Exploring Galectin Interactions with Human Milk Oligosaccharides and Blood Group Antigens Identifies BGA6 as a Functional Galectin-4 Ligand.

Galectins (Gals), a family of multifunctional glycan-binding proteins, have been traditionally defined as ß-galactoside binding lectins. However, certain members of this family have shown selective affinity towards specific glycan structures including human milk oligosaccharides (HMOs) and blood group antigens. In this work, we explored the affinity of human galectins (particularly Gal-1, -3, -4, -7 and -12) towards a panel of oligosaccharides including HMOs and blood group antigens using a complementary approach based on both experimental and computational techniques. While prototype Gal-1 and Gal-7 exhibited differential affinity for type I vs. type II Lac/LacNAc residues and recognized fucosylated neutral glycans, chimera-type Gal-3 showed high binding affinity towards poly-LacNAc structures including LNnH and LNnO. Notably, the tandem-repeat human Gal-12 showed preferential recognition of 3-fucosylated glycans, a unique feature among members of the galectin family. Finally, Gal-4 presented a distinctive glycan-binding activity characterized by preferential recognition of specific blood group antigens, also validated by saturation transfer difference nuclear magnetic resonance (STD-NMR) experiments. Particularly, we identified oligosaccharide blood group A type 6 (BGA6) as a biologically relevant Gal-4 ligand, which specifically inhibited IL-6 secretion induced by this lectin on human peripheral blood mononuclear cells. These findings highlight unique determinants underlying specific recognition of HMOs and blood group antigens by human galectins, emphasizing the biological relevance of Gal-4-BGA6 interactions, with critical implications in the development and regulation of inflammatory responses.

Disentangling Glycan-Protein Interactions: Nuclear Magnetic Resonance (NMR) to the Rescue.

The interactions of glycans with proteins modulate many events related to health and disease. In fact, the establishment of these recognition events and their biological consequences are intimately related to the three-dimensional structures of both partners, as well as to their dynamic features and their presentation on the corresponding cell compartments. NMR techniques are unique to disentangle these characteristics and, indeed, diverse NMR-based methodologies have been developed and applied to monitor the binding events of glycans with their associate receptors. This protocol outlines the procedures to acquire, process and analyze two of the most powerful NMR methodologies employed in the NMR-glycobiology field, 1H-Saturation transfer difference (STD) and 1H,15N-Heteronuclear single quantum coherence (HSQC) titration experiments, which complementarily offer information from the glycan and protein perspective, respectively. Indeed, when combined they offer a powerful toolkit for elucidating both the structural and dynamic aspects of molecular recognition processes. This comprehensive approach enhances our understanding of glycan-protein interactions and contributes to advancing research in the chemical glycobiology field.

Solid-Phase-Supported Chemoenzymatic Synthesis and Analysis of Chondroitin Sulfate Proteoglycan Glycopeptides.

Proteoglycans (PGs), consisting of glycosaminoglycans (GAGs) linked with the core protein through a tetrasaccharide linkage region, play roles in many important biological events. The chemical synthesis of PG glycopeptides is extremely challenging. In this work, the enzymes required for synthesis of chondroitin sulfate (CS) PG (CSPG) have been expressed and the suitable sequence of enzymatic reactions has been established. To expedite CSPG synthesis, the peptide acceptor was immobilized on solid phase and the glycan units were directly installed enzymatically onto the peptide. Subsequent enzymatic chain elongation and sulfation led to the successful synthesis of CSPG glycopeptides. The CS dodecasaccharide glycopeptide was the longest homogeneous CS glycopeptide synthesized to date. The enzymatic synthesis was much more efficient than the chemical synthesis of the corresponding CS glycopeptides, which could reduce the total number of synthetic steps by 80 %. The structures of the CS glycopeptides were confirmed by mass spectrometry analysis and NMR studies. In addition, the interactions between the CS glycopeptides and cathepsin G were studied. The sulfation of glycan chain was found to be important for binding with cathepsin G. This efficient chemoenzymatic strategy opens new avenues to investigate the structures and functions of PGs.

