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To date, the treatment for cysticercosis and neurocysticercosis consists of a single oral intake of praziquantel (5-10 mg/kg), which since it is only available as tablets, hinders its administration to pediatric patients. Praziquantel is a poorly water-soluble drug which represents a challenge for its formulation in solution, particularly for the pediatric population. Thus, this study aimed to develop a palatable solution for praziquantel using pharmaceutical-accepted co-solvent systems. A design of experiments approach was applied to identify the optimal conditions for achieving a suitable amount of praziquantel in solution using co-solvent mixtures. Thus, praziquantel solubility increased from 0.38 up to 43.50 mg/mL in the optimized system. A taste masking assay in healthy human volunteers confirmed a successful reduction of drug bitterness after the addition of selected flavors and a sweetener. Stability studies were also conducted at different temperatures (4, 25, and 40 °C) for 12 months Even though the presence of the three known impurities of praziquantel was observed, their amounts never exceeded the acceptance criteria of the USP. Thus, this novel approach should be considered a valuable alternative for further preclinical studies considering the high prevalence of this infection worldwide.

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Estrogen has a well-known effect of reducing salt intake in rats. This mini review focuses on recent findings regarding the interaction of estradiol with brain angiotensin II to control increased sodium palatability that occurs as a result of sodium appetite in spontaneously hypertensive rats.

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The risk of predation and the costs and benefits of diverse anti-predator strategies can shift across the life stages of an organism. Yet, empirical examples of ontogenetic switches in defense mechanisms are scarce. Anurans represent an alleged exception; previous meta-analytic work suggests that unpalatability of developing anurans is "rare", whereas adult anurans in many lineages are well defended by toxic and/or unpalatable skin secretions. Here, we revisit the question of the unpalatability of anuran young in a meta-analysis of the relative proportion of prey consumed within 922 predation tests, including 135 anuran species. We tested the hypotheses that a predator's propensity to consume anuran young depends on (1) prey family, (2) predator manipulation strategy, and (3) prey ontogenetic stage. We used a binomial mixed model approach with considerations for multiple effect sizes within studies to evaluate the log odds ratio of the proportion of prey consumed by individual predators. Prey consumption was highly variable, but toads (Bufonidae) were consumed in lower proportions. Chewing invertebrates consumed more anuran prey than biting vertebrates. Late stage tadpoles were more vulnerable to predation than other stages of anuran ontogeny. However, more studies are needed to unravel the roles of development and evolutionary history in the chemical ecology of anuran young. This synthesis provides clear meta-analytic evidence that relative unpalatability is an important component in the anti-predator defenses of young in some anuran families, calling into question the degree to which chemically defended anuran families undergo ontogenetic switches in anti-predator strategies.

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Estrogens reduce 0.3 M NaCl intake and palatability in a widely used model of essential hypertension, the spontaneously hypertensive rats (SHRs). Here we investigated whether the inhibitory effects of ß-estradiol (E2, 10 µg/kg b.w. subcutaneously for 8 days) on water deprived partially-rehydrated (WD-PR) ovariectomized (OVX) adult female SHRs (fSHRs, n = 4-10/group) are related to interferences on brain angiotensin II AT1 receptors (AT1r). After WD-PR, E2 reduced 0.3 M NaCl intake (1.3 ± 0.6, vs. vehicle: 3.5 ± 1.2 ml/30 min), the number of hedonic responses to intraoral NaCl infusion (57 ± 11, vs. vehicle: 176 ± 32/min), and the relative angiotensin AT1r (Agtr1a) mRNA expression in the hypothalamus. Losartan (AT1r antagonist, 100 µg) intracerebroventricularly in OVX fSHRs treated with vehicle subcutaneously abolished 0.3 M NaCl intake (0.1 ± 0.1 ml/30 min) and only transiently reduced hedonic responses to intraoral NaCl. Losartan combined with E2 decreased the number of hedonic and increased the number of aversive responses to intraoral NaCl and abolished 0.3 M NaCl intake. E2 also reduced the pressor and dipsogenic responses to intracerebroventricular angiotensin II. The results suggest that AT1r activation increases palatability and induces NaCl intake in WD-PR fSHRs. E2 reduced hypothalamic Agtr1a mRNA expression, which may account for the effects of E2 on NaCl intake and palatability and intracerebroventricular angiotensin II-induced pressor and dipsogenic responses in OVX fSHRs. Future studies considering natural fluctuations in estrogen secretion might help to determine the degree of such interference in brain neuronal activity.

