Towards phenotyping adaptive traits in camels: A study of the influence of hypotonic saline solutions on blood cell area.

Single-humped camels are livestock of physical, physiological, and biochemical adaptations to hot desert environments and to water scarcity. The tolerance of camels to water deprivation and their exceptional capacity for rapid rehydration requires blood cells with membranes of specialized organization and chemical composition. The objectives of this study are to examine the changes in the area (a proxy for volume) of camel blood cells in solutions with decreasing concentrations of NaCl and consequently identify the conditions under which blood cells can be phenotyped in a large population. Whole-blood samples from three healthy adult female camels were treated with four different concentrations of NaCl and examined at six incubation-periods. Observationally, red blood cells in all treatments remained intact and maintained their elliptical shape while white blood cells experienced some damage, lysing at concentrations below 0.90%. Average basal (in 0.90% NaCl) RBC area was ~15 µm² and swelled in the various treatments, in some cases reaching twice its original size. Excluding the damaged cells, the average area of combined WBCs, ~32.7 µm², expanded approximately three times its original size. We find that camel WBCs, like their RBCs, are adapted to hypotonic environments, and are capable of expanding while maintaining their structural integrity.

Simultaneous Study of Analysis of Anti-inflammatory Potential of Dryopteris ramosa (C. Hope) C. Chr. using GC-Mass and Computational Modeling on the Xylene-induced Ear Oedema in Mouse Model.

INTRODUCTION: In the present study, we aimed to investigate the extraction and identification of the potential phytochemicals from the Methanolic Extract of Dryopteris ramosa (MEDR) using GC-MS profiling for validating the traditional uses of MEDR its efficacy in inflammations by using in-vitro, in-vivo and in silico approaches in anti-inflammatory models. METHODS: GC-MS analysis confirmed the presence of a total of 59 phytochemical compounds. The human red blood cells (HRBC) membrane stabilization assay and heat-induced hemolysis method were used as in-vitro anti-inflammatory activity of the extract. The in-vivo analysis was carried out through the Xylene-induced mice ear oedema method. It was found that MEDR at a concentration of 20 µg, 30 µg, and 40 µg showed 35.45%, 36.01%, and 36.33% protection to HRBC in a hypotonic solution, respectively. At the same time, standard Diclofenac at 30 µg showed 45.31% protection of HRBC in a hypotonic solution. RESULTS: The extract showed inhibition of 25.32%, 26.53%, and 33.31% cell membrane lysis at heating at 20 µg, 30 µg, and 40 µg, respectively. In comparison, standard Diclofenac at 30 µg showed 50.49% inhibition of denaturation to heat. Methanolic extract of the plant exhibited momentous inhibition in xylene-induced ear oedema in mice treated with 30 µg extract were 47.2%, 63.4%, and 78.8%, while inhibition in mice ear oedema treated with 60 µg extract was 34.7%, 43.05%, 63.21% and reduction in ear thickness of standard drug were 57.3%, 59.54%, 60.42% recorded at the duration of 1, 4 and 24 hours of inflammation. Molecular docking and simulations were performed to validate the anti-inflammatory role of the phytochemicals that revealed five potential phytochemicals i.e. Stigmasterol,22,23dihydro, Heptadecane,8methyl, Pimaricacid, Germacrene and 1,3Cyclohexadiene,_5(1,5dimethyl4hexenyl)-2methyl which revealed potential or significant inhibitory effects on cyclooxygenase-2 (COX-2), tumour necrosis factor (TNF-α), and interleukin (IL-6) in the docking analysis. CONCLUSION: The outcome of the study signifies that MEDR can offer a new prospect in the discovery of a harmonizing and alternative therapy for inflammatory disease conditions.

Osmotic response during kidney perfusion with cryoprotectant in isotonic or hypotonic vehicle solution.

