OBJECTIVE: To evaluate the role of the addition of different concentrations of sodium chloride salt to conventional intracanal irrigants to vary their osmotic values and thereby compare their antibacterial efficacy.
METHODS: In an active attachment biofilm model, Enterococcus faecalis (ATCC 29212) biofilms were grown. Sodium chloride salts were added to 100 mL of distilled water to make 6M (hyperosmotic), 0.5M, and 0.25M (hypoosmotic) sodium chloride solutions, respectively. The experimental groups were divided into three groups: Group I: 5.25% sodium hypochlorite, group II: 2% chlorhexidine, and group III: 2% povidone iodine, and four subgroups within these three groups, such as subgroup A (without salt solution), subgroup B (with 6M of hyperosmotic salt solution), subgroup C (with 0.5M of hypoosmotic salt solution), and subgroup D (with 0.25M of hypoosmotic salt solution), respectively. Biofilms were treated with all the subgroups for a contact time of 15 min. A crystal violet assay was done to estimate the bacterial cell biomass.
RESULTS: The results revealed that subgroups IIIB, IB, and IID, ID had a statistical reduction in bacterial biomass at p < 0.05. There were no significant differences between subgroups IC, IIC, and IIIC and subgroups IA, IIA, and IIIA.
CONCLUSIONS: The antibacterial efficacy of all three irrigants was significantly affected by varying the osmolarities.
CONCLUSIONS: The results prove that the hyperosmotic and hypoosmotic salt solutions, along with irrigants, have enhanced antibacterial efficacy on E. faecalis biofilm due to its ability to vary the turgor pressure of cell wall, as well as the inherent properties of the irrigants such as hypochlorous acid formation, ionic interaction, and free radical interactions.

OBJECTIVE: The international guidelines for the treatment of diabetic ketoacidosis (DKA) advise against rapid changes in osmolarity and glucose; however, the optimal rates of correction are unknown. We aimed to evaluate the rates of change in tonicity and glucose level in intensive care patients with DKA and their relationship with mortality and altered mental status.
METHODS: This is an observational cohort study using 2 publicly available databases of U.S. intensive care patients (Medical Information Mart for Intensive Care-IV and Electronic Intensive Care Unit), evaluating adults with DKA and associated hyperosmolarity (baseline Osm ≥300 mOsm/L). The primary outcome was hospital mortality. The secondary neurologic outcome used a composite of diagnosed cerebral edema or Glasgow Coma Scale score of ≤12. Multivariable regression models were used to control for confounding factors.
RESULTS: On adjusted analysis, patients who underwent the most rapid correction of up to approximately 3 mmol/L/hour in tonicity had reduced mortality (n = 2307; odds ratio [OR], 0.21; overall P < .001) and adverse neurologic outcomes (OR, 0.44; P < .001). Faster correction of glucose levels up to 5 mmol/L/hour (90 mg/dL/hour) was associated with improvements in mortality (n = 2361; OR, 0.24; P = .020) and adverse neurologic events (OR, 0.52; P = .046). The number of patients corrected significantly faster than these rates was low. A maximal hourly rate of correction between 2 and 5 mmol/L for tonicity was associated with the lowest mortality rate on adjusted analysis.
CONCLUSIONS: Based on large-volume observational data, relatively rapid correction of tonicity and glucose level was associated with lower mortality and more favorable neurologic outcomes. Avoiding a maximum hourly rate of correction of tonicity >5 mmol/L may be advisable.

OBJECTIVE: Upper blepharoplasty may be related to dry eye symptoms since the function of the orbicularis oculi muscle may affect the tear film. We aimed to assess the effect of blepharoplasty with or without the removal of a strip of orbicularis oculi muscle on tear film dynamics and dry eye symptoms.
METHODS: A double-blind, randomized, controlled trial comparing upper blepharoplasty without (group A) or with (group B) orbicularis oculi muscle excision was performed on 54 healthy Caucasian patients. Tear film dynamics and dry eye symptoms were evaluated using multiple dry eye parameters, i.e. tear osmolarity, Schirmer test I, corneal/conjunctival staining, tear break-up time (TBUT), Oxford Scheme, Sicca Ocular Staining Score and Ocular Surface Disease Index questionnaire. All the parameters were assessed preoperatively and 6 and 12 months after upper blepharoplasty. All the groups\' outcomes were compared.
RESULTS: The differences were not significant between the two upper blepharoplasty techniques regarding most of the above-mentioned outcomes. Subjective symptoms of ocular irritation, consistent with dry eye disease and vision-related impairment, were reduced after upper blepharoplasty independent of the type of the technique applied, while the pre and postoperative outcomes of the objective tear dynamics did not differ 12 months after surgery. However, group B demonstrated a significant increase in tear osmolarity and TBUT at the 6-month follow-up visit.
CONCLUSIONS: An upper blepharoplasty alleviates subjective dry eye complaints in the long term, while not changing the tear dynamics. The improvement was independent of the blepharoplasty technique used.

