Intracellular Water Research Articles

Abstract 4116486: Association of assessment of clinical congestion in patients with heart failure compared with assessment using bioimpedance and microwave spectroscopy

Background: Physicians have to find a balance between decongestion therapy and the risk of dehydration so non-invasive methods assessing congestion are of great importance. Purpose: The study aimed to compare the clinical assessment of congestion to bioimpedance and microwave spectroscopy. Methods: 27 hospitalized HF patients with congestion (40% females) (Congestion Group) and 59 HF patients without fluid overload (66% females) (NON-Congestion Group) were included. Clinical examination, chest x-ray, laboratory results, echocardiography, non-invasive body mass analysis (Tanita Pro), NT-poBNP, and selected modern biomarkers concentrations [GDF-15, galectin-3, FABP, copeptin, VEGF were performed. Additionally, we assessed pulmonary congestion using a proprietary sensor with a microwave spectroscopy method based on analyzing the dielectric properties of an object (patent applications P.442466). Results: There were no differences in body mass index, blood pressure values, left ventricular ejection fraction (LVEF), and echocardiographic parameters of diastolic left ventricular function between groups. In the Congestion Group, we observed significantly more patients in NYHA Class 3 and 4 (p<0.001), lower values of fT3 (median 2.4 vs 2.7; p=0.02), higher a FIB-4 index (p=0.04), lower GFR MDRD (median 52.7 vs 66.7;p=0.04), higher concentrations of: NT-proBNP (pg/ml) (median 545 vs 101; p<0.001), galectin-3 (ng/ml) (median 15.01 vs 11.35; p=0.01), GDF-15 (pg/ml) (median 2069.27 vs 734.64; p=0.01), FABP (pg/ml) (median 293.6 vs 101; p=0.008) compared to NON-Congestion Group, and a larger number of detected congestion in chest x-ray (p<0.01) and more patients with limb edema (p= 0.0037). The patients with congestion also needed longer hospitalizations (p=0.008). Patients with congestion had lower total body water content in kg and intracellular water (ICW) (kg) (p=0.02 and p=0.01, respectively), and the higher extracellular water/total body water index (ECW/TBW) (p=0.001) assessed in bioimpedance and significantly higher Absorption Loss evaluated with the use of microwave spectroscopy (p=0.02). In a multiple logistic regression model, the factor that was independently associated with clinically diagnosed congestion was NT-proBNP >1095 pg/ml (OR 111.6, 95% CI: 2.6-50.6; p=0.001) (Figure 1). Conclusions: Absorption Loss and ECW/TBW are valuable new diagnostic tools in diagnosing lung congestion in patients with heart failure.

Astrocyte aquaporin mediates a tonic water efflux maintaining brain homeostasis.

Brain water homeostasis not only provides a physical protection, but also determines the diffusion of chemical molecules key for information processing and metabolic stability. As a major type of glia in brain parenchyma, astrocytes are the dominant cell type expressing aquaporin water channel. How astrocyte aquaporin contributes to brain water homeostasis in basal physiology remains to be understood. We report that astrocyte aquaporin 4 (AQP4) mediates a tonic water efflux in basal conditions. Acute inhibition of astrocyte AQP4 leads to intracellular water accumulation as optically resolved by fluorescence-translated imaging in acute brain slices, and in vivo by fiber photometry in mobile mice. We then show that aquaporin-mediated constant water efflux maintains astrocyte volume and osmotic equilibrium, astrocyte and neuron Ca2+ signaling, and extracellular space remodeling during optogenetically induced cortical spreading depression. Using diffusion-weighted magnetic resonance imaging (DW-MRI), we observed that in vivo inhibition of AQP4 water efflux heterogeneously disturbs brain water homeostasis in a region-dependent manner. Our data suggest that astrocyte aquaporin, though bidirectional in nature, mediates a tonic water outflow to sustain cellular and environmental equilibrium in brain parenchyma.

