Crystalloid Fluid Management of Non-Traumatic Hypotension by New South Wales Ambulance.

INTRODUCTION: Shock is circulatory insufficiency, inadequate oxygen delivery, and cellular hypoxia. Intravenous fluids are essential for shock management. Despite treatment, patients can face persistent shock with ongoing hypotension, contributing to higher mortality. This analysis aims to quantify hypotensive non-traumatic cases in an Australian ambulance service, determine persistent hypotension prevalence, and assess paramedic-administered intravascular fluids' impact on blood pressure changes. METHODS: This study is a retrospective analysis of prehospital fluid resuscitation by New South Wales Ambulance paramedics during 2022. Hypotension is defined as a systolic blood pressure of ≤ 90 mmHg, and persistent hypotension is a systolic blood pressure consistently below 90 mmHg across all observations, with a final blood pressure below 90 mmHg. This study aimed to determine the volume of fluid resuscitation at which a plateau in population-level systolic blood pressure response is observed, by calculating the derivative of the fitted logistic regression model. Moreover, this analysis identified the relative contribution of factors influencing the probability of an attempt at intravenous or intraosseous access using machine learning. RESULTS: Among 796,865 attendances, 23,049 (2.9%) involved non-traumatic patients with hypotension. In total 7,388 (32.1%) of the hypotensive cases resulted in persistent hypotension, of which 3,235 (43.8%) received Hartmann's solution and 1,745 (53.9%) received at least 500 ml of fluids but still had hypotension. The model showed that systolic blood pressure tends to stop increasing after 500-600 milliliters of fluid are given. This suggests that, on average, giving more fluid than this may not raise blood pressure further in a prehospital setting, though individual patient needs can differ. The top four factors from the machine learning shows that as initial respiratory rate goes up, the probability of intravascular access rises. Transport times less than 20 min are associated with a smaller chance of access and younger patients are less likely to receive an attempt. Finally, extremes of systolic blood pressure are more likely to receive access attempts. CONCLUSION: This study found that three percent of non-traumatic attendances have at least one episode of hypotension, and that more than half of these have persistent hypotension. Only 44% of persistently hypotensive received fluids, and half of persistently hypotensive patients stayed hypotensive despite a reasonable volume of prehospital crystalloids.

Alternatives to Fish Acute Whole Effluent Toxicity (WET) Testing: Predictability of RTgill-W1 Cells and Fathead Minnow Embryos with Actual Wastewater Samples.

Toxicity assays using fish cells and embryos continue to gain momentum as a more ethical and informative alternative to fish acute toxicity testing. The goal of our study was to test the accuracy of RTgill-W1 cells and the fathead minnow (Pimephales promelas) embryos to predict actual whole effluent toxicity (WET) in the fathead minnow larvae. The three models were compared concurrently using samples of various origins and treatment types. Additionally, the toxicity of reference toxicants (Cd, Cu, NH3-N, 3,4-dichloraniline, and benzalkonium chloride) spiked into a nontoxic wastewater was compared. The toxicity of reference toxicants was tested in isosmotic and hypoosmotic exposure media in RTgill-W1 cells. Of the 28 wastewater samples, 14 induced a toxic response in fish larvae. Embryos predicted 11 of the 14 wastewater samples toxic to the larvae, whereas RTgill-W1 cells predicted the toxicity of all 14 toxic samples to the larvae. In addition, embryos and RTgill-W1 cells predicted toxicity in two and six additional samples, respectively, that were nontoxic to larvae. Exposures in hypoosmotic medium significantly increased sensitivity of RTgill-W1 cells to all reference toxicants, excluding benzalkonium chloride, compared to exposures in isosmotic medium and showed toxicity levels similar to that in larvae. Thus, hypoosmotic exposure medium should be considered for aquatic toxicity testing applications. Overall, both gill cell and embryo models predicted toxicity in the majority of wastewater samples toxic to larvae and demonstrated their applicability for regulatory WET testing.

