Subsequent Rehydration Research Articles

Effectiveness of Ondansetron in comparison to Domperidone for treating vomiting in acute gastroenteritis among children in a tertiary care hospital setting: A quasi-experimental study

BACKGROUND & OBJECTIVE: There is inconsistent evidence on using antiemetic drugs (ondansetron and domperidone) in children with vomiting associated with gastroenteritis having dehydration. The study's objective was to compare the effectiveness of oral domperidone with ondansetron for treating vomiting during acute gastroenteritis in children with either mild or moderate dehydration.
 METHODOLOGY: This non-controlled quasi-experimental study was conducted at Allama Iqbal Teaching Hospital, Sialkot, in the department of Pediatrics from 1st October 2019 to 31st December 2019. Sixty children aged 1-12 years having acute gastroenteritis, with mild or moderate dehydration after the failure of initial oral rehydration therapy, were included. Children in-group A (n=30) received a single dose of an orally disintegrating tablet of ondansetron, and children in-group B (n=30) were treated with domperidone. The absence of vomiting for 6 hours and subsequent successful rehydration in these two groups was the primary outcome. The Chi-square test was applied to compare the frequency of primary outcome between the ondansetron and domperidone groups, considering p-value ≤0.05 was considered statistically significant.
 RESULTS: The mean age of patients was 4.4±1.8 years in group A compared to 5.1±2.7 years in group B. Oral Ondansetron was successful in controlling vomiting in 19(63.4%) patients compared to 11(36.6%) in domperidone group (p=0.39).
 CONCLUSION: The single dose of oral ondansetron compared to domperidone was significantly effective in controlling the vomiting in-patient with acute gastroenteritis presented with either mild or moderate dehydration, resulting in effective oral rehydration subsequently.

Localization of Lipid Droplets in Embryonic Axis Radicle Cells of Soybean Seeds under Various Imbibition Regimes Indicates Their Role in Desiccation Tolerance.

Desiccation tolerance allows plant seeds to remain viable during desiccation and subsequent re-hydration. In this study, we tried to develop an experimental system to understand the difference between desiccation tolerant and desiccation sensitive radicle cells by examining excised embryonic axes after re-desiccation and subsequent imbibition under various regimes. Embryonic axes excised from soybean (Glycine max (L.) Merr.) seeds imbibed for 3 h to 15 h which remained attached to the cotyledons during imbibition would grow normally after 24 h of desiccation and re-imbibition on wet filter paper. By contrast, when the embryonic axes excised after 3 h imbibition of seeds were kept on wet filter paper for 12 h to 16 h, their growth was significantly retarded after 24 h of desiccation and subsequent re-imbibition. Numerous lipid droplets were observed lining the plasma membrane and tonoplasts in radicle cells of desiccation tolerant embryonic axes before and after desiccation treatment. By contrast, the lipid droplets lining the plasma membrane and tonoplasts became very sparse in radicle cells that were placed for longer times on wet filter paper before desiccation. We observed a clear correlation between the amount of lipid droplets lining plasma membranes and the ability to grow after desiccation and re-imbibition of the excised embryonic axes. In addition to the reduction of lipid droplets in the cells, a gradual increase in starch grains was observed. Large starch grains accumulated in the radicle cells of those axes that failed to grow further.

Исследование процессов термического разложения и регидратации Mg-Al СДГ, полученных методом твердофазного синтеза

Mg-Al LDH samples of Mg4Al2(OH)12CO33,85HO composition were obtained by solid-phase synthesis. It was found that as a result of heat treatment with subsequent rehydration, synthesized Mg-Al LDH samples are reduced to the composition Mg4Al2(OH)12CO33HO, regardless of the medium and duration of treatment. It has been shown that rehydration in NaHCO3 solutions contributes to an increase in the crystallite sizes of Mg-Al LDH samples being recovered, which is not observed when Mg-Al LDH is reduced in an aqueous medium. An increase in the duration of hydration in NaHCO3 solutions leads to an increase in the crystallites of Mg-Al reduced LDH, which is not observed during rehydration in an aqueous medium.

Photosynthetic recovery in drought-rehydrated grapevines is associated with high demand from the sinks, maximizing the fruit-oriented performance.

