Cell Water Content Research Articles

Effect of water stress on the accumulation of dehydrins in callus culture cells from Pinus sylvestris L.

Intraspecific differences in the level of stress tolerance in woody plants remain understudied, even though this characteristic is important for tree breeding. Dehydrins are intracellular defense proteins that protect other proteins, as well as membranes, from damage caused by intracellular dehydration under water stress. The present paper aims to examine the possibility of detecting dehydrins produced in response to water stress, as well as interindividual differences in dehydrin accumulation in Pinus sylvestris L. (Scots pine) under in vitro conditions. In this work, callus culture derived from the branch and bud tissues of two Scots pine trees (T3 and T4) was used; for these trees, quantitative and qualitative differences in the composition of dehydrins were found. Interindividual differences in callus cultures were expressed as variations in the frequency of callus formation events and callus culture growth index. With the addition of 5 or 8% polyethylene glycol to the culture medium, the effect of water stress on the callus culture was expressed in a dose-dependent decrease of water content in callus cells, as well as the accumulation of shock protein Hsp70 and dehydrins having masses of 47, 42, and 27 kDa. The composition of dehydrins and the level of their accumulation differed between calluses derived from T3 and T4, suggesting different levels of water stress tolerance in the cells of these callus cultures. The existence of such differences may provide a basis for detecting dehydrins in Scots pine produced in response to water stress.

Demonstration of Fast Simultaneous Neutron and X-Ray Tomography for Fuel Cell Water Content Measurements

Neutron radiography has been a powerful tool for measuring water content within operating fuel cells. The resolution for neutron imaging has been steadily improving and has demonstrated the ability to measure water content in industrially relevant catalyst layers. The difficulty in measuring catalyst layer or interfacial water content with neutron radiography is that the method assumes that the layers of the MEA are flat and uniform with no variation which is a poor assumption. To combat this assumption, it is necessary to move to neutron tomography that resolves the fuel cell in three dimensions. Combining neutron tomography with simultaneous X-ray tomography improves layer and interface identification which facilitates better water saturation measurements. In addition to capturing the “waviness” of the MEA, this method can be applied to tracking water distribution in structured 3D electrodes. This talk will demonstrate current developments in fast simultaneous neutron and X-ray tomography, methods to improve saturation calculations within the various porous layers, and showcase new hardware developments available to the NIST user community.

Nanochelating-based fertilizers: Innovations for yield enhancement in hydroponic cultivation

The increasing human population has resulted in a rise in the use of chemical fertilizers to enhance crop efficiency and quality. However, the utilization of these fertilizers has led to significant environmental pollution and raised concerns, including the potential risk of cancer. Consequently, there is a growing need for innovative fertilizer formulations that reduce dependency on chemical fertilizers. Nanochelating, an advanced technology, offers a promising solution by synthesizing chelated nutrients with diameters smaller than 100 nm. These nanochelates have shown considerable effects on crop productivity, even at lower concentrations compared with traditional chemical fertilizers. In this hydroponic study, we investigated the effects of various concentrations of nanochelated fertilizers (NCF) using the standard formulation outlined by "Resh" (0.25×Resh, 0.5×Resh, 0.75×Resh, 1×Resh and 1.25×Resh) in the cultivation of tomato and cucumber. Control plants were treated with chemical fertilizers (CF). The NCF-treated plants exhibited improvements in fruit attributes and plant development. Notably, the addition of 0.5×Resh-NCF significantly enhanced vegetative growth, fruit quality, total soluble solids, fruit length, and diameter, and plant pigments. Cucumber and tomato plants treated with 0.5×Resh NCF, at half the strength of the CF treatment, displayed the highest yield, with tomatoes yielding approximately 2.02 times more and cucumbers yielding 3 times more than the CF treatment. CF-fed tomato and cucumber plants exhibited lower cell membrane stability and water content. Proline content, an indicator of plant stress, decreased in the NCF-treated plants but increased at the highest concentration. Furthermore, catalase and peroxidase activity increased in tomato and cucumber plants following NCF application. These findings underscore the potential of nanochelating-based fertilizers to enhance growth, productivity, and associated components while minimizing fertilizer usage in hydroponic greenhouses.

