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This study aimed to (1) document patterns of quadriceps muscle wasting in the first 10 days of admission and (2) determine the relationship between muscle ultrasonography and volitional measures. Twenty-two adults ventilated for more than 48 hours were included. Sequential quadriceps ultrasound images were obtained over the first 10 days and at awakening and intensive care unit (ICU) discharge. Muscle strength and function were assessed at awakening and ICU discharge. A total of 416 images were analyzed. There was a 30% reduction in vastus intermedius (VI) thickness, rectus femoris (RF) thickness, and cross-sectional area within 10 days of admission. Muscle echogenicity scores increased for both RF and VI muscles by +12.7% and +25.5%, respectively (suggesting deterioration in muscle quality). There was a strong association between function and VI thickness (r = 0.82) and echogenicity (r = −0.77). There was a moderate association between function and RF cross-sectional area (r = 0.71). Muscle wasting occurs rapidly in the ICU setting. Ultrasonography is a useful surrogate measure for identifying future impairment. Vastus intermedius may be an important muscle to monitor in the future because it demonstrated the greatest change in muscle quality and had the strongest relationship to volitional measures.

Carbonyl sulfide (OCS) is consumed by vegetation during photosynthesis in a one-way hydrolysis reaction, making measuring OCS vegetative uptake a means of inferring and quantifying global gross primary production. Recent studies highlight that uncertainties in OCS surface fluxes remain high and OCS datasets with better spatial coverage are required, particularly from satellite. Here OCS profiles are retrieved using measured radiances from the Infrared Atmospheric Sounding Interferometer (IASI) instruments. We estimate total column amounts over oceanic and inland water regions for the example year 2018, using an optimal estimation scheme, using the University of Leicester IASI retrieval scheme (ULIRS) for selected microwindows in the 2000–2100 cm−1 wavenumber range. Information content exceeds one between ±50° latitude and a peak in vertical sensitivity around 6–10 km (500–300 hPa) in the troposphere. Diurnal variations are limited to ±2 %, showing larger total column amounts at the daytime overpass. The IASI OCS observations show a correlation of at least 0.74 at half the ground-based flask measurement sites compared. Results also agree with the University of Leeds TOMCAT 3-D chemical transport model simulations within ±5 % throughout most tropical regions. This study demonstrates the ability of the IASI instrument to detect OCS in the troposphere and observe a reasonable seasonal cycle indicative of being driven by photosynthesis. Further data acquisition is recommended to gain insight into inter-annual variability in OCS. This novel work will also help improve our understanding of the role of vegetation in the carbon cycle, particularly when utilised in inversion methods.

Carbonyl sulfide (OCS) has emerged as a valuable proxy for photosynthetic uptake of carbon dioxide (CO2) and is known to be important in the formation of aerosols in the stratosphere. However, uncertainties in the global OCS budget remain large. This is mainly due to the following three flux terms: vegetation uptake, soil uptake and oceanic emissions. Bottom-up estimates do not yield a closed budget, which is thought to be due to tropical emissions of OCS that are not accounted for. Here we present a simulation of atmospheric OCS over the period 2004–2018 using the TOMCAT 3-D chemical transport model that is aimed at better constraining some terms in the OCS budget. Vegetative uptake of OCS is estimated by scaling gross primary productivity (GPP) output from the Joint UK Land Environment Simulator (JULES) using the leaf relative uptake (LRU) approach. The remaining surface budget terms are taken from available literature flux inventories and adequately scaled to bring the budget into balance. The model is compared with limb-sounding satellite observations made by the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) and surface flask measurements from 14 National Oceanic and Atmospheric Administration – Earth System Research Laboratory (NOAA-ESRL) sites worldwide. We find that calculating vegetative uptake using the LRU underestimates the surface seasonal cycle amplitude (SCA) in the Northern Hemisphere (NH) mid-latitudes and high latitudes by approximately 37 ppt (35 %). The inclusion of a large tropical source is able to balance the global budget, but further improvement to the SCA and phasing would likely require a flux inversion scheme. Compared to co-located ACE-FTS OCS profiles between 5 and 30 km, TOMCAT remains within 25 ppt (approximately 5 % of mean tropospheric concentration) of the measurements throughout the majority of this region and lies within the standard deviation of these measurements. This provides confidence in the representation of atmospheric loss and surface fluxes of OCS in the model. Atmospheric sinks account for 154 Gg S of the annual budget, which is 10 %–50 % larger than previous studies. Comparing the surface monthly anomalies from the NOAA-ESRL flask data to the model simulations shows a root-mean-square error range of 3.3–25.8 ppt. We estimate the total biosphere uptake to be 951 Gg S, which is in the range of recent inversion studies (893–1053 Gg S), but our terrestrial vegetation flux accounts for 629 Gg S of the annual budget, which is lower than other recent studies (657–756 Gg S). However, to close the budget, we compensate for this with a large annual oceanic emission term of 689 Gg S focused over the tropics, which is much larger than bottom-up estimates (285 Gg S). Hence, we agree with recent findings that missing OCS sources likely originate from the tropical region. This work shows that satellite OCS profiles offer a good constraint on atmospheric sinks of OCS through the troposphere and stratosphere and are therefore useful for helping to improve surface budget terms. This work also shows that the LRU approach is an adequate representation of the OCS vegetative uptake, but this method could be improved by various means, such as using a higher-resolution GPP product or plant-functional-type-dependent LRU. Future work will utilise TOMCAT in a formal inversion scheme to better quantify the OCS budget.

