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This study aimed to assess the influence of streptozotocin (STZ)-induced diabetes on the nociceptive behavior evoked by the injection of hypertonic saline (HS) into the masseter muscle of rats. Forty male rats were equally divided into four groups: a) isotonic saline control, which received 0.9% isotonic saline (IS), (Ctrl-IS); b) hypertonic saline control, which received 5% HS (Ctrl-HS); c) STZ-induced diabetic, which received IS, (STZ-IS); d) STZ-induced diabetic, which received HS (STZ-HS). Experimental diabetes was induced by a single intraperitoneal injection of STZ at dose of 60 mg/kg dissolved in 0.1 M citrate buffer, and 100 μL of HS or IS were injected into the left masseter to measure the nociceptive behavior. Later on, muscle RNA was extracted to measure the relative expression of the following cytokines: cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF-α), and interleukins (IL)-1β, -2, -6, and -10. One-way analysis of variance (ANOVA) was applied to the data (p < 0.050). We observed a main effect of group on the nociceptive response (ANOVA: F = 11.60, p < 0.001), where the Ctrl-HS group presented the highest response (p < 0.001). However, nociceptive response was similar among the Ctrl-IS, STZ-IS, and STZ-HS group (p > 0.050). In addition, the highest relative gene expression of TNF-α and IL-6 was found in the masseter of control rats following experimental muscle pain (p < 0.050). In conclusion, the loss of somatosensory function can be observed in deep orofacial tissues of STZ-induced diabetic rats.

Rodent studies demonstrated specialized sodium chloride (NaCl) sensing neurons in the circumventricular organs, which mediate changes in sympathetic nerve activity, arginine vasopressin, thirst, and blood pressure. However, the neural pathways involved in NaCl sensing in the human brain are incompletely understood. The purpose of this pilot study was to determine if acute hypernatremia alters the functional connectivity of NaCl-sensing regions of the brain in healthy young adults. Resting-state fMRI scans were acquired in 13 participants at baseline and during a 30 min hypertonic saline infusion (HSI). We used a seed-based approach to analyze the data, focusing on the subfornical organ (SFO) and the organum vasculosum of the lamina terminalis (OVLT) as regions of interest (ROIs). Blood chemistry and perceived thirst were assessed pre- and post-infusion. As expected, serum sodium increased from pre- to post-infusion in the HSI group. The primary finding of this pilot study was that the functional connectivity between the SFO and a cluster within the OVLT increased from baseline to the late-phase of the HSI. Bidirectional connectivity changes were found with cortical regions, with some regions showing increased connectivity with sodium-sensing regions while others showed decreased connectivity. Furthermore, the functional connectivity between the SFO and the posterior cingulate cortex (a control ROI) did not change from baseline to the late-phase of the HSI. This finding indicates a distinct response within the NaCl sensing network in the human brain specifically related to acute hypernatremia that will need to be replicated in large-scale studies., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: Reno-renal reflexes are disturbed in cardiovascular and hypertensive conditions when elevated levels of pro-inflammatory mediators/cytokines are present within the kidney. We hypothesised that exogenously administered inflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1β modulate the renal sympatho-excitatory response to chemical stimulation of renal pelvic sensory nerves., Methods: In anaesthetised rats, intrarenal pelvic infusions of vehicle [0.9% sodium chloride (NaCl)], TNF-α (500 and 1000 ng/kg) and IL-1β (1000 ng/kg) were maintained for 30 min before chemical activation of renal pelvic sensory receptors was performed using randomized intrarenal pelvic infusions of hypertonic NaCl, potassium chloride (KCl), bradykinin, adenosine and capsaicin., Results: The increase in renal sympathetic nerve activity (RSNA) in response to intrarenal pelvic hypertonic NaCl was enhanced during intrapelvic TNF-α (1000 ng/kg) and IL-1β infusions by almost 800% above vehicle with minimal changes in mean arterial pressure (MAP) and heart rate (HR). Similarly, the RSNA response to intrarenal pelvic adenosine in the presence of TNF-α (500 ng/kg), but not IL-1β, was almost 200% above vehicle but neither MAP nor HR were changed. There was a blunted sympatho-excitatory response to intrapelvic bradykinin in the presence of TNF-α (1000 ng/kg), but not IL-1β, by almost 80% below vehicle, again without effect on either MAP or HR., Conclusion: The renal sympatho-excitatory response to renal pelvic chemoreceptor stimulation is modulated by exogenous TNF-α and IL-1β. This suggests that inflammatory mediators within the kidney can play a significant role in modulating the renal afferent nerve-mediated sympatho-excitatory response., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Brain death (BD) compromises the viability of the lung for donation. Hypertonic saline solution (HSS) induces rapid intravascular volume expansion and immunomodulatory action. We investigated its role in ventilatory mechanics (VMs) and in the inflammatory activity of the lungs of rats subjected to BD., Methods: Wistar rats were divided into four groups: control, n = 10: intact rats subjected to extraction of the heart-lung block; BD, n = 8 (BD): rats treated with isotonic saline solution (4 mL/kg) immediately after BD; hypertonic saline 0 h, n = 9 (Hip.0'): rats treated with HSS (4 mL/kg) immediately after BD; and hypertonic saline 1 h, n = 9 (Hip.60'), rats treated with HSS (4 mL/kg) 60 min after BD. The hemodynamic characteristics, gas exchange, VMs, inflammatory mediators, and histopathological evaluation of the lung were evaluated over 240 min of BD., Results: In VMs, we observed increased airway resistance, tissue resistance, tissue elastance, and respiratory system compliance in the BD group (P < 0.037), while the treated groups showed no impairment over time (P > 0.05). In the histological analysis, the BD group showed a greater area of perivascular edema and a higher neutrophil count than the control group and the Hip.60' group (P < 0.05)., Conclusions: Treatment with HSS was effective in preventing changes in the elastic and resistive pulmonary components, keeping them at baseline levels. Late treatment reduced perivascular and neutrophilic edema in lung tissue., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Significance: Assessing the nanostructure of polymer solutions and biofluids is broadly useful for understanding drug delivery and disease progression and for monitoring therapy., Aim: Our objective is to quantify bronchial mucus solids concentration (wt. %) during hypertonic saline (HTS) treatment in vitro via nanostructurally constrained diffusion of gold nanorods (GNRs) monitored by polarization-sensitive optical coherence tomography (PS-OCT)., Approach: Using PS-OCT, we quantified GNR translational ( D T ) and rotational ( D R ) diffusion coefficients within polyethylene oxide solutions (0 to 3 wt. %) and human bronchial epithelial cell (hBEC) mucus (0 to 6.4 wt. %). Interpolation of D T and D R data is used to develop an assay to quantify mucus concentration. The assay is demonstrated on the mucus layer of an air-liquid interface hBEC culture during HTS treatment., Results: In polymer solutions and mucus, D T and D R monotonically decrease with increasing concentration. D R is more sensitive than D T to changes above 1.5 wt. % of mucus and exhibits less intrasample variability. Mucus on HTS-treated hBEC cultures exhibits dynamic mixing from cilia. A region of hard-packed mucus is revealed by D R measurements., Conclusions: The extended dynamic range afforded by simultaneous measurement of D T and D R of GNRs using PS-OCT enables resolving concentration of the bronchial mucus layer over a range from healthy to disease in depth and time during HTS treatment in vitro ., (© 2024 The Authors.)