Despite the reduced caloric content of artificially sweetened beverages (ASBs) relative to those sweetened with sucrose, consumption of ASBs fail to consistently decrease the risk of obesity and associated diseases. This failure may be due to the inability of ASBs to effectively reduce appetite and hence overall caloric intake. A variety of non-nutritive sweeteners (NNS), however, remain to be screened for effectiveness in promoting satiety and reducing calorie consumption. Erythritol is well-tolerated, low-calorie sugar alcohol widely used as a sugar substitute. It is unique among NNS due to its low sweetness index relative to glucose, meaning that it is typically served at much higher concentrations than other common NNS. Animal and human studies have noted correlations between osmolarity, satiety, and levels of satiety hormones, independent of the effects of sweetness or nutritive value. We hypothesized that consumption of a beverage sweetened with erythritol to the sweetness and osmolarity of a common soft drink will improve self-reported satiety and more strongly affect the magnitude of changes in the hormone ghrelin than would an iso sweet beverage sweetened only with aspartame, a sweetener with a high sweetness index relative to glucose. Using a randomized double-blind crossover trial, we found that serum ghrelin was significantly decreased after consumption of an erythritol-sweetened beverage compared to aspartame. Likewise, consumption of the erythritol-sweetened beverage increased various measures of satiety in volunteers. Knowledge gained from this project demonstrates that high-osmolarity NNS may be useful in formulating ASBs that are satiating and low in calories.

The potential contribution of serum osmolarity in the modulation of blood pressure has not been evaluated. This study was done to examine the relationship between hyperosmolarity and hypertension in a five-year longitudinal design. We enrolled 10,157 normotensive subjects without diabetes who developed hypertension subsequently as determined by annual medical examination in St. Luke\'s International Hospital, Tokyo, between 2004 and 2009. High salt intake was defined as >12 g/day by a self-answered questionnaire and hyperosmolarity was defined as >293 mOsm/L serum osmolarity, calculated using serum sodium, fasting blood glucose, and blood urea nitrogen. Statistical analyses included adjustments for age, gender, body mass index, smoking, drinking alcohol, dyslipidemia, hyperuricemia, and chronic kidney disease. In the patients with normal osmolarity, the group with high salt intake had a higher cumulative incidence of hypertension than the group with normal salt intake (8.4% versus 6.7%, p = 0.023). In contrast, in the patients with high osmolarity, the cumulative incidence of hypertension was similar in the group with high salt intake and in the group with normal salt intake (13.1% versus 12.9%, p = 0.84). The patients with hyperosmolarity had a higher incidence of hypertension over five years compared to that of the normal osmolarity group (p < 0.001). After multiple adjustments, elevated osmolarity was an independent risk for developing hypertension (OR (odds ratio), 1.025; 95% CI (confidence interval), 1.006-1.044), regardless of the amount of salt intake. When analyzed in relation to each element of calculated osmolarity, serum sodium and fasting blood glucose were independent risks for developing hypertension. Our results suggest that hyperosmolarity is a risk for developing hypertension regardless of salt intake.

We investigated the effect of gadopiclenol, a new gadolinium-based contrast agent, on the QTc interval at clinical and supraclinical dose, considering the relative hyperosmolarity of this product.
This was a single centre, randomized, double-blind, placebo- and positive-controlled, 4-way crossover study. Forty-eight healthy male and female subjects were included to receive single intravenous (i.v.) administrations of gadopiclenol at the clinical dose of 0.1 mmol kg-1 , standard for current gadolinium-based contrast agents, the supraclinical dose of 0.3 mmol kg-1 , placebo and a single oral dose of 400 mg moxifloxacin.
The largest time-matched placebo-corrected, mean change from-baseline in QTcF (ΔΔQTcF) was observed 3 hours after administration of 0.1 mmol kg-1 gadopiclenol (2.39 ms, 90% confidence interval [CI]: 0.35, 4.43 ms) and 5 minutes after administration of 0.3 mmol kg-1 (4.81 ms, 90%CI: 2.84, 6.78 ms). The upper limit of the 90% CI was under the threshold of 10 ms, demonstrating no significant effect of gadopiclenol on QTc interval. From 1.5 to 4 hours postdose moxifloxacin, the lower limit of the 90% CI of ΔΔQTcF exceeded 5 ms demonstrating assay sensitivity. Although there was a positive slope, the concentration-response analysis estimated that the values of ΔΔQTcF at the maximal concentration of gadopiclenol at 0.1 and 0.3 mmol kg-1 were 0.41 and 2.23 ms, respectively, with the upper limit of the 90% CI not exceeding 10 ms. No serious or severe adverse events or treatment discontinuations due to adverse events were reported.
This thorough QT/QTc study demonstrated that gadopiclenol did not prolong the QT interval at clinical and supraclinical doses and was well tolerated in healthy volunteers. The positive slope of the QTc prolongation vs concentration relationship suggests that hyperosmolarity could be associated with QTc prolongation. However, the amplitude of this effects is unlikely to be associated with proarrhythmia.