Falls on an inpatient rehabilitation spinal injuries unit: the characteristics, circumstances, and consequences.

STUDY DESIGN: Retrospective audit OBJECTIVES: To describe the nature of falls and fallers in a spinal injuries unit (SIU) and identify factors associated with having more than one fall (recurrent fallers) and falls with physical or psychological consequences (consequential falls). SETTING: An Australian inpatient rehabilitation SIU. METHODS: Data were retrospectively extracted from falls incident reports and electronic medical records over a 5-year period. Data were analysed descriptively to summarise participant and fall details. Univariate analyses identified candidate variables for further investigation in a multivariate model for recurrent fallers and consequential falls. RESULTS: Of the 566 persons admitted to the SIU, 132 (23%) participants experienced 207 falls over the 5 years. Of the fallers, 41 (31%) were recurrent fallers experiencing between 2 and 7 falls and 78 (59%) experienced a consequential fall. No significant variables were identified for recurrent fallers. For consequential falls, older age (OR = 1.038, 95% CI, 1.012 to 1.064, p = 0.004) and female gender (OR = 3.581, 95% CI, 1.269 to 10.103, p = 0.016) were significant, as well as falls that occurred on a Sunday (OR = 0.196, 95% CI, 0.061 to 0.630, p = 0.006). Falls while transferring were less likely to be consequential (OR = 4.100, 95% CI, 1.706 to 9.856, p = 0.002). CONCLUSIONS: Nearly one quarter of SIU inpatients experienced a fall with almost a third of those who fell experiencing recurrent falls. Older age, female gender, and Sundays were risk factors for falls with consequence.

A review of the characterizations of soft tissues used in human body modeling: Scope, limitations, and the path forward.

Soft tissue material properties are vital to human body models that evaluate interactions between the human body and its environment. Such models evaluate internal stress/strain responses in soft tissues to investigate issues like pressure injuries. Numerous constitutive models and parameters have been used to represent mechanical behavior of soft tissues in biomechanical models under quasi-static loading. However, researchers reported that generic material properties cannot accurately represent specific target populations due to large inter-individual variability. Two challenges that exist are experimental mechanical characterization and constitutive modeling of biological soft tissues and personalization of constitutive parameters using non-invasive, non-destructive bedside testing methods. It is imperative to understand the scope and appropriate applications for reported material properties. Thus, the goal of this paper was to compile studies from which soft tissue material properties were obtained and categorize them by source of tissue samples, methods used to quantify deformation, and material models used to describe tissues. The collected studies displayed wide ranges of material properties, and factors that affected the properties included whether tissue samples were in vivo or ex vivo, from humans or animals, the body region tested, body position during in vivo studies, deformation measurements, and material models used to describe tissues. Because of the factors that affected reported material properties, it is clear that much progress has been made in understanding soft tissue responses to loading, yet there is a need to broaden the scope of reported soft tissue material properties and better match reported properties to appropriate human body models.

Shifting loads as a result of chair articulations and associated perfusion responses in the context of pressure injuries: An investigation with able-bodied individuals.

Wheelchair users with spinal cord injuries experience pressure injuries at high rates, causing a decrease in quality of life and an increased financial burden. The soft tissue in the buttocks (beneath the ischial tuberosities) and lower back (behind the sacrum) experience large interface pressures over long periods while seated, putting them at high risk of pressure injury development. The goals of this research were to evaluate the ability of an articulating chair design to redistribute pressures on the body and to affect blood perfusion in the buttocks tissue over the ischial tuberosities. Using a unique, custom-designed chair developed for this research, pressure and blood perfusion were obtained for numerous seated positions that included recline, seat pan tilt, and back articulations. Reclining the chair back increased maximum pressures in the buttocks and lower back regions, while it decreased maximum pressures in the upper back and thigh regions. Increasing seat pan tilt, or rotating the anterior edge of the seat pan above the posterior edge, decreased maximum pressures in the buttocks and lower back regions and increased perfusion in the buttocks. Results suggested that using back recline and seat pan tilt together to create a whole-body tilt increased pressures in the back and decreased pressures in the buttocks. Changes in back articulation redistributed pressure in all back regions. Thus, the articulating chair design redistributed pressures in all areas of the body and promoted blood perfusion in the buttocks while seated. Pressure redistribution and perfusion promotion are fundamental to reducing pressure injury risk.