Introduction: An exaggerated immune response is considered the most important aspect of COVID-19 pathogenesis. Hypertonic saline (HS) has shown promise in combating inflammation in several respiratory diseases. We investigated the effects of nebulized HS on clinical symptoms and inflammatory status in patients with severe novel coronavirus infection (COVID-19) pneumonia., Materials and Methods: We randomly assigned 60 adults admitted to the intensive care unit (ICU) due to severe COVID-19 pneumonia to the experimental (received nebulized 5% saline) and control (received nebulized distilled water) groups. All interventions were applied 4 times daily for 5 days. The levels of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and other clinical factors from venous blood were evaluated before and after intervention application. Mortality rate, intubation rate, and durations of ICU and hospital stay were also compared between groups., Results: The levels of TNF-α (MD: -21.35 [-32.29, -10.40], P  =  0.000) and IL-6 (-9.94 [-18.86, -1.02], P  =  0.003) were lower in the experimental group compared to the control group after applying the interventions. The levels of white blood cell count, PO 2 , and serum sodium were also statistically significant differences between groups. However, we did not observe significant differences in terms of hospitalization durations and mortality rates., Conclusion: Nebulization of HS in patients with severe COVID-19 pneumonia appears to be effective in reducing inflammation, but does not appear to affect intubation rates, mortality, hospitalization, or length of stay in ICU., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Inhalation of hypertonic saline (HS) is standard of care in patients with cystic fibrosis (CF). However, it is unclear if adding salbutamol has-besides bronchodilation-further benefits, for example, on the mucociliary clearance. We assessed this in vitro by measuring the ciliary beating frequency (CBF) and the mucociliary transport rate (MCT) in nasal epithelial cells (NECs) of healthy volunteers and patients with CF. Aims: To investigate the effect of HS, salbutamol, and its combination on (muco)ciliary activity of NECs in vitro , and to assess potential differences between healthy controls and patients with CF. Methods: NECs obtained from 10 healthy volunteers and 5 patients with CF were differentiated at the air-liquid interface and aerosolized with 0.9% isotonic saline ([IS] control), 6% HS, 0.06% salbutamol, or combined HS and salbutamol. CBF and MCT were monitored over 48-72 hours. Results: In NECs of healthy controls, the absolute CBF increase was comparable for all substances, but CBF dynamics were different: HS increased CBF slowly and its effect lasted for an extended period, salbutamol and IS increased CBF rapidly and the effect subsided similarly fast, and HS and salbutamol resulted in a rapid and long-lasting CBF increase. Results for CF cells were comparable, but less pronounced. Similar to CBF, MCT increased after the application of all the tested substances. Conclusion: CBF and MCT of NECs of healthy participants and CBF of patients with CF increased upon treatment with aerosolized IS, HS, salbutamol, or HS and salbutamol, showing a relevant effect for all tested substances. The difference in the CBF dynamics can be explained by the fact that the properties of the mucus are changed differently by different saline concentrations.

Acutely elevated intracranial pressure (ICP) may have devastating effects on patient mortality and neurologic outcomes, yet its initial detection remains difficult because of the variety of manifestations that it can cause disease states it is associated with. Several treatment guidelines exist for specific disease processes such as trauma or ischemic stroke, but their recommendations may not apply to other causes. In the acute setting, management decisions must often be made before the underlying cause is known. In this review, we present an organized, evidence-based approach to the recognition and management of patients with suspected or confirmed elevated ICP in the first minutes to hours of resuscitation. We explore the utility of invasive and noninvasive methods of diagnosis, including history, physical examination, imaging, and ICP monitors. We synthesize various guidelines and expert recommendations and identify core management principles including noninvasive maneuvers, neuroprotective intubation and ventilation strategies, and pharmacologic therapies such as ketamine, lidocaine, corticosteroids, and the hyperosmolar agents mannitol and hypertonic saline. Although an in-depth discussion of the definitive management of each etiology is beyond the scope of this review, our goal is to provide an empirical approach to these time-sensitive, critical presentations in their initial stages.

Purpose: To evaluate effect of N-acetylcysteine (NAC) associated with Ringer lactate or hypertonic saline in inflammation and bacterial translocation on experimental intestinal obstruction (IO)., Methods: Wistar rats was subjected to IO. Six or 24 hours after, rats were subjected to enterectomy and fluid resuscitation: IO, RL (subjected to the same procedures but with fluid resuscitation using Ringer's lactate solution); RLNAC (added NAC to Ringer's solution); and HSNAC (surgical procedure + fluid reposition with 7.5% hypertonic saline and NAC). After 24 h, tissues were collected to cytokines, bacterial translocation, and histological assessments., Results: In kidney, interleukin-1beta (IL-1beta) was lower in the groups with fluid resuscitation compared to IO group. The RLNAC showed lower levels compared to the RL. Interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-alpha), and (IFN-gamma) were lower in the treatment groups than in IO. In lung, IL-1beta and IL-6 were lower in RLNAC compared to IO. IL-10 was lower in RL, RLNAC and HSNAC compared to IO. TNF-alpha was higher in HSNAC compared to both RL and RLNAC. Bacterial translocation was observed in all animals of IO group. In kidneys, inflammation and congestion degrees were lower in HSNAC compared to RL. In lungs, inflammation levels were higher in RLNAC compared with the sham group., Conclusions: The data indicates that NAC associated with RL can promote a decrease in the inflammatory process in the kidneys and lungs in rats, following intestinal obstruction and ischemia in rats.

Background: Brain edema is a rare and serious complication of assisted reproductive technology (ART). The increased intracranial pressure and injured brain parenchyma are life-threatening and may even result in death. The pathogenesis may involve increased vascular permeability mediated by vascular endothelial growth factor and other vasoactive substances, including interleukin 6, interleukin 1β, angiotensin II, insulin-like growth factor 1, transforming growth factor β, and the renin-angiotensin system., Case Presentation: We presented a unique case report of a 29-year-old woman developed sudden irritability, blurred consciousness, and vomiting 8 h after oocyte retrieval. Blood examinations showed hyponatremia and cranial computed tomography showed swelling of the brain parenchyma. After therapeutic use of hypertonic saline and mannitol infusion, the patient's consciousness recovered and her neurological state improved., Conclusions: Brain edema is a rare and serious complication of ART. Quick infusion of hypertonic salt solution and mannitol is a key treatment. A good prognosis can be achieved after prompt treatment., (© 2022. The Author(s).)

Background: Traumatic brain injury (TBI) causes mortality and long-term disability among young adults and imposes a notable cost on the healthcare system. In addition to the first physical hit, secondary injury, which is associated with increased intracranial pressure (ICP), is defined as biochemical, cellular, and physiological changes after the physical injury. Mannitol and Hypertonic saline (HTS) are the treatment bases for elevated ICP in TBI. This systematic review and meta-analysis evaluates the effectiveness of HTS in the management of patients with TBI., Methods: This study was conducted following the Joanna Briggs Institute (JBI) methods and PRISMA statement. A systematic search was performed through six databases in February 2022, to find studies that evaluated the effects of HTS, on increased ICP. Meta-analysis was performed using comprehensive meta-analysis (CMA)., Results: Out of 1321 results, 8 studies were included in the systematic review, and 3 of them were included in the quantitative synthesis. The results of the meta-analysis reached a 35.9% (95% CI 15.0-56.9) reduction in ICP in TBI patients receiving HTS, with no significant risk of publication bias (t-value = 0.38, df = 2, p-value = 0.73). The most common source of bias in our included studies was the transparency of blinding methods for both patients and outcome assessors., Conclusion: HTS can significantly reduce the ICP, which may prevent secondary injury. Also, based on the available evidence, HTS has relatively similar efficacy to Mannitol, which is considered the gold standard therapy for TBI, in boosting patients' neurological condition and reducing mortality rates., (© 2022. The Author(s).)

Background: Until now, it has remained difficult for doctors to make an informative decision as to which concentration of hypertonic saline (HTS) is more beneficial for patients with traumatic brain injury (TBI). We therefore investigate the effect of different concentrations of hypertonic saline on mortality and ICP lowering efficacy in this group of patients., Methods: Several databases including Ovid MEDLINE, Ovid EMBASE, PubMed, and Cochrane Central Register of Controlled Trials were searched comprehensively from inception to February 28, 2022. We only included RCTs that compared HTS with different concentrations and mannitol in adult patients with TBI. The main outcome was mortality from any cause. We reported relative risks (RR) and 95% confidence intervals (CIs) from direct meta-analysis and 95% credible intervals (CrIs) from network meta-analysis., Results: Overall, 13 trials containing 593 patients were included in this study. Direct analysis revealed that HTS was associated with decreased risk of all-cause mortality (RR, 1.29; 95% CI: 1.08 to 1.54). In the network meta-analysis, 5% HTS was associated with a significant decrease in all-cause mortality compared with mannitol (RR 0.34, 95% CrI: 0.14 to 0.72). We also found 7.5% HTS was associated with a significant increase in all-cause mortality compared with 5% HTS (RR, 2.87; 95% CrI: 1.00 to 8.99)., Conclusions: Among patients with TBI, the application of 5% HTS was associated with decreased all-cause mortality compared with mannitol and other concentration. Treatments with 10% and 15% HTS was more likely to decrease ICP compared with other fluids. More trials are needed to verify the current findings., Competing Interests: Declarations of Competing Interest None., (Copyright © 2022. Published by Elsevier Ltd.)