Ectopic callose deposition into woody biomass modulates the nano-architecture of macrofibrils

Plant biomass plays an increasingly important role in the circular bioeconomy, replacing non-renewable fossil resources. Genetic engineering of this lignocellulosic biomass could benefit biorefinery transformation chains by lowering economic and technological barriers to industrial processing. However, previous efforts have mostly targeted the major constituents of woody biomass: cellulose, hemicellulose and lignin. Here we report the engineering of wood structure through the introduction of callose, a polysaccharide novel to most secondary cell walls. Our multiscale analysis of genetically engineered poplar trees shows that callose deposition modulates cell wall porosity, water and lignin contents and increases the lignin–cellulose distance, ultimately resulting in substantially decreased biomass recalcitrance. We provide a model of the wood cell wall nano-architecture engineered to accommodate the hydrated callose inclusions. Ectopic polymer introduction into biomass manifests in new physico-chemical properties and offers new avenues when considering lignocellulose engineering.

Tissue characterization of benign cardiac tumors by cardiac magnetic resonance imaging, a review of core imaging protocol and benign cardiac tumors.

Generally, cardiac masses are initially suspected on routine echocardiography. Cardiac magnetic resonance (CMR) imaging is further performed to differentiate tumors from pseudo-tumors and to characterize the cardiac masses based on their appearance on T1/T2-weighted images, detection of perfusion and demonstration of gadolinium-based contrast agent uptake on early and late gadolinium enhancement images. Further evaluation of cardiac masses by CMR is critical because unnecessary surgery can be avoided by better tissue characterization. Different cardiac tissues have different T1 and T2 relaxation times, principally owing to different internal biochemical environments surrounding the protons. In CMR, the signal intensity from a particular tissue depends on its T1 and T2 relaxation times and its proton density. CMR uses this principle to differentiate between various tissue types by weighting images based on their T1 or T2 relaxation times. Generally, tumor cells are larger, edematous, and have associated inflammatory reactions. Higher free water content of the neoplastic cells and other changes in tissue composition lead to prolonged T1/T2 relaxation times and thus an inherent contrast between tumors and normal tissue exists. Overall, these biochemical changes create an environment where different cardiac masses produce different signal intensity on their T1- weighted and T2- weighted images that help to discriminate between them. In this review article, we have provided a detailed description of the core CMR imaging protocol for evaluation of cardiac masses. We have also discussed the basic features of benign cardiac tumors as well as the role of CMR in evaluation and further tissue characterization of these tumors.

Uterine junctional zone and adenomyosis: comparison of MRI, transvaginal ultrasound and histology.

The uterine junctional zone is the subendometrial area in the myometrium that contributes to peristalsis and aids in spermatozoa and blastocyst transport. Alterations in the appearance of the junctional zone on transvaginal sonography (TVS) or magnetic resonance imaging (MRI) are associated with adenomyosis. The lack of standardization of description of its appearance and ill-defined boundaries on both histology and imaging hamper understanding of the junctional zone and limit its role in the diagnosis of adenomyosis. The objectives of this review were to investigate the accordance in definition of the junctional zone across different diagnostic approaches and to examine how imaging findings can be linked to histological findings in the context of diagnosis of adenomyosis. A comprehensive literature review was conducted of articles describing the appearance on imaging and the histological structure of the uterine junctional zone. Our review suggests that the junctional zone is distinguished from the middle and outer myometrium by gradual changes in smooth-muscle cell density, extracellular space, connective tissue, water content and vascular properties. However, while the signal intensity from the junctional zone to the middle myometrium changes abruptly on MRI, the histopathological changes are gradual and its border may be difficult or impossible to distinguish on two-dimensional TVS. Moreover, the thickness of the junctional zone measured on MRI is larger than that measured on TVS. Thus, these two imaging modalities reflect this zone differently. Although a thickened junctional zone is often used to diagnose adenomyosis on MRI, the presence of adenomyosis can be described more accurately as interruptions of the junctional zone by endometrial tissue, which leads to direct signs on imaging such as subendometrial lines and buds on two- and three-dimensional TVS or bright foci on MRI. The histopathological criteria for diagnosis are based on enlargement of the uterus with severe adenomyosis, and might not reflect its early stages. Clinicians should be aware that findings on MRI cannot be extrapolated readily to ultrasound. An understanding of this is necessary when investigating the uterine junctional zone as a functional unit and the association between visualization of direct features of adenomyosis in the junctional zone and clinical symptoms. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Stability of Glass Ceramic Sealants in Atmospheres with Increased Water Contents

