Tissue Water Research Articles

Native T2 Predicts Myocardial Inflammation Irrespective of a Patient's Volume Status.

Myocardial inflammation and edema are major pathological features in myocarditis. Myocardial tissue water content and myocardial edema can be quantified via T2 mapping. Thus, cardiac magnetic resonance (CMR) is the noninvasive gold standard for diagnosing myocarditis. Several studies showed an impact of short-term volume changes on T2 relaxation time. Plasma volume status (PVS) is a good surrogate parameter to quantify a patient's volume status, and it is simple to use. The aim of this study was to determine the effect of PVS on the diagnostic value of T2 relaxation time in myocardial inflammation. Between April 2017 and December 2022, patients who were indicated for cardiac CMR were included in our prospective clinical registry. Patients with myocardial inflammation and those with unremarkable findings were analyzed in the present study. A blood sample was drawn, and PVS was calculated. Patients were separated into PVS tertiles to explore a possible nonlinear dose-response relationship. Logistic regression analysis was used to determine whether T2 is an independent predictor of myocardial inflammation. A total of 700 patients (47.43% female) were eligible for analysis. Of these, 551 patients were healthy (78.7%), while 149 (21.3%) showed signs of myocardial inflammation. The T2 relaxation time was elevated in patients with myocardial inflammation (40 ms [IQR 37-42 ms] vs. 38.0 ms [IQR 36-39 ms], p < 0.001). PVS showed no difference between the groups (-12.94 [IQR -18.4--7.28] vs.-12.19 [IQR -18.93--5.87], p = 0.384). T2 showed a clear dose-response relationship with PVS, with increasing T2 values along the PVS tertiles. In spite of this, T2 was found to be an independent marker of myocardial inflammation in logistic regression (OR T2 1.3 [95% CI 1.21-1.39], p < 0.001), even after adjusting for PVS (OR T2 [adj. PVS] 1.31 [95% CI 1.22-1.40], p < 0.001). Despite a dose-response relationship between T2 and the volume status, T2 was found to be an independent indicator of myocardial inflammation.

An Optimized Environmental DNA Method to Improve Detectability of the Endangered Sichuan Taimen (Hucho bleekeri)

Environmental DNA (eDNA) techniques have emerged as a cost-effective and non-invasive strategy for monitoring the distribution of endangered aquatic species. Despite their numerous advantages, operational uncertainty at each step of the process represents a significant challenge that can impact the reliability of results. Hence, the optimization of the eDNA analytic protocol is of utmost importance. In this study, the rare and endangered fish species Sichuan taimen was chosen as the target species to evaluate the concordance between different approaches (tissue, pond, and field water samples) for eDNA detection. The results showed that membrane filtration, collection of a 2-L water sample, and utilization of the DNeasy Tissue and Blood DNA extraction kit were suitable for the analysis of DNA in water samples. Furthermore, the mtDNA D-loop region demonstrated potential as a specific molecular marker for the precise identification of Sichuan taimen. Our results indicated that TaqMan fluorescence PCR can serve as the optimal detection method for reliable identification of target DNA even at extremely low concentrations in the field. This study established an optimized eDNA analysis protocol for Sichuan taimen detection, which will provide the basis for future resource investigations aimed at protection of this endangered aquatic species.

18 O enrichment of sucrose and photosynthetic and nonphotosynthetic leaf water in a C3 grass-atmospheric drivers and physiological relations.

The 18 O enrichment (Δ18 O) of leaf water affects the Δ18 O of photosynthetic products such as sucrose, generating an isotopic archive of plant function and past climate. However, uncertainty remains as to whether leaf water compartmentation between photosynthetic and nonphotosynthetic tissue affects the relationship between Δ18 O of bulk leaf water (Δ18 OLW ) and leaf sucrose (Δ18 OSucrose ). We grew Lolium perenne (a C3 grass) in mesocosm-scale, replicated experiments with daytime relative humidity (50% or 75%) and CO2 level (200, 400 or 800 μmol mol-1 ) as factors, and determined Δ18 OLW , Δ18 OSucrose and morphophysiological leaf parameters, including transpiration (Eleaf ), stomatal conductance (gs ) and mesophyll conductance to CO2 (gm ). The Δ18 O of photosynthetic medium water (Δ18 OSSW ) was estimated from Δ18 OSucrose and the equilibrium fractionation between water and carbonyl groups (εbio ). Δ18 OSSW was well predicted by theoretical estimates of leaf water at the evaporative site (Δ18 Oe ) with adjustments that correlated with gas exchange parameters (gs or total conductance to CO2 ). Isotopic mass balance and published work indicated that nonphotosynthetic tissue water was a large fraction (~0.53) of bulk leaf water. Δ18 OLW was a poor proxy for Δ18 OSucrose , mainly due to opposite Δ18 O responses of nonphotosynthetic tissue water (Δ18 Onon-SSW ) relative to Δ18 OSSW , driven by atmospheric conditions.

