for the AI tool. CONCLUSION: The automated spleen attenuation AI tool was highly accurate for detection of IVCM at a threshold of 65 HU.