Astrocyte aquaporin mediates a tonic water efflux maintaining brain homeostasis

Brain water homeostasis not only provides a physical protection, but also determines the diffusion of chemical molecules key for information processing and metabolic stability. As a major type of glia in brain parenchyma, astrocytes are the dominant cell type expressing aquaporin water channel. How astrocyte aquaporin contributes to brain water homeostasis in basal physiology remains to be understood. We report that astrocyte aquaporin 4 (AQP4) mediates a tonic water efflux in basal conditions. Acute inhibition of astrocyte AQP4 leads to intracellular water accumulation as optically resolved by fluorescence-translated imaging in acute brain slices, and in vivo by fiber photometry in mobile mice. We then show that aquaporin-mediated constant water efflux maintains astrocyte volume and osmotic equilibrium, astrocyte and neuron Ca2+ signaling, and extracellular space remodeling during optogenetically induced cortical spreading depression. Using diffusion-weighted magnetic resonance imaging (DW-MRI), we observed that in vivo inhibition of AQP4 water efflux heterogeneously disturbs brain water homeostasis in a region-dependent manner. Our data suggest that astrocyte aquaporin, though bidirectional in nature, mediates a tonic water outflow to sustain cellular and environmental equilibrium in brain parenchyma.

Positive association of the thigh muscle thickness to intracellular-water ratio with handgrip strength, but not with the risk of mortality in hospitalized cancer patients: a longitudinal study.

This study explored the relationship between handgrip strength, muscle thickness, and the intracellular water ratio (MT/ICW) in cancer patients. It aimed to identify a cut-off point for the MT/ICW ratio that might influence survival. Conducted as an exploratory, longitudinal study in a public hospital, it included patients from 2018 to 2022, with follow-up until August 31, 2023. The cut-off for the MT/ICW ratio was determined based on its sensitivity for mortality. Results indicated that patients with an MT/ICW ratio >0.97 had significantly lower extracellular water percentages and greater muscle thickness. A positive association was found between the MT/ICW ratio and handgrip strength, even after adjusting for age, sex, extracellular water, and body mass index. However, patients with an MT/ICW ratio ≤0.97 showed no significant mortality risk. In conclusion, MT/ICW ratio >0.97 mm/L in hospitalized cancer patients was positively associated with handgrip strength, but not risk of mortality.

Effect of Fontan circulation on body composition and correlation with exercise capacity

Abstract Background There is growing attention to body composition in Fontan patients (FP) and preliminary results suggest that FP have an increased fat mass and a decreased muscle mass compared to the healthy population. FP also have reduced exercise capacity compared to health peers. However, data are still limited. Purpose The aim of our study was to compare the body composition (BC) of adult patients with Fontan circulation and healthy controls and to assess the correlation with functional capacity. Material and Methods Case control study on adult patients with Fontan circulation (FP) and age and gender matched healthy controls (HC). The following characteristics were recorded: age, gender, morphology of the systemic ventricle, type of Fontan circulation, level of physical activity (PAR, 0-7 points, 0 = sedentary - 7 = running > 3hours/week). S-score muscle, T-score bone, fat mass (FM%), intra-muscular adipose tissue (IMAT), abdominal adipose tissue (AAT), intracellular water (ICW), extracellular water (ECW), total body water (TBW), were measured through multi-frequency bioelectrical impedance technology in the FP and in the HC. Correlation was made for FP between body composition and oxygen consumption at peak exercise (VO2 peak), VE/VCO2 slope and NYHA class as indicator of functional capacity. Results Thirty Fontan patients (FP, mean age 24±6 yrs, 70% males) and 30 matched healthy controls (HC) were recruited in the study. The systemic ventricle was dominant left in 14 patients (47%), dominant right in 16 (53%). Four patients had atrio-pulmonary connection, the remaining were palliated with a lateral tunnel (n=26, 87%). The analysed parameters are summarised in Table 1. PAR was reduced in FP compared to HC (median 4.0 points in FP versus 7.0 points in HC, p 0.024). There was no difference in the BMI, fat mass, and body water between FP and HC. However, FP showed significantly lower S and T scores compared to the HC (S-score: -0,75 in FP versus 0,0 in HC, p 0.003. T-score: -0.9 in FP versus -0.25 in HC, p 0.001). In FP, NYHA Class was I in 28 patients (93%), II in 1 (3,5%) and III in 1 (3.5%) patient. The mean VO2 was 23.4±5.4mlO2/kg/min and mean VE/VCO2 slope 32±7. There was a direct correlation between VO2 peak and the PAR (rho 0.443, p 0.044). No correlation was found between the VO2 peak, the VE/VCO2 slope or the NYHA Class and the analysed parameters of body composition. Conclusion FP have reduced muscle mass, and bone density compared to HC. In addition to the known reduced efficiency of the cardiac pump during exercise in FP, the lower level of conditioning contributes to the reduced exercise capacity in this population. Programs aiming to encourage physical activity are key and should be part of patients’ care.