Organ cryopreservation would revolutionize transplantation by overcoming the shelf-life limitations of conventional organ storage. To prepare an organ for cryopreservation, it is first perfused with cryoprotectants (CPAs). These chemicals can enable vitrification during cooling, preventing ice damage. However, CPAs can also cause toxicity and osmotic damage. It is a major challenge to find the optimal balance between protecting the cells from ice and avoiding CPA-induced damage. In this study, we examined the organ perfusion process to shed light on phenomena relevant to cryopreservation protocol design, including changes in organ size and vascular resistance. In particular, we compared perfusion of kidneys (porcine and human) with CPA in either hypotonic or isotonic vehicle solution. Our results demonstrate that CPA perfusion causes kidney mass changes consistent with the shrink-swell response observed in cells. This response was observed when the kidneys were relatively fresh, but disappeared after prolonged warm and/or cold ischemia. Perfusion with CPA in a hypotonic vehicle solution led to a significant increase in vascular resistance, suggesting reduced capillary diameter due to cell swelling. This could be reversed by switching to perfusion with CPA in isotonic vehicle solution. Hypotonic vehicle solution did not cause notable osmotic damage, as evidenced by low levels of lactate dehydrogenase (LDH) in the effluent, and it did not have a statistically significant effect on the delivery of CPA into the kidney, as assessed by computed tomography (CT). Overall, our results show that CPA vehicle solution tonicity affects organ size and vascular resistance, which may have important implications for cryopreservation protocol design.

The Ca2+ channel TRPV4 is dispensable for Ca2+ influx and cell volume regulation during hypotonic stress response in human keratinocyte cell lines.

Cell swelling as a result of hypotonic stress is counteracted in mammalian cells by a process called regulatory volume decrease (RVD). We have recently discovered that RVD of human keratinocytes requires the LRRC8 volume-regulated anion channel (VRAC) and that Ca2+ exerts a modulatory function on RVD. However, the ion channel that is responsible for Ca2+ influx remains unknown. We investigated in this study whether the Ca2+-permeable TRPV4 ion channel, which functions as cell volume sensor in many cell types, may be involved in cell volume regulation during hypotonic stress response of human keratinocytes. We interfered with TRPV4 function in two human keratinocyte cell lines (HaCaT and NHEK-E6/E7) by using two TRPV4-specific inhibitors (RN1734 and GSK2193874), and by creating a CRISPR/Cas9-mediated genetic TRPV4-/- knockout in HaCaT cells. We employed electrophysiological patch clamp analysis, fluorescence-based Ca2+ imaging and cell volume measurements to determine the functional importance of TRPV4. We could show that both hypotonic stress and direct activation of TRPV4 by the specific agonist GSK1016790A triggered intracellular Ca2+ response. Strikingly, the Ca2+ increase upon hypotonic stress was neither affected by genetic knockout of TRPV4 in HaCaT cells nor by pharmacological inhibition of TRPV4 in both keratinocyte cell lines. Accordingly, hypotonicity-induced cell swelling, downstream activation of VRAC currents as well as subsequent RVD were unaffected both in TRPV4 inhibitor-treated keratinocytes and in HaCaT-TRPV4-/- cells. In summary, our study shows that keratinocytes do not require TRPV4 for coping with hypotonic stress, which implies the involvement of other, yet unidentified Ca2+ channels.

Aporte de fluidos en el pacientes pediátricos hospitalizados / Fluid intake in hospitalized pediatric patients

El aporte de fluidos constituye un elemento central en la atención del paciente pediátrico hospitalizado, existiendo aún controversias acerca de cuál es la composición óptima, la dosis adecuada y la mejor estrategia para administrar los mismos. El propósito de este artículo de actualización es brindar al médico que se desempeña en las diferentes áreas de la internación pediátrica, conceptos y enfoques terapéuticos que lo ayuden en la asistencia de los pacientes que por diversos motivos requieren la administración de fluidos endovenosos. La recomendación de utilizar cristaloides en la reanimación es casi uniforme. Se observa una clara tendencia al uso de soluciones isotónicas balanceadas para la reposición del déficit previo y el aporte de fluidos de mantenimiento. En relación a la dosis y a la estrategia, es generalizada la recomendación de un enfoque más restrictivo en el aporte de volumen, aún en los pacientes con shock, donde es necesario lograr un balance entre una resucitación efectiva y el riesgo de sobrecarga de fluidos. Respecto a la administración de albúmina al 20% en el paciente crítico con hipoalbuminemia, la evidencia existente es escasa y no permite formular recomendaciones. Sin embargo, es frecuente su uso en la práctica asistencial

Intravenous fluids administration is a central element in the care of hospitalized pediatric patients, and there are still controversies about what is the optimal composition, the appropriate dose, and the best strategy for their administration. The purpose of this narrative review is to provide the physicians who works in the different areas of pediatric hospitalization, concepts and therapeutic approaches that help them in the care of patients who for diverse reasons require administration of intravenous fluids. The recommendation to use crystalloids in resuscitation is almost uniform. There is a clear trend towards the use of balanced isotonic solutions to replace the previous deficit and the supply of maintenance fluids. In relation to the dose and strategy, the recommendation of a more restrictive approach in volume administration is generalized, even in patients with shock, where it is necessary to strike a balance between effective resuscitation and the risk of fluid overload. Regarding the administration of 20% albumin in critically ill patients with hypoalbuminemia, the existing evidence is scarce and does not allow recommendations to be formulated. However, it is frequently used in healthcare practice

[Perioperative Management in Pediatric Neurosurgery].