Key Components Related to Pressure Injury Formation: An Initial Investigation Into Pressure Distribution and Blood Perfusion Responses in Wheelchair Users.

Soft tissue around bony prominences in the buttocks and back are high-risk areas prone to the development of pressure injuries. From a clinical perspective, prevention of pressure injuries all together is the ideal situation. Unfortunately, prevalence rates still reach 47% with recurrence rates even higher. The goals of this study were to evaluate the effects of a series of wheelchair movements, some that currently exist in commercial wheelchairs and some new, on interface pressures and perfusion under the buttocks. Twenty-seven chair positions were obtained by varying back recline, seat pan tilt, and articulation of two supports along the back. Although back recline is commonly taught by therapists to be used as a pressure relieving posture, results indicated an increase in pressures under the ischial tuberosities and sacral areas in reclined positions. Articulation of the back supports produced changes in posture moving from an "erect" to "slouched" position. These movements successfully shifted pressures across back regions. Seat pan tilt was effective in shifting pressures off the ischial tuberosity regions. Additionally, in a portion of the participants, seat pan tilt consistently increased perfusion under the ischial tuberosity region. The findings of this research suggest that movements other than back recline should be considered to more effectively alter interface pressures, particularly in high-risk regions like the sacrum and ischial tuberosities.

Involvement of a gut-retina axis in protection against dietary glycemia-induced age-related macular degeneration.

Age-related macular degeneration (AMD) is the major cause of blindness in developed nations. AMD is characterized by retinal pigmented epithelial (RPE) cell dysfunction and loss of photoreceptor cells. Epidemiologic studies indicate important contributions of dietary patterns to the risk for AMD, but the mechanisms relating diet to disease remain unclear. Here we investigate the effect on AMD of isocaloric diets that differ only in the type of dietary carbohydrate in a wild-type aged-mouse model. The consumption of a high-glycemia (HG) diet resulted in many AMD features (AMDf), including RPE hypopigmentation and atrophy, lipofuscin accumulation, and photoreceptor degeneration, whereas consumption of the lower-glycemia (LG) diet did not. Critically, switching from the HG to the LG diet late in life arrested or reversed AMDf. LG diets limited the accumulation of advanced glycation end products, long-chain polyunsaturated lipids, and their peroxidation end-products and increased C3-carnitine in retina, plasma, or urine. Untargeted metabolomics revealed microbial cometabolites, particularly serotonin, as protective against AMDf. Gut microbiota were responsive to diet, and we identified microbiota in the Clostridiales order as being associated with AMDf and the HG diet, whereas protection from AMDf was associated with the Bacteroidales order and the LG diet. Network analysis revealed a nexus of metabolites and microbiota that appear to act within a gut-retina axis to protect against diet- and age-induced AMDf. The findings indicate a functional interaction between dietary carbohydrates, the metabolome, including microbial cometabolites, and AMDf. Our studies suggest a simple dietary intervention that may be useful in patients to arrest AMD.

Metabolic Predictors of Incident Coronary Heart Disease in Women.

