Replacement Of Sodium Research Articles

Proton and deuteron electrodiffusion in a D263T borosilicate glass by controlled charge attachment from a fs-plasma

The femtosecond laser plasma charge attachment induced transport (fs-plasma CAIT) technique is considerably extended and applied to study ion transport in a borosilicate glass. The technique is based on attaching polarity selected charge carriers from a fs-laser to the front side of a sample, which induces transport of mobile charge carriers in this sample. The plasma-CAIT spectrometer is placed into a housing allowing the control of the plasma medium and its pressure. A model system is described, which allows the determination of the internal resistance of the plasma. This in turn provides access to absolute ionic conductivities without the need of external calibration. The improved fs-plasma CAIT technique is applied to study alkali ion conductivity in a D263T glass by attachment of protons or deuterons from a hydrogen and deuterium plasma, respectively. The range of conductivities is extended by one and a half orders of magnitude compared to previous work. Ex-situ analysis of the irradiated D263T samples by time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed a replacement of sodium and potassium ions being the native mobile charge carriers in the glass by external proton and deuterons, respectively, over up-to 100 nm. The concentration depth profiles generated by the electrodiffusion involve a local pile-up of the potassium concentration above the bulk concentration and a concomitant further depletion of the faster sodium at the H+ / D+ diffusion front. The results are fully in line with previous observation in a Cs+ CAIT experiment. The significant advancement of the current work lies in the demonstration that alkali ion transport can be probed by using protons or deuterons as markers for replacement in the native sites of the alkali ions. Ultimately the plasma medium can be freely chosen from a large range of chemical species turning the plasma-CAIT technique into an almost universal tool to study DC transport in solid ionics.

Field Strength of Network-Modifying Cation Dictates the Structure of (Na-Mg) Aluminosilicate Glasses

Aluminosilicate glasses are materials with a wide range of technological applications. The field strength of network-modifying cations strongly influences the structure of aluminosilicate glasses and their suitability for various applications. In this work, we study the influence of the field strength of network-modifying cations on the structure of [(Na2O)1–x(MgO)x(Al2O3)0.25(SiO2)1.25] glasses. Due to the higher cation field strength of magnesium than sodium, magnesium prefers the role of network modifier, while sodium preferentially acts as a charge compensator. When magnesium replaces sodium as network modifier, Q3 silicon species are converted into Q2 species. The replacement of sodium with magnesium as charge compensator leads to the following changes: (1) the proportion of aluminum-rich Q4 species [Q4(4Al) and Q4(3Al)] decreases, while the proportion of aluminum-deficient Q4 species [Q4(2Al) and Q4(1Al)] increases; and (2) there is an increased tendency for phase separation between silica-rich and alumina-rich glasses.

Effect of cement additive on physical and mechanical properties of high calcium fly ash geopolymer mortars

AbstractGeopolymer mortars were produced by replacement of high calcium fly ash with cement at the percentages of 5%, 10%, 15%, 20%, 25%, and 100%. Sodium hydroxide was used as the activator and sodium/binder ratios, by weight, were 10%, 12%, 14%, 16%, 18%, and 20% in mortar mixtures. Some physical properties such as unit weight, water absorption, apparent porosity and ultrasound pulse velocity tests were performed on specimens kept in ambient temperature. Flexural and compressive strength tests were made on specimens kept in ambient temperature, and exposed to temperatures of 200°C, 400°C, 600°C, and 800°C for residual performances of mortars. After exposing of specimens to high temperatures, ultrasound pulse velocity and loss in weights were also determined for deterioration levels. An experimental design is also achieved to find optimum solutions for Na/binder and cement/fly ash ratios by using D‐optimal design method after establishing response surface models for compressive and flexural tensile strengths. The highest compressive strength of 35.65 MPa was obtained in mortar specimens containing 14% sodium at 20% cement replacement with fly ash. Similarly, residual strengths were observed higher than those of other mortar specimens at the same sodium and cement replacement ratios.