Impedance Spectroscopy Measures of Whole and Segmental Skeletal Muscle Quantity Associated With Strength and Power in Collegiate Ice Hockey Players.

Otremba, JR, Heesch, AJ, Morgan, RM, Poolman, MA, Schindler, GD, and Fitzgerald, JS. Bioelectrical impedance spectroscopy measures of whole and segmental skeletal muscle quantity associated with strength and power in collegiate ice hockey players. J Strength Cond Res XX(X): 000-000, 2024-Bioelectrical impedance spectroscopy (BIS) is a promising monitoring tool for body water compartment assessment, particularly intracellular water (ICW), in which acute decreases are associated with increased muscle damage and reduced function, and chronic changes are associated with muscle quantity. Because little is known about the predictive utility of BIS-derived measures in athletes, this study aimed to assess the association between whole-body and segmental compartment water measured by BIS and maximal-intensity exercise performance in athletes. Twenty-five National Collegiate Athletic Association Division I collegiate hockey players completed 2 consecutive testing sessions. Body water and composition were assessed using a SOZO BIS device. Strength and explosive strength were measured on a force platform during the isometric belt squat and squat jump, respectively. Peak power was assessed using the 6-Second Test on a Wattbike. Pearson's r and partial correlation were used to assess relationships. Select body water and composition BIS variables were strong correlates of strength ( r = 0.51-0.63, p < 0.05), moderate correlates of power ( r = 0.41-0.44, p < 0.05), and lacked association with explosive strength. Segmental leg variables tended to be the strongest correlates of strength and power. Body water and traditional lean mass variables expressed similar predictive utility. Intracellular water/extracellular water lacked associated with exercise performance in bivariate and adjusted models. We provide evidence of the criterion validity of whole-body (i.e., ICW, fat-free mass, skeletal muscle mass [SMM]) and segmental (i.e., leg ICW, leg SMM) BIS variables, related to the quantity of SMM, to predict body-size dependent maximal-intensity exercise performance. Practitioners can use this information to determine which variables to track for performance readiness monitoring.

Habitual water intake impacted the body composition of young male athletes in free-living conditions: a cross-sectional study.

The study aimed to explore the associations between water intake and body composition and differences of body composition in different water itake and hydration statuses among young male athletes. A cross-sectional study was conducted among 111 young male athletes in Beijing, China. Total drinking fluids (TDF) and water from food were assessed using a 7-day, 24-h fluid intake record questionnaire and the duplicate portion method, respectively. The osmolality of 24-hour urine and blood samples was tested. Body composition was measured using a bioelectrical impedance analyzer twice at 5-min intervals. Participants were divided into two groups based on the recommendations of total water intake (TWI) and TDF in China, as well as into three groups based on 24-h urine osmolality. Pearson's correlation coefficients were calculated to determine the relationship between water intake and body composition. Chi-square tests and Student's t-tests were used to compare differences. A total of 109 participants completed the study. TDF (r = 0.230, p = 0.016; r = 0.234, p = 0.014; r = 0.242, p = 0.011) and TWI (r = 0.275, p = 0.004; r = 0.243, p = 0.011; r = 0.243, p = 0.011) were positively correlated with total body water (TBW), intracellular water (ICW), and extracellular water (ECW). TBW/body weight (BW) was positively associated with TDF percentage of BW (TDF/BW) (r = 0.267, p = 0.005), water from food percentage of BW (r = 0.217, p = 0.024), and TWI percentage of BW (TWI/BW) (r = 0.316, p = 0.001). Participants who met the TDF recommendation of China had 1.3 kg higher skeletal muscle mass (SMM), 0.9 kg higher ICW, and 0.5% higher TBW/BW than those who did not (all p < 0.05), with fat-free mass (FFM) and TBW being higher (p = 0.051; p = 0.050). Those who met the TWI recommendation of China had 1.3 kg higher SMM, 2.4 kg higher FFM, 1.1 kg higher ICW, 0.6 kg higher ECW, and 1.7 kg higher TBW than their counterparts (all p < 0.05). Moderate associations were found between water intake and body composition. No significant differences were observed among participants in three hydration statuses (all p > 0.05). Participants who met the TWI or TDF recommendations had better body composition distribution than their counterparts. Thus, habitual water intake, not hydration status, affects body composition among athletes in free-living conditions.