Functional response and resistance to drought in seedlings of six shrub species with contrasting leaf traits from the Mediterranean Basin and California.

Extreme drought events during post-fire regeneration are becoming increasingly frequent in Mediterranean-type ecosystems. Understanding how plants with different traits and origins respond to such conditions during early life stages is therefore critical for assessing the effect of climate change. Here, seedlings of three Cistus (semi-deciduous malacophylls from the Mediterranean Basin) and three Ceanothus (evergreen sclerophylls from California) species, two post-fire seeder genera with contrasting leaf traits, were subjected to complete water deprivation for three months in a common garden experiment. The leaf and plant structure, as well as plant tissue water relations were characterized before the drought, and the functional response (water availability, gas exchange, and fluorescence) were monitored during the drought. Both genera exhibited contrasting leaf structure and tissue water relations traits, with higher leaf area, specific leaf area, as well as higher osmotic potential at maximum turgor and turgor loss point in Cistus than Ceanothus. During drought, Ceanothus showed a more conservative use of water than Cistus, with a water potential less sensitive to decreasing soil moisture and a strong decline in photosynthesis and stomatal conductance in response to water deficit, but also a level of fluorescence more responsive to drought than Cistus. However, we could not find a different degree of drought resistance between the genera. This was particularly clear between Cistus ladanifer and Ceanothus pauciflorus, the two most functionally contrasting species, but at the same time the two most drought resistant. Our findings demonstrate that species with different leaf traits and functional responses to water stress may not differ in their degree of drought resistance, at least during the seedling stage. This underlines the need to take general categorizations by genus or functional traits with caution and deepen our knowledge about Mediterranean-type species ecophysiology, especially during early life stages, for anticipating their vulnerability to climate change.

Concurrent Optical- and Magnetic-Stimulation-Induced Changes on Wound Healing Parameters, Analyzed by Hyperspectral Imaging: An Exploratory Case Series.

The effects of concurrent optical and magnetic stimulation (COMS) therapy on wound-healing-related parameters, such as tissue oxygenation and water index, were analyzed by hyperspectral imaging: an exploratory case series. Background: Oedema and inadequate perfusion have been identified as key factors in delayed wound healing and have been linked to reduced mitochondrial respiration. Targeting mitochondrial dysfunction is a promising approach in the treatment of therapy refractory wounds. This sub-study aimed to investigate the effects of concurrent optical and magnetic stimulation (COMS) on oedema and perfusion through measuring tissue oxygenation and water index, using hyperspectral imaging. Patients and methods: In a multi-center, prospective, comparative clinical trial, eleven patients with chronic leg and foot ulcers were treated with COMS additively to Standard of Care (SOC). Hyperspectral images were collected during patient visits before and after treatment to assess short- and long-term hemodynamic and immunomodulatory effects through changes in tissue oxygenation and water index. Results: The average time for wound onset in the eleven patients analyzed was 183 days, with 64% of them being considered unresponsive to SOC. At week 12, the rate of near-complete and complete wound closure was 64% and 45%, respectively. COMS therapy with SOC resulted in an increased short-term tissue oxygenation over the 8-week treatment phase, with oxygen levels decreasing in-between patient visits. The study further found a decrease in tissue water content after the therapy, with a general accumulation of water levels in-between patient visits. This study's long-term analysis was hindered by the lack of absolute values in hyperspectral imaging and the dynamic nature of patient parameters during visits, resulting in high interpatient and intervisit variability. Conclusions: This study showed that COMS therapy as an adjunct to SOC had a positive short-term effect on inflammation and tissue oxygenation in chronic wounds of various etiologies. These results further supported the body of evidence for safety and effectiveness of COMS therapy as a treatment option, especially for stagnant wounds that tended to stay in the inflammatory phase and required efficient phase transition towards healing.