Operating solid oxide cells (SOC) in the fuel cell moder as well as in electrolyser mode increases the demands on the stability of glass-based sealants due to higher cell voltages and water contents in the steam atmospheres. Glasses in the system BaO-CaO-Al2O3-SiO2 with B2O3 and La2O3-additions form glass ceramics with extraordinary high CTE-values, suitable as sealants compatible with Crofer 22 APU interconnect in electrolyte supported stacks. The intrinsic properties of a set of glasses are characterized. Sandwich type sealing samples are exposed to a dual atmosphere at 850 °C with an electric voltage of 1,3 V applied across the sealants and a water content of 50 % in the steam atmosphere. In this out-of-stack environment, the resistance of the sealants is recorded. Their resistance over aging time indicates degradation phenomena like interface reactions. By SEM analysis, reactions between sealants and steel interconnect can be correlated with insulating characteristics.

Abstract #1398160: A Rare Case of Water Clear Cell Parathyroid Adenoma Escaping Sestamibi Scan and Neck Ultrasound – A Diagnostic Conundrum of a Rare Pathological Intity with a Rare Presentation

Parathyroid water-clear cell hyperplasia (WCCH) and water-clear cell adenoma (WCCA) are extremely rare causes of primary hyperparathyroidism (PHPT). WCCH contributes to < 1% of all PHPT however WCCA is exceptionally rare and has been reported only in less than 30 case reports. We are presenting a very rare indolent pathological entity with a very rare presentation escaping common diagnostic measures of Sestamibi scan and neck ultrasound. A 63-year-old female presented for evaluation of severe osteoporosis with a T-score of -3.6. Laboratory workup revealed elevated parathyroid hormone (PTH) of 122 pg/ml (reference range 12-88 pg/ml), Normal calcium 9.8 mg/dl, Normal vitamin D 50 ng/ml, and normal magnesium 2.2 mg/dl. 24-hour urine calcium was 421 mg/24H. Diagnosis was consistent with normocalcemic PHPT and meeting surgical criteria with osteoporosis and high urine calcium. Sestamibi scan did not identify any focal activity. CT H&N revealed an 8 mm mass inferior and posterior to right thyroid lobe with partial washout and slightly different enhancement compared to thyroid gland. Neck ultrasound (US) reported that previously noted tissue activity on the CT H&N is not visualized and most likely represents normal thyroid tissue. Patient was referred to otolaryngology surgery and underwent four gland explorations, including right inferior and left superior parathyroidectomy. Pathology of superior parathyroid gland revealed parathyroid water clear cell adenoma. 3-month Postoperative PTH 29.4 pg/ml and calcium level of 9.3 mg/dl. Solitary parathyroid adenoma (SPA) attributes to 80-85% of PHPT. Majority of cases is due to Chief cell adenomas, less frequent pathologies include oxyphil cell adenoma, lipoadenoma, WCCA or mixed type. Scientific literature regarding WCCA presentation and diagnosis is blurred due to its rarity. Clinical presentation of WCCA resembles other etiologies of PHPT, though some data suggest that is frequently indolent and manifests with mild PHPT. Literature suggests that WCCA has low biochemical activity and most cases had normal to mildly elevated calcium-our patient support this hypothesis-. Hypercalcemia does not manifest until significant growth of the adenoma, though few reported cases manifested with hypercalcemia. Unlike other SPA where Sestamibi scan sensitivity is 91%, literature suggests possibility of false-negative results with WCCA which is hypothesized to be attributed to its different histology of glycogen-rich vacuolized cytoplasm that leads to fast Sestamibi wash-out, for the same reason data suggest that US is more decisive given high water content of cells -Our patient didn’t follow this rule and escaped Sistamibi and US though seen on CT- which still makes the diagnosis of WCCA a conundrum. Some cases underwent surgical excision based on clinical diagnosis which led to revision of PHPT and/or hypercalcemia. There is no available data suggesting different long-term follow-up regimens for WCCA compared to other SPA. Further literature with longer follow-up is needed for this extremely rare entity for a comprehensive understanding of its natural course.