The utility of fetal heart rate deceleration's descending slope in searching for a non-National Institute of Child Health and Human Development parameter for the detection of fetal acidosis.

OBJECTIVE: To identify new parameters predicting fetal acidemia. METHODS: A retrospective case-control study in a cohort of deliveries from a tertiary referral hospital-based cohort deliveries in Zaragoza, Spain between 2018 and 2021 was performed. To predict fetal acidemia, the NICHD categorizations and non-NICHD parameters were analyzed in the electronic fetal monitoring (EFM). Those included total reperfusion time, total deceleration area and the slope of the descending limb of the fetal heart rate of the last deceleration curve. The accuracy of the parameters was evaluated using the specificity for (80%, 85%, 90%, 95%) sensitivity and the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 10 362 deliveries were reviewed, with 224 cases and 278 controls included in the study. The NICHD categorizations showed reasonable discriminatory ability (AUC = 0.727). The non-NICHD parameters measured during the 30-min fetal monitoring, total deceleration area (AUC = 0.807, 95% CI: 0.770, 0.845) and total reperfusion time (AUC = 0.750, 95% CI: 0.707, 0.792), exhibited higher discriminatory ability. The slope of the descending limb of the fetal heart rate of the last deceleration curve had the best AUC value (0.853, 95% CI: 0.816, 0.889). The combination of total deceleration area or total reperfusion time with the slope demonstrated high discriminatory ability (AUC = 0.908, 95% CI: 0.882, 0.933; specificities of 71.6% and 72.7% for a sensitivity of 90%). CONCLUSIONS: The slope of the descending limb of the fetal heart rate of the last deceleration curve is the strongest predictor of fetal acidosis, but its combination with the total reperfusion time shows better clinical utility.

Evolución de la producción científica generada sobre la dehiscencia del canal semicircular posterior / Evolution of the scientific production generated on posterior semicircular canal dehiscence

Introducción: La dehiscencia del canal semicircular posterior es una vestibulopatía rara, de baja prevalencia y cuya sintomatología se explica por el fenómeno de la tercera ventana. No fue hasta 2003 cuando Krombach describe los primeros casos. Objetivo: Evaluar mediante análisis bibliométrico y temático la producción científica sobre trabajos de dehiscencia del canal semicircular posterior (DCSP) y su incidencia a nivel de la comunidad científica mediante una revisión bibliográfica. Método: Se realiza búsqueda, revisión, selección y estudio a partir de ítems relacionados con DCSP indexados en la base de datos Pubmed, Web of Science, Alcorze y Scopus, desde el año 2003 hasta 2019, seleccionando 90 artículos. Resultados: Los 90 artículos han sido publicados en un total de 48 revistas, siendo 52% originales, 38% casos clínicos, 9% revisiones y 1% conferencias. La temática predominante fue la clínica (32%) y la etiología (27%). Los artículos estaban escritos en ocho idiomas diferentes, predominando el inglés (85%), y siendo Estados Unidos el país con más publicaciones (42%). Los índices de actividad institucional y autoría son bajos. La calidad de las revistas es alta, ya que el 70% de las publicaciones se encontraban en los cuartiles Q1-Q2. El área principal es Otorrinolaringología, con 66 trabajos, seguida por Radiología con 14. El número de descargas fue 6958, con una media de 77,31 por artículo, y las citaciones fueron 1193, equivalente a una media de 13,25. Conclusión: Los datos bibliométricos revelan cómo los trabajos sobre dehiscencia del canal semicircular posterior representan una pequeña producción científica, el tema está en fase de crecimiento sostenido, los índices de autoría, institucionalidad y colaboración son bajos y las publicaciones se concentran en pocas revistas, con una orientación claramente anglófona, pero de alta calidad e importante visualización. (AU)

