Nutritional programming in tropical gar: effect of cornstarch on blood parameters

El pejelagarto es una especie carnívora, en la que se ha demostrado una mejora en el crecimiento durante el larvicultivo al incluir almidón de maíz en su dieta, así como una eficiencia en la ruta de la gluconeogénesis al utilizar hasta 23% de carbohidratos en sus dietas. El objetivo de esta investigación fue determinar si el uso de almidón de maíz en el larvicultivo puede producir un afecto de programación metabólica, determinado mediante la bioquímica sanguínea durante la etapa juvenil. Los peces fueron divididos en 3 grupos, los cuales se alimentaron durante 73 días con las dietas experimentales, que tenían diferente porcentaje de inclusión de almidón de maíz (13.8, 22.5 y 28.9 % de carbohidratos). Posteriormente, los peces de los 3 grupos fueron sometidos a una prueba de tolerancia a la glucosa y se midió la concentración de glucosa, triglicéridos y colesterol a las 0, 1.5, 3 y 5 h después de aplicar una descarga de dextrosa intraperitonealmente. Los resultados demuestran que la concentración de carbohidratos y lípidos suministrada mediante la dieta durante la etapa temprana de crianza puede modificar de forma permanente las concentraciones de glucosa y triglicéridos en plasma de los pejelagartos juveniles.The tropical gar is a carnivorous species that has shown improvement in growth during larviculture by including cornstarch in its diet, as well as an efficiency in the gluconeogenesis pathway by using up to 23% carbohydrates in their diets. The objective of this research was to determine if the use of cornstarch in larviculture can produce a metabolic programming effect determined by blood parameters during the juvenile stage. The fish were fed 3 diets with different inclusion of corn starch (13.8, 22.5 y 28.9 % carbohydrates) for 73 days. Subsequently, the fish of the 3 groups were subjected to a glucose tolerance test and the concentration of glucose, triglycerides and cholesterol was measured at 0, 1.5, 3 and 5 h after applying a dextrose discharge intraperitoneally. The results demonstrate that the concentration of carbohydrates and lipids supplied through the diet during the early stage of rearing can permanently modify the concentrations of glucose and triglycerides in the plasma of tropical gar juvenile

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Nutritional programming in Tropical gar

Nutritional programming in the tropical gar (Atractosteus tropicus) and the effect on intermediate metabolis

Changes in digestive enzymes activities during the initial ontogeny of wolf cichlid, Parachromis dovii (Perciformes: Cichlidae)

Wolf cichlid, Parachromis dovii, is a species with a high potential for aquaculture in Central America; however, the knowledge of the digestive physiology in larvae period is limited. For these reason, this study evaluated the changes on digestive enzymes (alkaline and acid proteases, trypsin, chymotrypsin, aminopeptidase, carboxypeptidase, lipases, amylases, and phosphatases) during early ontogeny by biochemical analysis. All digestive enzymes were detected at first feeding (6 days after hatching, DAH, 9.49 mm, 168 degree-days DD). Afterwards all enzymes reached two main peaks in activity at 14 or 22 DAH (15.10 mm, 364 DD and 20.83 mm, 550 DD, respectively). Later, there was a gradual decrease in activity for trypsin and acid and alkaline phosphatases until reach the lowest values at 41 DAH. In the case of acid proteases, chymotrypsin, aminopeptidase, carboxypeptidase, lipase and amylase, all activities reached their maximum values at the end of the larval period, except for alkaline proteases, which showed the maximum value at 14 DAH (15.10 mm, 364 DD). Parachromis dovii larvae have an early capability to hydrolyze exogenous food, agreeing with other carnivorous neotropical cichlid species, for this reason we proposed that the weaning process could begin at 14 DAH.El guapote lagunero (Parachromis dovii) es una especie con un alto potencial para la acuicultura en la región de América Central; sin embargo, existe un conocimiento limitado sobre la capacidad digestiva en el periodo larval. Por este motivo, este estudio evaluó los cambios de las enzimas digestivas (proteasas alcalinas y ácidas, tripsina, quimotripsina, aminopeptidasa, carboxipeptidasa, lipasas, amilasas y fosfatasas) durante la ontogenia temprana mediante análisis bioquímico. Todas las enzimas digestivas analizadas se detectaron en la primera alimentación (6 días después de la eclosión, DAH, 9.49 mm, 168 día-grados DD). Después, todas las enzimas alcanzaron dos picos máximos a los 14 o 22 DAH (15.10 mm, 364 DD and 20.83 mm, 550 DD, respectivamente). Después las actividades tripsina, fosfatasas ácidas y alcalina disminuyeron a sus valores más bajos a los 41 DAH. En el caso de las proteasas ácidas y alcalinas, quimotripsina, aminopeptidasa, carboxipeptidasa, lipasa y amilasa, los niveles de actividad aumentaron y alcanzaron su máximo valor al final del período larvario, excepto las proteasas alcalinas, que mostraron su máximo valor a los 14 DAH (15.10 mm, 364 DD). Las larvas de P. dovii tienen una capacidad temprana para hidrolizar alimentos exógenos, lo que concuerda con otras especies de cíclidos neotropicales carnívoros, por lo que proponemos que el proceso de destete inicie a los 14 DAH.Universidad Juárez Autónoma de Tabasco, MéxicoUniversidad Nacional, Costa RicaEscuela de Ciencias Biológica