Asthma is one of the most common chronic diseases. Mucus overproduction is consistently linked to asthma morbidity and mortality. Despite the knowledge of the importance of mucus, little data exist on how mucus is transported in asthma and the immediate effects of therapeutic intervention. We therefore used microscopic optical coherence tomography (mOCT) to study spontaneous and induced mucus transport in an interleukin-13 (IL-13)-induced asthma mouse model and examined the effects of isotonic (0.9% NaCl) and hypertonic saline (7% NaCl), which are used to induce mucus transport in cystic fibrosis. Without intervention, no bulk mucus transport was observed by mOCT and no intraluminal mucus was detectable in the intrapulmonary airways by histology. Administration of ATP-γ-S induced mucus secretion into the airway lumen, but it did not result in bulk mucus transport in the trachea. Intraluminal-secreted immobile mucus could be mobilized by administration of isotonic or hypertonic saline but hypertonic saline mobilized mucus more reliably than isotonic saline. Irrespective of saline concentration, the mucus was transported in mucus chunks. In contrast to isotonic saline solution, hypertonic saline solution alone was able to induce mucus secretion. In conclusion, mOCT is suitable to examine the effects of mucus-mobilizing therapies in vivo. Although hypertonic saline was more efficient in inducing mucus transport, it induced mucus secretion, which might explain its limited benefit in patients with asthma.

Objective: Physiological systems responsible for water homeostasis and energy metabolism are interconnected. This study hypothesized altered responses to dehydration including thirst, ad libitum water intake, and copeptin in men with obesity., Methods: Forty-two men (22 lean and 20 with obesity) were stimulated by a 2-hour hypertonic saline infusion and a 24-hour water deprivation. In each dehydrating condition, thirst, ad libitum water intake after dehydration, and urinary and hormonal responses including copeptin were assessed., Results: After each dehydration condition, ad libitum water intake was similar between both groups (p > 0.05); however, those with obesity reported feeling less thirsty (p < 0.05) and had decreased copeptin response and higher urinary sodium concentrations when stressed (p < 0.05). Angiotensin II, aldosterone, atrial and brain natriuretic peptides, and apelin concentrations did not differ by adiposity group and did not explain the different thirst or copeptin responses in men with obesity. However, leptin was associated with copeptin response in lean individuals during the hypertonic saline infusion (p < 0.05), but the relationship was diminished in those with obesity., Conclusions: Diminished thirst and copeptin responses are part of the obesity phenotype and may be influenced by leptin. Adiposity may impact pathways regulating thirst and vasopressin release, warranting further investigation., (© 2022 The Obesity Society (TOS). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Objective: To compare the effects of 7.2% hypertonic and 0.9% isotonic saline (sodium chloride) solutions on cardiovascular parameters and plasma arginine vasopressin (AVP) concentrations in healthy, isoflurane-anesthetized horses., Animals: 8 healthy horses., Procedures: In a prospective, randomized, crossover study, horses were anesthetized with isoflurane twice with a 14-day washout period between anesthetic episodes. While anesthetized, horses received a bolus (4 mL/kg) of 7.2% hypertonic saline solution (HS) or 0.9% isotonic saline solution (IS). Heart rate; systolic, mean, and diastolic arterial blood pressures; and central venous and pulmonary artery pressures were measured every 5 minutes; cardiac output was measured by means of thermodilution every 15 minutes. Systemic vascular resistance (SVR) was calculated. Blood samples were collected before and during anesthesia, and plasma AVP concentrations were determined with a validated ELISA. Data were analyzed with repeated-measures ANOVA and Pearson correlations., Results: HS caused an increase in systolic (P = .003) and mean (P = .023) arterial blood pressures that lasted for 30 minutes. The SVR was increased (P < .001) for 45 minutes with HS compared with the SVR after IS administration. Mean plasma AVP concentration increased (P = .03) 15 minutes after HS administration, with the increase lasting 90 minutes., Clinical Relevance: A bolus of HS resulted in a clinically relevant increase in blood pressure in healthy, isoflurane-anesthetized horses. This effect was attributed to volume recruitment and an increase in SVR. Administration of HS offers an option for improving arterial blood pressure in anesthetized horses.

Background: Brain death (BD) is associated with systemic inflammatory compromise, which might affect the quality of the transplanted organs. This study investigated the expression profile of cardiac microRNAs (miRNAs) after BD, and their relationship with the observed decline in myocardial function and with the changes induced by hypertonic saline solution (HSS) treatment., Methods: Wistar rats were assigned to sham-operation (SHAM) or submitted to BD with and without the administration of HSS. Cardiac function was assessed for 6 h with left ventricular (LV) pressure-volume analysis. We screened 641 rodent miRNAs to identify differentially expressed miRNAs in the heart, and computational and functional analyses were performed to compare the differentially expressed miRNAs and find their putative targets and their related enriched canonical pathways., Results: An enhanced expression in canonical pathways related to inflammation and myocardial apoptosis was observed in BD induced group, with 2 miRNAs, miR-30a-3p, and miR-467f, correlating with the level of LV dysfunction observed after BD. Conversely, HSS treated after BD and SHAM groups showed similar enriched pathways related to the maintenance of heart homeostasis regulation, in agreement with the observation that both groups did not have significant changes in LV function., Conclusions: These findings highlight the potential of miRNAs as biomarkers for assessing damage in BD donor hearts and to monitor the changes induced by therapeutic measures like HSS, opening a perspective to improve graft quality and to better understand the pathophysiology of BD. The possible relation of BD-induced miRNA's on early and late cardiac allograft function must be investigated., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To compare the impact of an IV bolus of hydroxyethyl starch 130/0.4 (HES) or hypertonic saline 7.5% (HS) on hemostasis in dogs resuscitated for gastric-dilation-volvulus (GDV)., Design: Open-label, parallel-group randomized clinical trial., Animals: Twenty-three client-owned dogs., Interventions: Dogs affected by GDV and shock were randomly assigned to receive HES at 10 mL/kg or HS at 4 mL/kg every 15 minutes. Blood samples were collected for blood gas analysis, PCV, total plasma protein, albumin, standard coagulation profile, and thromboelastometry (ROTEM) at baseline (T0) and at the end of bolus (T1). To assess the differences between the 2 groups at T1, Student's t-test or Wilcoxon rank-sum test was used. To evaluate the differences between T0 and T1, ANOVA for paired data or Wilcoxon matched-pairs signed-ranks test was used. P < 0.05 was considered significant., Measurement and Main Results: Hemostasis was evaluated by means of prothrombin time, activated partial thromboplastin time, fibrinogen, and ROTEM. The study included 13 dogs in the HES group and 10 dogs in the HS group. Differences were found between groups at T1: increase in clotting time (P = 0.018) and decrease in fibrinogen level (P = 0.021) in the HS-treated group. Between T0 and T1, there were differences for the HES group: increase in clot formation time (P = 0.046), decrease in maximum clot firmness (P = 0.002) in ex-TEM profile, and decrease in maximum clot firmness (P = 0.0117) in fib-TEM profile. Between T0 and T1, the following differences were noted for the HS group: increase in clotting time (P = 0.048) and clot formation time (P = 0.0019), decrease in maximum clot firmness (P = 0.031) and α angle (P = 0.036) in ex-TEM profile, decrease in α angle (P = 0.036) in in-TEM profile, and decrease in maximum clot firmness (P = 0.017) in fib-TEM profile., Conclusion: In dogs affected by GDV, HES or HS infusion caused a similar tendency toward hypocoagulability, with few differences between the 2 groups., (© Veterinary Emergency and Critical Care Society 2021.)