Device for detection of activity-dependent changes in neural spheroids at MHz and GHz frequencies

Intracellular processes triggered by neural activity include changes in ionic concentrations, protein release, and synaptic vesicle cycling. These processes play significant roles in neurological disorders. The beneficial effects of brain stimulation may also be mediated through intracellular changes. There is a lack of label-free techniques for monitoring activity-dependent intracellular changes. Electromagnetic (EM) waves at frequencies larger than 1x106 Hz (1 MHz) were previously used to probe intracellular contents of cells, as cell membrane becomes “invisible” at this frequency range. EM waves interact with membranes of intracellular organelles, proteins, and water in the MHz – GHz range. In this work, we developed a device for probing the interaction between active neurons’ intracellular contents and EM waves. The device used an array of grounded coplanar waveguides (GCPWs) to deliver EM waves to a three-dimensional (3D) spheroid of rat cortical neurons. Neural activity was evoked using optogenetics, with synchronous detection of propagation of EM waves. Broadband measurements were conducted in the MHz-GHz range to track changes in transmission coefficients. Neuronal activity was found to reversibly alter EM wave transmission. Pharmacological suppression of neuronal activity abolished changes in transmission. Time constants of changes in transmission were in the seconds – tens of seconds range, suggesting the presence of relatively slow, activity-dependent intracellular processes. This study provides the first evidence that EM transmission through neuronal tissue is activity-dependent in MHz – GHz range. Device developed in this work may find future applications in studies of the mechanisms of neurological disorders and the development of new therapies.

The early prognostic value of the 1–4-day BCM/PA trend after admission in neurocritical patients

The purpose of this study was to investigate early stage dynamic changes in relevant indicators in neurocritical patients to identify biomarkers that can predict a poor prognosis at an early stage (1–4 days after admission). This study retrospectively collected clinical data, inflammatory indicators, and nutritional indicators from 77 patients at the neurology intensive care unit. The 3-month modified Rankin scale score was used as the outcome indicator. A linear mixed model was used to analyze changes in inflammatory indicators and nutritional indicators in neurocritical patients over time from 1–4 days after admission. Logistic regression was used to determine the independent risk factors for a poor prognosis in neurocritical patients and to construct a predictive model. The predictive efficacy of the model was verified using leave-one-out cross-validation and decision curve analysis methods. The analysis results showed that 1–4 days after admission, the inflammatory indicators of white blood cell and absolute monocyte counts and the nutritional indicators of body cell mass(BCM), fat-free mass, body cell mass/phase angle (BCM/PA), intracellular water, extracellular water, and skeletal muscle index increased overall, while the nutritional indicators of albumin and visceral fat area decreased overall. The logistic multivariate regression model showed that the Charlson comorbidity index (CCI) (odds ratio (OR) = 2.526, 95% CI [1.202, 5.308]), hemoglobin (Hb)(on admission)-Hb(min) (OR = 1.049, 95% CI [1.015, 1.083), BCM(on admission) (OR = 0.794, 95% CI [0.662, 0.952]), and the change in BCM/PA 1–4 days after admission (OR = 1.157, 95% CI [1.070, 1.252]) were independent risk factors for a poor prognosis in neurocritical patients. The predictive analysis showed that the predictive power of Model 1 with BCM/PA (area under the curve (AUC) = 0.95, 95% CI (0.90, 0.99)) was 93%, 65%, 141%, and 133% higher than that of Model 2 without BCM/PA, the CCI, the APACHE II score, and the NRS2002 score (all P < 0.05), respectively. The CCI, Hb(on admission)-Hb(min), BCM(on admission), and an increase in BCM/PA 1–4 days after admission were independently associated with a poor prognosis in neurocritical patients. Of these variables, BCM/PA may be a valid indicator for early stage prediction of a poor prognosis in neurocritical patients.