Application of multi-frequency ultrasonic thawing on pork: Thawing rate, quality properties and microstructure

This study investigated the effects of ultrasonication on thawing rate, physicochemical properties, water migration, distribution and microstructure of pork at different frequency combination modes (mono-, dual- or tri-frequency sequential and simultaneous modes). The results showed that ultrasonic-assisted thawing increased the thawing rate and shortened the thawing time by 26.72–64.99 % compared to water immersion thawing, and inhibited the lipid oxidation. Regarding the quality characteristics of frozen pork, the samples thawed by combined tri-frequency sequential ultrasound mode (TSEU) at 20/50/35 kHz exhibited better water retention (lower thawing loss and cooking loss) and physicochemical quality (lowest hardness, highest tenderness, lower TBARS values). Low-field nuclear magnetic resonance results displayed that the mobility and loss of bound and free water in pork tissue reduced effectively after ultrasound treatment at 20/50/35 kHz. The microstructure analysis revealed that the microstructure of pork thawed by 20/50/35 kHz was closest to that of fresh meat, and the distribution of muscle fibers was close and regular. Therefore, TSEU at 20/50/35 kHz was considered to be the most appropriate treatment for pork thawing, which could significantly accelerate the thawing rate and maintaining the meat quality.

Association of brain tissue cerebrospinal fluid fraction with age in healthy cognitively normal adults.

Our objective was to apply multi-compartment T2 relaxometry in cognitively normal individuals aged 20-80 years to study the effect of aging on the parenchymal CSF fraction (CSFF), a potential measure of the subvoxel CSF space. A total of 60 volunteers (age range, 22-80 years) were enrolled. Voxel-wise maps of short-T2 myelin water fraction (MWF), intermediate-T2 intra/extra-cellular water fraction (IEWF), and long-T2 CSFF were obtained using fast acquisition with spiral trajectory and adiabatic T2prep (FAST-T2) sequence and three-pool non-linear least squares fitting. Multiple linear regression analyses were performed to study the association between age and regional MWF, IEWF, and CSFF measurements, adjusting for sex and region of interest (ROI) volume. ROIs include the cerebral white matter (WM), cerebral cortex, and subcortical deep gray matter (GM). In each model, a quadratic term for age was tested using an ANOVA test. A Spearman's correlation between the normalized lateral ventricle volume, a measure of organ-level CSF space, and the regional CSFF, a measure of tissue-level CSF space, was computed. Regression analyses showed that there was a statistically significant quadratic relationship with age for CSFF in the cortex (p = 0.018), MWF in the cerebral WM (p = 0.033), deep GM (p = 0.017) and cortex (p = 0.029); and IEWF in the deep GM (p = 0.033). There was a statistically highly significant positive linear relationship between age and regional CSFF in the cerebral WM (p < 0.001) and deep GM (p < 0.001). In addition, there was a statistically significant negative linear association between IEWF and age in the cerebral WM (p = 0.017) and cortex (p < 0.001). In the univariate correlation analysis, the normalized lateral ventricle volume correlated with the regional CSFF measurement in the cerebral WM (ρ = 0.64, p < 0.001), cortex (ρ = 0.62, p < 0.001), and deep GM (ρ = 0.66, p < 0.001). Our cross-sectional data demonstrate that brain tissue water in different compartments shows complex age-dependent patterns. Parenchymal CSFF, a measure of subvoxel CSF-like water in the brain tissue, is quadratically associated with age in the cerebral cortex and linearly associated with age in the cerebral deep GM and WM.

A study on the delayed effect of tilapia skin collagen on skin aging for mice and its possible mechanism.