Maintenance of the corneal refractive power and tissue transparency is essential for normal vision. Real-time characterization of changes in corneal cells during suffering stresses or wound healing may provide a way to identify novel targets, whose therapeutic manipulation can improve the outcome of this response induced by injury. Here we describe a novel user friendly and effective confocal real-time confocal microscopy attachment that monitors the effects of anisoosmotic stress on cell morphology and corneal thickness in situ. Corneal epithelial nuclei gradually became highly reflective in the isotonic group and the corneal stroma was slightly thickened as compared with that seen prior to 60 min exposure to a hypotonic solution. After 30 min of exposure to hypertonic stress, the corneal stromal cells became crenate and shriveled. The hyper-reflective area of the corneal stroma in the hypo-osmotic group was significantly larger than that in the other two groups, as demonstrated by 3D reconstruction imaging. The hypotonic fresh chlorinated pool water was observed to cause atrophy of corneal epithelial nuclei, while the isosmotic bee venom solution caused high reflection of the corneal stroma layer and corneal endothelial cell damage. With the microscopic attachment, the inward movement of corneal epithelial cells toward the denuded central region was detected in the serum-treated group. The microscopy attachment is an effective system for obtaining a more detailed understanding of the time dependent losses in the corneal cell structure and tissue architecture of full thickness corneas induced by osmotic stress or cytotoxic agents., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Cystic fibrosis (CF) is a life-threatening multiorgan genetic disease, particularly affecting the lungs, where recurrent infections are the main cause of reduced life expectancy. In CF, mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein impair transepithelial electrolyte and water transport, resulting in airway dehydration, and a thickening of the mucus associated with abnormal viscoelastic properties. Our aim was to develop a rheological method to assess the effects of hypertonic saline (NaCl) and NaHCO 3 on CF sputum viscoelasticity in vitro, and to identify the critical steps in sample preparation and in the rheological measurements., Methods: Sputum samples were mixed with hypertonic salt solutions in vitro in a ratio of either 10:4 or 10:1. Distilled water was applied as a reference treatment. The rheological properties of sputum from CF patients, and the effects of these in vitro treatments, were studied with a rheometer at constant frequency and strain, followed by frequency sweep tests, where storage modulus (G'), loss modulus (G″) and loss factor were determined., Results: We identified three distinct categories of sputum: (i) highly elastic (G' > 100,000 Pa), (ii) elastic (100,000 Pa > G' > 1000 Pa), and (iii) viscoelastic (G' < 1000). At the higher additive ratio (10:4), all of the added solutions were found to significantly reduce the gel strength of the sputum, but the most pronounced changes were observed with NaHCO 3 (p < 0.001). Samples with high elasticity exhibited the greatest changes while, for less elastic samples, a weakening of the gel structure was observed when they were treated with water or NaHCO 3 , but not with NaCl. For the viscoelastic samples, the additives did not cause significant changes in the parameters. When the lower additive ratio (10:1) was used, the mean values of the rheological parameters usually decreased, but the changes were not statistically significant., Conclusion: Based on the rheological properties of the initial sputum samples, we can predict with some confidence the treatment efficacy of each of the alternative additives. The marked differences between the three categories suggest that it is advisable to evaluate each sample individually using a rheological approach such as that described here., (© 2021. The Author(s).)

Background: There has been growing interest in the use of hypertonic sodium lactate (HSL) solution following traumatic brain injury (TBI) in humans. However, little is known about the effects of HSL on functional deficits with respect to the hyperosmotic nature of HSL., Methods: We have compared the effects of HSL solution and isotonic saline solution using sensorimotor and cognitive tests for 14 days post-trauma in animals. Thirty minutes after trauma (impact-acceleration model), anesthetized rats were randomly allocated to receive a 2-h infusion of isotonic saline solution (TBI-saline group) or HSL (TBI-HSL group) (n = 10 rats per group). In another series of experiments using a similar protocol, the effects of equiosmolar doses of HSL and hypertonic saline solution (HSS) were compared in TBI rats (n = 10 rats per group). Blood lactate and ion concentrations were measured during the 2-h infusions., Results: Compared to the TBI-saline group, the TBI-HSL group had a reduced latency to complete the adhesive removal test: 6 s (5-9) (median [25-75th centiles]) versus 13 s (8-17) on day 7, and 5 s (5-9) versus 11 s (8-26) on day 14 (P < 0.05), respectively, and a shorter delay to complete the radial arm maze test on day 7: 99 s (73-134) versus 176 s (127-300), respectively (P < 0.05). However, no differences were found between the TBI-HSL and TBI-HSS groups in neurocognitive tests performance. Compared to the TBI-saline group, the HSL and HSS groups had higher serum osmolality: 318 mOsm/Kg (315-321) and 315 mOsm/Kg (313-316) versus 307 mOsm/Kg (305-309), respectively (P < 0.05), and the HSL group had a higher serum lactate concentration: 6.4 mmol/L (5.3-7.2) versus 1.5 mmol/L (1.1-1.9) and 1.6 mmol/L (1.5-1.7), respectively (P < 0.05)., Conclusions: These results indicate that improvements in cognitive and sensorimotor tests with HSL infusion post-TBI could be related to elevation of serum osmolality, not to exogenous administration of lactate.

Objective: We conducted this prospective self-crossover controlled trial to compare the efficacy and safety of 10 % hypertonic saline (HS) and 20 % mannitol in doses of similar osmotic burden for the treatment of increased intracranial pressure (ICP) in patients with large hemispheric infarction (LHI)., Patients and Methods: Patients with LHI were enrolled from January 2017 to January 2018. We used an alternating treatment protocol to compare the effects of HS with mannitol given for episodes of increased ICP in patients with LHI. Indicators such as ICP, mean arterial pressure (MAP) and cerebral perfusion pressure (CPP) were continuously monitored at regular intervals for 240 min after initiation of infusion. Electrolytes, plasma osmolality and renal functions were measured before and 240 min after initiation of infusion to compare the efficacy and safety of the two drugs., Results: A total of 49 episodes of increased ICP occurred in 14 patients with LHI, of which 24 were infused with 10 % HS and 25 with 20 % mannitol. Both the treatments were equally effective in reducing ICP (P < 0.01). The differences in the duration and degree of reduction were not significant between the groups (P > 0.05). Although both the osmolar agents decreased MAP, the degree was greater in the mannitol group (P < 0.05) at T120. The increase in CPP was greater in the HS group compared with the mannitol group (P < 0.05) at T120. However, HS was associated with faster heart rate (HR) and higher serum chloride levels (P < 0.05). Changes in serum sodium levels and osmolality were not significant between the groups in spite of being higher in the HS group., Conclusions: Both the drugs can serve as first-line agents for treating intracranial hypertension caused by LHI and should be selected rationally according to the differences in efficacy and adverse effects., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: The aim of this study was to explore whether the antibrain edema of hypertonic saline (HS) is associated with alleviating ischemic blood-brain barrier (BBB) permeability by downregulating astrocyte-derived vascular endothelial growth factor (VEGF), which is mediated by microglia-derived NOD-like receptor protein 3 (NLRP3) inflammasome., Methods: The infarct volume and BBB permeability were detected. The protein expression level of VEGF in astrocytes in a transient focal brain ischemia model of rats was evaluated after 10% HS treatment. Changes in the NLRP3 inflammasome, IL-1β protein expression, and the interleukin-1 receptor (IL1R1)/pNF-кBp65/VEGF signaling pathway were determined in astrocytes., Results: HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulates IL-1β expression by inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulates VEGF expression by inhibiting the phosphorylation of NF-кBp65 mediated by IL-1β in astrocytes., Conclusions: HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulated IL-1β expression via inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulated VEGF expression through inhibiting the phosphorylation of NF-кBp65 mediated by IL-1β in astrocytes., (© 2020 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd.)

Background: To compare the effects of 3% hypertonic saline solution and 20% mannitol solution on intracranial hypertension., Methods: WAN-FANGDATA, CNKI, and CQVIP databases were searched, and relevant literatures of randomized controlled trials comparing 3% hypertonic saline solution with mannitol in reducing intracranial hypertension from 2010 to October 2019 were collected. Meta-analysis was performed using RevMan software., Results: As a result, 10 articles that met the inclusion criteria were finally included. A total of 544 patients were enrolled in the study, 270 in the hypertonic saline group and 274 in the mannitol group. There was no significant difference in the decrease of intracranial pressure and the onset time of drug between the 2 groups after intervention (all P > .05). There was a statistically significant difference between the hypertonic saline group and the mannitol group in terms of duration of effect in reducing intracranial pressure (95% confidence interval: 0.64-1.05, Z = 8.09, P < .00001) and cerebral perfusion pressure after intervention (95% confidence interval: 0.15-0.92, Z = 2.72, P = .007)., Conclusion: Both 3% hypertonic saline and mannitol can effectively reduce intracranial pressure, but 3% hypertonic saline has a more sustained effect on intracranial pressure and can effectively increase cerebral perfusion pressure.