A Population-Wide Assessment of Decrease in Intracellular Hydration with Age and Certain Health Conditions

Objectives: The membrane hypothesis of aging suggests that age-related changes in the balance of Intracellular Water (ICW) to Extracellular Water (ECW) may play a significant role in the degenerative processes associated with aging.

The Relationship between Body Compositions and Serum Vitamin D Levels in Obese Adolescents

Purpose: Obesity and vitamin D deficiency is a significant public health problem with increasing frequency in childhood. Although numerous studies explored the correlation between obesity and vitamin D, the study is aimed to investigate such relationship in consideration of few/no studies on vitamin D and body compositions in obese people. Methods: A total of 62 adolescents aged 12 to 18 were included in the study, comprising 33 obese adolescents and 29 with normal weight. Blood samples were analyzed for 25-hydroxyvitamin D (25(OH)D), calcium (Ca), phosphorus (P), magnesium (Mg), alkaline phosphatase (ALP), parathyroid hormone (PTH), insulin, C-reactive protein (CRP), total cholesterol, LDL cholesterol (LDL), triglycerides (TG), and HDL cholesterol (HDL). Body fluid status and composition were assessed using bioimpedance spectroscopy (BIS) for both the obese and control groups. Results: Total body water (TBW), extracellular water (ECW), intracellular water (ICW), ECW/ICW (E/I) ratio, lean tissue index (LTI), adipose tissue index (FTI), lean tissue mass (LTM), adipose tissue mass (ATM), body cell mass (BCM) values were significantly higher in the obese group in comparison with the control group (p ˂ 0.05). There was no significant difference in 25(OH)D levels in the obese and control groups (p ˃ 0.05). The distribution of 25(OH)D values below and above 20 did not differ significantly in the obese and control groups (p ˃ 0.05). Cholesterol, insulin and HOMA-IR values were detected significantly higher in the obese group than in the control group (p ˂ 0.05). HDL and Ca values were significantly lower in the obese group than in the control group (p ˂ 0.05). A significant positive correlation was discovered between BMI value and TBW, ECW, ICW, E/I, LTI, FTI, LTM, ATM, BCM values (p ˂ 0.05). A significant positive correlation was discovered between HOMA IR value and TBW, ECW, ICW, E/I, FTI, FAT, ATM values (p&lt; 0.05). No significant correlation was encountered between ....

BIA-assessed cellular hydration and strength in healthy older adults

ObjectivesThe objective of this research was to evaluate the differential relationships between various BIA-estimated compartments of body water and strength, among healthy older adults, by age range and sex. DesignDescriptive and correlational study. Setting and ParticipantsA total of 234 healthy older adults (72.59±7.60 years) participated in the study. Participants were recruited from community centers around Portugal and Spain. Data were recorded during May 2023. This is a physically active sample: all the participants are physically active for a minimum of three days a week. MethodsFor the study of body composition the variables extracted from the Tanita were: fat mass (FM), fat free mass (FFM), visceral fat rating (VFR), total body water (TBW), extracellular water (ECW) and intracellular water (ICW). Handgrip Strength was used to evaluate upper body strength and the Chair Stand Test for lower body strength. ResultsDifferences across the various data sets were recorded in the gender variable.When looking into the gender variable, significant correlations were recorded for the body composition variables analyzed for all age groups in the upper body strength test, except for BMI(r=0.125-0.878) and Fat mass (0.056 - -0.634). For the lower body strength test, no significant correlations were recorded for the Fat-Free mass variables (r= 0.164 - 0.380), as well as for the Visceral Fat Rating(r= 0.082 - 0.213) and the body water variables (TBW, ECW, ICW). ConclusionsThe hydration parameters analyzed can be related to muscle performance for Handgrip in an independent older adult population with ages ranging from 60 to 90 years.