Study the possible mechanism and delayed effect of tilapia skin collagen on skin aging for mice. Kunming (KM) mice were randomly divided into the aging model group, the normal group, the positive control group (vitamin E) and the low, medium, high dose tilapia skin collagen groups (2.0, 4.0, 8.0 mg/g). The normal group was only injected with saline at the back and the neck. The other groups were injected subcutaneously with 5% D-galactose and ultraviolet light jointly to establish the aging model. After modeling, the positive control group was treated with a dose of 10% vitamin E once a day, and the low, medium, high dose tilapia skin collagen group was separately applied 2.0, 4.0, 8.0 mg/g of tilapia skin collagen for 40 days. The changes of skin tissue morphology, water content, hydroxyproline (Hyp) content, and superoxide dismutase (SOD) activity in mice were studied at the day 10, 20, 30, 40, 50. Compared with the normal group, the skin of mice in the aging model group was thinner, looser, and the skin moisture content, Hyp content, SOD activity were all decreased. For mice of the low, medium, high dose tilapia skin collagen group, the thickness of dermis increased, possessing close arrangement, and the moisture content, Hyp content, SOD activity were up-regulated significantly, which effectively alleviated the aging process of skin. The dose of tilapia skin collagen was directly proportional to the anti-aging effect. Tilapia skin collagen has an obvious effect on improving skin aging.

#4196 MAGNETIC RESONANCE IMAGING ASSESSMENT OF SKIN AND MUSCLE SODIUM IN HAEMODIALYSIS

Abstract Background and Aims Haemodialysis (HD) is life sustaining for patients with end-stage kidney disease (ESKD) but is associated with a marked increase in incidence of cardiovascular disease (CVD) and high annual mortality rates. Sodium balance is regulated by the kidneys in health but has to be achieved by sodium removal during HD for those with ESKD. Recent evidence suggests that non-osmotically stored sodium in the muscle and/or skin may be a critical factor impacting the development of hypertension and CVD. Sodium magnetic resonance imaging (23Na MRI) allows assessment of skin and muscle sodium storage and may provide a valuable tool in evaluating sodium storage in dialysis patients. In this study, we used 23Na MRI to measure muscle and skin sodium content in younger and older healthy individuals and people receiving HD, and investigated the effect of a single dialysis session on muscle and skin sodium content. Method 23Na MRI was acquired on a 3T Philips Ingenia scanner using a custom-made 23Na RF coil. 3D GRE 23Na scans (3 × 3 × 30mm3, 10 slices) were acquired in a 15-minute scan. Four reference bottles of increasing sodium concentration were placed in the RF coil above the leg to calibrate sodium concentration. In the same imaging session, 1H MR images were acquired to delineate muscle groups, skin structures and tissue water content. 23Na concentration maps were generated using custom software and regions of interest of each muscle and the skin were manually segmented. Data was collected on 14 younger (23-38yrs,7M:7F) and three older (66-77yrs,3M:1F) healthy volunteers (HVs), and 5 male HD patients (55-68 yrs) who had been on HD for more than 3-months. HD patients underwent a pre-dialysis 23Na MRI calf scan, then had their usual dialysis session with a dialysate Na prescription of 137 mmol/L, followed by a repeat 23Na MRI calf scan post dialysis. Patient demographics, dialysis vintage, residual renal function, and ultrafiltration volume were collected, along with blood samples at the start and end of the dialysis session, including serum sodium. Results Figure 1 shows 23Na images in the younger and older HV group and HD patients pre-dialysis. Muscle and skin sodium was increased in older HVs compared to younger, with HD patients pre-dialysis tending to be lower than older HVs (Fig. 2). HD patients’ demographics and clinical measures pre- and post-dialysis are shown in Table 1. HD treatment reduced muscle sodium whilst skin sodium showed little change (Fig. 3). Conclusion We have optimised methods for measuring muscle and skin sodium. 23Na concentration in muscle and skin is higher in older subjects. HD patients’ 23Na values fall between those observed in the older and younger HV groups. These values are consistent with published data from patients dialysed against 137mmol/l sodium dialysate, but lower than other studies in which dialysate sodium levels were higher. Further studies are planned to study the effect of dialysate sodium on skin and muscle sodium concentrations and mechanistic links to cardiovascular disease.

Shortwave infrared diffuse optical wearable probe for quantification of water and lipid content in emulsion phantoms using deep learning.