Different pharmacologic agents have been tested in the effort to prevent contrast-induced acute kidney injury (AKI) in the last two decades. To date, however, no individual drug has received unanimous approval for this aim. Since 2014 statins have been included as preventive treatment in the European guidelines for revascularization procedures in cardiac patients. The present update presents the latest findings in this field focusing on the changing paradigms in the definition and consequently the approach to nephroprotection that considers clinical prognosis as the major issue. We note the current shift from attention to contrast-induced AKI to contrast-associated AKI., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The suprachiasmatic nucleus (SCN) serves as the body's master circadian clock that adaptively coordinates changes in physiology and behaviour in anticipation of changing requirements throughout the 24-h day-night cycle 1-4 . For example, the SCN opposes overnight adipsia by driving water intake before sleep 5,6 , and by driving the secretion of anti-diuretic hormone 7,8 and lowering body temperature 9,10 to reduce water loss during sleep 11 . These responses can also be driven by central osmo-sodium sensors to oppose an unscheduled rise in osmolality during the active phase 12-16 . However, it is unknown whether osmo-sodium sensors require clock-output networks to drive homeostatic responses. Here we show that a systemic salt injection (hypertonic saline) given at Zeitgeber time 19-a time at which SCN VP (vasopressin) neurons are inactive-excited SCN VP neurons and decreased non-shivering thermogenesis (NST) and body temperature. The effects of hypertonic saline on NST and body temperature were prevented by chemogenetic inhibition of SCN VP neurons and mimicked by optogenetic stimulation of SCN VP neurons in vivo. Combined anatomical and electrophysiological experiments revealed that osmo-sodium-sensing organum vasculosum lamina terminalis (OVLT) neurons expressing glutamic acid decarboxylase (OVLT GAD ) relay this information to SCN VP neurons via an excitatory effect of γ-aminobutyric acid (GABA). Optogenetic activation of OVLT GAD neuron axon terminals excited SCN VP neurons in vitro and mimicked the effects of hypertonic saline on NST and body temperature in vivo. Furthermore, chemogenetic inhibition of OVLT GAD neurons blunted the effects of systemic hypertonic saline on NST and body temperature. Finally, we show that hypertonic saline significantly phase-advanced the circadian locomotor activity onset of mice. This effect was mimicked by optogenetic activation of the OVLT GAD → SCN VP pathway and was prevented by chemogenetic inhibition of OVLT GAD neurons. Collectively, our findings provide demonstration that clock time can be regulated by non-photic physiologically relevant cues, and that such cues can drive unscheduled homeostatic responses via clock-output networks.

Objective: To evaluate the effects of 7.5% hypertonic saline solution (HSS) on whole blood coagulation in healthy dogs and to compare electrolyte and osmolality measurements between in vivo and in vitro dilution with HSS., Design: Experimental study., Setting: University teaching hospital., Animals: Twelve adult purpose-bred Beagles., Interventions: All 12 dogs received 5 mL/kg 7.5% HSS at 1 mL/kg/min. After a 14-day washout period, 5 of these dogs were randomly selected and received the same volume of 0.9% NaCl. Blood samples were collected before infusion, immediately after infusion, and at 30, 60, and 90 minutes after infusion for the measurement of coagulation using thromboelastography. For comparison of electrolyte concentrations and osmolality between in vitro dilution and in vivo dilution of HSS, 6-mL blood samples were diluted with 7.5% HSS (1:18 ratio) at baseline., Measurements and Main Results: None of the thromboelastography variables differed significantly between the 7.5% HSS group and the 0.9% NaCl group. The sodium and chloride levels, and the osmolality, were significantly increased at all postinfusion time points compared to baseline, while those levels were significantly higher with in vitro dilution than all postinfusion time points. However, almost all the values gradually decreased and became similar to baseline values in case of in vivo dilution., Conclusions: The clinically relevant dose of 7.5% HSS (5 mL/kg) did not affect whole blood coagulation significantly in healthy Beagles. Further studies are necessary to assess the effect of HSS on blood coagulation in canine patients with shock., (© Veterinary Emergency and Critical Care Society 2020.)

Competing Interests: Competing interests: The authors have completed the ICMJE uniform disclosure form (available upon request from the corresponding author) and declare no conflicts of interest.

Objective: To assess the in vitro effects of crystalloid and colloid IV fluids on the thromboelastographic (TEG) variables of canine whole blood., Design: In vitro experimental study., Setting: Veterinary teaching hospital., Animals: Twenty-two healthy dogs., Intervention: Citrated whole blood samples collected from healthy dogs were diluted with 3.4% hypertonic saline (HTS 3.4), 7% hypertonic saline (HTS 7), and 20% mannitol at 8% and 16% dilutions; hydroxyethyl starch 130/0.4 (HES 130/0.4) at 16% dilution; lactated Ringer's solution (LRS) at 16%, 33%, and 66% dilutions; and HTS 7-HES 130/0.4 at 25% and 50% dilutions. Kaolin-activated TEG analysis was concurrently performed on diluted and control (undiluted) samples., Measurements and Main Results: Dilution of canine whole blood with LRS compared to control reduced α angle and MA at both 33% (P = 0.009 and P = 0.011, respectively) and 66% dilution (P < 0.001 and P < 0.001, respectively), and prolonged K time at 66% dilution (P = 0.003). At 16% dilution, HTS 3.4, prolonged R time (P = 0.007), while mannitol, a fluid iso osmolar to HTS 3.4, prolonged K time (P = 0.006), reduced α angle (P < 0.001), MA (P = 0.046), and LY60 (P = 0.015). At 8% dilution, HTS 7, a fluid of high osmolarity and tonicity, prolonged R time (P = 0.009) and reduced MA (P = 0.015), while all measured TEG variables were altered at the 16% dilution (P < 0.01 for all variables). HES 130/0.4 reduced α angle (P = 0.031) and MA (P = 0.001) and increased LY60 (P < 0.001) at 16% dilution. Comparing different fluid types, HES 130/0.4 and HTS 3.4 had no to minor, mannitol intermediate, and HTS 7 profound effects on TEG variables (P < 0.05) when compared to LRS at the same dilution., Conclusions: In vitro dilution of canine whole blood with commonly used IV fluids leads to thromboelastographic changes consistent with hypocoagulability in a dose dependent manner for all fluid types tested. Viscoelastic changes are also influenced by fluid characteristics, specifically tonicity and osmolarity., (© Veterinary Emergency and Critical Care Society 2020.)

Aerosol inhalation is a promising strategy for the delivery of antibiotic agents. The efficacy of antibiotic treatment by aerosol inhalation is reduced by the formation of microbial biofilms in the respiratory system and excessive airway mucus build-up. Various approaches have been taken in order to overcome this barrier. In this in vitro study, we used hypertonic saline (7%, by weight), a low cost Food and Drug Administration-approved reagent, as an aerosol carrier to study its effects with the antibiotic, gentamicin, on the most common respiratory opportunistic pathogen, Pseudomonas aeruginosa, present in the mucus. The results indicated that the hypertonic saline aerosol containing gentamicin, a low cost antibiotic, significantly eliminated biofilm growth by ~3-fold, compared to the regular saline aerosol containing gentamicin. In addition to enhancing the penetration efficiency of drug molecules by 70%, bacterial motility also decreased (~50%) after treatment with aerosolised hypertonic saline. In conclusion, our results demonstrate that hypertonic saline can significantly enhance the efficacy of antibiotic aerosols, which may contribute to the current use of inhaled therapeutic compounds.

Both the autonomic nervous system and the neuroendocrine system are activated by osmotic stimulation (OS) evoking cardiovascular effects. The current study investigated the mechanisms involved in the cardiovascular responses evoked by an acute osmotic stimulus with intraperitoneal (i.p.) injection of either isotonic (0.15 M NaCl) or hypertonic saline (0.6 M NaCl) in conscious rats. Hypertonic saline increased mean arterial pressure (MAP) and heart rate (HR) for 30 min, as well as plasma osmolality and sodium content. Urinary sodium and urinary volume were also increased. Pretreatment with the ganglion blocker pentolinium (i.v.) did not affect the pressor response, but significantly decreased the tachycardic response caused by OS. Pretreatment with the V 1 -vasopressin receptor antagonist dTyr(CH 2 ) 5 (Me)AVP (i.v.) reduced the pressor response, without affecting the tachycardic response evoked by the hypertonic OS. Neither the pressor nor the tachycardic response to OS was affected by pretreatment with either the oxytocin receptor antagonist atosiban or the α1-antagonist prazosin. Pretreatment with the β1-antagonist atenolol had no effect on the pressor response, but markedly decreased the tachycardic response evoked by OS. Results indicate that i.p. hypertonic OS-evoked pressor response is mediated by the release of vasopressin, with a minor influence of the vascular sympathetic input.LAY SUMMARYIncreased plasma osmolality, such as that observed during dehydration or salt intake, is a potent stimulus yielding to marked cardiovascular and neuroendocrine responses. The intraperitoneal (i.p.) injection of hypertonic saline solution is a commonly used animal model to cause a sustained increase in plasma osmolality, leading to a cardiovascular response characterized by sustained blood pressure and heart increases, whose systemic mechanisms were presently studied. Our findings indicate that the pressor response to the i.p. osmotic stimulus (OS) is mediated mainly by the release of vasopressin into the blood circulation with a minor or even the noninvolvement of the vascular sympathetic nervous system, whereas activation of the sympathetic-cardiac system mediates the tachycardic response to OS.