BACKGROUND: Although metabolomic profiling offers promise for the prediction of coronary heart disease (CHD), and metabolic risk factors are more strongly associated with CHD in women than men, limited data are available for women. METHODS: We applied a liquid chromatography-tandem mass spectrometry metabolomics platform to measure 371 metabolites in a discovery set of postmenopausal women (472 incident CHD cases, 472 controls) with validation in an independent set of postmenopausal women (312 incident CHD cases, 315 controls). RESULTS: Eight metabolites, primarily oxidized lipids, were significantly dysregulated in cases after the adjustment for matching and CHD risk factors in both the discovery and validation data sets. One oxidized phospholipid, C34:2 hydroxy-phosphatidylcholine, remained associated with CHD after further adjustment for other validated metabolites. Subjects with C34:2 hydroxy-phosphatidylcholine levels in the highest quartile had a 4.7-fold increase in CHD odds in comparison with the lowest quartile; C34:2 hydroxy-phosphatidylcholine also significantly improved the area under the curve (P<0.01) for CHD. The C34:2 hydroxy-phosphatidylcholine findings were replicated in a third replication data set of 980 men and women (230 cardiovascular events) with a stronger association observed in women. CONCLUSIONS: These data replicate known metabolite predictors, identify novel markers, and support the relationship between lipid oxidation and subsequent CHD.

Extent of surrounding edema does not correlate with acute complications after radiosurgery for melanoma brain metastases.

AIM: To assess whether extent of surrounding edema correlates with acute adverse clinical outcomes within 3 months after stereotactic radiosurgery (SRS) for melanoma brain metastases (BM). METHODS: Patients with melanoma BM treated with SRS were included in a single center retrospective analysis. A contrast-enhanced magnetic resonance image (MRI) brain was acquired on the day of treatment and used to calculate the volume of the largest lesion (the index BM) and total volume of all BM. Their corresponding volume of surrounding edema was defined based on the fluid attenuated inversion recovery (FLAIR) sequence. After SRS, MRI was performed every 3 months for at least 2 years if the patient remained well enough to do so. Adverse neurologic events after SRS were defined using common terminology criteria for adverse events (CTCAE) version 5.0. Multivariate regression analyses assessed for associations between BM size and edema at baseline with increasing edema and neurologic adverse events within 3 months after SRS. RESULTS: Mean volume of the index BM reduced from 2.2 to 0.5 cm3 at 3 months after SRS (p = 0.03). Mean volume of edema surrounding the index BM was 6.4 cm3 at baseline, 10.2 cm3 at 3 months and 5.5 cm3 at 6 months. There were 7/43 (16%) patients that experienced an adverse neurological event within 3 months (attributable to any cause) and 4/43 (9%) were associated with an increase in BM edema. On univariate and multivariate analyses, there were no correlations between any baseline factors and volume of edema at 3 months. However, SRS dose delivered and systemic therapy use within 4 weeks of SRS both correlated with a reduction in edema surrounding the index BM. CONCLUSION: A transient increase in mean volume of edema was apparent at 3 months after SRS. However, this resolved by 6 months and did not correlate with adverse events or dexamethasone requirement. Thus, the clinical significance is uncertain.

Gut Microbial-Related Choline Metabolite Trimethylamine-N-Oxide Is Associated With Progression of Carotid Artery Atherosclerosis in HIV Infection.

We examined associations of 5 plasma choline metabolites with carotid plaque among 520 HIV-infected and 217 HIV-uninfected participants (112 incident plaque cases) over 7 years. After multivariable adjustment, higher gut microbiota-related metabolite trimethylamine-N-oxide (TMAO) was associated with an increased risk of carotid plaque in HIV-infected participants (risk ratio = 1.25 per standard deviation increment; 95% confidence interval, 1.05-1.50; P = .01). TMAO was positively correlated with biomarkers of monocyte activation and inflammation (sCD14, sCD163). Further adjustment for these biomarkers attenuated the association between TMAO and carotid plaque (P = .08). Among HIV-infected individuals, plasma TMAO was associated with carotid atherosclerosis progression, partially through immune activation and inflammation.

Plasma Tryptophan-Kynurenine Metabolites Are Altered in Human Immunodeficiency Virus Infection and Associated With Progression of Carotid Artery Atherosclerosis.