Appropriate perioperative management can facilitate good outcomes in pediatric neurosurgical patients. This section discusses infusion therapy, prophylactic antibiotics, and antiepileptic drugs in the perioperative management of pediatric neurosurgical patients. Fluid requirements were calculated using the Holiday and Segar formula and the 4-2-1 rule for determining hourly infusion requirements based on metabolic rate and body weight. Recently, the risk of hyponatremia with the use of hypotonic solutions has been reported, and an isotonic electrolyte solution with 1-2.5% glucose is recommended for maintenance infusions in the perioperative period. Pediatric perioperative prophylactic antibiotics have been recommended as follows: application of cephazolin(30 mg/kg)with a redosing interval of 3 h intraoperatively and continuation for 48 h or less postoperatively. However, even for shunt surgery, there are currently no evidence-based protocols regarding specific antibiotic recommendations or the duration of prophylactic antibiotics. Early antiepileptic prophylaxis is recommended in cases of severe head trauma in children, especially infants. Available intravenous antiepileptic drugs should be used with an understanding of their indications, characteristics, and side effects.

Ratiometric ECL sensor based on Apt-AuNS@Lu nanoprobe for analyzing cell swelling-induced ATP release.

A novel ratiometric electrochemiluminescence (ECL) system based on gold nanostars (AuNSs) support was constructed for the determination of hypotonicity-induced ATP release from HepG2 cells. AuNS@Lu nanoprobe was used as anodic luminophore and K2S2O8 as cathodic luminophore as well as anodic co-reactant. AuNS with the large specific surface was adopted to adsorb plentiful luminol to form solid-state probe and as affinity support to immobilize ATP aptamer (Apt). The obtained nanocomposite (Apt-AuNS@Lu) generated a strong ECL signal at + 0.4 V (vs. Ag/AgCl) with co-reactant K2S2O8, because of excellent conductivity and catalytic activity of AuNS. Furthermore, graphene oxide was reduced onto indium tin oxide (ITO) electrodes to facilitate the electron transfer. Following, polydopamine (PDA) film was formed via self-polymerization, improving stability and adhesion of the electrode surface. To immobilize ATP capture aptamer (AptC), abounding AuNSs were attached to RGO/PDA surface. When the sensor was incubated in the mixture solution of Apt-AuNS@Lu and target ATP, the ECL signal of Apt-AuNS@Lu increased with the increase of ATP concentration, meanwhile, the signal of K2S2O8 declined. The ratio of the two luminophores was used for the quantitative determination of ATP. The linear range was 5 to 250 nM, and the limit of detection was 1.4 nM at (3σ)/S. The method was successfully applied to analyze ATP release from HepG2 cells stimulated by 0.45% NaCl hypotonic solution. The results showed that the release kinetics profile of ATP had a sigmoidal shape with rapid release within 10 min and then slowed. Compared to the isotonic groups, the intracellular ATP concentration was 3.7 ± 0.3 µM (n = 3) decreasing by 40.3% and the extracellular was 23.4 ± 1.2 nM (n = 3) increasing by 9.2 times in the hypotonicity for 10 min, which showed ATP release from cells and good agreement with commercial ELISA test. The proposed strategy would be beneficial to broadening application of ECL technology in studying cell biological functions.

0.45% Versus 0.9% Saline in 5% Dextrose as Maintenance Fluids in Children Admitted With Acute Illness: A Randomized Control Trial.