The shortwave infrared (SWIR, to 2000nm) holds promise for label-free measurements of water and lipid content in thick tissue, owed to the chromophore-specific absorption features and low scattering in this range. In vivo water and lipid estimations have potential applications including the monitoring of hydration, volume status, edema, body composition, weight loss, and cancer. To the best of our knowledge, there are currently no point-of-care or wearable devices available that exploit the SWIR wavelength range, limiting clinical and at-home translation of this technology. To design and fabricate a diffuse optical wearable SWIR probe for water and lipid quantification in tissue. Simulations were first performed to confirm the theoretical advantage of SWIR wavelengths over near infrared (NIR). The probe was then fabricated, consisting of light emitting diodes at three wavelengths (980, 1200, 1300nm) and four source-detector (S-D) separations (7, 10, 13, 16mm). In vitro validation was then performed on emulsion phantoms containing varying concentrations of water, lipid, and deuterium oxide (). A deep neural network was developed as the inverse model for quantity estimation. Simulations indicated that SWIR wavelengths could reduce theoretical water and lipid extraction errors from to when compared to NIR wavelengths. The SWIR probe had good signal-to-noise ratio ( up to 10mm S-D) and low drift ( up to 10mm S-D). Quantification error in emulsion phantoms was for water and for lipid. Water estimation during a dilution experiment had an error of . This diffuse optical SWIR probe was able to quantify water and lipid contents in vitro with good accuracy, opening the door to human investigations.

Root phenological and physiological response of maize (Zea mays L.) for adaptation under drought stress at vegetative and reproductive stages ​

Drought stress is known to negatively affect vegetative growth and biomass production, as well as the development of reproductive organs and yield characteristics in maize. The crop root systems are crucial for adaptability to various biotic and abiotic stresses, but studies addressing this are quite limited. The experiment was conducted simultaneously in both glasshouse and field condition during summer 2022 at TNAU, Coimbatore. The study was focussed to assess the root system architecture (RSA) of the drought tolerant and drought susceptible hybrids using PVC cylinders by imposing stress at V4 stage and root pulled out from the fieldby imposing stress at V14 stage. The results from the study showed that the significant variation was observed in both latter vegetative and mature root system under drought stress. Apart, the reduction in relative water content, SPAD values and increase of proline content were observed. The photosynthetic rate and gas exchange parameters were decreased upon exposure to drought stress. On considering, the hybrid N10-51 × DQL80 can accumulate osmolytes, maintaining tissue water potential and photosynthetic functionality for longer time when compared to other hybrids. This hybrid also exhibited the deep rooting ability with high yield under drought stress. Hence, it was identified as the drought tolerant hybrid and could be commercialized after testing their yield stability.

FAR-INFRARED IRRADIATION INHIBITS CELL PROLIFERATION IN BASAL AND PDGF-STIMULATED RAT VASCULAR SMOOTH MUSCLE CELLS THROUGH REGULATION AMPK/MTOR/P70S6K SIGNALING AXIS

Objective: Far-infrared (FIR) rays are invisible electromagnetic radiation with a wavelength of 3-1000 um, which elicits molecular vibrations in water and other organic molecules in cells and tissues, thereby FIR rays may have various biological effects. Aberrant proliferation of vascular smooth muscle cells (VSMCs) is associated with the development of diverse vascular diseases including atherosclerosis. Although FIR irradiation is reported to inhibit cell proliferation in various types of cells, effect of FIR irradiation on VSMC proliferation and the underlying mechanism remain elusive. Here, we investigated the molecular mechanism by which FIR irradiation inhibited VSMC proliferation. Design and method: We performed cell proliferation and viability assay, inhibitor studies, transfection of dominant negative (dn)-AMP-activated protein kinase (AMPK) alpha 1 gene, and western blot analyses. We also conducted confocal microscopic image analyses and ex vivo studies using isolated rat aortas. Results: FIR irradiation for 30 min decreased VSMC proliferation with no alteration in cell viability, which was accompanied by decreased phosphorylation of mammalian target of rapamycin (mTOR) at Ser2448 (p-mTOR-Ser2448) and p70 S6 kinase (p70S6K) at Thr389 (p-p70S6K-Thr389). Furthermore, FIR irradiation increased phosphorylation of AMP-activated protein kinase (AMPK) at Thr172 (p-AMPK-Thr172). Pre-treatment with compound C, a specific AMPK inhibitor, or ectopic expression of dn-AMPK alpha 1 gene, significantly reversed FIR irradiation-decreased VSMC proliferation, p-mTOR-Ser2448, and p-p70S6K-Thr389. However, hyperthermal stimulus (39 degrees) did not change VSMC proliferation and AMPK/mTOR/p70S6K phosphorylation. Similar to in vitro results, FIR irradiation increased p-AMPK-Thr172, and decreased p-mTOR-Ser2448 and p-p70S6K-Thr389 in isolated rat aortas. Finally, FIR irradiation attenuated platelet-derived growth factor (PDGF)-stimulated VSMC proliferation by increasing p-AMPK-Thr172, and decreasing p-mTOR-Ser2448 and p-p70S6K-Thr389 in PDGF-induced in vitro atherosclerosis model. Conclusions: We demonstrate that FIR irradiation decreases VSMC proliferation, at least in part, by regulating AMPK/mTOR/p70S6K signaling axis. These observations suggest that FIR ray therapy can be used to treat arterial narrowing diseases including atherosclerosis and in-stent restenosis.