Background: It is unknown whether disrupted tryptophan catabolism is associated with cardiovascular disease (CVD) in human immunodeficiency virus (HIV)-infected individuals. Methods: Plasma tryptophan and kynurenic acid were measured in 737 women and men (520 HIV+, 217 HIV-) from the Women's Interagency HIV Study and the Multicenter AIDS Cohort Study. Repeated B-mode carotid artery ultrasound imaging was obtained from 2004 through 2013. We examined associations of baseline tryptophan, kynurenic acid, and kynurenic acid-to-tryptophan (KYNA/TRP) ratio, with risk of carotid plaque. Results: After a 7-year follow-up, 112 participants developed carotid plaque. Compared to those without HIV infection, HIV-infected participants had lower tryptophan (P < .001), higher KYNA/TRP (P = .01), and similar kynurenic acid levels (P = .51). Tryptophan, kynurenic acid, and KYNA/TRP were correlated with T-cell activation (CD38+HLA-DR+) and immune activation markers (serum sCD14, galectin-3) but had few correlations with interleukin-6, C-reactive protein, or CVD risk factors (blood pressure, lipids). Adjusted for demographic and behavioral factors, each standard deviation (SD) increment in tryptophan was associated with a 29% (95% confidence interval [CI], 17%-38%) decreased risk of carotid plaque (P < .001), while each SD increment in kynurenic acid (P = .02) and KYNA/TRP (P < .001) was associated with a 34% (6%-69%) and a 47% (26%-73%) increased risk of carotid plaque, respectively. After further adjustment for CVD risk factors and immune activation markers, these associations were attenuated but remained significant. Conclusions: Plasma tryptophan-kynurenine metabolites are altered in HIV infection and associated with progression of carotid artery atherosclerosis.

Trends and predicted trends in presentations of older people to Australian emergency departments: effects of demand growth, population aging and climate change.

Objectives The aim of the present study was to describe trends in and age and gender distributions of presentations of older people to Australian emergency departments (EDs) from July 2006 to June 2011, and to develop ED utilisation projections to 2050. Methods A retrospective analysis of data collected in the National Non-admitted Patient Emergency Department Care Database was undertaken to assess trends in ED presentations. Three standard Australian Bureau of Statistics population growth models, with and without adjustment for current trends in ED presentation growth and effects of climate change, were examined with projections of ED presentations across three age groups (0-64, 65-84 and ≥85 years) to 2050. Results From 2006-07 to 2010-11, ED presentations increased by 12.63%, whereas the Australian population over this time increased by only 7.26%. Rates of presentation per head of population were greatest among those aged ≥85 years. Projections of ED presentations to 2050 revealed that overall ED presentations are forecast to increase markedly, with the rate of increase being most marked for older people. Conclusion Growth in Australian ED presentations from 2006-07 to 2010-11 was greater than that expected from population growth alone. The predicted changes in demand for ED care will only be able to be optimally managed if Australian health policy, ED funding instruments and ED models of care are adjusted to take into account the specific care and resource needs of older people. What is known about the topic? Rapid population aging is anticipated over coming decades. International studies and specific local-level Australian studies have demonstrated significant growth in ED presentations. There have been no prior national-level Australian studies of ED presentation trends by age group. What does this paper add? The present study examined national ED presentation trends from July 2006 to June 2011, with specific emphasis on trends in presentation by age group. ED presentation growth was found to exceed population growth in all age groups. The rate of ED presentations per head of population was highest among those aged ≥85 years. ED utilisation projections to 2050, using standard Australian Bureau of Statistics population modelling, with and without adjustment for current ED growth, were developed. The projections demonstrated linear growth in ED presentation for those aged 0-84 years, with growth in ED presentations of the ≥85 year age group demonstrating marked acceleration after 2030. What are the implications for practitioners? Growth in ED presentations exceeding population growth suggests that current models of acute health care delivery require review to ensure that optimal care is delivered in the most fiscally efficient manner. Trends in presentation of older people emphasise the imperative for ED workforce planning and education in care of this complex patient cohort, and the requirement to review funding models to incentivise investment in ED avoidance and substitutive care models targeting older people.

Pre-amplification in the context of high-throughput qPCR gene expression experiment.