BACKGROUND: The safety of giving intravenous (IV) maintenance fluids according to Holliday and Segar's recommendations of 1957 has recently been questioned after reports of complications caused by iatrogenic hyponatremia in children receiving hypotonic fluids. However, the current practice of choice of maintenance IV fluids for hospitalized children varies worldwide. This study was planned to compare 0.45% and 0.9% saline in 5% dextrose at standard maintenance rates in hospitalized children aged 3 months to 12 years. OBJECTIVE: Primary objective was to study change in serum sodium level at 24 hours in children receiving total IV fluid maintenance therapy as 0.45% or 0.9% normal saline in 5% dextrose. Secondary objectives of this study were to estimate change in serum sodium levels from the baseline to 48 or 72 hours, if IV fluids were continued, and to find incidence of hyponatremia and hypernatremia after administering these 2 types of maintenance fluids. METHODS: This study was an open-label, randomized control trial conducted at the Department of Pediatrics of a tertiary care hospital from July 22, 2019, to October 28, 2019. Two hundred children aged 3 months to 12 years admitted in pediatric emergency and requiring IV maintenance fluid were randomized into 2 groups (group A received 0.45% saline in 5% dextrose, group B received 0.9% normal saline in 5% dextrose) with 100 in each group. RESULTS: Both groups were comparable for baseline characteristics. Fall in mean serum sodium from baseline was more with increasing duration of IV fluids until 24 hours in 0.45% saline group as compared with 0.9% saline group, which was statistically significant (P < 0.001). The incidence of mild and moderate hyponatremia was significantly more in hypotonic group at 12 hours (P < 0.001) and 24 hours (P < 0.001). However, there was no significant difference at 48 hours. CONCLUSIONS: The fall in serum sodium values was significant, and there was significant risk of hyponatremia with the use of hypotonic fluids at 12 and 24 hours. Hence, the use of isotonic fluids seems to be more appropriate among the hospitalized children.Trial Registration: CTRI/2019/10/021791.

Effect of mechanical properties of Jurkat cell on adhesion properties of Jurkat integrin and VCAM-1: An AFM study.

Mechanical properties play key roles in the immune system, especially the activation, transformation and subsequent effector responses of immune cells. As transmembrane adhesion receptors, integrins mediate the adhesion events of both cells and cell-extracellular matrix (ECM). Integrin affinity would influence the crosslinking of cytoskeleton, leading to the change of elastic properties of cells. In this study, the cells were treated with F-actin destabilizing agent Cytochalasin-D (Cyt-D), fixed by Glutaraldehyde, and cultivated in hypotonic solution respectively. We used Atomic force microscopy (AFM) to quantitatively measure the elasticity of Jurkat cells and adhesion properties between integrins and vascular cell adhesion molecule-1 (VCAM-1), and immunofluorescence to study the alteration of cytoskeleton. Glutaraldehyde had a positive effect on the adhesion force and Young's modulus. However, these mechanical properties decreased in a hypotonic environment, confirming the findings of cellular physiological structure. There was no significant difference in the bond strength and elasticity of Jurkat cells treated with Cytochalasin-D, probably because of lower importance of actin in suspension cells. All the treatments in this study pose a negative effect on the adhesion probability between integrins and VCAM-1, which demonstrates the effect of structural alteration of the cytoskeleton on the conformation of integrin. Clear consistency between adhesion force of integrin/VCAM-1 bond and Young's modulus of Jurkat cells was shown. Our results further demonstrated the relationship between cytoskeleton and integrin-ligand by mechanical characteristics.

Mechanosensitive cation currents through TRPC6 and Piezo1 channels in human pulmonary arterial endothelial cells.

Mechanosensitive cation channels and Ca2+ influx through these channels play an important role in the regulation of endothelial cell functions. Transient receptor potential canonical channel 6 (TRPC6) is a diacylglycerol-sensitive nonselective cation channel that forms receptor-operated Ca2+ channels in a variety of cell types. Piezo1 is a mechanosensitive cation channel activated by membrane stretch and shear stress in lung endothelial cells. In this study, we report that TRPC6 and Piezo1 channels both contribute to membrane stretch-mediated cation currents and Ca2+ influx or increase in cytosolic-free Ca2+ concentration ([Ca2+]cyt) in human pulmonary arterial endothelial cells (PAECs). The membrane stretch-mediated cation currents and increase in [Ca2+]cyt in human PAECs were significantly decreased by GsMTX4, a blocker of Piezo1 channels, and by BI-749327, a selective blocker of TRPC6 channels. Extracellular application of 1-oleoyl-2-acetyl-sn-glycerol (OAG), a membrane permeable analog of diacylglycerol, rapidly induced whole cell cation currents and increased [Ca2+]cyt in human PAECs and human embryonic kidney (HEK)-cells transiently transfected with the human TRPC6 gene. Furthermore, membrane stretch with hypo-osmotic or hypotonic solution enhances the cation currents in TRPC6-transfected HEK cells. In HEK cells transfected with the Piezo1 gene, however, OAG had little effect on the cation currents, but membrane stretch significantly enhanced the cation currents. These data indicate that, while both TRPC6 and Piezo1 are involved in generating mechanosensitive cation currents and increases in [Ca2+]cyt in human PAECs undergoing mechanical stimulation, only TRPC6 (but not Piezo1) is sensitive to the second messenger diacylglycerol. Selective blockers of these channels may help develop novel therapies for mechanotransduction-associated pulmonary vascular remodeling in patients with pulmonary arterial hypertension.