White-light emitting diodes’ spectrum effect on photosynthesis and nutrient use efficiency in Podocarpus macrophyllus seedlings

Fast urbanization and population increase resulted in the demand for ornamental seedling supply in a high efficiency under the culture of continuous artificial lighting. Light emitting diode (LED) can be considered as the replacement of high-pressure sodium (HPS) lamps by providing lights with specific wavelengths for plant growth at low energy cost. In this study, nutrient use efficiency was detected in Podocarpus macrophyllus seedlings under lighting spectra generated by white light-emitting diodes (LEDs) (red (R)/green (G)/blue (B)=8.4:75:16.6) and high-pressure sodium (HPS) lamps (R/G/B/=4.3:69.3:26.5). Compared to seedlings under the HPS spectrum, those under white LED spectrum had better growth, greater biomass accumulation, higher photosynthesis and gas exchange. In contrast, LED-spectrum treated seedlings had greater nitrogen (N) and phosphorus (P) contents than HPS-spectrum treated ones. The LED spectrum promoted nutrient use index for both N and P in seedlings compared to the HPS spectrum. The LED spectrum induced steady-state uptake of P but resulted in the dilution of N. In conclusion, white LED can be considered to replace the usage of HPS lamps for the culture of tree seedlings due to the spectrum effect on N utilization, P uptake and the use efficiencies of N and P.

Sodium Status and Replacement in Children and Adults Living with Cystic Fibrosis: A Narrative Review

Patients with cystic fibrosis (CF) have a two- to four-fold higher sodium chloride sweat content compared with healthy controls. This high sweat salt loss increases the risk for electrolyte disturbances, associated with subacute or chronic complications. Sodium status therefore needs to be adequately monitored and salt intake adjusted to individual needs. The lack of current evidence to formulate specific recommendations and assess sodium status is reflected in a variability of recommendations in international guidelines. This narrative review presents an overview of the current evidence. Infants with CF in particular are at risk for severe sodium deficiency, potentially leading to metabolic alkalosis due to low intake and high sweat losses. More research on the assessment of sodium status and efficacy of sodium chloride supplements in the population of patients with CF, especially given the changing era of CF transmembrane conductance regulator modulatory treatment, is warranted.

Current Sodium Intakes in the United States and the Modeled Effects of Glutamate Incorporation Into Select Savory Products

Abstract Objectives Most Americans have dietary sodium intakes that far exceed recommendations. Given the association of high sodium with hypertension, strategies to reduce sodium intakes are an important public health target. Glutamates, such as monosodium glutamate, represent a potential strategy to reduce overall intakes while preserving product palatability; therefore, this project aimed to model sodium replacement with glutamates. Methods The National Cancer Institute Method was used to estimate current sodium intakes, as well as intakes resulting from glutamate substitution (25–45%) in a limited set of food groups for which substitution is possible. Data sets for individuals aged ³1 year enrolled in the U.S. National Health and Nutrition Examination Survey 2013–2016 (n = 161,83) were used in these analyses. Glutamate substitution of U.S. Department of Agriculture food codes was modeled by conservatively altering estimates of sodium intake reductions derived from the published peer-reviewed literature. Results The addition of glutamates to certain food categories has the potential to reduce the population's sodium intake by approximately 3% overall and by 7–8% among consumers of ≥1 product category in which glutamates were substituted for sodium chloride. Conclusions Although using glutamates to substitute the amount of sodium among certain food groups may show modest effects on intakes across the population, it is likely to have a more substantial effect on individuals who consume specific products. Funding Sources Ajinomoto.

ELBW infants receive inadvertent sodium load above the recommended intake.

To determine total sodium load, including inadvertent load, during the first 2 postnatal weeks, and its influence on serum sodium, morbidity, and mortality in extremely low birth weight (ELBW, birth weight <1000 g) infants and to calculate sodium replacement models. Retrospective data analysis on ELBW infants with a gestational age <28 + 0/7 weeks. Ninety patients with a median birth weight of 718 g and a median gestational age of 24 + 6/7 weeks were included. Median sodium intake during the first 2 postnatal weeks was 10.2 mmol/kg/day, which was significantly higher than recommended (2-5 mmol/kg/day). Sodium intake did not affect the risk for hypernatremia. Each mmol of sodium intake during the first postnatal week was associated with an increased risk of bronchopulmonary dysplasia (45%) and higher-grade intraventricular hemorrhage (31%), during the second postnatal week for necrotizing enterocolitis (19%), and during both postnatal weeks of mortality (13%). Calculations of two sodium replacement models resulted in a decrease in sodium intake during the first postnatal week of 3.2 and 4.0 mmol/kg/day, respectively. Sodium load during the first 2 postnatal weeks of ELBW infants was significantly higher than recommended owing to inadvertent sodium intake and was associated with a higher risk of subsequent morbidity and mortality, although the study design does not allow conclusions on causality. Replacement of 0.9% saline with alternative carrier solutions might reduce sodium intake. Sodium intake in ELBW infants during the first 2 postnatal weeks was twofold to threefold higher than recommended; this was mainly caused by inadvertent sodium components. High sodium intake is not related to severe hypernatremia but might be associated with a higher morbidity in terms of BPD, IVH, and NEC. Inadvertent sodium load can be reduced by replacing high sodium-containing carrier solutions with high levels of sodium with alternative hypotonic and/or balanced fluids, model based.