BACKGROUND: With the introduction of the first high-throughput qPCR instrument on the market it became possible to perform thousands of reactions in a single run compared to the previous hundreds. In the high-throughput reaction, only limited volumes of highly concentrated cDNA or DNA samples can be added. This necessity can be solved by pre-amplification, which became a part of the high-throughput experimental workflow. Here, we focused our attention on the limits of the specific target pre-amplification reaction and propose the optimal, general setup for gene expression experiment using BioMark instrument (Fluidigm). RESULTS: For evaluating different pre-amplification factors following conditions were combined: four human blood samples from healthy donors and five transcripts having high to low expression levels; each cDNA sample was pre-amplified at four cycles (15, 18, 21, and 24) and five concentrations (equivalent to 0.078 ng, 0.32 ng, 1.25 ng, 5 ng, and 20 ng of total RNA). Factors identified as critical for a success of cDNA pre-amplification were cycle of pre-amplification, total RNA concentration, and type of gene. The selected pre-amplification reactions were further tested for optimal Cq distribution in a BioMark Array. The following concentrations combined with pre-amplification cycles were optimal for good quality samples: 20 ng of total RNA with 15 cycles of pre-amplification, 20x and 40x diluted; and 5 ng and 20 ng of total RNA with 18 cycles of pre-amplification, both 20x and 40x diluted. CONCLUSIONS: We set up upper limits for the bulk gene expression experiment using gene expression Dynamic Array and provided an easy-to-obtain tool for measuring of pre-amplification success. We also showed that variability of the pre-amplification, introduced into the experimental workflow of reverse transcription-qPCR, is lower than variability caused by the reverse transcription step.

Environmental Implications of Ionic Liquid and Deep Eutectic Solvent in Geothermal Application: Comparing Traditional and New Approach Methods.

The significant surge of ionic liquids (ILs) research over the past decade has led to the formation of various novel ionic liquid compounds and their diverse applications. Enhanced geothermal systems (EGS) for geothermal power generation are an emerging IL application as a heat extraction fluid. The once widely held belief in the environmentally friendly characteristics of ionic liquids, mainly due to their insignificant vapor pressure, is now being scrutinized. It has become apparent that while ILs do not readily evaporate into the atmosphere, they are not guaranteed to remain entirely isolated from the environment. Recent attention has been directed toward toxicological studies, including ecotoxicity impacts, with the long-accepted assumption of ILs having low toxicity being invalid. This paper aims to shed light on the toxicity of hexylepyradinium bromide (HPyBr) IL and a deep eutectic solvent (DES) comprising choline chloride with magnesium chloride hexahydrate (ChCl:MgCl2·6H2O) to five test species, an algal species (Raphidocelis subcapitata), the water flea (Ceriodaphnia dubia and Daphina magna), the fathead minnow (Pimephales promelas), and the earthworm (Eisenia fetida), to measure acute and chronic toxicity. Additionally, new approach methods (NAMs) are presented using the fathead minnow embryo and the rainbow trout (Oncorhynchus mykiss) gill cell line and the RTgill-W1 assay to compare sensitivity across species. Overall, ChCl:MgCl2·6H2O displayed lower toxicity, while HPyBr demonstrated higher toxicity, highlighting the need for caution in handling it to prevent harm to aquatic ecosystems. Comparative analysis underscored the potential threat of ChCl:MgCl2·6H2O to aquatic life, highlighting the cumulative effects of the environmental components.

Barriers to health care and pregnancy experiences in relation to Black, low-income mothers' perinatal attachment and depression.