Cloning and functional characterization of medaka TRPV4.

Medaka, Oryzias latipes is distributed in fresh water of South Asia. To study roles of TRPV4 in osmosensing and adaption mechanism of medaka during changes in salinity environment, we isolated the cDNA for TRPV4 from medaka (olTRPV4) and characterized it. The electrophysiological analysis using Xenopus oocytes revealed that olTRPV4 can be activated by a TRPV4-specific agonist, GSK1016790A and acid at pH 5. Further, olTRPV4 was sensitive to 2-APB. Although warm temperatures activate mammalian TRPV4, olTRPV4 was activated by cold and hot stimulation. The threshold for cold activation was determined as 13.13 ± 0.60 °C, and the heat-activation threshold was 40.26 ± 0.25 °C. Further, when olTRPV4-expressing oocytes were stimulated by hypotonic solution, an apparent activation was observed. We further found that the expression of this hypotonic sensor, olTRPV4 was significantly down-regulated in gills but up-regulated in brains of sea water-acclimated medaka. Results demonstrated that olTRPV4 must function as an osmosensor and play important roles in adaption mechanism of medaka fish in various salinity environments.

Abdominoplasty Panniculus as a Source for Human Acellular Dermis: A Preliminary Report.

BACKGROUND: In extensive deep dermal burn injuries, split-thickness skin graft (STSG) has been the most preferred treatment option for resurfacing burn wounds. A thick split-thickness skin graft is ideal for preventing graft contracture but is associated with delayed donor healing and the lack of adequate donor skin. When applied with STSG, the dermal substitutes offer better-reconstructed skin than STSG alone. Human-derived acellular dermal matrix (HADM) obtained from cadaver skin is a dermal equivalent with good clinical outcomes. However, high cost and limited cadaver donor skin availability limit its clinical utility. Developing a low-cost preparation method and finding an alternate source of human donated skin can help reduce the cost. The objective of this study was to explore the feasibility of making HADM from abdominoplasty panniculus skin. METHODS: Skin samples were collected from the abdominoplasty panniculus of ten eligible donors with their informed consent. A combination of low-cost reagents-sodium chloride and hypotonic solution (water for injection) was used for decellularizing the skin. Characterization of the prepared Acellular Dermis Matrix prototype was done. RESULTS: The skin was deepidermized with one molar NaCl treatment at 37 °C for 24 h. The deepidermized dermis became acellular with hypotonic solution treatment at 4 °C for two weeks. The hematoxylin and eosin staining and cytotoxicity test confirmed the acellularity and non-cytotoxicity of the prepared HADM prototype. The HADM prototype also facilitated the formation of neo-epithelium in the 3D cell co-culture model. CONCLUSION: This study confirms that abdominoplasty panniculus can be a viable alternative for HADM preparation. Further characterization studies are required to prove the concept.

Impaired Regulatory Volume Decrease and Characterization of Underlying Volume-Activated Currents in Cystic Fibrosis Human Cholangiocyte Cell Line.

The volume-activated chloride channel (VACC) serves vital cellular functions in secretion and cell volume regulation via regulatory volume decrease (RVD) in various epithelia. Previously, we have shown that RVD in primary CF mouse cholangiocytes is impaired. Thus, the effect of CFTR defect on VACC and RVD in CF human immortalized cholangiocyte cell (HBDC) was examined in comparison with those in normal HBDC by using cell volume measurement and whole-cell patch clamp techniques, respectively. The CF HBDC had an impaired RVD, which was not further inhibited by removing the extracellular calcium or administering BAPTA-AM, NPPB, or DIDS. When exposed to a hypotonic solution, CF HBDC exhibited large, outwardly rectified currents with time-dependent inactivation at a positive potential. The amplitude of the outward currents was about three times that of the inward currents. The amplitude and reversal potential of VACC was dependent on chloride concentration. The VACC was significantly inhibited by replacing chloride with gluconate, glutamate, sucrose, or acetate in the hypotonic solution as well as by an administration of NPPB or tamoxifen, classical VACC inhibitors. Surprisingly, the VACC amplitude is greater in CF HBDC than in normal HBDC, suggesting that the channel density or open probability of VACC is increased, thus CFTR may have inhibitory effects on VACC. On the contrary, the amplitude of the volume-activated potassium current is lower in CF HBDC, suggesting the potassium channel density or open probability is decreased in CF cholangiocytes and/or CFTR may have regulatory effects on volume-activated potassium current. In conclusion, RVD is impaired in CF human cholangiocytes. The VACC of CF human cholangiocytes has similar electrophysiological characteristics as that of normal cholangiocytes but its activity is augmented in CF cholangiocytes, while volume-activated potassium current is decreased in CF human cholangiocytes, providing a fundamental underlying pathophysiologic mechanism for the impaired RVD in CF cholangiocytes.