Sodium reduction by hyposodic salt on quality and chemical composition of hamburgers

This work evaluated the effect of NaCl reduction on the quality and sensorial attributes of hamburgers. Three treatments were tested: control (CON), 100% NaCl; reduction of 25% NaCl (T25), and one with 50% NaCl (T50). The pH, color, lipid oxidation, cooking losses, and texture were analyzed during 120 days of freezing storage. Chemical composition and sensory analyses were performed. The chemical composition was similar for all treatments. The pH value remained within acceptable limits throughout storage. The color, lipid oxidation, cooking losses, and texture were not influenced by the sodium replacement and freezing storage. Sensorial acceptability was also not influenced by sodium reduction. Thus, the results indicated that up to 50% replacement of NaCl by KCl could be carried out in hamburger production without altering the quality and sensorial acceptability.

Integrated safety profile of selinexor in multiple myeloma: experience from 437 patients enrolled in clinical trials

Selinexor is an oral, small molecule inhibitor of the nuclear export protein exportin 1 with demonstrated activity in hematologic and solid malignancies. Side effects associated with selinexor include nausea, vomiting, fatigue, diarrhea, decreased appetite, weight loss, thrombocytopenia, neutropenia, and hyponatremia. We reviewed 437 patients with multiple myeloma treated with selinexor and assessed the kinetics of adverse events and impact of supportive care measures. Selinexor reduced both platelets and neutrophils over the first cycle of treatment and reached a nadir between 28 and 42 days. Platelet transfusions and thrombopoietin receptor agonists were effective at treating thrombocytopenia, and granulocyte colony stimulating factors were effective at resolving neutropenia. The onset of gastrointestinal side effects (nausea, vomiting, and diarrhea) was most common during the first 1–2 weeks of treatment. Nausea could be mitigated with 5-HT3 antagonists and either neurokinin 1 receptor antagonists, olanzapine, or cannbainoids. Loperamide and bismuth subsalicylate ameliorated diarrhea. The primary constitutional side effects of fatigue and decreased appetite could be managed with methylphenidate, megestrol, cannabinoids or olanzapine, respectively. Hyponatremia was highly responsive to sodium replacement. Selinexor has well-established adverse effects that mainly occur within the first 8 weeks of treatment, are reversible, and respond to supportive care.

Risk Factors and Effects of Severe Late-Onset Hyponatremia on Long-Term Growth of Prematurely Born Infants.

PurposeSodium is an essential nutritional electrolyte that affects growth. A low serum sodium concentration in healthy premature infants beyond 2 weeks of life is called late-onset hyponatremia (LOH). Here, we investigated the association between LOH severity and growth outcomes in premature infants.MethodsMedical records of premature infants born at ≤32 weeks of gestation were reviewed. LOH was defined as a serum sodium level <135 mEq/L regardless of sodium replacement after 14 days of life. Cases were divided into two groups, <130 mEq/L (severe) and ≥130 mEq/L (mild). Characteristics and growth parameters were compared between the two groups.ResultsA total of 102 premature infants with LOH were included. Gestational age ([GA] 27.7 vs. 29.5 weeks, p<0.001) and birth weight (1.04 vs. 1.34 kg, p<0.001) were significantly lower in the severe group. GA was a risk factor of severe LOH (odds ratio [OR], 1.328, p=0.022), and severe LOH affected the development of bronchopulmonary dysplasia (OR, 2.950, p=0.039) and led to a poor developmental outcome (OR, 9.339, p=0.049). Growth parameters at birth were lower in the severe group, and a lower GA and sepsis negatively affected changes in growth for 3 years after adjustment for time. However, severe LOH was not related to growth changes in premature infants.ConclusionSevere LOH influenced the development of bronchopulmonary dysplasia and developmental outcomes. However, LOH severity did not affect the growth of premature infants beyond the neonatal period.