Background: Hypertonic saline (23.4%, HTS) bolus administration is common practice for refractory intracranial hypertension, but its effects on coagulation are unknown. We hypothesize that 23.4% HTS in whole blood results in progressive impairment of coagulation in vitro and in vivo in a murine model of traumatic brain injury (TBI)., Study Design: For the in vitro study, whole blood was collected from 10 healthy volunteers, and citrated native thrombelastography was performed with normal saline (0.9%, NS) and 23.4% HTS in serial dilutions (2.5%, 5%, and 10%). For the in vivo experiment, we assessed the effects of 23.4% HTS bolus vs NS on serial thrombelastography and tail-bleeding times in a TBI murine model (n = 10 rats with TBI and 10 controls)., Results: For the in vitro work, clinically relevant concentrations of HTS (2.5% dilution) shortened time to clot formation and increased clot strength (maximum amplitude) compared with control and NS. With higher HTS dosing (5% and 10% blood dilution), there was progressive prolongation of time to clot formation, decreased angle, and decreased maximum amplitude. In the in vivo study, there was no significant difference in thrombelastography measurements or tail-bleeding times after bolus administration of 23.4% HTS compared with NS at 2.5% blood volume., Conclusions: At clinically relevant dilutions of HTS, there is a paradoxical shortening of time to clot formation and increase in clot strength in vitro and no significant effects in a murine TBI model. However, with excess dilution, caution should be exercised when using serial HTS boluses in TBI patients at risk for trauma-induced coagulopathy., (Copyright © 2019 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

Escherichia coli cells were suspended in phosphate-buffered saline solutions (pH 7.4) at physiological (0.9 %) and hyperosmotic (3.5, 5.0, and 10.0 %) concentrations of sodium chloride (NaCl) and stored at 5, 10, 15, 20, and 25 °C up to 48 d. During storage at 5 and 10 °C, viable cell counts decreased approximately from 9 log CFU/ml to 6-7 log CFU/ml, and NaCl showed slight protective effect on the decrease. When stored at 15, 20, and 25 °C, the counts decreased with increases in NaCl concentration and/or storage temperature. The cells in 10.0 % NaCl suspension became nondetectable after storage at 25 °C for 28 d. Under some storage conditions (NaCl ≤ 5 %, 20 and 25 °C), the counts approached constant values, indicating possible adaptation to NaCl. Injured cells were observed at 5.0 and 10.0 % NaCl. However, recovery was observed only at 5.0 % NaCl during storage at 20 °C. In addition, more cells were detected on nonselective medium when incubated at 37 °C than at 25 °C. Higher hyperosmotic NaCl solutions at higher storage temperatures reduced more viable cells of E. coli.

Introduction: Hyperosmotic agents are used to decrease intracranial pressure (ICP). We aim to compare the effect of euvolemic solutions of 3% hypertonic saline (HTS) and 20% mannitol on intraoperative brain relaxation in patients with clinical or radiological evidence of raised ICP undergoing surgery for supratentorial tumors., Materials and Methods: A., prospective double-blind study was conducted on 30 patients randomized into two equal groups. Each patient was administered 5 ml/kg of either 20% mannitol or 3% HTS over 15 minutes (min) after skin incision. Hemodynamic data, brain relaxation and serum electrolyte levels were recorded., Results: Intraoperative brain relaxation was comparable between the two groups. There was a statistically significant difference in the mean arterial pressures (MAPs) between the two groups after one minutes (min) with a greater degree of decrease in blood pressure recorded in the mannitol group (P = 0.041). MAP with mannitol was significantly lower than the preinduction value after 75 min of administration of drug (P = 0.003). Urine output was significantly higher in the mannitol group (P = 0.00). Administration of HTS was associated with a transient increase in serum sodium concentrations, which was statistically significant but returned to normal within 48 h (P < 0.001)., Conclusions: Both mannitol and HTS provided adequate intraoperative brain relaxation. On the contrary, there was no statistically significant fall in blood pressure with HTS. Thus, we advocate the use of HTS over mannitol as it maintains better hemodynamic stability., Competing Interests: None

In our present studies, we seek to determine whether increased osmolarity stimulates deflation-activated receptors (DARs). In anesthetized, open-chest, and mechanically ventilated rabbits, we recorded single-unit activities from typical slowly adapting receptors (SARs; responding only to lung inflation) and DAR-containing SARs (DAR-SARs; responding to both lung inflation and deflation) and identified their receptive fields in the lung. We examined responses of these two groups of pulmonary sensory units to direct injection of hypertonic saline (8.1% sodium chloride; 9-fold in tonicity) into the receptive fields. Hypertonic saline decreased the activity in most SAR units from 40.3 ± 5.4 to 34.8 ± 4.7 imp/s ( P < 0.05, n = 12). In contrast, it increased the activity in DAR-SAR units quickly and significantly from 15.9 ± 2.2 to 43.4 ± 10.0 imp/s ( P < 0.01, n = 10). Many units initially had increased activity, mainly in the deflation phase. DAR-SAR activities largely returned to the control level 30 s after injection. Since hypertonic saline stimulated DAR-SAR units but not SAR units, we conclude that hypertonic saline activates DARs.

Background: Fluid loading and hyperosmolar solutions can modify the cortical brain microcirculation and the endothelial glycocalyx (EG). This study compared the short-term effects of liberal fluid loading with a restrictive fluid intake followed by osmotherapy with hypertonic saline (HTS) on cerebral cortical microcirculation and EG integrity in a rabbit craniotomy model., Methods: The experimental rabbits were allocated randomly to receive either <2 mL/kg/h (group R, n=14) or 30 mL/kg/h (group L, n=14) of balanced isotonic fluids for 1 hour. Then, the animals were randomized to receive 5 mL/kg intravenous infusion of either 3.2% saline (group HTS, n=14) or 0.9% saline (group normal saline, n=13) in a 20-minute infusion. Microcirculation in the cerebral cortex based on sidestream dark-field imaging, a morphologic index of glycocalyx damage to sublingual and cortical brain microcirculation (the perfused boundary region), and serum syndecan-1 levels were evaluated., Results: Lower cortical brain perfused small vessel density (P=0.0178), perfused vessel density (P=0.0286), and total vessel density (P=0.0447) were observed in group L, compared with group R. No differences were observed between the HTS and normal saline groups after osmotherapy. Cerebral perfused boundary region values (P=0.0692) and hematocrit-corrected serum syndecan-1 levels (P=0.0324) tended to be higher in group L than in group R animals., Conclusions: Liberal fluid loading was associated with altered cortical cerebral microcirculation and EG integrity parameters. The 3.2% saline treatment did not affect cortical cerebral microcirculation or EG integrity markers.

The aim of the present study was to explore the possible mechanisms by which hypertonic saline (HS) effectively ameliorates cerebral oedema via the vascular endothelial growth factor receptor 2 (VEGFR2)‑mediated endothelial nitric oxide synthase (eNOS) pathway of endothelial cells in rats. A middle cerebral artery occlusion (MCAO) model in Sprague‑Dawley rats and an oxygen‑glucose deprivation (OGD) model in cells were used in the present study. Evans blue (EB) staining and a horseradish peroxidase flux assay were performed to evaluate the protective effect of 10% HS on the blood‑brain barrier (BBB). The expression levels of vascular endothelial growth factor (VEGF), VEGFR2, zonula occludens 1 (ZO1) and occludin were quantified. The results demonstrated that 10% HS effectively reduced EB extravasation in the peri‑ischaemic brain tissue. At 24 h after MCAO, the protein expression levels of VEGF and VEGFR2 in the peri‑ischaemic brain tissue were downregulated following treatment with 10% HS. In vitro experiments demonstrated that the permeability of a monolayer endothelial cell barrier was decreased significantly following HS treatment. In addition, VEGF and VEGFR2 protein expression levels were increased in endothelial cells under hypoxic conditions, but that effect was suppressed by HS treatment. Furthermore, HS inhibited the downregulation of ZO1 and occludin effectively, possibly through the VEGFR2/phospholipase C γ1 (PLCγ1)/eNOS signalling pathway. In conclusion, 10% HS may alleviate cerebral oedema through reducing ischaemia‑induced BBB permeability, as a consequence of inhibiting VEGFR2/PLCγ1/eNOS‑mediated downregulation of ZO1 and occludin.