Avaliação de soluções eletrolíticas e vias da administração sobre o teor de umidade das fezes de equinos desidratados experimentalmente / Evaluation of electrolyte solutions and administration routes on the moisture content of feces of experimentally dehydrated horses

A ocorrência de processos fisiopatológicos que cursam com desidratação da ingesta no trato gastrointestinal dos equinos é comum na rotina clínica. Fatores como diminuição da motilidade intestinal e sobrecarga intraluminal de conteúdo desidratado podem levar a compactação em segmentos como estômago, ceco e cólons. Este estudo objetivou realizar a comparação entre soluções eletrolíticas enterais hipotônica (SeHIPO) e isotônica (SeISO) e a solução Ringer com lactato de sódio (RL IV) sobre o teor de umidade das fezes de equinos submetidos a um período de desidratação experimental (PD). Foram utilizados seis equinos adultos, todas fêmeas com idades entre 10 e 15 anos, média de 440 kg de peso corpóreo. O PD constou de 36 horas de jejum hídrico e alimentar associadas a duas administrações intravenosas de furosemida, sendo a primeira imediatamente no início (T-36) e a segunda 12 horas após o início do PD. Os tratamentos utilizados foram: SeHIPO e SeISO, ambas administradas por via nasogástrica em fluxo contínuo (HETfc), e RL IV administrada pela via intravenosa. Todos os tratamentos foram administrados a uma taxa de infusão contínua de 15mL kg-1 h-1 durante 8 horas consecutivas. O delineamento experimental utilizado foi o crossover6x3, onde cada animal foi submetido, em sistema de rodízio, aos três tratamentos em momentos distintos. As soluções eletrolíticas enterais demonstraram maior eficácia na recomposição do teor de umidade das fezes quando comparadas à terapia RL IV. A hidratação enteral com soluções isotônicas e hipotônicas administrada em fluxo contínuo são eficazes em restaurar o teor de umidade das fezes, podendo ofertar uma opção econômica, segura e eficiente na reidratação de pacientes e nas afecções que cursam como obstruções intraluminais simples.

The occurrence of pathophysiological processes that curse with digesta dryness in the gastrointestinal tract of horses is common in clinical routine, factors such as decreased intestinal motility and intraluminal overload of dry content can lead to compaction in segments such as cecum and colon. This study aimed to compare a hypotonic enteral solution (SeHIPO), an isotonic enteral solution (SeISO) and a Ringer with sodium lactate solution (RL IV) over the moisture content of equine feces submitted to an experimental dehydration protocol. Six adult horses were used, all females aged between 10 and 15 years, average body weight of 440 kg. The PD consisted of a 36 hours period of water and food fasting associated with two intravenous administrations of furosemide, the first immediately at the beginning (T-36) and the second 12 hours after the beginning of the PD. The treatments used were: SeHIPO (hypotonic enteral solution administered via nasogastric), SeISO (enteral isotonic solution administered via nasogastric) and RL IV (Ringer's solution with sodium lactate administered intravenously), all treatments were administered by continuous infusion at a rate of 15mL kg-1 h-1 for 8 consecutive hours. The experimental design used was the 6x3 crossover, where each animal is submitted, in a rotation system, to the three treatments at different times. Enteral fluid therapy with isotonic and hypotonic solutions administered in continuous flow are effective in restoring the moisture content of feces, and may offer an economical, safe, and efficient option for rehydrating patients and in conditions that progress as simple intraluminal obstructions.

Comparison of isotonic and hypotonic intravenous fluids in term newborns: is it time to quit hypotonic fluids.