To understand how grapevine sinks compete with each other during water stress and subsequent rehydration, carbon (C) allocation patterns in drought-rehydrated vines (REC) at the beginning of fruit ripening were compared with control vines maintained under drought (WS) or fully irrigated (WW). In the 30 days following rehydration, the quantity and distribution of newly fixed C between leaves, roots and fruits was evaluated through 13 CO2 pulse-labeling and stable isotope ratio mass spectrometry. REC plants diverted the same percentage of fixed C towards the berries as the WS plants, although the percentage was higher than that of WW plants. Net photosynthesis (measured simultaneously with root respiration in a multichamber system for analysis of gas exchange above- and below-ground) was approximately two-fold greater in REC compared to WS treatment, and comparable or even higher than in WW plants. Maximizing C assimilation and delivery in REC plants led to a significantly higher amount of newly fixed C compared to both control treatments, already 2 days after rehydration in root, and 2 days later in the berries, in line with the expression of genes responsible for sugar metabolism. In REC plants, the increase in C assimilation was able to support the requests of the sinks during fruit ripening, without affecting the reserves, as was the case in WS. These mechanisms clarify what is experienced in fruit crops, when occasional rain or irrigation events are more effective in determining sugar delivery towards fruits, rather than constant and satisfactory water availabilities.

Comparative proteomic changes in rabbit vocal folds undergoing systemic dehydration and systemic rehydration

BackgroundA considerable body of clinical evidence suggests that systemic dehydration can negatively affect voice production, leading to the common recommendation to rehydrate. Evidence for the corrective benefits of rehydration, however, is limited with mixed conclusions, and biological data on the underlying tissue changes with rehydration is lacking. In this study, we used a rabbit model (n = 24) of acute (5 days) water restriction-induced systemic dehydration with subsequent rehydration (3 days) to explore the protein-level changes underlying the molecular transition from euhydration to dehydration and following rehydration using LC-MS/MS protein quantification in the vocal folds. We show that 5-day water restriction led to an average 4.3% decrease in body weight with relative increases in anion gap, Cl-, creatinine, Na+, and relative decreases in BUN, iCa2+, K+, and tCO2 compared to control (euhydrated) animals. A total of 309 differentially regulated (p < 0.05) proteins were identified between the Control and Dehydration groups. We observed a noteworthy similarity between the Dehydration and Rehydration groups, both well differentiated from the Control group, highlighting the distinct timelines of resolution of the clinical symptoms of systemic dehydration and the underlying molecular changes. SignificanceVoice disorders are a ubiquitous problem with considerable economic and psychological impact. Maintenance of proper hydration is commonly prescribed as a general vocal hygiene practice. There is evidence that dehydration negatively impacts phonation, but our understanding of the state of vocal folds in the context of systemic dehydration are limited, particular from a molecular perspective. Further, ours is a novel molecular study of the short-term impact of rehydration on the tissue. Given the relatively minimal difference in vocal fold proteomic profiles between the Dehydration and Rehydration groups, our data demonstrate a complex physiological response to acute systemic dehydration, and highlight the importance of considering persistent underlying molecular pathology despite the rapid resolution of clinical measures. This study sets a foundation for future research to confirm the nature of potential beneficial outcomes of clinical recommendations related to hydration.

Effect of spray freeze drying on the structural modification and rehydration characteristics of micellar casein powders

Micellar casein (MC) is usually spray-dried into powder form for transportation and storage. However, the micellar structure maintained by colloidal calcium phosphate (CCP) and hydrophobic forces leads to poor rehydration ability of MC powders, which limits its potential applications. Here, spray freeze drying (SFD) with controlled droplet size was used to produce MC powders. Their effects on the structure of MC and the subsequent rehydration characteristics including wetting, dispersion and dissolution were investigated. The results showed SFD powders obtained from smaller droplet size caused more than 50% of serum Ca2+ and PO43− to release from the micellar structure. These powder particles exhibited extremely high porosity (92%) and spherical morphology, which thus greatly shortened their wetting time. Furthermore, the smallest droplets during SFD were believed to produce the MC powders with the quickest dispersion and best solubility, as over 80% of the solids could be completely dissolved in just 15 min.

Desiccation-rehydration measurements in bryophytes: current status and future insights.