Nanoscale biomaterials for terahertz imaging: A non-invasive approach for early cancer detection

Terahertz (THz) technology is developing a non-invasive imaging system for biosensing and clinical diagnosis. THz medical imaging mainly benefits from great sensitivity in detecting changes in water content and structural variations in diseased cells versus normal tissues. Compared to healthy tissues, cancerous tumors contain a higher level of water molecules and show structural changes, resulting in different THz absorption. Here we described the principle of THz imaging and advancement in the field of translational biomedicine and early detection of pathologic tissue, with a particular focus on oncology. In addition, although the main forte of THz imaging relies on detecting differences in water content to distinguish the exact margin of tumor, THz displays limited contrast in living tissue for in-vivo clinical imaging. In the last few years, nanotechnology has attracted attention to aid THz medical imaging and various nanoparticles have been investigated as contrast enhancements to improve the accuracy, sensitivity, and specificity of THz images. Most of these multimodal contrast agents take advantage of the temperature-dependent of THz spectrum to the conformational variation of the water molecule. We discuss advances in developing THz contrast agents to accelerate the advancement of non-invasive THz imaging with improved sensitivity and specificity for translational clinical oncology.

Comprehensive single-shot biophysical cytometry using simultaneous quantitative phase imaging and Brillouin spectroscopy

Single-cell analysis, or cytometry, is a ubiquitous tool in the biomedical sciences. Whereas most cytometers use fluorescent probes to ascertain the presence or absence of targeted molecules, biophysical parameters such as the cell density, refractive index, and viscosity are difficult to obtain. In this work, we combine two complementary techniques—quantitative phase imaging and Brillouin spectroscopy—into a label-free image cytometry platform capable of measuring more than a dozen biophysical properties of individual cells simultaneously. Using a geometric simplification linked to freshly plated cells, we can acquire the cellular diameter, volume, refractive index, mass density, non-aqueous mass, fluid volume, dry volume, the fractional water content of cells, both by mass and by volume, the Brillouin shift, Brillouin linewidth, longitudinal modulus, longitudinal viscosity, the loss modulus, and the loss tangent, all from a single acquisition, and with no assumptions of underlying parameters. Our methods are validated across three cell populations, including a control population of CHO-K1 cells, cells exposed to tubulin-disrupting nocodazole, and cells under hypoosmotic shock. Our system will unlock new avenues of research in biophysics, cell biology, and medicine.

An improved MPPT control-based ANFIS method to maximize power tracking of PEM fuel cell system

The main benefits of proton exchange membrane fuel cell (PEMFC) Include high efficiency, long lifetime and low operating temperature. Due to the mentioned benefits, the PEM fuel cell is used widely in applications such as buses, recreation vehicles, and lightweight vehicles. Nevertheless, the main limitations of them Include the high dependency of their output power on the temperature of cell and membrane water content. There exist one unique operating point for such a system with maximum output under variation operation circumstances. Consequently, it is required for the PEM fuel cell to extract the maximum power to improve efficiency. Accordingly, a promoted MPPT strategy is designed in this paper deploying the Incremental conductance (Inc) method optimized by employing a modified fluid search optimization algorithm (MFSO) algorithm-based adaptive neuro-fuzzy inference system (ANFIS). This technique Includes two stages specifying the optimal values of power by deploying the MFSO algorithm taking into consideration variations of temperature and membrane water content used as the input–output training information set in the ANFIS in the first stage. The second stage, the Inc technique would initialize at this value and seek the maximum power point (MPP). One of the merits associated with using the ANFIS-based Inc technique is the smaller dataset needed for the training purpose. In this regard, in case the ANFIS does not specify the definite point, the Inc approach would do it. The proposed method is simulated, and the results derived verify that the MFSO-ANFIS-based Inc MPPT algorithm would efficiently lead to the global maxima taking into account various climate conditions. This method is also highly efficient, fast, and stable. The efficiency of the suggested method is properly investigated by considering a 7 kW PEMFC fed by a DC-DC boost converter in Matlab/Simulink environment.

Variability in Essential Oil Constituents, Antioxidant Activities and Yield of Elite Small Cardamom Lines (Elettaria cardamomum Maton) Under Moisture Deficit Stress