Renal replacement therapy, especially hemodialysis, can exacerbate brain injury. The excessive ultrafiltration and rapid changes in blood pressure directly impact cerebral perfusion pressure. Substances that are typically added or removed during hemodialysis treatments alter serum osmolarity, shifting fluids into or out of the intracranial cavity. This results in changes in the intracranial pressure due to shrinking or swelling of the cerebral parenchyma, which if left untreated, can result in death. This article describes a case of dialysis disequilibrium syndrome and is an example of how astute nephrology nurses can directly impact the care of critically ill neurological patients.

Cells present ancestral conserved mechanisms to maintain their volume in response to alterations in environmental osmolarity. Changes in environmental osmolarities are therefore conserved as primitive stress signals. Innate immune cells, such as macrophages, express receptors to respond and shape immune response to stress, damage, or infection. The NLRP3 inflammasome is a multiprotein complex expressed in macrophages that senses pathogen- and danger-associated signals. The basic mechanisms of cell swelling and regulatory volume decrease are sensed by the NLRP3 inflammasome. Here, we present methods to study NLRP3 inflammasome activation in response to cell swelling.

BACKGROUND: The osmolal gap has been used for decades to screen for exposure to toxic alcohols. However, several issues may affect its reliability. We aimed to develop equations to calculate osmolarity with improved performance when used to screen for intoxication to toxic alcohols.
METHODS: Retrospective cohort study.
METHODS: 7,525 patients undergoing simultaneous measurements of osmolality, sodium, potassium, urea, glucose, and ethanol or undergoing similar measurements performed within 30 minutes of a measurement of toxic alcohol levels at a single tertiary-care center from April 2001 to June 2016. Patients with detectable toxic alcohols were excluded.
METHODS: Equations to calculate osmolarity using multiple linear regression.
RESULTS: The performance of new equations compared with published equations developed to calculate osmolarity, and to diagnose toxic alcohol intoxications more accurately.
RESULTS: We obtained 7,525 measurements, including 100 with undetectable toxic alcohols. Among them, 3,875 had undetectable and 3,650 had detectable ethanol levels. In the entire cohort, the best equation to calculate osmolarity was 2.006×Na + 1.228×Urea + 1.387×Glucose + 1.207×Ethanol (values in mmol/L, R2=0.96). A simplified equation, 2.0×Na + 1.2×Urea + 1.4×Glucose + 1.2×Ethanol, had a similar R2 with 95% of osmolal gap values between -10.9 and 13.8. In patients with undetectable ethanol concentrations, the range of 95% of osmolal gap values was narrower than previous published formulas, and in patients with detectable ethanol concentrations, the range was narrower or similar. We performed a subanalysis of 138 cases for which both the toxic alcohol concentration could be measured and the osmolal gap could be calculated. Our simplified equation had superior diagnostic accuracy for toxic alcohol exposure.
CONCLUSIONS: Single center, no external validation, limited number of cases with detectable toxic alcohols.
CONCLUSIONS: In a large cohort, coefficients from regression analyses estimating the contribution of glucose, urea, and ethanol were higher than 1.0. Our simplified formula to precisely calculate osmolarity yielded improved diagnostic accuracy for suspected toxic alcohol exposures than previously published formulas.

Limited or delayed availability of parenteral nutrition (PN) solutions, as well as difficulties in ordering are often identified as reasons for non-compliance with international guidelines in newborns. This study aims at assessing the modality of use and safety of premixed standardized PN solutions in a nationwide prospective cohort of newborns treated in clinical practice.
Two premixed fixed formulations with respective osmolarity of 715 and 790 mOsm/L specifically designed for neonates were made available throughout the country for clinical use from birth onwards. Descriptive data and modality of use were prospectively collected in a case report form, whereas all related and unrelated adverse events were recorded on a separate adverse event form.
A total of 14,167 infants were prospectively included and 16,640 parenteral nutrition periods were analyzed. Mean age was 33 weeks of gestation, and mean weight was 2086 g. The majority of infants (81%) started the parenteral nutrition the first day of life or the day after. The route of parenteral nutrition delivery was peripheral in 47% of the parenteral nutrition periods. During the whole study, a total of 72 adverse events occurring in 68 infants were reported. Of these adverse events, 59 (0.37% of the nutrition periods), among which 19 serious adverse events, were reported as related to the parenteral nutrition solutions. The events related to parenteral nutrition solutions were general disorders and administration site conditions (n = 42 including 9 cases of cutaneous necrosis), and nutrition and metabolism disorders (n = 17). There was no case of thrombophlebitis. Six of the 19 serious events related to the parenteral nutrition solutions (32%) were due to the misuse of the infusion bag.
These data support the concept that ready-to-use parenteral nutrition formulations can safely provide parenteral nutrition from birth onwards. They further support that parenteral solutions with an osmolarity up to 800 mOsm/L are well-tolerated when infused on a peripheral vein. Considering the potential risk of errors and misuses, this study also highlights the need for nutrition practice care guidelines for neonates and for regular campaigns providing information and strategies for a safe use of parenteral nutrition solutions.