Continuous veno-venous hemofiltration in the treatment of severely burned patients with acute hypernatremia: A retrospective study of 13 cases.

This study aimed to evaluate the clinical effects of continuous veno-venous hemofiltration in the treatment of severely burned patients with acute hypernatremia. A total of 13 severely burned patients with acute hypernatremia admitted to Xijing Hospital were included in this study. All patients received continuous veno-venous hemofiltration treatment in addition to conventional treatment. The original sodium level in the replacement fluid was set to be lower than the serum sodium level by 8 mmol/L and subsequently undergoes a reduction rate of 2.16 ± 0.18 mmol/L every 4 h. Patients' clinical features, serum laboratory tests, hemodynamic variables, changes in sodium levels in serum, and replacement fluid during continuous veno-venous hemofiltration treatment were monitored. Patients had an average total burn surface area of 66.69% ± 20.28%. Two patients died of systematic Pseudomonas aeruginosa infections, and 11 patients survived. After continuous veno-venous hemofiltration treatment, patients showed a significant reduction in the serum sodium level (168.91 ± 4.88 mmol/L vs 144.62 ± 2.98 mmol/L, p < 0.01). Likewise, the serum levels of urea and creatinine decreased from 24.8 ± 6.5 mmol/L to 14.9 ± 8.3 mmol/L and from 278.6 ± 155.3 μmol/L to 152.6 ± 29.7 μmol/L, respectively (p < 0.05). The patients also displayed improvements in the Acute Physiology and Chronic Health Evaluation II and Glasgow scores (p < 0.05) and showed a significant reduction in hemoglobin and serum albumin levels (p < 0.05), but no obvious change in levels of platelets, alanine aminotransferase, and aspartate aminotransferase (p > 0.05). Our results indicate that continuous veno-venous hemofiltration with gradient sodium replacement fluid is effective in treating hypernatremia in severely burned patients with the controllable sodium reduction rate and satisfactory clinical outcomes.

The Impact of Dietary Sodium Intake on Sweat Sodium Concentration in Response to Endurance Exercise: A Systematic Review

The collection, processing, and analysis of sweat samples to determine sodium losses during endurance exercise is common amongst sports and exercise nutrition practitioners, and necessary for researchers investigating sodium losses and replacement strategies. Several factors influence sweat sodium concentration ([Na+]) that need to be controlled or considered when interpreting results. Dietary sodium intake in the days preceding exercise is one factor that may influence sweat [Na+]. A systematic review was undertaking using six databases (CINAHL, Embase, Medline Ovid, Scopus, SPORTDiscus, and Web of Science) to determine the impact of dietary sodium intake on sweat [Na+] in response to endurance exercise. Six papers met the inclusion criteria. They varied in the level of sodium intake (<196 to 9177 mg/d), intervention timeframe (3 to 42 days), exercise modality (cycling ergometry, treadmill walking and running), and sweat collection method (whole body washdown and regional patch techniques). Two studies showed significant differences in sweat [Na+] due to diet, two showed no significant difference, and two were not analysed statistically. No relationship was found across studies comparing the difference in sodium intake between interventions and sweat [Na+]. Several limitations were identified, including lack of validation of the intervention, collecting regional sweat samples from limited sites or averaging results across sites or collection days, and lack of statistical analysis. It is concluded that the impact of dietary sodium intake on sweat [Na+] in response to endurance exercise remains uncertain, however the review provides useful insights into the optimal study design for future research in this area.

Current Sodium Intakes in the United States and the Modelling of Glutamate's Incorporation into Select Savory Products.