Introduction: The dehiscence of the posterior semicircular canal is a rare vestibulopathy, of low prevalence and whose symptomatology is explained by the phenomenon of the third window. It was not until 2003 that Krombach described the first cases. Objective: Evaluate the scientific production about the dehiscence of the posterior semicircular canal (DCSP) by a bibliometric and thematic analysis and observes its incidence at the scientific community level. Method: A search with subsequent review, selection and study was carried out using items related to DCSP indexed in the Pubmed, Web of Science, Alcorze and Scopus databases, from 2003 to 2019, selecting a total of 90 articles. Results: The 90 articles have been published in a total of 48 magazines. 52% were originals, 38% clinical cases, 9% reviews and 1% conferences. Clinical (32%) and etiology (27%) were the main themes. The articles were written in eight different languages, predominantly English (85%), and the United States has been the country with the highest number of publications (42%). Institutional activity and authorship rates are low. The quality of the journals is high: 70% of the publications were in the Q1-Q2 quartiles. The main area corresponds to otorhinolaryngology, with a total of 66 works, followed by radiology (14). The total number of downloads was 6958, with an average of 77.31 per article and the total citations were 1193, 13.25 per article. Conclusions: The bibliometric results reveal how the works on dehiscence of the posterior semicircular canal present a small scientific production, the subject is in a phase of sustained growth, the authorship, institutional and collaboration index are low, the publications are concentrated in a few journals of high quality and important visualization, with a clearly anglophone orientation. (AU)

Nuevas formas de motivación en la enseñanza de la anatomía humana / New forms of motivation in the teaching of human anatomy

Introducción: Las nuevas generaciones de alumnos (generación Z o nativa digital) en la actualidad han provocado la necesidad de implantar nuevas metodologías docentes en las que el alumnado sea un sujeto activo y participativo en su propio proceso de aprendizaje. Entre estas metodologías, el uso del aprendizaje basado en juegos puede considerarse una alternativa que refuerce a la clásica ‘clase magistral’ y las clases prácticas en la docencia universitaria. Sujetos y métodos: Utilización del aprendizaje basado en juegos (juegos serios) en los alumnos matriculados de la asignatura de Anatomía Humana I (Aparato Locomotor), de primer curso del grado de Medicina en la Universidad de Zaragoza. Resultados: El uso de esta metodología ha sido valorado, mediante encuesta de evaluación de respuesta voluntaria, de manera muy positiva, haciendo hincapié en el efecto que tiene sobre la motivación, la participación y la integración de contenidos teóricos y prácticos. Conclusión: El aprendizaje basado en juegos debe considerarse como una potente alternativa que mejora la motivación, la participación y la integración de contenido en el aula de educación superior.(AU)

Introduction: The new generations of students, such as the current generation Z or digital natives, have provoked the need to implement new teaching methodologies where students are active and participative subjects in their own learning process. Among these methodologies, the use of game-based learning can be considered an alternative to reinforce the classic ‘master class’ in university teaching. Subjects and methods: Use of game-based learning (serious games), in students enrolled in the subject of Human Anatomy I (Locomotor System), first year of the Degree of Medicine at the Universidad de Zaragoza. Results: The use of this methodology has been evaluated, by means of a voluntary evaluation survey, in a very positive way, emphasizing the effect on motivation, participation and integration of theoretical and practical contents. Conclusion: Game-based learning should be considered as a powerful alternative that improves motivation, participation and content integration in the higher education classroom.(AU)

End-To-End Procedure For IORT in Brain Metastases and Film Dosimetry.

Purpose: The study is intended to perform an end-to-end test of the entire intraoperative process using cadaver heads. A simulation of tumor removal was performed, followed by irradiation of the bed and measurement of absorbed doses with radiochromic films. Materials and Methods: Low-energy X-ray intraoperative radiotherapy (IORT) was used for irradiation. A computed tomography study was performed at each site and the absorbed doses calculated by the treatment planning system, as well as absorbed doses with radiochromic films, were studied. Results: The absorbed doses in the organs at risk (OAR) were evaluated in each case, obtaining maximum doses within the tolerance limits. The absorbed doses in the target were verified and the deviations were <1%. Conclusions: These tests demonstrated that this comprehensive procedure is a reproducible quality assurance tool which allows continuous assessment of the dosimetric and geometric accuracy of clinical brain IORT treatments. Furthermore, the absorbed doses measured in both target and OAR are optimal for these treatments.