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The aim of this study was to evaluate the nycterohemeral patterns of ingestive behavior at 24, 48, and 72 h (Trial I) of sheep fed different roughages and the palatability index (Trial II) for sheep and goats fed different roughages used in a semiarid region. In the study, five sources of roughage were evaluated, namely: (1) Nopalea cochenillifera (L.) Salm-Dyck cladodes + urea + sugarcane bagasse (NUB); (2) Opuntia stricta (Haw.) Haw cladodes + urea + sugarcane bagasse (OUB); (3) Tifton hay; (4) corn silage; and (5) sorghum silage. Five Soinga sheep were used and arranged in a 5 × 5 Latin square design in Trial I. Six female Santa Ines sheep and six female Saanen goats were used to study the preferences for different roughages in Trial II, and three tests were carried out to determine the palatability index, comparing two roughage types at a time: test 1 - corn silage versus Nopalea cladodes + urea + sugarcane bagasse (NUB); test 2 - corn silage versus Opuntia cladodes + urea + sugarcane bagasse (OUB); and test 3 - NUB versus OUB. The highest dry matter (DM) intake was for diets composed by NUB. Feeding time (min/d) was higher for sorghum silage (291 min d-1), while rumination time was higher (P < 0.05) for corn silage (604.0 min d-1), sorghum silage (561.7 min d-1), and Tifton hay (529.7 min d-1). No difference (P > 0.05) was observed for feeding, rumination, and idleness time between species (sheep and goats), and there was no roughage × species interaction (P > 0.05). The palatability indexes were 76 and 77% (tests 1 and 2) for NUB and OUB, respectively. Sheep fed with roughage containing cactus cladodes associated with urea and sugarcane bagasse spent less time on ingestion and rumination activities. The ingestive behavior can be evaluated in a period of 48 h, using instantaneous scanning.

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Resumen El objetivo de este trabajo fue determinar la palatabilidad de Monstera deliciosa Liebm, Eugenia myrtifolia sims y Justicia carnea lindl en programas de alimentación de mono araña de cabeza negra (Ateles fusciceps robustus). Esta investigación se desarrolló en la Fundación Zoológico Santacruz, localizada en el San Antonio del Tequendama (Colombia). Se utilizaron ocho animales adultos en cautiverio, los cuales tuvieron una ración complementaria. Asimismo, se ofreció forraje producido en el centro de conservación con 60 días de rebrote. Además, se determinó el consumo de forraje verde y materia seca de la planta completa y de cada fracción (hojas y tallos); y se evaluó la relación hoja: tallo y la calidad nutricional de la planta completa y de cada fracción. En el proceso, se empleó un diseño dado completamente al azar y de estadística descriptiva; para ello, se utilizó el programa Infostat®. Se presentaron diferencias entre especies en el consumo de forraje verde y materia seca de la planta completa (p = 0,0001, p < 0,0001, respectivamente) y de las fracciones hoja (p = 0,0002, p = 0,0001, respectivamente) y tallo (p < 0,0001, p < 0,0001, respectivamente). Como resultado, las especies presentaron buena calidad nutricional, siendo mayor en J. carnea, seguida de M. deliciosa y E. myrtifolia y se notó una relación positiva hoja: tallo, aunque se presentaron diferencias (p < 0,0001) entre las especies. Las especies evaluadas presentan potencial para ser utilizadas en los centros de conservación en cautiverio en planes de alimentación para Ateles fusciceps robustus.