Graded levels of dietary pink oyster mushroom, Pleurotus djamor meal, affects growth, feed efficiency, lipase activity and fiber content in final whole body of Nile tilapia fingerlings, Oreochromis niloticus

Expansion of aquaculture industry is evidently accompanied by an urgent necessity of aquaculture feed production. Traditionally, fish meal (FM) and soybean meal (SBM) have been the primary protein source ingredient in aquaculture diets.  However, over exploitation of these commodities has conducted to their unsustainability. Hence, research of unconventional protein alternatives has emerged. Mushroom meal is one of them. To date, mushroom meals have been investigated when supplemented in low levels in aquaculture diets. Furthermore, effects of diets supplemented with mushroom meals have assessed different parameters such as, haematology, immunity, anti–bacterial & anti–oxidant activities, and heat stress. Present study, is aimed to study the effects of graded levels of dietary pink oyster mushroom (Pleurotus djamor) meal (POMM), in growth, feed efficiency, protein utilization, digestive enzymes activities and whole body proximate composition of Nile tilapia (Oreochromis niloticus) fingerlings. Experimental design included a control diet (POMM0) formulated with soybean meal, as main protein source, and four diets designed with increasing levels of POMM: 25%(POMM25); 50%(POMM50); 75%(POMM75); and 100%(POMM100). Experimental diets and final whole body were submitted to a proximate composition analysis. Growth, feed efficiency, protein utilization, and digestive enzyme activities were assessed.  Compared to POMM0 and POMM25, weight gain (WG), and specific growth rate (SGR), significantly (

Graded levels of dietary pink oyster mushroom, Pleurotus djamor meal, affect growth, feed efficiency, lipase activity, and fiber content in final whole body of fingerlings of the Nile tilapia, Oreochromis niloticus (Actinopterygii: Cichliformes: Cichlidae)

The presently reported study was aimed to determine the effects of graded levels of dietary pink oyster mushroom (Pleurotus djamor) meal (POMM), in growth, feed efficiency, protein utilization, digestive enzymes activities, and whole-body proximate composition of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), fingerlings (0.3 ± 0.01 g). The experimental design included a control diet (POMM0) formulated with soybean meal, as the main protein source, and four diets designed with increasing levels of POMM: 25% (POMM25); 50% (POMM50); 75% (POMM75); and 100% (POMM100). Experimental diets were administered to 420 fish, randomly distributed in 15, 100-L tanks. The feeding experiment lasted 45 days. Diets and the final whole body were submitted to a proximate composition analysis. Growth, feed efficiency, protein utilization, and digestive enzyme activities were assessed. Compared to POMM0 and POMM25, weight gain (WG), and specific growth rate (SGR), significantly (P < 0.05) decreased in fish that were fed POMM50, POMM75, and POMM100%. Feed conversion ratio (FCR), protein efficiency ratio (PER), and survival rate (SR) were not significantly affected by experimental diets. Daily feed intake (DFI), and daily protein intake (DPI), decreased as POMM increased in diets. Compared to POMM0 experimental group, condition factor (K), showed a significantly higher value in fish that were fed POMM50, and POMM100 experimental diets. Crude fiber of the final whole body of POMM100 resulted in significantly higher (P < 0.05) compared to that shown in fish fed the rest of the experimental diets. Acid and alkaline proteases, trypsin, chymotrypsin, leucine aminopeptidase, and amylase of Nile tilapia fingerlings, were not significantly affected by experimental diets. Compared to fish fed POMM0 and POMM25 diets, experimental fish fed POMM50, POMM75, and POMM100 showed a reduction in lipase activity. In conclusion, a POMM level higher than 25% affects growth and lipase activity. While a POMM level higher than 50% affects fiber content in a whole body of the final fish