Anatomical study about the variations in renal vasculature.

Renal vascularization is classically described as a renal artery and vein. However, this vascular pattern presents numerous anatomical variations in terms of their number, origin and course due to ontogenetic alterations. The aim was to carry out a descriptive study of the renal vascular pattern observed during the dissection of cadavers intended for teaching purposes. A descriptive and observational study of renal vascular anatomy was carried out by dissecting 16 renal blocks from 8 cadavers donated to science and used for teaching at the Faculty of Medicine of the University of Zaragoza. The prevalence of arterial variations was 75% (56.3% for polar renal arteries, 12.5% for pre-hilar branching and 6.25% for double communicating arterial arch) and venous was 62.5% (12.5% for polar renal veins, 25% for late venous confluence, 6.25% for triple renal vein and 18.75% for double circumaortic renal vein). We conclude that the renal vascular anomalies occur with high frequency; for this reason, knowledge of these anomalies is extremely important for the correct planning of numerous medical-surgical activities.

Failure of early non-invasive ventilation in preterm infants with respiratory distress syndrome in current care practice in Spanish level-III neonatal intensive care units - a prospective observational study.

Introduction: Despite advances in respiratory distress syndrome (RDS) management over the past decade, non-invasive ventilation (NIV) failure is frequent and associated with adverse outcomes. There are insufficient data on the failure of different NIV strategies currently used in clinical practice in preterm infants. Methods: This was a prospective, multicenter, observational study of very preterm infants [gestational age (GA) <32 weeks] admitted to the neonatal intensive care unit for RDS that required NIV from the first 30 min after birth. The primary outcome was the incidence of NIV failure, defined as the need for mechanical ventilation for <72 h of life. Secondary outcomes were risk factors associated with NIV failure and complication rates. Results: The study included 173 preterm infants with a median GA of 28 (IQR 27-30) weeks and a median birth weight of 1,100 (IQR 800-1,333) g. The incidence of NIV failure was 15.6%. In the multivariate analysis, lower GA (OR, 0.728; 95% CI, 0.576-0.920) independently increased the risk of NIV failure. Compared to NIV success, NIV failure was associated with higher rates of unfavorable outcomes, including pneumothorax, intraventricular hemorrhage, periventricular leukomalacia, pulmonary hemorrhage, and a combined outcome of moderate-to-severe bronchopulmonary dysplasia or death. Conclusion: NIV failure occurred in 15.6% of the preterm neonates and was associated with adverse outcomes. The use of LISA and newer NIV modalities most likely accounts for the reduced failure rate. Gestational age remains the best predictor of NIV failure and is more reliable than the fraction of inspired oxygen during the first hour of life.

Nitrogen management in farming systems under the use of agricultural wastes and circular economy.