The goal of this study was to examine whether barriers to accessing health care and negative pregnancy experiences would predict depressive symptomatology and attachment to their neonates among Black mothers from low-income backgrounds across the perinatal period. We were also interested in examining whether these mothers' engagement in prenatal health practices would buffer against their pregnancy experiences to promote positive postnatal maternal functioning. Participants were 118 Black pregnant women from low-income backgrounds, recruited from WIC and Early Head Start programs. A prenatal assessment between 28 and 40 weeks gestation measured pregnancy experiences and prenatal health practices, and a postnatal assessment about 4 weeks postpartum measured maternal functioning in the form of depressive symptoms and attachment to their neonates. Linear regressions with prenatal health practices included as a moderator suggested that while engaging in positive health practices during pregnancy could potentially buffer against negative pregnancy experiences and prenatal depressive symptoms, it is unlikely to buffer against barriers to accessing health care. These results imply the need to provide support for accessing health care among pregnant women to address disparities in the United States. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Achieving a textbook outcome in patients undergoing gastric resections in a low incidence, high-volume Australian Upper GI unit.

BACKGROUND: Textbook outcome (TBO) has been proposed as a composite measure of quality in esophagogastric surgery, and achieving a TBO has been associated with improved overall survival (OS). The Dutch Upper Gastrointestinal Cancer Audit group determined their TBO rate for gastrectomy to be 32.1%, using 10 parameters. Our study aimed to assess the TBO rate in patients who had a gastrectomy for cancer in an Australian Upper GI unit, allowing for comparisons with international specialist centers. METHODS: Retrospective analysis of a prospectively maintained database of patients who had a gastrectomy for cancer performed by the surgeons in a single Australian center between 2013 and 2018. Postoperative complications were analyzed using Clavien-Dindo (CD) ≥2 and CD ≥3 definitions. Baseline factors and their association with TBO were analyzed using multivariable logistical regression. The association between TBO and survival rates was determined by Cox proportional hazards regression analysis. RESULTS: In 136 patients, 84 (62%) achieved a TBO when complications were graded as CD ≥2. Greatest negative impact on TBO was the complication rate, lymph node yield, and length of stay. Patients more likely to achieve a TBO were younger, with an increased body mass index and absence of underlying respiratory disease. A nonsignificant trend toward improved OS was seen when TBO was achieved. CONCLUSION: Our TBO rate compares favorably with published data from high-volume centers. Assessment of a unit's TBO may provide a stronger evaluation of quality when assessing where complex surgery should be performed within Australia.

Role of UV radiation and oxidation on polyethylene micro- and nanoplastics: impacts on cadmium sorption, bioaccumulation, and toxicity in fish intestinal cells.

This study investigated the role of ultraviolet (UV) radiation and oxidation in high-density polyethylene microplastics (2-15 µm) and nanoplastics (0.2-9.9 µm) (NMPs) on particle chemistry, morphology, and reactivity with cadmium (Cd). Additionally, toxicity of NMPs alone and with Cd was evaluated using RTgutGC cells, a model of the rainbow trout (Oncorhynchus mykiss) intestine. The role on NMPs on Cd bioaccumulation in RTgutGC cells was also evaluated. Dynamic light scattering indicated that after UV radiation NPs agglomerated size increased from 0.8 to 28 µm, and to 8 µm when Cd was added. Oxidized MPs agglomerated size increased from 11 and 7 to 46 and 27 µm in non-UV- and UV-aged oxidized MPs when adding Cd, respectively. Cd-coated particles exhibited generally significantly higher zeta potential than non-Cd-coated particles, while attenuated total reflectance-Fourier transform infrared spectroscopy showed that the functional chemistry of the particles was oxidized and modified after being exposed to UV radiation. Presence of NMPs resulted in a significant decrease in Cd bioaccumulation in RTgutGC cells (100.5-87.9 ng Cd/mg protein) compared to Cd alone (138.1 ng Cd/mg protein), although this was not quite significant for co-exposures with UV-aged NPs (105.7 ng Cd/mg protein). No toxicity was observed in RTgutGC cells exposed to NMPs alone for 24 h. Moreover, co-exposures with Cd indicated that NMPs reduce the toxicity of Cd. Altogether these results show that UV aging enhances NMP surface reactivity, increasing Cd absorption in solution, which resulted in a reduction in Cd bioavailability and toxicity.

Bioaccumulation of Microplastics in Decedent Human Brains Assessed by Pyrolysis Gas Chromatography-Mass Spectrometry.