Desiccation-rehydration experiments have been employed over the years to evaluate desiccation tolerance of bryophytes (Bryophyta, Marchantiophyta, and Anthocerotophyta). Researchers have applied a spectrum of protocols to induce desiccation and subsequent rehydration, and a wide variety of techniques have been used to study desiccation-dependent changes in bryophyte molecular, cellular, physiological, and structural traits, resulting in a multifaceted assortment of information that is challenging to synthesize. We analysed 337 desiccation-rehydration studies, providing information for 351 species, to identify the most frequent methods used, analyse the advances in desiccation studies over the years, and characterize the taxonomic representation of the species assessed. We observed certain similarities across methodologies, but the degree of convergence among the experimental protocols was surprisingly low. Out of 52 bryophyte orders, 40% have not been studied, and data are lacking for multiple remote or difficult to access locations. We conclude that for quantitative interspecific comparisons of desiccation tolerance, rigorous standardization of experimental protocols and measurement techniques, and simultaneous use of an array of experimental techniques are required for a mechanistic insight into the different traits modified in response to desiccation. New studies should also aim to fill gaps in taxonomic, ecological, and spatial coverage of bryophytes.

Rehydration of the Tendon Fascicle Bundles Using Simulated Body Fluid Ensures Stable Mechanical Properties of the Samples.

In this work, we investigate the influence of dehydration and subsequent rehydration of tendon fascicle bundles on their structural and mechanical properties by using distilled water, 0.9% NaCl, 10% NaCl, SBF, and double concentrated SBF (SBFx2). The properties of tendon fascicle bundles were investigated by means of uniaxial tests with relaxation periods and hysteresis for samples with various interfascicular matrix content, dissected from the anterior and posterior areas of bovine tendon. Uniaxial tests with relaxation periods and analysis of sample geometry and weight showed that dehydration alters the modulus of elasticity dependent on the interfascicular matrix content and influences the viscoelastic properties of tendon fascicle bundles. Tensile and relaxation tests revealed that changes resulting from excessive sample drying can be reversed by rehydration in an SBF bath solution for elastic strain range above the toe region. Rehydration in SBF solution led to minor differences in mechanical properties when compared to control samples. Moreover, anterior samples with greater interfascicular matrix content, despite their lower stiffness, are less sensitive to sample drying. The obtained results allow us to limit the discrepancies in the measurement of mechanical properties of wet biological samples and can be useful to researchers investigating soft tissue mechanics and the stability of transplant materials.

Gas-bentonite interactions: Towards a better understanding of gas dynamics in Engineered Barrier Systems

Bentonite is a common backfill material used in Engineered Barrier Systems (EBS) for radioactive waste disposal. Its thermal, hydraulic, and chemical properties have been extensively studied. However, empirical evidence on the interactions with the free gas phase present in its pore space under conditions close to those prevailing in deep geological repositories (i.e., exposure to multiple gas species at temperature and humidity conditions close to those of freshly backfilled EBS) is scarce. This limits the prediction/assessment of the evolution of the gas composition in EBS. Here we present the outcome of laboratory experiments targeting such gas-bentonite interactions using two different types of bentonite (Italian bentonite; Wyoming bentonite) being exposed to atmospheric air in sealed stainless-steel vessels. The results indicate that gas sorption on bentonite can occur at repository-like conditions and is likely to play a significant role in the overall gas dynamics in the backfill of EBS. Drying of both bentonites was shown to partly re-activate their CO2 sorption capacity during a subsequent re-hydration phase. Furthermore, the grinding of Wyoming bentonite resulted in the generation of new pyrite surfaces that significantly enhanced O2 removal from the free gas phase by oxidation. Our initial investigations call for more systematic and extensive series of laboratory experiments in order to quantitatively constrain the different processes involved in gas-bentonite interactions.

Pectin self-assembly and its disruption by water: insights into plant cell wall mechanics.

Plant cell walls undergo multiple cycles of dehydration and rehydration during their life. Calcium crosslinked low methoxy pectin is a major constituent of plant cell walls. Understanding the dehydration-rehydration behavior of pectin gels may shed light on the water transport and mechanics of plant cells. In this work, we report the contributions of the microstructure to the mechanics of pectin-Ca gels subjected to different extents of dehydration and subsequent rehydration. This is investigated using a pectin gel composition that forms 'egg-box bundles', a characteristic feature of the microstructure of low methoxy pectin-Ca gels. Large amplitude oscillatory shear (LAOS) rheology along with small angle neutron scattering and near infrared (NIR) spectroscopy on pectin gels is used to elucidate the mechanical and microstructural changes during dehydration-rehydration cycles. As the extent of dehydration increases, the reswelling ability, strain-stiffening behavior and yield strain decrease. These effects are more prominent at faster rates of dehydration and are not completely reversible upon rehydration to the initial undried state. Microstructural changes due to the aggregation of egg-box bundles and single chains and the associated changes in the water configurations lead to these irreversible changes.