Ultrastructural and thermal analyses reveal novel insights into low-temperature survival mechanisms of hydrated seeds of Poaceae species from alpine regions

Global warming leads to snow cover loss in the alpine ecosystem, exposing seeds to extreme diurnal temperature fluctuations during the growing season. The risk of freezing increases as seeds have increased moisture content. Studying the survival mechanisms of seeds at low temperatures can help analyze changes in alpine meadow populations and target conservation efforts. Here, we used three species of Poaceae as a model to understand freezing stress.Fully imbibed Elymus dahuricus, Festuca elata, and Lolium multiflorum seeds were subjected to programmed cooling at fast and slow rates (-1.0/0.05°C/min) and then assessed for survival. Differential Scanning Calorimetry was used to analyze thermal transitions during cooling. HE-stained paraffin sections and a Transmission Electron Microscope were employed to observe internal morphology and ultrastructural changes.E. dahuricus seeds exhibited greater tolerance to low temperatures than those of the other two species, with an LT50 of approximately -20°C for both cooling rates and maintained relatively intact ultrastructure. The observed Low-temperature exotherm (LTE) correlated with seed survival, with viability decreasing extensively below LTE.Fast cooling caused fewer changes to seed morphology and ultrastructure than slow cooling, suggesting that the primary survival mechanism during fast cooling is freezing avoidance through supercooling. Seeds exhibited greater freeze tolerance under slow than fast cooling, primarily by migrating intracellular water to extracellular spaces where it froze, causing considerable damage to cell ultrastructure and forming apparent cavities in some seeds.

Enhancement in Dewatering Efficiency of Disrupted Sludge through Ultrasonication and Re-Flocculation—Sustainable Sludge Management

The solids in sewage sludge are primarily composed of organic matter and offer new possibilities for sustainable sludge management, if considered as a stable biomass source in terms of quantity and quality. Reducing the volume of sludge with an extremely high moisture content is challenging, and enhanced dewatering through mechanical treatment is crucial from an environmental and sustainability perspective because it alleviates the reliance on thermal treatment. This study employed ultrasonication to enhance the dewatering efficiency of activated sludge. The disruption of sludge induced by ultrasonication notably facilitated the elimination of intracellular water during mechanical expression. Additionally, the ultrasonicated sludge was verified to be re-flocculated by introducing inorganic electrolytes such as Ca2+ (divalent cations), Al3+ (trivalent cations), and polyferric sulfate. Conversely, no re-flocculation of disrupted sludge was observed upon applying organic polymer flocculant. Under optimized conditions, the sludge re-flocculation progressed to form large flocs, leading to a decreased suspended solids (SS) value from 1423 to 73 mg/L and reduction in capillary suction time (CST) from over 2000 to 18 s. Following pretreatment, the moisture content of the mechanically expressed cake at 500 kPa decreased significantly from 76 wt% (untreated sludge) to less than 60 wt% (treated sludge) due to the elimination of intracellular water.

Bioimpedance analysis of fat free mass and its subcomponents and relative associations with maximal oxygen consumption in facioscapulohumeral dystrophy.

Fat free mass (FFM) is considered the metabolically active component of human body and is positively associated with maximal oxygen uptake ( ). However, FFM is composed of metabolically active and inactive subcomponents whose proportion can vary depending on body composition and clinical condition, possibly affecting such association. Although it is known that in facioscapulohumeral dystrophy (FSHD) peculiar changes in body composition occur, it is unclear whether there are alterations in FFM composition and, if so, whether such alterations affect the association towards compared to healthy subjects (HS). To address this issue, 27 FSHD patients (mean age 37.3; 9 female) and 27 sex and age matched HS, underwent an assessment of by cardiopulmonary exercise tests (CPET) and body composition, with reference to FFM and its subcomponents, by bioimpedance analysis. In between-groups comparison, patients showed lower amounts of body cell mass (BCM) and intracellular water (ICW) which reflect in lower BCM/FFM ratio and higher extracellular to intracellular water ratio (ECW/ICW). Patients' was lower than HS and, even if with lower associative values than HS, correlated with FFM and BCM, while BCM/FFM and ECW/ICW ratios associations were observed only in HS. FSHD patients showed lower amount of BCM and ICW. BCM resulted as the parameter with the highest associative value with VO2max in both groups. Since is associated with functional ability in dystrophic patients, BCM, rather than FFM, could be an additional body composition-based clinical stratification factor.