IMPACT OF EXTRACELLULAR WATER ON BLOOD PRESSURE DEPENDING ON AGE AND GENDER IN THE CROSS SECTION STUDY KARDIOVIZE 2030

Objective: A random sample of 2146 volunteers from the Brno population aged 25-64 (1173 women and 973 men) was selected as part of the Kardiovision 2030 cross-section study. Study participants were approached based on the databases of health insurance companies and examined using the Czech Post-MONICA Study methodology. Design and method: Data from the Kardiovize 2030 study were used for the purposes of the work. Basic anthropometric data, blood pressure values, history of hypertension and measurements by direct segmental multifrequency bioelectrical impedance method were obtained. Study participants were approached based on the databases of health insurance companies. We characterized the majority of hypertensives in our group with simple parameters such as fat tissue and body water in different compartments by multichannel bioimpedance analysis. Results: The chance of hypertension occurs when the extracellular water (ECW) increases by 1 L The Impact of extracellular water demonstrated by spatial thin-plate models increase with age. Conclusions: The impact of extracellular water on the level of pressure is statistically significant against the normotonic population. Extracellular pressure has a major influence on systolic pressure and its influence increases with age. The impact of ECW is greater in women.

Histopathologic Validation of Stress T1 Mapping in Myocardial Ischemia: Another Step toward Clinical Translation?

Histopathologic Validation of Stress T1 Mapping in Myocardial Ischemia: Another Step toward Clinical Translation?

Does competition management improve the ecophysiological response to water shortage of mixed woodland species of North Patagonia?

Globally, the increasing forests vulnerability and drought-induced forest mortality events, extended to a larger scale, may have the potential to rapidly alter forest functioning and the provision of ecosystem services. Patagonian forests in Southern South America constitute an extensive reservoir of wildlife, but at the same time they have high productive potential. These low-mixed forests are composed of co-dominant species that are highly disturbed by local population, both for cattle raising and wood extraction; and different efforts are being dedicated to improve their management. Very little is known about the response of their different woody species to climatic variation, particularly to severe drought in particular, that may guide management strategies to improve productivity and resilience in context of drought stress and climate change. The present study aimed at characterizing the physiological strategies of response to drought to identify the most vulnerable and most resilient species to drought and how they respond under different competition levels. The response of four species of the Andean Patagonian low mixed forest was quantified at three moments of the 2018–2019 growing season in three sites through measurements of the net carbon exchange, vulnerability to xylem cavitation, tissue water relations, and damage of the photosynthetic apparatus. Additionally, records of average monthly values of precipitation and air temperature were used to calculate a standardized precipitation-evapotranspiration index. The normal climatic conditions of NW Patagonia region are characterized by water deficits during the spring-summer growing season, but the studied season presented lower values of standardized precipitation-evapotranspiration index respect to the historical mean values, indicating drier than normal conditions. Analysis of the tissue water relations showed that, in all cases, competition had no effect over the different studied parameters. There were species-specific differences in the models fitted to the vulnerability to cavitation curves; as a whole, all the species differed from each other. Overall, for all the physiological response traits studied, the Site, Species, and Season factors were important predictors in the minimum adequate model. Although there is an effect of competition on the individual annual growth, that effect is not evidenced in physiological variables of punctual measurement. Our results suggest that the effect of summer drought cannot be modulated by density management. The productivity of the species of interest can be improved, but not their adaptability, at least to severe events such as the one of the year of study.