Rising global concentrations of environmental micro- and nanoplastics (MNPs) drive concerns for human exposure and health outcomes. Applying pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) methods to isolate and quantify MNPs from human samples, we compared MNP accumulation in kidneys, livers, and brains. Autopsy samples from the Office of the Medical Investigator in Albuquerque, NM, collected in 2016 and in 2024, were digested for Py-GC/MS analysis of 12 polymers. Brains exhibited higher concentrations of MNPs than liver or kidney samples. All organs exhibited significant increases from 2016 to 2024. Polyethylene was the predominant polymer; the relative proportion of polyethylene MNPs was greater in brain samples than in liver or kidney. Transmission electron microscopy verified the nanoscale nature of isolated particles, which largely appeared to be aged, shard-like plastics remnants across a wide range of sizes. Results demonstrate that MNPs are selectively accumulated into the human brain and concentrations are rising over time.

Emerging investigator series: open dumping and burning: an overlooked source of terrestrial microplastics in underserved communities.

Open dumping and burning of solid waste are widely practiced in underserved communities lacking access to solid waste management facilities; however, the generation of microplastics from these sites has been overlooked. We report elevated concentrations of microplastics (MPs) in soil of three solid waste open dump and burn sites: a single-family site in Tuttle, Oklahoma, USA, and two community-wide sites in Crow Agency and Lodge Grass, Montana, USA. We extracted, quantified, and characterized MPs from two soil depths (0-9 cm and 9-18 cm). The average of abundance of particles found at community-wide sites three sites (18, 460 particles kg-1 soil) equals or exceeds reported concentrations from currently understood sources of MPs including biosolids application and other agricultural practices. Attenuated total reflectance Fourier transformed infrared (ATR-FTIR) identified polyethylene as the dominant polymer across all sites (46.2-84.8%). We also detected rayon (≤11.5%), polystyrene (up to 11.5%), polyethylene terephthalate (≤5.1), polyvinyl chloride (≤4.4%), polyester (≤3.1), and acrylic (≤2.2%). Burned MPs accounted for 76.3 to 96.9% of the MPs found in both community wide dumping sites. These results indicate that solid waste dumping and burning activities are a major source of thermally oxidized MPs for the surrounding terrestrial environment with potential to negatively affect underserved communities.

Quantitation and identification of microplastics accumulation in human placental specimens using pyrolysis gas chromatography mass spectrometry.

The exponential increase in global plastic usage has led to the emergence of nano- and microplastic (NMP) pollution as a pressing environmental issue due to its implications for human and other mammalian health. We have developed methodologies to extract solid materials from human tissue samples by saponification and ultracentrifugation, allowing for highly specific and quantitative analysis of plastics by pyrolysis-gas chromatography and mass spectrometry (Py-GC-MS). As a benchmark, placenta tissue samples were analyzed using fluorescence microscopy and automated particle count, which demonstrated the presence of >1-micron particles and fibers, but not nano-sized plastic particles. Analyses of the samples (n = 10) using attenuated total reflectance-Fourier transform infrared spectroscopy indicated presence of rayon, polystyrene, polyethylene, and unclassified plastic particles. By contrast, among 62 placenta samples, Py-GC-MS revealed that microplastics were present in all participants' placentae, with concentrations ranging widely from 6.5 to 685 µg NMPs per gram of placental tissue, averaging 126.8 ± 147.5 µg/g (mean±SD). Polyethylene was the most prevalent polymer, accounting for 54% of total NMPs and consistently found in nearly all samples (mean 68.8 ± 93.2 µg/g placenta). Polyvinyl chloride and nylon each represented approximately 10% of the NMPs by weight, with the remaining 26% of the composition represented by 9 other polymers. Together, these data demonstrate advancements in the unbiased quantitative resolution of Py-GC-MS applied to the identification and quantification of NMP species at the maternal-fetal interface. This method, paired with clinical metadata, will be pivotal to evaluating potential impacts of NMPs on adverse pregnancy outcomes.