A field study was conducted at ICAR-Indian Institute of Spices Research, Regional Station, Madikeri, Karnataka during 2018 and 2019 to evaluate elite lines of small cardamom (Elettaria cardamomum Maton) for capsule yield, essential oil constituents, photosynthesis and antioxidant enzyme activities under moisture stress condition. Eight small cardamom lines were selected for the study and were grown under irrigated and moisture stress conditions adopting all the package of practices. Photosynthetic gas exchange, relative water content, total soluble proteins and antioxidant enzyme activities were determined at panicle initiation stage during summer. Yield and essential oil components were recorded after harvest. The results showed that moisture stress significantly reduced the soluble protein content and stomatal conductance in the leaves thereby lowering net photosynthetic rate, thus inhibiting growth and yield. Antioxidant enzyme activities viz. catalase, peroxidase, superoxide dismutase and polyphenol oxidase were significantly influenced by moisture stress. Among the genotypes, IC584058 showed bold capsules, higher and less reduction in yield under irrigated and moisture stress condition, respectively. It is suggested that the soluble protein and antioxidant enzymes in leaves play important role in maintaining cell water content and photosynthetic gas exchange during panicle initiation stage leading to less reduction in yield under moisture deficit condition. The essential oil components of three lines namely IC584058, IC584078 and IC584090 showed drastic variation under moisture stress. Though the α-terpinyl acetate content decreased (P<0.05), the oxygenated monoterpenes significantly increased in stress tolerant genotype IC584058 which influences antioxidant and antimicrobial activities leading to plant adaptive defense mechanism under moisture.

Material Properties and Cell Compatibility of Photo-Crosslinked Sericin Urethane Methacryloyl Hydrogel.

There is a need to develop novel cytocompatible hydrogels for cell encapsulation and delivery in regenerative medicine. The objective of this work was to synthesize isocyanato ethyl methacryloyl-functionalized sericin and determine its material properties as a natural hydrogel for the encapsulation and delivery of human mesenchymal stem cells (MSCs) in regenerative medicine. Sericin extracted from silk cocoons was reacted with 2-isocyanatoethyl methacrylate (IEM) or methacrylic anhydride (MA) to produce sericin urethane methacryloyl (SerAte-UM) or sericin methacryloyl (SerAte-M, control) biopolymers, respectively. The hydrogels produced by photo-crosslinking of the biopolymers in an aqueous solution were characterized with respect to gelation kinetics, microstructure, compressive modulus, water content, degradation, permeability, and viability of encapsulated cells. The secondary structure of citric acid-extracted sericin was not affected by functionalization with IEM or MA. SerAte-UM hydrogel was slightly more hydrophilic than SerAte-M. The gelation time of SerAte-UM hydrogel decreased with an increasing degree of modification. The photo-polymerized SerAte-UM hydrogel had a highly porous, fibrous, honeycomb microstructure with an average pore size in the 40–50 µm range. The compressive modulus, swelling ratio, and permeability of SerAte-UM hydrogel depended on the degree of modification of sericin, and the mass loss after 21 days of incubation in aqueous solution was <25%. Both SerAte-UM and SerAte-M hydrogels supported viability and growth in encapsulated MSCs. The SerAte-UM hydrogel, with its higher hydrophilicity compared to SerAte-M, is promising as a matrix for encapsulation and delivery of stem cells in tissue engineering.

Increase in the Intracellular Bulk Water Content in the Early Phase of Cell Death of Keratinocytes, Corneoptosis, as Revealed by 65 GHz Near-Field CMOS Dielectric Sensor.

While bulk water and hydration water coexist in cells to support the expression of biological macromolecules, how the dynamics of water molecules, which have long been only a minor role in molecular biology research, relate to changes in cellular states such as cell death has hardly been explored so far due to the lack of evaluation techniques. In this study, we developed a high-precision measurement system that can discriminate bulk water content changes of ±0.02% (0.2 mg/cm3) with single-cell-level spatial resolution based on a near-field CMOS dielectric sensor operating at 65 GHz. We applied this system to evaluate the temporal changes in the bulk water content during the cell death process of keratinocytes, called corneoptosis, using isolated SG1 (first layer of stratum granulosum) cells in vitro. A significant irreversible increase in the bulk water content was observed approximately 1 h before membrane disruption during corneoptosis, which starts with cytoplasmic high Ca2+ signal. These findings suggest that the calcium flux may have a role in triggering the increase in the bulk water content in SG1 cells. Thus, our near-field CMOS dielectric sensor provides a valuable tool to dissect the involvement of water molecules in the various events that occur in the cell.