Most Americans have dietary sodium intakes that far exceed recommendations. Given the association of high sodium with hypertension, strategies to reduce sodium intakes are an important public health target. Glutamates, such as monosodium glutamate, represent a potential strategy to reduce overall intakes while preserving product palatability; therefore, this project aimed to model sodium replacement with glutamates. The National Cancer Institute method was used to estimate current sodium intakes, and intakes resulting from glutamate substitution (25%–45%) in a limited set of food groups for which substitution is possible. Data sets for individuals aged ≥1 year enrolled in the U.S. National Health and Nutrition Examination Survey 2013–2016 (n = 16,183) were used in the analyses. Glutamate substitution in accordance with the U.S. Department of Agriculture’s food codes was modeled by conservatively altering estimates of sodium intake reductions derived from the published, peer-reviewed literature. The addition of glutamates to certain food categories has the potential to reduce the population’s sodium intake by approximately 3% overall and by 7%–8% among consumers of ≥1 product category in which glutamates were substituted for sodium chloride. Although using glutamates to substitute the amount of sodium among certain food groups may show modest effects on intakes across the population, it is likely to have a more substantial effect on individuals who consume specific products.

Copper-Exchanged Philippine Natural Zeolite as Potential Alternative to Noble Metal Catalysts in Three-Way Catalytic Converters

Natural and synthetic zeolites are microporous hydrated aluminosilicate minerals known for their high thermal stability and their use in various catalytic applications. In this study, the potential of modified Philippine natural zeolite as a cheap alternative to noble metal catalysts in three-way catalytic converters was investigated. The natural zeolite (Z) of the heulandite variety was treated using hydrochloric acid and then ion-exchanged with sodium (NaZ) and copper (CuZ) ions in succession. Energy-dispersive X-ray spectroscopy analysis revealed successful replacement of sodium and other exchangeable cations by copper in the zeolite at 1.19%. Morphological features using scanning electron microscope have shown uniform dispersion of copper as well as uniform particle distribution. In the emission study, a stationary two-stroke 125 cm3 spark-ignition gasoline engine motorcycle at three different speeds of 10 (low), 40 (medium) and 70 (high) kilometers per hour (kph) was used to investigate the catalytic properties of CuZ with the non-catalytic setup as baseline. Using the modified zeolite catalyst, emission test results have shown significant reduction in carbon monoxide (CO) and hydrocarbon (HC) emissions in all speeds, while nitrogen monoxide (NO) emission was significantly reduced from medium to high speeds, suggesting that NO reduction was highly influenced by reaction temperature. Highest reduction in CO emission was 59.61% at medium speed, while highest HC and NO emissions were 66.52% and 76.63%, respectively, at high speed. While further tests are recommended, results show the potential of modified Philippine natural zeolite as a cheap alternative material for three-way catalytic converters.

Sorption of Eu(III) on MXene-derived titanate structures: The effect of nano-confined space

Developing versatile materials that rapidly and efficiently adsorb radionuclides is an urgent objective for environmental remediation in response to radioactive contamination. Herein, we report the preparation of hierarchical titanate nanostructures (HTNs) by a in situ chemical conversion strategy using a two-dimensional MXene crystal precursor. These HTNs are very stable and can efficiently remove Eu(III) with large sorption capacities, owing to well-maintained layered structures and abundantly exchangeable guest cations. The replacement of sodium or potassium ions with Eu(III) in HTN interlayers has been confirmed by X-ray diffraction (XRD), photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). The extended X-ray sorption fine structure (EXAFS) results, in combination with density functional theory (DFT) calculations, further indicate that the sequestration of Eu(III) is realized by forming inner-sphere surface complexes in nano-confined space, evidenced by the decrease of Eu-O distances (R) and coordination numbers (N). The finding of the inner-sphere complexation induced by Ti−O/Ti−OH coordination and confinement effect provides new insights into the interaction mechanism between radionuclides and titanates. Given their extraordinary sorption capacity and facile synthesis under mild conditions, these HTNs are promising candidates for the efficient removal of trivalent lanthanides and actinides from aqueous solutions during the cleanup of radioactive pollution in the environment.

How extracellular sodium replacement affects the conduction velocity distribution of rats’ peripheral nerves

How extracellular sodium replacement affects the conduction velocity distribution of rats’ peripheral nerves

A role for the OsHKT 2;1 sodium transporter in potassium use efficiency in rice.