Objective: There are various protoscolicidal agents for inactivation of protoscoleces of hydatid cysts before and during surgical operation. The present study was aimed to evaluate the protoscolicidal effect of two concentrations of Eucalyptus globulus on protoscoleces of Echinococcus granulosus sensu lato under in vitro condition and to compare its efficacy with hypertonic saline, povidone iodine and silver nitrate., Methods: Live protoscoleces obtained from the liver of naturally infected sheep were exposed to 0.5% and 1% of Eucalyptus globulus essential oil, 5% hypertonic saline, 10% povidone iodine and 0.5% silver nitrate for 1 and 3minutes. Phosphate buffered saline was used as a negative control. One percent eosin staining method was used to test the viability of protoscoleces in different groups., Results: While the mean percentage of dead protoscoleces was 6.08% in the control group, the scolicidal power of 5% hypertonic saline was only 6.54% and 6.60% after 1 and 3min respectively. 0.5% E. globulus EO demonstrated 97.38% and 100% scolicidal activity after 1 and 3min respectively. The mean protoscolicidal power of 1% E. globulus EO, 10% povidone iodine and 0.5% silver nitrate was 100% after one minute., Conclusions: According to the results of this study, E. globulus EO demonstrated high scolicidal power in a short period of time. Hence, this herbal product could be considered as a potent natural scolicidal agent that could be used before and during surgery of hydatid disease., (Copyright © 2019. Published by Elsevier Masson SAS.)

Objective and Design: Hypertonic saline administered during fluid resuscitation may mitigate endothelial glycocalyx (EG) shedding and inflammation. The objective of this pilot randomised controlled trial was to measure the effect of hypertonic saline, compared to isotonic saline, on biomarkers of EG shedding and inflammation in emergency department patients with suspected sepsis., Methods: Patients received either 5 mL/kg of 3% saline (hypertonic group, n = 34) or 10 mL/kg of 0.9% saline (isotonic group, n = 31). Change in serum biomarker concentrations of syndecan-1, hyaluronan, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, interleukin-6, -8, -10, interferon-γ, neutrophil gelatinase-associated lipocalin and resistin were compared from baseline (T0) to after fluid (T1), 3 h (T3) and 12-24 h (T24) later, as was serum osmolality, using linear mixed effects models., Results: The hypertonic group had significantly increased mean serum osmolality compared to the isotonic group at T1 (P < .001) and T3 (P = .004). Minor differences were found in some biomarker outcomes, including a decreased fold-change in syndecan-1 at T1 (P = .012) and in interleukin-10 at T24 (P = .006) in the isotonic group, compared to the hypertonic group., Conclusions: Although a single bolus of hypertonic saline increased serum osmolality, it did not reduce biomarkers of EG shedding or inflammation, compared to patients that received isotonic saline., Trial Registration: ANZCTR.org.au, ACTRN12611001021965, Registered on 23rd September 2011., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Proper fluid resuscitation can relieve visceral damage and improve survival in severely burned patients. This study compared the effectiveness of resuscitation with 400mEq/L hypertonic saline (HS) and sodium lactate Ringer's solution (LR) in rats with kidney injury caused by burn trauma., Methods: Rats (Sprague-Dawley) underwent burn injury and were randomized into sham, LR, and HS groups. Samples from the kidney were assayed for water content ratio, histopathology, and oxidative stress (superoxide dismutase (SOD) and malondialdehyde (MDA)). Serum sodium, renal function (creatinine and cystatin (Cys)-C), and inflammatory response (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and high mobility group protein box (HMGB)-1) were also examined as serum markers., Results: Hypertonic saline resuscitation reduced the renal water content ratio and improved renal histopathology caused by severe burns. This effect was accompanied by reductions in serum creatinine and Cys-C as well as TNF-α, IL-1β, and HMGB1. Serum sodium concentration and SOD activity were increased, whereas MDA content was decreased in the kidney tissue of the HS group., Conclusions: The data indicate that 400mEq/L HS solution reduces hyponatremia and renal edema, inhibits the release of inflammatory mediators, and alleviates oxidative stress injury, thus protecting against kidney injury induced by severe burns., (Copyright © 2018 Elsevier Ltd and ISBI. All rights reserved.)

Background: Brain death (BD) induces hemodynamic instability with microcirculatory hypoperfusion, leading to increased organ inflammation and dysfunction. This study investigated the effects of 7.5% hypertonic saline solution (HSS) on mesenteric microcirculatory dysfunction and inflammation in a rat model of BD., Methods: Male Wistar rats were anesthetized and mechanically ventilated. BD was induced by rapidly inflating an intracranial balloon catheter. The rats were randomly divided into: SH, sham-operated rats subjected to trepanation; NS, rats treated with NaCl 0.9%, 4 mL/kg immediately after BD; T1, rats treated with HSS (NaCl 7.5%, 4 mL/kg) immediately or 60 min after BD, T60. All groups were analyzed 180 min after the start of the experiment., Results: Rats in BD groups presented with a similar hypertensive peak, followed by hypotension. Proportion of perfused small vessels was decreased in the NS group (46%) compared with the SH group (74%, P = 0.0039). HSS restored the proportion of perfused vessels (T1 = 71%, P = 0.0018). The anti-endothelial nitric oxide synthase (eNOS) protein expression significantly increased in rats given HSS (T1, and T60, P = 0.0002). Similar results were observed regarding endothelin-1 (P < 0.0001). Increased numbers of rolling (P = 0.0015) and migrated (P = 0.0063) leukocytes were observed in the NS group compared with the SH group. Rats given HSS demonstrated an overall reduction in leukocyte-endothelial interactions. The ICAM-1 levels increased in the NS group compared with the SH group, and decreased in the HSS-treated groups (P = 0.0002)., Conclusions: HSS may improve the density of mesenteric perfused small vessels due to its effects on eNOS and endothelin-1 protein expression, and reduces inflammation by decreasing leukocyte adhesion and migration in a rat model of BD.

Background: Osmotic therapy is a critical component of medical management for cerebral edema. While up to 90% of neurointensivists report using these treatments, few quantitative clinical measurements guide optimal timing, dose, or administration frequency. Its use is frequently triggered by a qualitative assessment of neurologic deterioration and/or pupil size, and anecdotally appears to improve pupil asymmetry suggestive of uncal herniation. However, subjective pupil assessment has poor reliability, making it difficult to detect or track subtle changes. We hypothesized that osmotic therapy reproducibly improves quantitative pupil metrics., Methods: We included patients at two centers who had recorded quantitative pupil measurements within 2 h before and after either 20% mannitol or 23.4% hypertonic saline in the neurosciences intensive care unit. The primary outcome was the Neurologic Pupil Index (NPi), a composite metric ranging from 0 to 5 in which > 3 is considered normal. Secondary outcomes included pupil size, percent change, constriction and dilation velocity, and latency. Results were analyzed with Wilcoxon signed-rank tests, Chi-square and multi-level linear regression to control for other edema-reducing interventions., Results: Out of 72 admissions (403 paired pupil observations), NPi significantly differed within 2 h of osmotic therapy when controlling for other commonly used interventions in our whole cohort (β = 0.08, p = 0.0168). The effect was most pronounced (β = 0.57) in patients with abnormal NPi prior to intervention (p = 0.0235)., Conclusions: Pupil reactivity significantly improves after osmotic therapy in a heterogenous critically ill population when controlling for various other interventions. Future work is necessary to determine dose-dependent effects and clinical utility.