Abstract This article aims to determine the palatability of Monstera deliciosa Liebm, Eugenia myrtifolia sims and Justicia carnea lindl in marimonda (Ateles fusciceps robustus) feeding programs. This research was developed at the Santacruz Zoo Foundation, located in San Antonio del Tequendama (Colombia). In the study, eight adult animals in captivity were used, which had a complementary ration. Likewise, forage produced in the conservation center was offered with 60 days of regrowth, the consumption of green forage and dry matter of the complete plant and of each fraction (leaves and stems) was determined. Also, the leaf: stem ratio and the nutritional quality of the complete plant and of each fraction were evaluated. It is worth to mention, a design was used for completely randomized and descriptive statistics, and the Infostat® program was used. There were differences between species in the consumption of green forage and dry matter of the whole plant (p = 0.0001, p < 0.0001, respectively) and of the leaf fractions (p = 0.0002, p = 0.0001, respectively) and stem (p < 0.0001, p < 0.0001, respectively). In the explored case, the species presented good nutritional quality, being higher in J. carnea, followed by M. delicious and E. myrtifolia and positive leaf: stem ratio were apparent, although there were differences (p < 0.0001) between species. The evaluated species have the potential to be used in captive conservation centers as feeding plans for Ateles fusciceps robustus.

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The intensity of sucrose (its perceived concentration) and its palatability (positive hedonic valence associated with ingestion) are two taste attributes that increase its attractiveness and overconsumption. Although both sensory attributes covary, in that increases in sucrose concentration leads to similar increases in its palatability, this covariation does not imply that they are part of the same process or whether they represent separate processes. Both these possibilities are considered in the literature. For this reason, we tested whether sucrose's perceived intensity could be separated from its hedonically positive palatability. To address this issue, rats were trained in a sucrose intensity task to report the perceived intensity of a range of sucrose concentrations before and after its palatability was changed using a conditioned taste aversion (CTA) protocol. We found that the subjects' performance remained essentially unchanged, although its palatability was changed from hedonically positive to negative. Overall, these data demonstrate that sucrose's perceived intensity and its positive palatability can be dissociated, meaning that changes of one taste attribute render the other mostly unaffected. Thus, the intensity attribute is sufficient to inform the perceptual judgments of sucrose's concentrations.

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ABSTRACT As palatability of medical formulas has been documented as unpleasant, new options are required to improve acceptance and adherence in people with inborn errors of metabolism (IEM). Miracle fruit (Synsepalum dulcificum) has a glycoprotein named miraculin that transforms a sour, bitter taste such as the one found in metabolic formula, into a sweet perception. The objective of this work is to analyze the response in the taste perception of metabolic formula with the use of the miraculin tablets in patients with IEM and healthy adults. To test this hypothesis a prospective, longitudinal, quasi-experimental, analytical study was performed. Patients with IEM and healthy adults were recruited. All participants assessed 3 different liquids (lemon, apple cider vinegar and metabolic formula) before and after the administration of miraculin tablets and completed a questionnaire. The sensory responses were evaluated using hedonic scales, analyzed with nonparametric tests for paired data. Seven patients with IEM and 14 healthy subjects were included. After miraculin intake 57% of patients (Z ≤ -1.89 p= 0.059) and healthy adults (Z≤ -2.31 p= 0.021) had a positive change in their taste perception. The absolute frequency of patients who did not like the metabolic formula decreased from 4 to 1, and in patients who liked it or loved, it increased from 0 to 2 and from 0 to 1 respectively; the frequency of patients who perceived the metabolic formula as indifferent or hated it, did not change. Response in taste perception had a positive change of 57% in both groups. The use of miraculin tablets may improve palatability of metabolic formula.