Identification of resurrection genes from the transcriptome of dehydrated and rehydrated Selaginella tamariscina

ABSTRACT Selaginella tamariscina is a lycophyta species that survives under extremely dry conditions via the mechanism of resurrection. This phenomenon involves the regulation of numerous genes that play vital roles in desiccation tolerance and subsequent rehydration. To identify resurrection-related genes, we analyzed the transcriptome between dehydration conditions and rehydration conditions of S. tamariscina. The de novo assembly generated 124,417 transcripts with an average size of 1,000 bp and 87,754 unigenes. Among these genes, 1,267 genes and 634 genes were up and down regulated by rehydration compared to dehydration. To understand gene function, we annotated Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). The unigenes encoding early light-inducible protein (ELIP) were down-regulated, whereas pentatricopeptide repeat-containing protein (PPR), late embryogenesis abundant proteins (LEA), sucrose nonfermenting protein (SNF), trehalose phosphate phosphatase (TPP), trehalose phosphate synthase (TPS), and ABC transporter G family (ABCG) were significantly up-regulated in response to rehydration conditions by differentially expressed genes (DEGs) analysis. Several studies provide evidence that these genes play a role in stress environment. The ELIP and PPR genes are involved in chloroplast protection during dehydration and rehydration. LEA, SNF, and trehalose genes are known to be oxidant scavengers that protect the cell structure from the deleterious effect of drought. TPP and TPS genes were found in the starch and sucrose metabolism pathways, which are essential sugar-signaling metabolites regulating plant metabolism and other biological processes. ABC-G gene interacts with abscisic acid (ABA) phytohormone in the stomata opening during stress conditions. Our findings provide valuable information and candidate resurrection genes for future functional analysis aimed at improving the drought tolerance of crop plants.

Importance of Water in Maintaining Softwood Secondary Cell Wall Nanostructure.

Water is one of the principal constituents by mass of living plant cell walls. However, its role and interactions with secondary cell wall polysaccharides and the impact of dehydration and subsequent rehydration on the molecular architecture are still to be elucidated. This work combines multidimensional solid-state 13C magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) with molecular dynamics modeling to decipher the role of water in the molecular architecture of softwood secondary cell walls. The proximities between all main polymers, their molecular conformations, and interaction energies are compared in never-dried, oven-dried, and rehydrated states. Water is shown to play a critical role at the hemicellulose–cellulose interface. After significant molecular shrinkage caused by dehydration, the original molecular conformation is not fully recovered after rehydration. The changes include xylan becoming more closely and irreversibly associated with cellulose and some mannan becoming more mobile and changing conformation. These irreversible nanostructural changes provide a basis for explaining and improving the properties of wood-based materials.

States of water in recast Nafion® films

The amount and states of water in a polymer electrolyte significantly affect the material's morphology as well as its mechanical and transport properties, and thus determine performance in many important applications such as fuel cells, electrolyzers, and other electrochemical energy conversion devices. In this study, recast H+-Nafion® films were characterized using attenuated total internal reflection FTIR (ATR-FTIR) spectroscopy before and after thermal annealing and subsequent rehydration. The states of water in the hydrated films were determined by analyzing the O–H stretching band of water using principle component analysis and multivariate curve resolution. It was found that annealing at a temperature above the glass transition temperature caused the water hydrogen-bonding networks in the water-ionic clusters to become restricted, suggesting that annealing forms a robust polymer matrix confining the water-ionic clusters. The evolution of film morphology with increasing thermal-annealing temperature was confirmed with small-angle X-ray scattering (SAXS) and CO2 diffusion measurements. Fuel cell performance tests using annealed and unannealed Nafion® in the cathode catalyst layer found improved stability when the cathode catalyst was annealed, indicating that thermal history is an important design parameter in electrochemical energy conversion device fabrication.

Effects of low temperatures on the conformation of apo-lactoferrin and its interactions with α-lactalbumin and β-lactoglobulin: Application of in silico approaches