OBJECTIVE: Hypotonic fluids have been traditionally used in newborns. National Institute for Health and Clinical Excellence-2015 (NICE) fluid therapy guideline recommends the use of isotonic fluids as maintenance fluid therapy in term newborns. However, there is no clear evidence supporting this recommendation. This study aims to compare isotonic (5% dextrose in 0.9% sodium chloride (NaCl)) and hypotonic (5% dextrose in 0.45% NaCl) parenteral fluid therapies in hospitalized term newborns with regard to changes in plasma Na (pNa) and complications related with fluid therapy. METHODS: This was a retrospective cohort study performed in a tertiary university hospital NICU between January 2016 and April 2018. Term newborns who were initially isonatremic or mildly dysnatremic (pNa <130 or >155 meq/L) and receiving fluid therapy for maintenance or replacement therapy after 48th postnatal hours were eligible for the study. Infants having specific diagnoses requiring extraordinary fluids were excluded. The primary outcome evaluated was the change in mean plasma Na (ΔpNa meq/L/h) at 24 h or at the end of intravenous (i.v.) fluid therapy. Secondary outcomes evaluated were the risk of hyponatremia, hypernatremia, and adverse events attributable to fluid administration. RESULTS: Among the 108 included newborns, 57 received hypotonic fluid (5% dextrose solution in 0.45% NaCl) and the remaining received isotonic fluid (5% dextrose solution in 0.9% NaCl) therapy. The hypotonic fluid group showed a greater ΔpNa compared to the isotonic group (0.48 ± 0.28 vs. 0.27 ± 0.21 meq/L/h, p = .001). The risk of experiencing unsafe plasma Na decrease in the hypotonic fluid group (ΔpNa >0.5 meq/L/h) was higher than the isotonic fluid group (odd ratio: 8.46; 95% confidence interval (CI): 2.3-30.06). Six mildly hypernatremic babies between 48 and 72 h of postnatal age showed insufficient Na reduction despite the appropriate amount of fluid. No significant difference was found between the two groups in terms of other outcomes. CONCLUSION: The results of this study suggested that as maintenance or replacement fluid therapy in the newborn, hypotonic fluids, even 5% dextrose in 0.45% NaCl, can lead to unsafe plasma Na decreases in term newborns, while isotonic fluids are safe when started after the first few days of life. Although the results parallel NICE guidelines, before making recommendations regarding the removal of hypotonic fluids entirely from clinical practice in term newborns following the renal adaptation period; larger randomized controlled studies involving a wide range of babies are needed.

Comparison of isotonic versus hypotonic intravenous fluid for maintenance fluid therapy in neonates more than or equal to 34 weeks of gestational age - a randomized clinical trial.

BACKGROUND AND OBJECTIVES: The use of hypotonic fluids as maintenance therapy in the neonatal population has been in practice for a long time, but there is a lack of evidence for the choice of this fluid in neonates. This study compared isotonic (sodium chloride, 0.9%, and dextrose, 5%) versus hypotonic (sodium chloride, 0.15%, and dextrose, 5%) intravenous fluid for maintenance fluid therapy in neonates more than or equal to 34 weeks of gestational age. METHODS: In this triple-blind randomized clinical trial, we recruited 60 neonates admitted to a neonatal intensive care unit of a tertiary care children's hospital from June 2017 through May 2018 with normal baseline serum sodium levels, anticipated to require intravenous maintenance fluids for 24 hours or longer (intention-to-treat analyses). Patients were randomized to receive isotonic or hypotonic intravenous fluid at maintenance rates for 72 hours. The primary outcome was the incidence of hyponatremia (defined as serum sodium <135mEq/L) at 24 hours in both groups. The secondary outcomes were incidence of hypernatremia at 24 hours (defined as serum sodium >145 mEq/L), the incidence of hypo and hypernatremia at 48 and 72 hours, mean serum sodium at 24, 48, and 72 hours, rate of change of serum sodium during the study period, mean serum osmolality at the end of the study period, the absolute difference in osmolality during the study period, the absolute difference in weight during the study period and edema during the study period. RESULTS: Of 60 enrolled neonates, 31 received isotonic fluids and 29 received hypotonic fluids. Three patients in the hypotonic group developed hyponatremia and none in isotonic group at 24 h (RR = 0.13; 95% CI = 0.007 - 2.485; p = .106). Fourteen neonates developed hypernatremia in the isotonic group and one in hypotonic group at 24 h (RR = 13.09; 95% CI = 1.83 - 93.4; p = .0001). CONCLUSIONS: Our study results do not support the hypothesis that isotonic fluid is superior to hypotonic fluid in reducing the proportion of neonates developing hyponatremia after 24 hours of intravenous fluid therapy. The proportion of neonates developing hypernatremia is significantly higher after using isotonic fluid for maintenance therapy. TRIAL REGISTRATION CTRI/2017/05/008585.