Analysis of cellular water content in T cells reveals a switch from slow metabolic water gain to rapid water influx prior to cell division

Cell growth is driven by the acquisition and synthesis of both dry biomass and water mass. In this study, we examine the increase of water mass in T cell during cell growth. We found that T-cell growth is characterized by an initial phase of slow increase in cellular water, followed by a second phase of rapid increase in water content. To study the origin of the water gain, we developed a novel methodology we call cold aqua trap-isotope ratio mass spectrometry, which allows analysis of the isotope composition of intracellular water. Applying cold aqua trap-isotope ratio mass spectrometry, we discovered that glycolysis-coupled metabolism of water accounts on average for 11 fl out of the 20 fl of water gained per cell during the initial slow phase. In addition, we show that at the end of the rapid phase before initiation of cell division, a water influx occurs, increasing the cellular water mass by threefold. Thus, we conclude that activated T cells switch from metabolizing water to rapidly taking up water from the extracellular medium prior to cell division. Our work provides a method to analyze cell water content as well as insights into the ways cells regulate their water mass.

Impact of Single and Combined Salinity and High-Temperature Stresses on Agro-Physiological, Biochemical, and Transcriptional Responses in Rice and Stress-Release.

Here, for the first time, we aimed to identify in rice the key mechanisms and processes underlying tolerance to high-temperature (HT) or salt stress (SS) alone, the co-occurrence of both stresses, and recovery using physiological and biochemical measurements and gene expression analysis. We also investigated whether recovery from the two stressors depended on the relative intensities/relief of each stressor. Wild type (‘Yukinkomai’) rice plants were found to be more susceptible to salinity or heat applied individually. SS leads to a depletion of cellular water content, higher accumulation of Na+, and alterations in photosynthetic pigments. The stress-tolerant cultivar ‘YNU31-2-4’ (YNU) displayed a lower Na+/K+ ratio, higher water content in cells and improved photosynthetic traits, antioxidant system, and expression of defence genes. Strikingly, the SS + HT combination provided a significant level of protection to rice plants from the effects of SS alone. The expression pattern of a selected set of genes showed a specific response and dedicated pathways in plants subjected to each of the different stresses, while other genes were explicitly activated when the stresses were combined. Aquaporin genes were activated by SS, while stress-related (P5CS, MSD1, HSPs, and ions transporters) genes were shaped by HT. Hierarchical clustering and principal component analyses showed that several traits exhibited a gradually aggravating effect as plants were exposed to the combined stresses and identified heat as a mitigating factor, clearly separating heat + salt-stressed from salt-non-heat-stressed plants. Furthermore, seedling recovery was far more dependent on the relative intensities of stressors and cultivars, demonstrating the influence of one stressor over another upon stress-release. Taken together, our data show the uniqueness and complexity of the physiological and molecular network modules used by rice plants to respond to single and combined stresses and recovery.

Critical Membrane Concentration and Mass-Balance Model to Identify Baseline Cytotoxicity of Hydrophobic and Ionizable Organic Chemicals in Mammalian Cell Lines.

All chemicals can interfere with cellular membranes and this leads to baseline toxicity, which is the minimal toxicity any chemical elicits. The critical membrane burden is constant for all chemicals; that is, the dosing concentrations to trigger baseline toxicity decrease with increasing hydrophobicity of the chemicals. Quantitative structure-activity relationships, based on hydrophobicity of chemicals, have been established to predict nominal concentrations causing baseline toxicity in human and mammalian cell lines. However, their applicability is limited to hydrophilic neutral compounds. To develop a prediction model that includes more hydrophobic and charged organic chemicals, a mass balance model was applied for mammalian cells (AREc32, AhR-CALUX, PPARγ-BLA, and SH-SY5Y) considering different bioassay conditions. The critical membrane burden for baseline toxicity was converted into nominal concentration causing 10% cytotoxicity by baseline toxicity (IC10,baseline) using a mass balance model whose main chemical input parameter was the liposome-water partition constants (Klip/w) for neutral chemicals or the speciation-corrected Dlip/w(pH 7.4) for ionizable chemicals plus the bioassay-specific protein, lipid, and water contents of cells and media. In these bioassay-specific models, log(1/IC10,baseline) increased with increasing hydrophobicity, and the relationship started to level off at log Dlip/w around 2. The bioassay-specific models were applied to 392 chemicals covering a broad range of hydrophobicity and speciation. Comparing the predicted IC10,baseline and experimental cytotoxicity IC10, known baseline toxicants and many additional chemicals were identified as baseline toxicants, while the others were classified based on specificity of their modes of action in the four cell lines, confirming excess toxicity of some fungicides, antibiotics, and uncouplers. Given the similarity of the bioassay-specific models, we propose a generalized baseline-model for adherent human cell lines: log[1/IC10,baseline (M)] = 1.23 + 4.97 × (1 - e-0.236logDlip/w). The derived models for baseline toxicity may serve for specificity analysis in reporter gene and neurotoxicity assays as well as for planning the dosing for cell-based assays.