High salt diet alters cardiovascular control by increasing concentration of sodium ions (Na + ) in cerebrospinal fluid (CSF) and is a risk factor for hypertension. Hypernatremic conditions activate microglia and upregulate renin-angiotensin system in the brain. Thus, we checked if chronic elevation of CSF Na + affects neural control of circulatory system via microglia and brain angiotensin type 1 receptors (AT1Rs). Normotensive adult male Sprague-Dawley rats received two-week intracerebroventricular (ICV) infusion of either isoosmotic saline (0.9% NaCl); hyperosmotic saline (5% NaCl); 5% NaCl with minocycline - inhibitor of microglia; 5% NaCl with losartan - AT1R blocker. Fluid intake, urine output, and urinary Na + excretion were measured before and during ICV infusions. At the end of ICV infusions, blood pressure and heart rate were recorded in awake rats at rest, in response to acute air jet stressor, during pharmacological evaluation of baroreflex, and after autonomic ganglia blockade. CSF and blood were collected for evaluation of Na + concentration. Baroreflex was blunted in rats ICV infused with 5% NaCl. ICV treatment with losartan or minocycline prevented decrease in baroreflex sensitivity. Hemodynamic parameters at rest, in response to acute stressor and autonomic ganglia blockade were similar in all groups. Neither treatment affected water intake, urine output and urinary Na + excretion. ICV infusion of 5% NaCl resulted in higher concentration of Na + in CSF than in control group (0.9% NaCl) and in plasma. Our results indicate that chronic ICV infusion of hyperosmotic saline blunts baroreflex in normotensive rats and this desensitization is mediated by microglia and AT1Rs., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To determine if 3 resuscitative fluid therapy strategies increase N-terminal pro-brain natriuretic peptide (NT proBNP) levels in healthy dogs., Design: Randomized crossover trial., Setting: Veterinary teaching hospital., Animals: Plasma NT proBNP concentrations were measured in 6 healthy purpose-bred dogs that received 3 resuscitative fluid therapy protocols., Measurements and Main Results: Crystalloid, synthetic colloid, or hypertonic saline fluids were administered at resuscitative doses. Blood samples were collected via an indwelling catheter before, and at set time points between 0.5 and 36 h after fluid therapy and analyzed for NT-proBNP. A general linear mixed model was used to estimate the differences in NT-proBNP over time and among treatments. None of the resuscitative fluid therapy protocols caused increases of serum NT-proBNP beyond the previously reported cutoff concentration used to differentiate cardiac versus noncardiac causes of respiratory signs. Dogs receiving crystalloid fluid therapy had the most significant and prolonged increase in serum NT-proBNP concentration above baseline compared to dogs receiving either resuscitative doses of colloids or hypertonic saline., Conclusions: Serum NT-proBNP concentration in normal dogs was not increased beyond concentrations previously established to equate to cardiac disease after receiving resuscitative fluid therapy with either a balanced crystalloid solution, hypertonic saline, or a synthetic colloid solution in this study., (© Veterinary Emergency and Critical Care Society 2019.)

Hypertonicity increases water permeability, independently of vasopressin, in the inner medullary collecting duct (IMCD) by increasing aquaporin-2 (AQP2) membrane accumulation. We investigated whether protein kinase C (PKC) and adenosine monophosphate kinase (AMPK) are involved in hypertonicity-regulated water permeability. Increasing perfusate osmolality from 150 to 290 mosmol/kgH 2 O and bath osmolality from 290 to 430 mosmol/kgH 2 O significantly stimulated osmotic water permeability. The PKC inhibitors chelerythrine (10 µM) and rottlerin (50 µM) significantly reversed the increase in osmotic water permeability stimulated by hypertonicity in perfused rat terminal IMCDs. Chelerythrine significantly increased phosphorylation of AQP2 at S261 but not at S256. Previous studies show that AMPK is stimulated by osmotic stress. We tested AMPK phosphorylation under hypertonic conditions. Hypertonicity significantly increased AMPK phosphorylation in inner medullary tissues. Blockade of AMPK with Compound C decreased hypertonicity-stimulated water permeability but did not alter phosphorylation of AQP2 at S256 and S261. AICAR, an AMPK stimulator, caused a transient increase in osmotic water permeability and increased phosphorylation of AQP2 at S256. When inner medullary tissue was treated with the PKC activator phorbol dibutyrate (PDBu), the AMPK activator metformin, or both, AQP2 phosphorylation at S261 was decreased with PDBu or metformin alone, but there was no additive effect on phosphorylation with PDBu and metformin together. In conclusion, hypertonicity regulates water reabsorption by activating PKC. Hypertonicity-stimulated water reabsorption by PKC may be related to the decrease in endocytosis of AQP2. AMPK activation promotes water reabsorption, but the mechanism remains to be determined. PKC and AMPK do not appear to act synergistically to regulate water reabsorption.

There are no antivirals to treat viral upper respiratory tract infection (URTI). Since numerous viruses cause URTI, antiviral therapy is impractical. As we have evidence of chloride-ion dependent innate antiviral response in epithelial cells, we conducted a pilot, non-blinded, randomised controlled trial of hypertonic saline nasal irrigation and gargling (HSNIG) vs standard care on healthy adults within 48 hours of URTI onset to assess recruitment (primary outcome). Acceptability, symptom duration and viral shedding were secondary outcomes. Participants maintained a symptom diary until well for two days or a maximum of 14 days and collected 5 sequential mid-turbinate swabs to measure viral shedding. The intervention arm prepared hypertonic saline and performed HSNIG. We recruited 68 participants (2.6 participants/week; November 2014-March 2015). A participant declined after randomisation. Another was on antibiotics and hence removed (Intervention:32, Control:34). Follow up data was available from 61 (Intervention:30, Control:31). 87% found HSNIG acceptable, 93% thought HSNIG made a difference to their symptoms. In the intervention arm, duration of illness was lower by 1.9 days (p = 0.01), over-the-counter medications (OTCM) use by 36% (p = 0.004), transmission within household contacts by 35% (p = 0.006) and viral shedding by ≥0.5 log 10 /day (p = 0.04). We hence need a larger trial to confirm our findings.

Inhaled hypertonic saline (HTS) treatment is used to improve lung health in patients with cystic fibrosis (CF). The current consensus is that the treatment generates an osmotic gradient that draws water into the airways and increases airway surface liquid (ASL) volume. However, there is evidence that HTS may also stimulate active secretion of ASL by airway epithelia through the activation of sensory neurons. We tested the contribution of the nervous system and airway epithelia on HTS-stimulated ASL height increase in CF and wild-type swine airway. We used synchrotron-based imaging to investigate whether airway neurons and epithelia are involved in HTS treatment-triggered ASL secretion in CFTR -/- and wild-type swine. We showed that blocking parasympathetic and sensory neurons in airway resulted in ~50% reduction of the effect of HTS treatment on ASL volume in vivo. Incubating tracheal preparations with inhibitors of epithelial ion transport across airway decreased secretory responses to HTS treatment. CFTR -/- swine ex-vivo tracheal preparations showed substantially decreased secretory response to HTS treatment after blockage of neuronal activity. Our results indicated that HTS-triggered ASL secretion is partially mediated by the stimulation of airway neurons and the subsequent activation of active epithelia secretion; osmosis accounts for only ~50% of the effect.

New Findings: What is the central question of this study? Does carotid body input contribute to the hyperosmotic responses? What is the main finding and its importance? The response to NaCl overload is sympathorespiratory excitation. Eliminating the carotid body input reduced sympathoexcitation but did not affect the increase in phrenic burst frequency, whereas eliminating the hypothalamus prevented the tachypnoea and sympathoexcitation. We conclude that the carotid body inputs are essential for the full expression of the sympathetic activity during acute NaCl overload, whereas the tachypnoea depends on hypothalamic mechanisms., Abstract: Acute salt excess activates central osmoreceptors, which trigger an increase in sympathetic and respiratory activity. The carotid bodies also respond to hyperosmolality of the extracellular compartment, but their contribution to the sympathoexcitatory and ventilatory responses to NaCl overload remains unknown. To evaluate their contribution to acute NaCl overload, we recorded thoracic sympathetic (tSNA), phrenic (PNA) and carotid sinus nerve activities in decorticate in situ preparations of male Holtzman rats (60-100 g) while delivering intra-arterial infusions of hyperosmotic NaCl (0.17, 0.3, 0.7, 1.5 and 2.0 mol l -1 ; 200 μl infusion over 25-30 s, with a 10 min time interval between solutions) or mannitol (0.3, 0.5, 1.0, 2.7 and 3.8 mol l -1 ) progressively. The cumulative infusions of hyperosmotic NaCl increased the perfusate osmolality to 341 ± 5 mosmol (kg water) -1 and elicited an immediate increase in PNA and tSNA (n = 6, P < 0.05) in sham-denervated rats. Carotid body removal attenuated sympathoexcitation (n = 5, P < 0.05) but did not affect the tachypnoeic response. A precollicular transection disconnecting the hypothalamus abolished the sympathoexcitatory and tachypnoeic responses to NaCl overload (n = 6, P < 0.05). Equi-osmolar infusions of mannitol did not alter the PNA and tSNA in sham-denervated rats (n = 5). Sodium chloride infusions increased carotid sinus nerve activity (n = 10, P < 0.05), whereas mannitol produced negligible changes (n = 5). The results indicate that carotid bodies are activated by acute NaCl overload, but not by mannitol. We conclude that the carotid bodies contribute to the increased sympathetic activity during acute NaCl overload, whereas the ventilatory response is mainly mediated by hypothalamic mechanisms., (© 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.)