Increasing the potassium use efficiency (KUE) of crops is important for agricultural sustainability. However, a greater understanding of this complex trait is required to develop new, high-KUE cultivars. To this end, a genome-wide association study (GWAS) was applied to diverse rice (Oryza sativa L.) genotypes grown under potassium-stressed and -replete conditions. Using high-stringency criteria, the genetic architecture of KUE was uncovered, together with the breadth of physiological responses to low-potassium stress. Specifically, three quantitative trait loci (QTLs) were identified, which contained >90 candidate genes. Of these, the sodium transporter gene OsHKT2;1 emerged as a key factor that impacts on KUE based on (i) the correlation between shoot Na+ and KUE, and (ii) higher levels of HKT2;1 expression in high-KUE lines.

Effect of Sodium Chloride Replacement with Potassium Chloride on Quality Traits of Bicarbonate-Marinated Turkey Breast Meat

ABSTRACT This study aims to evaluate the possibility to formulate low-sodium bicarbonate-marinated turkey breast meat. In total, 60 meat cuts (100 × 50 × 30mm) were divided into four treatments: B1 (0.5% sodium bicarbonate and 0% sodium chloride replacement), B2 (0.5% sodium bicarbonate and 15% sodium chloride replacement), B3 (0.5% sodium bicarbonate and 30% sodium chloride replacement), and B4 (0.5% sodium bicarbonate and 45% sodium chloride replacement). The results showed that sodium replacement up to 45% had no impact on texture (as represented by Allo-Kramer shear values) and water activity. After cooking, Group B1 exhibited the highest L* value (72.1) and the lowest b* (6.6) when compared to other groups. In conclusion, replacing sodium chloride with potassium chloride up to 45% in the presence of sodium bicarbonate did not affect negatively several quality traits (sensory traits, composition, and texture, etc.).

Choline and NMDG directly reduce outward currents: reduced outward current when these substances replace Na+ is alone not evidence of Na+-activated K+ currents.

Choline chloride is often, and N-methyl-d-glucamine (NMDG) sometimes, used to replace sodium chloride in studies of sodium-activated potassium channels. Given the high concentrations used in sodium replacement protocols, it is essential to test that it is not the replacement substances themselves, as opposed to the lack of sodium, that cause any observed effects. We therefore compared, in lobster stomatogastric neurons and leech Retzius cells, the effects of applying salines in which choline chloride replaced sodium chloride, and in which choline hydroxide or sucrose was added to normal saline. We also tested, in stomatogastric neurons, the effect of adding NMDG to normal saline. These protocols allowed us to measure the direct effects (i.e., effects not due to changes in sodium concentration or saline osmolarity or ionic strength) of choline on stomatogastric and leech currents, and of NMDG on stomatogastric currents. Choline directly reduced transient and sustained depolarization-activated outward currents in both species, and NMDG directly reduced transient depolarization-activated outward currents in stomatogastric neurons. Experiments with lower choline concentrations showed that adding as little as 150 mM (stomatogastric) or 5 mM (leech) choline reduced at least some depolarization-activated outward currents. Reductions in outward current with choline chloride or NMDG replacement alone are thus not evidence of sodium-activated potassium currents. NEW & NOTEWORTHY We show that choline or N-methyl-d-glucamine (NMDG) directly (i.e., not due to changes in extracellular sodium) decrease outward currents. Prior work studying sodium-activated potassium channels in which sodium was replaced with choline or NMDG without an addition control may therefore be artifactual.

Mielinolisis central pontina como complicación de hiperemesis gravidica

La mielinolisis pontina central, o síndrome de desmielinización osmolar, es un trastorno que consiste en desmielinización no inflamatoria, que involucra la protuberancia secundaria a inflamación o edema neuronal en pacientes con hiponatremia grave sometidos a reemplazo rápido de sodio, el cual se considera el principal mecanismo fisiopatológico. Las manifestaciones clínicas son diversas y se han informado casos en embarazadas con hiponatremia severa inducida por hiperémesis gravídica. No existe evidencia con respecto al tratamiento o pronóstico óptimo, por lo que es esencial reconocer la hiponatremia y realizar la corrección adecuada de los niveles de sodio para evitar esta complicación. Se presenta un caso de una mujer de 21 años con embarazo de 12 semanas que presentó trastornos de la marcha, polidipsia, alteraciones del habla, disfonía y vómitos intensos junto con alteraciones de las concentraciones séricas de sodio. Las imágenes de resonancia magnética cerebral revelaron lesiones hipointensas simétricas en la región de la protuberancia, sin efecto de masa o compresión de estructuras adyacentes sugestivas de desmielinización osmótica.