A quantitative method for aquaporin-1 protein using magnetic preconcentration and probe-based immunoassay coupling to inductively coupled plasma mass spectrometry in urine analysis

BackgroundAquaporin-1 (AQP1) protein plays a crucial role in intracellular and extracellular water homeostasis and fluid transport in organs and tissues associated with diverse life activities and is extremely abundant in the kidney. Accurate detection of AQP1 in urine can be applied as screening of early-stage disease. Application of magnetic preconcentration and probe-based signal amplification strategy coupling to inductively coupled plasma mass spectrometry (ICP-MS) is a more accurate, sensitive and specific detection method for AQP1 in complex biological samples compared to conventional methods. ResultsWe described an element-labelling strategy based on magnetic preconcentration and probe-based immunoassay coupling to ICP-MS detection. The magnetic beads (MBs) modified with epoxy groups were capable of enriching AQP1 proteins and separating them from complex matrices. The probe constructed by conjugating anti-AQP1 antibody molecules on the surface of gold nanoparticles could specifically recognize AQP1 proteins attached on MBs and be analyzed by ICP-MS. The concentration of AQP1 protein could be precisely quantified and amplified by 14,000 times through the corresponding signal of Au atoms. This assay for AQP1 protein quantification achieved a detection limit down to 0.023 ng mL−1, a broad linear calibration curve between 0.3 ng mL−1 and 30 ng mL−1, as well as outstanding specificity. SignificanceThe proposed method was successfully applied to detect AQP1 protein in human urine samples, showing the potential for its applications concerning accurate AQP1 quantification. It can also screen a wide range of proteins provided the antibodies specific to these target proteins are available.

Effects of Low-Phosphorus Stress on Use of Leaf Intracellular Water and Nutrients, Photosynthesis, and Growth of Brassica napus L.

Phosphorus (P) deficiency is one of the main reasons limiting plant production of Brassica napus L. Exploring the dynamics of leaf intracellular substances and the correlations with photosynthesis and growth helps to understand the response mechanisms of B. napus L. to P deficiency. This study conducted experiments on B. napus L. plants by measuring the leaf electrophysiological parameters, leaf structure, elastic modulus (Em), photosynthesis, and growth indices under different P treatment conditions. The dynamics of leaf intracellular water and nutrients of B. napus L. were calculated and analyzed by using the electrophysiological parameters, and the plant tolerance threshold to low-P stress was discovered. The results indicated that the status of the leaf intracellular water and nutrients remained stable when the P concentration was not lower than 0.250 mmol·L−1, but maximized the photosynthesis and growth at a P level of 0.250 mmol·L−1. The 0.125 mmol·L−1 P concentration significantly decreased the mesophyll cell volume, and the palisade–sponge ratio and tightness degree of leaf tissue structure were remarkably increased. This led to an increase in cell elastic modulus, and significantly improved the water retention capacity of leaf cells. At the same time, the intracellular water use efficiency and total nutrient transport capacity of leaves remained stable. As a result, the photosynthesis and growth of plants were maintained at the same level as that of the control group. However, photosynthesis and growth were clearly inhibited with a further decrease in P concentration. Therefore, 0.125 mmol·L−1 was the tolerance threshold of B. napus L. to low P. With the help of electrophysiological information, the effects of the dynamics of intracellular substances on photosynthesis and growth of B. napus L. under low-P stress can be investigated, and the plant’s adaptive response can be revealed. However, the findings of the current hydroponic study are not directly applicable to field conditions with naturally P-deficient soils.

Study on Optimization of Liquid Fermentation Medium and Antitumor Activity of the Mycelium on Phyllopora lonicerae.

Phylloporia lonicerae is an annual fungus that specifically parasitizes living Lonicera plants, offering significant potential for developing new resource food and medicine. However, wild resources and mycelium production of this fungus is limited, and its anti-tumor active ingredients and mechanisms remain unclear, hampering the development of this fungus. Thus, we optimized the fermentation medium of P. lonicerae and studied the anti-tumor activity of its mycelium. The results indicated that the optimum fermentation medium consisted of 2% sucrose, 0.2% peptone, 0.1% KH2PO4, 0.05% MgSO4·7H2O, 0.16% Lonicera japonica petals, 0.18% P fungal elicitor, and 0.21% L. japonica stem. The biomass reached 7.82 ± 0.41 g/l after 15 days of cultivation in the optimized medium, a 142% increase compared with the potato dextrose broth medium, with a 64% reduction in cultivation time. The intracellular alcohol extract had a higher inhibitory effect on A549 and Eca-109 cells than the intracellular water extract, with half-maximal inhibitory concentration values of 2.42 and 2.92 mg/ml, respectively. Graded extraction of the alcohol extract yielded petroleum ether phase, chloroform phase, ethyl acetate phase, and n-butanol phase. Among them, the petroleum ether phase exhibited a better effect than the positive control, with a half-maximal inhibitory concentration of 113.3 μg/ml. Flow cytometry analysis indicated that petroleum ether components could induce apoptosis of Eca-109 cells, suggesting that this extracted component can be utilized as an anticancer agent in functional foods. This study offers valuable technical support and a theoretical foundation for promoting the comprehensive development and efficient utilization of P. lonicerae.