Population growth leads to an increase in the demand for energy, water, and food as cities grow and urbanize. However, the Earth's limited resources are unable to meet these rising demands. Modern farming practices increase productivity, but waste resources and consume too much energy. Agricultural activities occupy 50 % of all habitable land. After a rise of 80 % in 2021, fertilizer prices have increased by nearly 30 % in 2022, representing a significant cost for farmers. Sustainable and organic farming has the potential to reduce the use of inorganic fertilizers and increase the utilization of organic residues as a nitrogen (N) source for plant nutrition. Agricultural management typically prioritizes nutrient cycling and supply for crop growth, whereas the mineralization of added biomass regulates crop nutrient supply and CO2 emissions. To reduce overconsumption of natural resources and environmental damage, the current economic model of "take-make-use-dispose" must be replaced by "prevention-reuse-remake-recycle". The circular economy model is promising for preserving natural resources and providing sustainable, restorative, and regenerative farming. Technosols and organic wastes can improve food security, ecosystem services, the availability of arable land, and human health. This study intends to investigate the nitrogen nutrition provided by organic wastes to agricultural systems, reviewing the current state of knowledge and demonstrating how common organic wastes can be utilized to promote sustainable farming management. Nine waste residues were selected to promote sustainability in farming based on circular economy and zero waste criteria. Using standard methods, their water content, organic matter, total organic carbon, Kjeldahl nitrogen, and ammonium levels were determined, along with their potential to improve soil fertility via N supply and technosol formulation. 10 % to 15 % of organic waste was mineralized and analysed during a six-month cultivation cycle. Through the results, the combination of organic and inorganic fertilization to increase crop yield is recommended, as is the search for realistic and practical methods of dealing with massive amounts of organic residues within the context of a circular economy.

Chemometric and Physico-Chemical Characterization of Fruit and Olive Oils from Autochthonous Cultivars Grown in Aragon (Spain).

Olive tree crops and the olive oil market are becoming less and less diverse due to the rise of intensive growth varieties, with the consequent loss of varietal richness provided by oils from minority and autochthonous cultivars. "Royal de Calatayud" and "Negral de Sabiñán" are two local minority cultivars in Aragon (Spain). Fruit parameters such as ripening, fresh weight, and oil yield were evaluated, as well as physico-chemical and chemical composition parameters in olive oil in comparison with "Arbequina", a cultivar widespread in Spain and other countries. Fruits were harvested from October to December in 2017 and 2019. Chemometric analysis revealed significant varietal differences among the three cultivars. In comparison with "Arbequina", higher oil yields were obtained in the two local cultivars. "Royal de Calatayud" has a higher oleic acid content and a greater quantity of phenolic compounds. It thus displays a better nutritional profile than "Arbequina". This preliminary study shows that "Royal de Calatayud" could be regarded as an excellent alternative to the "Arbequina" cultivar in the parameters analyzed.

Synthetic Zwitterionic Streptococcus pneumoniae Type 1 Oligosaccharides Carrying Labile O-Acetyl Esters.

We herein report the first total synthesis of the Streptococcus pneumoniae serotype 1 (Sp1) oligosaccharide, a unique zwitterionic capsular polysaccharide carrying labile O-acetyl esters. The target oligosaccharides, featuring rare α-2,4-diamino-2,4,6-trideoxy galactose (AAT) and α-galacturonic acids, were assembled up to the 9-mer level, in a highly stereoselective manner using trisaccharide building blocks. The lability of the O-acetyl esters imposed a careful deprotection scheme to prevent migration and hydrolysis. The migration was investigated in detail at various pD values using NMR spectroscopy, to show that migration and hydrolysis of the C-3-O-acetyl esters readily takes place under neutral conditions. Structural investigation showed the oligomers to adopt a right-handed helical structure with the acetyl esters exposed on the periphery of the helix in close proximity of the neighboring AAT residues, thereby imposing conformational restrictions on the AATα1-4GalA(3OAc) glycosidic linkages, supporting the helical shape of the polysaccharide, that has been proposed to be critical for its unique biological activity.

Pulsed electric field increases the extraction yield of extra virgin olive oil without loss of its biological properties.

Introduction: Pulsed electric field (PEF) has been used for improving extraction of extra virgin olive oil (EVOO). However, the biological changes induced by the consumption of pulsed electric field-obtained extra virgin olive oil (PEFEVOO) have not been studied yet. Materials and methods: EVOO oils from Empeltre variety were prepared by standard (STD) cold pressure method involving crushing of the olives, malaxation and decanting and by this procedure including an additional step of PEF treatment. Chemical analyses of EVOO oils were done. Male and female Apoe-deficient mice received diets differing in both EVOOs for 12 weeks, and their plasma, aortas and livers were analyzed. Results: PEF application resulted in a 17% increase in the oil yield and minimal changes in chemical composition regarding phytosterols, phenolic compounds and microRNA. Only in females mice consuming PEF EVOO, a decreased plasma total cholesterol was observed, without significant changes in atherosclerosis and liver steatosis. Conclusion: PEF technology applied to EVOO extraction maintains the EVOO quality and improves the oil yield. The equivalent biological effects in atherosclerosis and fatty liver disease of PEF-obtained EVOO further support its safe use as a food.