Summary Aging leads to dysregulation of multiple components of the immune system that results in increased susceptibility to infections and poor response to vaccines in the aging population. The dysfunctions of adaptive B and T cells are well documented, but the effect of aging on innate immunity remains incompletely understood. Using a heterogeneous population of peripheral blood mononuclear cells (PBMCs), we first undertook transcriptional profiling and found that PBMCs isolated from old individuals (≥ 65 years) exhibited a delayed and altered response to stimulation with TLR4, TLR7/8, and RIG-I agonists compared to cells obtained from adults (≤ 40 years). This delayed response to innate immune agonists resulted in the reduced production of pro-inflammatory and antiviral cytokines and chemokines including TNF[alpha], IL-6, IL-1[beta], IFN[alpha], IFN[gamma], CCL2, and CCL7. While the major monocyte and dendritic cell subsets did not change numerically with aging, activation of specific cell types was altered. PBMCs from old subjects also had a lower frequency of CD40+ monocytes, impaired up-regulation of PD-L1 on monocytes and T cells, and increased expression of PD-L2 and B7-H4 on B cells. The defective immune response to innate agonists adversely affected adaptive immunity as TLR-stimulated PBMCs (minus CD3 T cells) from old subjects elicited significantly lower levels of adult T-cell proliferation than those from adult subjects in an allogeneic mixed lymphocyte reaction (MLR). Collectively, these age-associated changes in cytokine, chemokine and interferon production, as well as co-stimulatory protein expression could contribute to the blunted memory B- and T-cell immune responses to vaccines and infections.

Over the last decade, neuromuscular ultrasonography has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves, including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent articles outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasonography is well suited for use in electrodiagnostic laboratories, where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management.

People with HIV (PWH) are at increased risk for atherosclerotic cardiovascular disease (ASCVD). Proportions of vascular homing monocytes are enriched in PWH; however, little is known regarding monocyte-derived macrophages (MDMs) that may drive atherosclerosis in this population. We isolated PBMCs from people with and without HIV, and cultured these cells for 5 days in medium containing autologous serum to generate MDMs. Differential gene expression (DGE) analysis of MDMs from PWH identified broad alterations in innate immune signaling (IL-1β, TLR expression, PPAR βδ) and lipid processing (LXR/RXR, ACPP, SREBP1). Transcriptional changes aligned with the functional capabilities of these cells. Expression of activation markers and innate immune receptors (CD163, TLR4, and CD300e) was altered on MDMs from PWH, and these cells produced more TNFα, reactive oxygen species (ROS), and matrix metalloproteinases (MMPs) than did cells from people without HIV. MDMs from PWH also had greater lipid accumulation and uptake of oxidized LDL. PWH had increased serum levels of free fatty acids (FFAs) and ceramides, with enrichment of saturated FAs and a reduction in polyunsaturated FAs. Levels of lipid classes and species that are associated with CVD correlated with unique DGE signatures and altered metabolic pathway activation in MDMs from PWH. Here, we show that MDMs from PWH display a pro-atherogenic phenotype; they readily form foam cells, have altered transcriptional profiles, and produce mediators that likely contribute to accelerated ASCVD.

Despite efforts to visualize all the movements of tongue and oropharynx in individuals with focal movement disorders (specifically tardive dyskinesia (TD)), clinicians can miss the complete picture and additional tools may be required to reach an accurate diagnosis. We present three cases with TD where ultrasound assisted in diagnoses. These individuals had difficulty swallowing and abnormal sensations in the tongue, which remained undiagnosed until we performed ultrasound of oropharynx which allowed for characterization of these movements. Ultrasound is an ideal modality for imaging the tongue and oropharynx in TD. Further research should include large case series and standardized protocols for evaluation of these disorders.

Background We aimed to evaluate differences in dementia risk profiles according to age, birthplace and First Nations status. Methods The sample included 6171 (62% female, < 1% non-binary/other) middle-aged and older adults who self-administered the CogDrisk assessment online and consented to their data being used for research from May 2023 to May 2024. The majority were aged 40–64 (‘midlife’; 67.9%) or aged 65–96 (‘later-life’; 25.8%); 6.3% were aged 18–40. More than a third (36.2%) were born overseas, 95% resided in Australia, and 66.0% had a university degree. Results Key midlife risk factors were hypertension 27.7%, pesticide exposure 24.6%, high cholesterol 25.1%, head injury 15.3%, diabetes 7.6%, and atrial fibrillation (AFib) 7.3%. Key later-life risk factors were hypertension 45.4%, pesticide exposure 33.0%, AFib 18.3% head injury 16.4%, and diabetes 11.7%. Midlife respondents born in the Pacific and New Zealand (NZ) had high rates of vascular risk factors and those born in NZ reported high rates of head injury and depression. The highest rates of heavy drinking and insufficient physical activity were reported by respondents born in the UK and Asia respectively. Using published estimates from validation studies, 20% of those aged 65 + had a high dementia risk (CogDrisk score > 12). Conclusions High rates of multiple risk factors were identified and varied according to age group and birthplace. This study provides evidence for tailoring risk reduction intervention and advice by age and birthplace.

The diagnosis and evaluation of neuromuscular disorders traditionally involves electrodiagnostic (EDx) testing, including nerve conduction studies (NCSs) and electromyography (EMG). These tools can cause pain and discomfort, an important consideration when performed on children. Neuromuscular ultrasound is noninvasive, cost-effective, and increasingly utilized for the detection of neuromuscular pathology. Studies investigating the performance and clinical implementation of ultrasound have primarily been performed in adult populations. Ultrasound in children has the potential to guide EDx testing and ultimately improve diagnostic efficiency and accuracy. This review aims to describe key features of neuromuscular ultrasound in the pediatric population based on the available studies, including our own institutional experience.