Sex and mental health are related to subcortical brain microstructure

Some mental health problems such as depression and anxiety are more common in females, while others such as autism and attention deficit/hyperactivity (AD/H) are more common in males. However, the neurobiological origins of these sex differences are poorly understood. Animal studies have shown substantial sex differences in neuronal and glial cell structure, while human brain imaging studies have shown only small differences, which largely reflect overall body and brain size. Advanced diffusion MRI techniques can be used to examine intracellular, extracellular, and free water signal contributions and provide unique insights into microscopic cellular structure. However, the extent to which sex differences exist in these metrics of subcortical gray matter structures implicated in psychiatric disorders is not known. Here, we show large sex-related differences in microstructure in subcortical regions, including the hippocampus, thalamus, and nucleus accumbens in a large sample of young adults. Unlike conventional T1-weighted structural imaging, large sex differences remained after adjustment for age and brain volume. Further, diffusion metrics in the thalamus and amygdala were associated with depression, anxiety, AD/H, and antisocial personality problems. Diffusion MRI may provide mechanistic insights into the origin of sex differences in behavior and mental health over the life course and help to bridge the gap between findings from experimental, epidemiological, and clinical mental health research.

Screening of New Dendrobium officinale Strains Adapted to Karst Forest Environmental Stress Based on Electrophysiological Detection Method

At present, the main methods of breeding Dendrobium officinale (D. officinale) include introduction and domestication, selective breeding, hybrid breeding, and mutation breeding. In the process, traditional methods of field investigation of agronomic traits are often used to select resistant varieties. Although these breeding methods are effective, they have a certain degree of subjectivity and empiricism, and the breeding cycle is long. Electrophysiological instruments were used in this experiment to test the material transport and metabolic capacity of D. officinale in a karst forest epiphytic environment and to quickly evaluate the suitability of different strains of D. officinale in a drought environment. These instruments detected the data on electrophysiological information of leaves of different strains of D. officinale under long-term drought conditions, providing immediate access to the inherent electrophysiological information of the leaves of these strains. Based on the electrophysiological parameters of D. officinale leaves as defined by the inherent electrophysiological information of plants, the water metabolism, nutrient transport, and metabolic capacity in different leaves were evaluated. The key electrophysiological indexes were verified by combining the results of chlorophyll fluorescence and chlorophyll content. The results indicate the following: (1) Parameters defined based on electrophysiological information effectively characterized the differences in intracellular water utilization, the nutrient transport status, and the metabolic capacity of different D. officinale strains. (2) The intrinsic physiological resistance, intrinsic physiological reactance, active nutrient transport capacity, and passive nutrient transport capacity were closely related to the growth status and chlorophyll function of D. officinale leaves. These electrophysiological parameters could serve as critical indicators for evaluating the drought resistance of D. officinale. (3) Under severe drought stress, strain LH1 exhibited less leaf damage, adequate water/nutrient supply, vigorous life activities, and excellent drought resistance. We found that strain LH1 demonstrates better adaptation to the arid environment of karst forest lands. The electrophysiological detection method employed in this study offers a new technique for screening wild-cultivated D. officinale resistance strains. The results indicate that the real-time online leaf electrophysiological information measured by the method in this study can characterize the energy and material metabolism of crops, greatly improving the efficiency of crop-variety selection and reducing costs. These conclusions can be used to obtain real-time information on the transmission of water and nutrients within plant cells and can provide theoretical support for studying the adaptation mechanisms of crops to adverse environments.