Introducing isotonic fluids into pediatric oncology.

Objective: Hypotonic fluids are commonly used in pediatric oncology despite evidence that these fluids can lead to hospital-acquired hyponatremia. This practice is most likely due to lack of data evaluating risks and benefits of isotonic fluids in pediatric oncology. To address this issue, our study investigates the effects of exchanging hypotonic fluids with isotonic fluids in a large pediatric oncology unit. Study Design: Prevalence of laboratory disorders before and after the change to balanced, isotonic fluids for all patients are compared in this retrospective analysis. Disturbances in electrolyte levels, fluid-, acid-base balance and kidney function were examined. Results: The rate of hyponatremia was reduced using isotonic fluids. There were no hypernatremic events. Volume overload might increase the use of furosemide when using isotonic fluids. Potassium and bivalent cation levels increased. The risk of acidosis is greatly reduced, whereas alkalosis was more frequent due to furosemide use. The rate of acute kidney injury did not increase. Conclusion: Using isotonic fluids for hyper-hydration in pediatric oncology lead to a modest reduction of hospital-acquired hyponatremia without causing hypernatremia, but the effects on fluid balance need further investigation. The additional intake of bivalent cations and buffering anions in balanced fluids has measurable effects.

Severe hospital-acquired hyponatremia in acutely ill children receiving moderately hypotonic fluids.

BACKGROUND: Hypotonic fluids have been associated with hospital-acquired hyponatremia. The incidence of life-threatening severe hyponatremia associated with hypotonic fluids has not been evaluated. METHODS: This was a population-based cohort study of 46,518 acutely ill children 15 years of age or under who visited the pediatric emergency department (ED) at Oulu University Hospital, Finland, between 2007 and 2017. We retrieved all electrolyte measurements from the comprehensive electronic laboratory system and reviewed medical records for all patients with severe hyponatremia. RESULTS: The overall occurrence of severe hyponatremia (serum sodium < 125 mmol/L) was found in 27 out of 46,518 acutely ill children (0.06%, 95% confidence interval 0.04-0.08%). After admission, severe hyponatremia developed in seven of 6,984 children receiving moderately hypotonic fluid therapy (0.1%, 95% confidence interval 0.04-0.2%), usually within 8 h of admission. All children who developed severe hyponatremia during hospitalization were severely ill. CONCLUSION: In this register-based cohort study of children presenting to the ED, severe hyponatremia developed in one of 998 acutely ill children receiving moderately hypotonic fluid therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Comparison of efficacy and safety of accelerated trans-epithelial crosslinking for keratoconus patients with corneas thicker and thinner than 380µm.

PURPOSE: Accelerated trans-epithelial cross-linking (ATE-CXL), a therapy to halt keratoconus progression, has the merit of widening the indications for thinner corneas (<380 µm). Since a hypotonic solution affects the swollen cornea, corneas of <380 µm thickness at preoperative measurement can be an indication for ATE-CXL. The aim of this retrospective study was to compare the efficacy and safety of ATE-CXL for keratoconus between corneas with thicknesses <380 µm and ≥380 µm. MATERIALS AND METHODS: Thirty-four eyes of 27 patients who underwent ATE-CXL (30 mW/cm2; 3 minutes) with completion of a 24-month follow-up, were enrolled and divided into two groups: Group 1, thinnest corneal thickness (TCT), <380 µm (n = 10) and Group 2, TCT, ≥380 µm (n = 24). A hypotonic solution was administered to Group 1 until the corneal thickness increased by >380 µm before UV-A irradiation. We measured uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), maximum and average keratometric values (Kmax and AveK), central corneal thickness (CCT), TCT by anterior segment optical coherence tomography, and corneal endothelial cell density (ECD) using specular microscopy. The changes from baseline to 24 months postoperatively between the two groups were compared accordingly. RESULTS: The changes in Kmax and AveK from baseline to 24 months in Group 1 (ΔKmax: -7.8 ± 7.7 D, ΔAveK: -4.3 ± 6.1 D) showed significant decreases compared to those in Group 2 (ΔKmax: 0.2 ± 3.0 D, ΔAveK: 0.6 ± 2.7 D) (p = .004 and p = .001), and there were no significant changes from baseline to 24 months postoperatively in UCVA, BCVA, CCT, TCT, and ECD in both groups. CONCLUSION: ATE-CXL is effective and safe for keratoconic corneas in both groups. The effect of reducing keratometric values was greater in the group with thinner corneas.