Lactoferrin (LF) is a multi-functional protein that is primarily found in milk. The apo form of LF (apo-LF) is devoid of iron, and as a result, may serve as an iron scavenger with attendant anti-pathogenic properties, thereby, endowing apo-LF with promising health benefits. Despite these advantages, the structural stability of apo-LF may be perturbed by various processing conditions. One of the strategies employed to stabilise the activity of apo-LF is to encapsulate it as part of an oligomeric complex, composed of apo-LF, α-lactalbumin (α-La) and β-lactoglobulin (β-Lg). Accordingly, the aim of this study is to investigate the structural changes of apo-LF and its interactions with α-La and β-Lg under the temperature conditions of freeze-drying (−30, 0, and 20 °C). Using in silico approaches, molecular dynamics simulations showed apo-LF had limited structural perturbation when processed at these temperatures. Both α-La and β-Lg stabilise apo-LF by enhancing and maintaining the structural integrity and cohesion of the tertiary structure of apo-LF. These stabilities are the result of electrostatic interactions, binding apo-LF and the protective proteins into a multimeric complex. The secondary structure and the anti-bacterial derivatives in apo-LF were also sustained under these simulated conditions. Furthermore, inter-residue contact maps in apo-LF predict an increase in intramolecular contacts at simulated freeze-drying conditions, resulting in agglomeration and, therefore potential proteins dispersibility during subsequent rehydration. Overall, this work demonstrates the advantages of computational approaches to understand the macromolecular conformations, interactions, and functional implications of a multimeric complex composed of apo-LF, α-La, and β-Lg at low temperatures.

The role of rehydration in enhancing the basic properties of Mg–Al hydrotalcites for biodiesel production

An Mg–Al hydrotalcite with a Mg/Al molar ratio of 3 was prepared via co-precipitation. The XRD and FTIR analyses proved the presence of the hydrotalcite structure in the uncalcined solid, its destruction after calcination and its reconstruction after rehydration. TG-DSC analyses revealed a higher thermal stability of the rehydrated solids compared to the uncalcined solid. CO2-TPD analyses showed the presence of stronger and more abundant basic sites for the rehydrated solids. All prepared solids were then tested in the transesterification of sunflower oil [catalyst to oil ratio (CTOR) of 10 wt%, methanol to oil molar ratio (MOMR) of 12:1, temperature of 60 °C and reaction time of 2 h]. The uncalcined and calcined solids all exhibited low activities as evidenced by very low FAME yields (<1.5%). The catalytic activity was significantly improved for most of the rehydrated solids due to their higher basicity. Calcination of the fresh Mg–Al solid at 450 °C followed by subsequent rehydration (Mg6Al2-450RH) allowed the obtainment of a FAME yield of 56%. No biodiesel was formed in the presence of the rehydrated catalysts previously calcined at temperatures greater than 500 °C due to a reduced “memory effect”. The effects of reaction conditions such as the duration of rehydration treatment, reaction temperature, MOMR and CTOR on the activity of Mg6Al2-450RH were also studied. The obtained results in this work demonstrate the potential of rehydrated Mg–Al solids for biodiesel production. They could also be useful for optimizing the preparation conditions of reconstructed hydrotalcites as basic catalysts and contribute to the search for ideal conditions for biodiesel production.

The occurrence of Phycocalidia tanegashimensis (Bangiaceae) in the splash zone may be related to the tolerance of photochemical efficiency to temperature, irradiance, desiccation, and salinity

The combined effects of temperature and irradiance and the influences of desiccation and salinity on the photochemical efficiency in a subtropical red alga, Phycocalidia tanegashimensis (= Pyropia tanegashimensis, Bangiaceae) from Tanegashima Island, Japan, were determined to reveal how this species has adapted to its habitat in the splash zone. Continuous 6-h exposure to irradiance of 200 (low) and 1000 (high) µmol photons m−2 s−1 at 12, 20, and 28 °C showed a decline in the effective quantum yields (ΔF/Fm′) of photosystem II (PSII) during the exposures; nevertheless, the maximum quantum yields (Fv/Fm) of PSII measured in subsequent 14-h dim-light acclimation almost returned to initial values at 20 and 28 °C, revealing its high capacity to recovery. In contrast, those under both low and high irradiances at 12 °C did not recover to initial values even after 14-h dim-light acclimation, signifying enhanced inhibition under irradiance at low temperature. The response to continuous desiccation (~ 480 min) under 50% humidity at 24 °C showed that the ΔF/Fm′ decreased with decreasing absolute water content (AWC). However, for the samples with an AWC above 10%, ΔF/Fm′ mostly recovered to initial levels after subsequent 1-day rehydration in seawater, suggesting relatively strong tolerance to desiccation. This alga also tolerated a broad range of salinity (i.e., 10–60 psu) under 3-day exposures. The adaptations of P. tanegashimensis to relatively high irradiance, warm temperature, and a strong osmotic (desiccation and salinity) tolerance may explain its high capacity to flourish in the splash zone in the subtropical environment of Japan.

Longevity of Raw and Lyophilized Crude Urease Extracts

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.