The influence of complex matrices on method performance in extracting and monitoring for microplastics

Previous studies have evaluated method performance for quantifying and characterizing microplastics in clean water, but little is known about the efficacy of procedures used to extract microplastics from complex matrices. Here we provided 15 laboratories with samples representing four matrices (i.e., drinking water, fish tissue, sediment, and surface water) each spiked with a known number of microplastic particles spanning a variety of polymers, morphologies, colors, and sizes. Percent recovery (i.e., accuracy) in complex matrices was particle size dependent, with ∼60–70% recovery for particles >212 μm, but as little as 2% recovery for particles <20 μm. Extraction from sediment was most problematic, with recoveries reduced by at least one-third relative to drinking water. Though accuracy was low, the extraction procedures had no observed effect on precision or chemical identification using spectroscopy. Extraction procedures greatly increased sample processing times for all matrices with the extraction of sediment, tissue, and surface water taking approximately 16, 9, and 4 times longer than drinking water, respectively. Overall, our findings indicate that increasing accuracy and reducing sample processing times present the greatest opportunities for method improvement rather than particle identification and characterization.

Tissue Dielectric Constant and Skin Stiffness Relationships in Lower Extremity Lymphedema.

Background: Lower extremity lymphedema or edema (LELE) may progressively transition from a state of excess tissue fluid to increased fat accumulation and collagen deposition, with tissue fibrosis and hardening. Such changes may lead to altered tissue water holding and thereby impact tissue dielectric constant (TDC). This study seeks to evaluate the relationship between TDC and tissue indentation force (TIF) in patients with LELE and assess the utility of the leg/arm TDC ratio (LAR) as an indicator of LELE. Methods and Results: Thirty females (49-91 years) with previously diagnosed LELE were evaluated during a scheduled session. TDC and TIF were measured 8 cm proximal to the medial malleolus on the medial and lateral aspects of both legs and on one forearm 8 cm distal to the antecubital fossa. The TDC-TIC relationship and the LAR were subsequently determined. Main results showed an absence of a significant correlation between TDC and TIF on medial or lateral leg sites but a positive correlation on the normal forearm site. Further, LAR values exceeded the published proposed threshold of 1.35 for 29/30 patients when using medial-side TDC values and 28/30 patients when using lateral-side TDC values. Conclusions: Findings suggest that for patients with LELE, TDC values are significantly elevated on medial and lateral standardized sites. The LAR determined using either medial or lateral sites that are similar to each other and have values consistent with a lymphedema threshold of 1.35. In edematous legs of the type evaluated herein, there is no apparent relationship between TDC values and indentation force.

Early Intervention with a Compression Sleeve in Mild Breast Cancer-Related Arm Lymphedema: A 12-Month Prospective Observational Study.

In our previous randomized controlled trial (RCT), the progression/no progression of mild breast cancer-related arm lymphedema (BCRL) was examined among women randomized to a compression group (CG) with a compression sleeve (compression class (ccl) 1) or not (NCG) for 6 months. In the present prospective study, BCRL in the CG and NCG was followed for 12 months. At the end of the RCT, 33 women with mild BCRL were eligible in the CG and 37 in the NCG. The proportional differences in no progression/progression of BCRL were defined as a >2% increase from start of RCT or exceeding 10% in the lymphedema relative volume as measured by the water displacement method. In addition, changes in the lymphedema relative volume and tissue dielectric constant ratio, which measures local tissue water, were examined. At the end of the RCT (i.e., after 6 months), a one-month break of the compression treatment was made in the CG. If the lymphedema relative volume progressed by definition, the compression treatment was resumed and continued, with follow-up of all women at 9 and 12 months. A larger proportion of women in the NCG showed progression (57%, 61%, 67%) compared to the CG (16%, 22%, 31%) at 6, 9, and 12 months (p < 0.001, 0.005, 0.012), respectively. Twelve (33%) women in the NCG did not progress at all. No changes of the lymphedema relative volume and local tissue water were found over time at any follow-ups, but were stable on a low level. To avoid the progression of mild BCRL into a chronic issue in the long-term, compression sleeve ccl 1 may be applied immediately after early diagnosis of mild BCRL.