Parent-infant closeness after preterm birth and depressive symptoms: A longitudinal study.

Background: Preterm birth increases the risk for postpartum depression in both mothers and fathers, calling for strategies to alleviate and prevent depressive symptoms in parents of preterm infants. The aim of this study was to assess the association between early parent-infant closeness and later depressive symptoms among parents of preterm infants. We hypothesized that longer duration of closeness associate with fewer depressive symptoms in both parents. Methods: This prospective cohort study included 23 neonatal intensive care units (NICUs) from 15 countries in 2018 to 2020. Each unit recruited families with preterm infants aiming to 30 families. The total duration of parents' presence in the NICU, and separately parent-infant skin-to-skin contact and holding, were measured using a Closeness Diary up to 14  days. The Edinburgh Postnatal Depression Scale (EPDS) was used at discharge and at 4  months corrected age of the infant. Results: The study included 684 mothers and 574 fathers. The median presence was 469  min (Q1 258 and Q3 1,087) per 24   h for the mothers and 259   min (Q1 100 and Q3 540) for the fathers; mean EPDS scores were 9.2 (SD 5.0) and 6.3 (SD 4.4) at discharge and 6.6 (4.7) and 4.3 (4.2) at 4  months, respectively. Parents' presence and depressive symptoms varied greatly between the units. Parents' presence as the total measure, or skin-to-skin contact and holding separately, did not associate with depressive symptoms in either mothers or fathers at either time point (adjusted). Conclusion: No association was found between the duration of parent-infant closeness in the neonatal unit and parents' depressive symptoms. The beneficial effects of family-centered care on parents' depression seem to be mediated by other elements than parent-infant physical closeness. More research is needed to identify the critical elements which are needed to alleviate parents' depression after NICU stay.

Authenticity in Olive Oils from an Empeltre Clonal Selection in Aragon (Spain): How Environmental, Agronomic, and Genetic Factors Affect Sterol Composition.

Sterol composition is used as a "fingerprint" to demonstrate the authenticity of olive oils. Our study's objective was to exhaustively characterize the sterol composition of Empeltre olive oils from clonal selection during the ripening period in 2017, 2018, and 2019. We likewise assessed the influence of crop year, fruit ripening, and clonal selection on the oils' regulatory compliance in terms of sterol composition. Empeltre olive oils were shown to have medium-range ß-sitosterol and Δ5-avenasterol content, along with elevated amounts of campesterol and Δ7-stigmastenol. A total of 26% and 12% of the samples were non-compliant in terms of apparent ß-sitosterol and Δ7-stigmastenol, respectively. Crop year was the most influential factor in the case of most sterols. Clone type was the least influential factor, except in the case of campesterol. Olive maturity was only significant for Δ7-sterols. We likewise applied a discriminant analysis, with "crop year" as the grouping variable: 94.9% of the oils were thereby classified correctly.

Rheological Properties and Stability of Thickeners for Clinical Use.