The effects of four stressors, irradiance, temperature, desiccation, and salinity on the photosynthesis of a red alga, Agarophyton vermiculophyllum (Gracilariales) from a native distributional range in Japan

We examined the effects of four stressors, irradiance, temperature, desiccation, and salinity on the photosynthesis of a red alga, Agarophyton vermiculophyllum (= Gracilaria vermiculophylla, Gracilariales, Rhodophyta) from its native distributional range in Hokkaido and Kagoshima, Japan. Photosynthesis–irradiance (P–E) curves at 8, 16, and 28°C showed that the maximum net-photosynthetic rates (NPmax) and saturation irradiance (Ek) were highest at 28°C for both strains. Gross-photosynthesis determined at 8–40°C at 200 μmol photons m-2 s-1 showed that the maximum gross-photosynthetic rate (GPmax) occurred at 25.3°C for Hokkaido and 28.0°C for Kagoshima ( $$ {T}_{opt}^{GP} $$ ), which is almost consistent with the summer-time seawater temperature at each habitat. The temperature responses (4–40°C) of effective quantum yields (ΔF/Fm') of photosystem II during 7-day exposures were similar to that of oxygenic photosynthesis and the optimum temperature ( $$ {T}_{opt}^{\varDelta F/ Fm\prime } $$ ) was 20.0°C for Hokkaido and 30.1°C for Kagoshima. In the desiccation experiment, the ΔF/Fm' decreased with decreasing absolute water content (AWC); nevertheless, for samples with an AWC above 20%, ΔF/Fm' retuned to initial levels after subsequent 1-day rehydration in seawater, suggesting relatively strong tolerance to desiccation. This alga also showed a broad range of tolerance to salinity ranging from 20 to 60 psu in 7-day exposures, and the ΔF/Fm' tolerated 0 psu at 3-day exposure. The adaptations of A. vermiculophyllum from its native range in Japan to relatively high irradiance, a broad range of temperature, and strong osmotic (desiccation and salinity) tolerance explain its potentially high invasive capacity.

Storage stability and delivery potential of cytochalasin B induced membrane vesicles

Cell-free therapies based on extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) are considered as a promising tool for stimulating regeneration and immunomodulation. The need to develop a practical approach for large-scale production of vesicles with homogenous content led to the implementation of cytochalasin B-induced to induce microvesicles (CIMVs) biogenesis. CIMVs mimic natural EVs in size and composition of the surrounding cytoplasmic membrane. Previously we observed that MSC derived CIMVs demonstrate the same therapeutic angiogenic and immunomodulatory activity as the parental MSCs, making them a potentially scalable cell-free therapeutic option. However, little is known about their storage stability and delivery potential. We determined that different storage conditions alter the protein concentration within the solution used to store CIMVs over time, this concided with a decrease in the amount of CIMVs due to gradual degradation. We established that freezing and storage CIMVs in saline at -20 °C reduces degredation and prolongs their shelf life. Additionally, we found that freeze-thawing preserved the CIMVs morphology better than freeze drying and subsequent rehydration which resulted in aggregation of CIMVs. Collectively our data demonstrates for the first time, that the most optimal method of CIMVs storage is freezing at -20 °C, to preserve the CIMVs in the maximum quantity and quality with retention of effective delivery. These findings will benefit the formation of standardized protocols for the use of CIMVs for both basic research and clinical application.

Anhydrobiosis in yeast: role of cortical endoplasmic reticulum protein Ist2 in Saccharomyces cerevisiae cells during dehydration and subsequent rehydration.

Two Saccharomyces cerevisiae strains, BY4741 and BY4741-derived strain lacking the IST2 gene (ist2Δ), were used to characterise the possible role of cortical endoplasmic reticulum (ER) protein Ist2 upon cell dehydration and subsequent rehydration. For the first time, we show that not only protein components of the plasma membrane (PM), but also at least one ER membrane protein (Ist2) play an important role in the maintenance of the viability of yeast cells during dehydration and subsequent rehydration. The low viability of the mutant strain ist2∆ upon dehydration-rehydration stress was related to the lack of Ist2 protein in the ER. We revealed that the PM of ist2∆ strain is not able to completely restore its molecular organisation during reactivation from the state of anhydrobiosis. As the result, the permeability of the PM remains high regardless of the type of reactivation (rapid or gradual rehydration). We conclude that ER protein Ist2 plays an important role in ensuring the stability of molecular organisation and functionality of the PM during dehydration-rehydration stress. These results indicate an important role of ER-PM interactions during cells transition into the state of anhydrobiosis and the subsequent restoration of their physiological activities.