Variation in Leg Tissue Dielectric Constant Values of Healthy Young Adult Females With and Without Compression Bandaging.

Background The clinical efficacy of acompression application has been often limited to the assessment of the change in limb volume, change in clinical symptoms (i.e., wound size, pain, range of motion, incidence of cellulitis), or vascular hemodynamics of the whole limb.Assessing compression-related biophysical changes of a localized area, such as around a wound, or in an area outside of an extremity cannot be objectively assessed by these measurements.Tissue dielectric constant (TDC) values, which provide a measure of the local tissue water (LTW) content, offer an alternative method to document variation in the LTW content of the skin in a specific location. The goals of the present research were (1) to characterize TDC values, expressed as percentage tissue water, from multiple areas along the medial aspect of the lower leg of healthy volunteers and (2) to explore the potential utilization of the TDC values to assess change in tissue water content in a localized area following compression applications. Methods TDC was measured at 10, 20, 30, and 40 cm proximal to the medial malleolus on the medial aspect of the right leg of 18 young adult healthy women with an age range of 18-23 years and a body mass index of 18.7 to 30.7kg/m2.. TDC was measured at baseline and after 10 minutes of exercise with compression in place on three separate days during which three different compression applications were assessed: a longitudinal elastic stockinette, a two-layer cohesive compression kit, and a combination of the two.Leg circumferences and compression-related interface pressures were also measured. Results Test-Retest Reliability of circumferential measurements and TDC values evaluated using Intraclass correlation coefficient (ICC 3,1) revealed excellent and moderate-to-good reliability, respectively.Analysis of TDC values along the length of the limb using Friedman's test, revealed a small but statistically significant overall difference among baseline TDC values attributable to a smaller value at 40 cm. The largest difference in cumulative average was 7.7% which occurred between 20 and 40 cm, with all other differences between locations less than 1%.No significant differences between the compression applications were observed. Conclusion The present findings demonstrate the utility of TDC measurements as a modality to assess compression-related changes in the legs of healthy women as a foundation for their potential use in assessing outcomes of compression treatments for persons with lower extremity edema or lymphedema. The absence of a significant change in TDC values in these healthy non-edematous conditions and the demonstrated reliability of the TDC measurements on three different days provides further support for the utility of such applications of TDC measurements. The extension to patients with lower extremity edema or lymphedema needs to be evaluated.

The Effect of Manual Lymph Drainage and Compression Bandaging for Stage 2 Breast Cancer-Related Lymphedema: A Randomized Controlled Trial.

Aim: To explore the effect of manual lymph drainage (MLD), compression bandaging (CB), or combined decongestive therapy (CDT), including MLD and CB, on stage 2 breast cancer-related lymphedema (BCRL). Methods: Sixty women with stage 2 BCRL were enrolled. They were randomly divided into the MLD group, the CB group or the CDT group. Each group, respectively, received MLD alone, CB alone, or CDT composed of MLD and CB, for 2 weeks. The volume and the local tissue water (LTW) of affected arms were measured before and after treatment. Arm circumferences were measured at 4 cm interval starting from the wrist to the shoulder with a tape measure. LTW was detected using the (tissue dielectric constant, TDC) method and was expressed as TDC value in two sites on the ventral midpoint of upper arm and forearm. Results: The volume of affected arms in each group after 2-weeks' treatment was lower than their baseline and the difference was statistically significant (p < 0.05). But there was no significant difference in volume change among three groups. The TDC value of the upper arm and forearm in the group CB and the group CDT decreased distinctly compared with baseline (p < 0.05). But the TDC value of the upper arm and forearm after MLD did not change (p > 0.05). Compared with the group MLD and the group CDT, the reduction of the TDC value in the group CB was more significant (p < 0.05). Conclusions: MLD or CB alone could effectively reduce the volume of affected arms for patients with stage 2 BCRL, and CB also could reduce the LTW more significantly. CDT did not seem to show an extra advantage. Therefore, CB may be the first choice for stage 2 BCRL. But for patients who are unwilling or intolerant to CB, MLD can be selected.