The adaptation of liquids for patients with dysphagia requires precision and individualization in the viscosities used. We describe the variations of viscosity in water at different concentrations and evolution over time of the three compositions of commercial thickeners that are on the market (starch, starch with gums, and gum). By increasing the concentration in water, the viscosity of gum-based thickeners increases linearly, but it did not reach pudding texture, whereas the viscosity of the starch-based thickeners (alone or mixed with gums) rapidly reaches very thick textures. We modeled the viscosity at different concentrations of the four thickeners using regression analysis (R2 > 0.9). We analyzed viscosity changes after 6 h of preparation. The viscosity of gum-based thickeners increased by a maximum of 6.5% after 6 h of preparation, while starch-based thickeners increased by up to 43%. These findings are important for correct handling and prescription. Gum-based thickeners have a predictable linear behavior with the formula we present, reaching nectar and honey-like textures with less quantity of thickener, and are stable over time. In contrast, starch thickeners have an exponential behavior which is difficult to handle, they reach pudding-like viscosity, and are not stable over time.

pH modulates interaction of 14-3-3 proteins with pollen plasma membrane H+ ATPases independently from phosphorylation.

Pollen grains transport the sperm cells through the style tissue via a fast-growing pollen tube to the ovaries where fertilization takes place. Pollen tube growth requires a precisely regulated network of cellular as well as molecular events including the activity of the plasma membrane H+ ATPase, which is known to be regulated by reversible protein phosphorylation and subsequent binding of 14-3-3 isoforms. Immunodetection of the phosphorylated penultimate threonine residue of the pollen plasma membrane H+ ATPase (LilHA1) of Lilium longiflorum pollen revealed a sudden increase in phosphorylation with the start of pollen tube growth. In addition to phosphorylation, pH modulated the binding of 14-3-3 isoforms to the regulatory domain of the H+ ATPase, whereas metabolic components had only small effects on 14-3-3 binding, as tested with in vitro assays using recombinant 14-3-3 isoforms and phosphomimicking substitutions of the threonine residue. Consequently, local H+ influxes and effluxes as well as pH gradients in the pollen tube tip are generated by localized regulation of the H+ ATPase activity rather than by heterogeneous localized distribution in the plasma membrane.

Institutionalized elderly are able to detect small viscosity variations in thickened water with gum-based thickeners: should texture classifications be reviewed?

BACKGROUND: The prevalence of dysphagia is very high in institutionalized elderly. Knowledge of the rheological and sensory characteristics of the various thickeners in elderly is limited, although it has been seen that there are differences between the rheological behaviors of gum-based thickeners with different composition. Moreover, we have not found sensory studies of viscosity in institutionalized elderly. Our hypothesis was that viscosity ranges established by the scientific societies, such as the National Dysphagia Diet Task Force (NDD), seem to be very wide and individuals might be able to detect small differences within the same texture range. The objectives of our study were 1) comparing the rheological characteristics of two commercial gum-based thickeners with different composition, dissolved in water under standard conditions, and 2) perform a sensory analysis (with both adults and institutionalized elderly) to detect different viscosities within the same texture (nectar and honey). METHODS: Two commercial thickeners based on gums (NC and RC) were studied analyzing their viscosity in water with different concentrations (shear rate: 50 s- 1; temperature: 22-25 °C). A sensory analysis involving 26 elderly and 29 adult controls was carried out to evaluate whether differences within nectar and honey textures among gum-based thickeners could be distinguished. RESULTS: As the shear rate increases, viscosity decreases (non-Newtonian and pseudoplastic behavior). At the same concentration, each thickener produces a different viscosity (p < 0.05). Institutionalized elderly detected viscosity differences in nectar range of 49.9 (2.5) mPa·s (p < 0.05) and 102.2 (4.7) mPa·s (p < 0.0001). They also detected viscosity differences in honey texture range of 134.6 (9.7) mPa·s (p < 0.05) y 199.3 (9.2) mPa·s (p < 0.0001). Their caregivers also detected viscosity differences in both viscosity ranges (p < 0.0001) and with greater intensity than the elderly in honey texture (p: 0.016). CONCLUSIONS: Our results suggest that the accepted viscosity ranges by NDD for the different textures might be too wide because institutionalized elderly and their caregivers are able to discern small differences in viscosity in nectar and honey textures. Gum-based thickeners with different composition showed differences in viscosity capacity, so they are not interchangeable.