RESUMEN La palatabilidad de las fórmulas médicas se ha reportado como desagradable, se requieren nuevas opciones para mejorar la aceptación en personas con errores innatos del metabolismo (EIM). La fruta milagrosa (Synsepalum dulcificum) contiene una glucoproteína llamada miraculina que transforma el sabor agrio y amargo en dulce. El objetivo fue analizar la respuesta en la percepción del sabor de la fórmula metabólica con el uso de las tabletas de miraculina en pacientes con EIM y adultos sanos. Se realizó un estudio analítico prospectivo, longitudinal, cuasi-experimental. Los participantes evaluaron la percepción de 3 líquidos (limón, vinagre de manzana y fórmula metabólica) antes y después de la administración de tabletas de miraculina y completaron un cuestionario. Las respuestas sensoriales se evaluaron mediante escalas hedónicas, analizadas con pruebas no paramétricas para datos pareados. Se incluyeron 7 pacientes con EIM y 14 adultos sanos. Después de la miraculina el 57% de los pacientes (Z ≤ -1,89 p= 0,059) y adultos sanos (Z≤ -2,31 p= 0,021) tuvieron un cambio positivo en su percepción del sabor. La frecuencia absoluta de pacientes a los que no les gustó la fórmula disminuyó de 4 a 1, y en quienes les gustó o les encantó, aumentó de 0 a 2 y de 0 a 1 respectivamente; la frecuencia de los pacientes que percibieron la fórmula como indiferente u odiada, no cambió. La respuesta en la percepción del sabor cambió positivamente en el 57% en ambos grupos. El uso de miraculina puede mejorar la palatabilidad de la fórmula metabólica.

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The aim of this study was to (i) gain an overview of the protocols of food preference tests in cats through a systematic review, (ii) assess the effects of test duration, time of day, and sex, and (iii) propose a statistical approach based on power analysis to determine sample size and analyze the results. The manuscripts included in this review had marked variations in the number of days (2-56), sample size (9-60 cats), feeding times (2.5-1440 min), and number of meals per day (1-2) during the test. Additionally to the literature review, three palatability tests (lasting 10 days each) were conducted with 40 cats (22 males and 18 females, 1.8 ± 0.16 years, 3.73 ± 0.90 kg) to assess the effects of test duration, time of day, and gender on the results. From the second day of the test, the sensitivity of the results was higher, because on the first day the results in one of the tests differed from the others (p = .0058). There was no difference (p > .05) between times of day (morning vs afternoon) or gender (males vs females) on the results of the feed intake ratio. For a SD of 0.20, p < .05, and delta of 0.10, the minimum number of cats for two-bowl assays is 23 (test power higher than 0.75).The sample size and test duration are critical factors in the decision making by the investigators about the design of food preference tests in cats. The use of a power test is recommended upon planning a food preference test protocol in cats.

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Sucrose is attractive to most species in the animal kingdom, not only because it induces a sweet taste sensation but also for its positive palatability (i.e., oromotor responses elicited by increasing sucrose concentrations). Although palatability is such an important sensory attribute, it is currently unknown which cell types encode and modulate sucrose's palatability. Studies in mice have shown that activation of GABAergic LHAVgat+ neurons evokes voracious eating; however, it is not known whether these neurons would be driving consumption by increasing palatability. Using optrode recordings, we measured sucrose's palatability while VGAT-ChR2 transgenic mice performed a brief access sucrose test. We found that a subpopulation of LHAVgat+ neurons encodes palatability by increasing (or decreasing) their activity as a function of the increment in licking responses evoked by sucrose concentrations. Optogenetic gain of function experiments, where mice were able to choose among available water, 3% and 18% sucrose solutions, uncovered that opto-stimulation of LHAVgat+ neurons consistently promoted higher intake of the most palatable stimulus (18% sucrose). In contrast, if they self-stimulated near the less palatable stimulus, some VGAT-ChR2 mice preferred water over 18% sucrose. Unexpectedly, activation of LHAVgat+ neurons increased quinine intake but only during water deprivation, since in sated animals, they failed to promote quinine intake or tolerate an aversive stimulus. Conversely, these neurons promoted overconsumption of sucrose when it was the nearest stimulus. Also, experiments with solid foods further confirmed that these neurons increased food interaction time with the most palatable food available. We conclude that LHAVgat+ neurons increase the drive to consume, but it is potentiated by the palatability and proximity of the tastant.