Using some growth stimuli, a comparative study of salt tolerance in two tomatoes cultivars and a related wild line with special reference to superoxide dismutases and related micronutrients.

Salinity is a major global problem that threatens the agricultural sector, especially in areas that suffer from a shortage of water. It motivates ionic toxicity, osmotic and oxidative stresses, which greatly inhibits plant performances and crop productivites. However, micronutrients (MNs) or plant extracts, like germinated maize grain extract (gMGE), have been reported to minimize the effects of salt stress on plant growth and returns. Therefore, this study aimed at evaluating the influences of MNs or gMGE applied as foliar sprays on growth, physio-biochemical indices, and antioxidative system components in three genotypes of tomato plants stressed by 9 dS m−1 NaCl. This salinity level markedly increased Na+ content, lipid peroxidation, ion leakage, and markers related to oxidative stress (superoxide; O2•− and hydrogen peroxide; H2O2). Besides, marked increases in activities of enzymatic (especially different forms of superoxide dismutase; SODs) and non-enzymatic antioxidants and osmoprotectant compounds were also observed. In contrast, growth, photosynthetic capacity including hill reaction activity (HRA), K+/Na+ ratio, tissue cell integrity (e.g., cell water content and membrane stability), and K+ and MNs contents decreased significantly under stress. However, compared to MNs, gMGE significantly improved the activities of the antioxidative system components (particularly SODs) and osmoprotectants, which were reflected in reduced Na+ accumulation, lipid peroxidation, ion leakage, and oxidative stress. These results were coupled with remarkable elevations in photosynthetic capacity including HRA, K+/Na+ ratio, tissue cell integrity, K+ content, and MNs contents, all of which were reflected in the enhancement of plant growth. Compared to local tomato cultivars (e.g., Castle Rock and C10), the wild line “0043-1” had better results. The interaction of three factors; salt stress, promoters, and tomato genotypes was significant. The wild tomato line “0043-1” as the best salt-tolerant is a good candidate for implication in breeding programs for tolerance to salinity to produce salt-tolerant cultivars for use to maximize tomato growth and productivity in saline environments.

Cell Surface Area to Volume Relationship During Apoptosis and Apoptotic Body Formation.

Apoptosis is a programmed form of cell death culminating in packing cell content and corpse dismantling into membrane sealed vesicles called apoptotic bodies (ABs). Apoptotic bodies are engulfed and disposed by neighboring and immune system cells without eliciting a noxious inflammatory response, thus preventing sterile tissue damage. AB formation requires a total surface area larger than the apparent, initial cell's surface area. Apoptotic volume decrease (AVD) is a two-stage process leading to an isotonic, osmotic reduction in cell water content driven by net K+ and Cl- extrusion. In this article, the role of AVD is presented from a geometric point of view through the process of AB formation. AVD decisively contributes to (i) endowing the cell with the appropriate electrolytic environment for apoptotic execution; (ii) increasing the membrane surface area-to-volume ratio, along with the mobilization of membrane reservoirs (cell rounding, membrane folds and endosomal membranes), so that the cell corpse can be dismantled into ABs; and (iii) reducing plasmalemmal stretch, tension and stiffness, thus facilitating membrane bulging, blebbing and vesicle expansion ultimately leading to separation and release.

Energy absorption of human red blood cells and conductivity of the cytoplasm influenced by temperature

The energy absorbed into tissues is known as the specific energy absorption (SAR) which is dependent on conductivity of the tissue. We calculated cytoplasmic conductivity of human red blood cell (HRBC) using the intracellular ionic concentrations and the Debye-Hückel-Onsager relation. The overall concentration is determined by cell volume and cell water content. The calculated HRBC conductivity at 25 o C was σc,25 = 0.5566 ± 0.0146 S m−1, ±SE). It is exponentially related to temperature: Q10 ≈ 1.866. At 37 o C, the calculated SAR value is 1.6 W kg−1 using a linear temperature compensation of conductivity. However, if using a biologically realistic non-linear temperature compensated conductivity, the SAR is ≈ 2.62 ± 0.05 W kg−1. The relationship between SAR and temperature increase is not straightforward. Since there is a wide variance in cellular ionic and water perfusion rates more tissue-specific SAR limits which consider temperature-related factors would be valuable.