Expression of long-chain polyunsaturated fatty acids biosynthesis genes during the early life-cycle stages of the tropical gar Atractosteus tropicus

Long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA), including eicosapentaenoic acid (EPA, 20:5n-3), arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), are essential in multiple physiological processes, especially during early development of vertebrates. LC-PUFA biosynthesis is achieved by two key families of enzymes, fatty acyl desaturases (Fads) and elongation of very long-chain fatty acid (Elovl). The present study determined the expression patterns of genes encoding desaturases (fads1 and fads2) and elongases (elovl2 and elovl5) involved in the LC-PUFA biosynthesis during early life-stages of the tropical gar Atractosteus tropicus. We further analyzed the fatty acid profiles during early development of A. tropicus to evaluate the impact of Fads and Elovl enzymatic activities. Specific oligonucleotides were designed from A. tropicus transcriptome to perform qPCR (quantitative polymerase chain reaction) on embryonic and larval stages, along with several organs (intestine, white muscle, brain, liver, heart, mesenteric adipose, kidney, gill, swim bladder, stomach, and spleen) collected from juvenile specimens. Fatty acid content of feeds and embryonic and larval stages were analyzed. Results show that fads1, fads2, elovl2 and elovl5 expression was detected from embryonic stages with expression peaks from day 15 post hatching, which could be related to transcriptional and dietary factors. Moreover, fads1, fads2 and elovl2 showed a higher expression in intestine, while elovl5 showed a higher expression in liver, suggesting that the tropical gar activates its LC-PUFA biosynthetic machinery to produce ARA, EPA and DHA to satisfy physiological demands at crucial developmental milestones during early development.The study was financially supported by Consejo Nacional de Ciencia y Tecnología (CONACyT) by project CB-2016-01-282765. Authors thank CONACyT for the fellowship grants

Dietary live yeast (Debaryomyces hansenii) provides no advantages in tropical gar, Atractosteus tropicus (Actinopterygii: Lepisosteiformes: Lepisosteidae), juvenile aquaculture

Tropical gar, Atractosteus tropicus Gill, 1863, is an ancient freshwater fish that is commercially cultivated in southern Mexico. Currently, there is a specific diet for its culture; however, the addition of probiotics has not been investigated. The objective of this study was to evaluate the supplementation of live yeast Debaryomyces hansenii for A. tropicus juveniles on growth, productive parameters, survival, somatic index, digestive enzyme activity, and immune system gene expressions (interleukin 10, il-10, Transforming growth factor β1, tgf-β1, and β2 microglobulin, b2m). Three experimental diets increased the dose of live yeast (0.5, 1.0, and 1.5%; 1014, 1015, and 1016 CFU g diet–1, respectively) and a control diet (CD; without yeast) were designed. Daily weight gain and specific growth rate were higher in fish fed with CD and 0.5% D. hansenii. High activities of trypsin, chymotrypsin LAP, and α-amylase, as well as overexpression of il-10 in the spleen, were detected in fish feed 0.5% D. hansenii. The inclusion of D. hansenii had no positive effect on aquaculture for A. tropicus, lower doses should be tested to optimize the diet

Integrating morphological and genetic data at different spatial scales in a cosmopolitan marine turtle species: challenges for management and conservation

Patterns of genetic structure in highly mobile marine vertebrates may be accompanied by phenotypic variation. Most studies in marine turtles focused on population genetic structure have been performed at rookeries. We studied whether genetic and morphological variation of the endangered green turtle (Chelonia mydas) is consistent geographically, focusing on foraging grounds. An association between population genetic structure and body shape variation at broad (inter-lineage) and fine (foraging grounds) scales was predicted and analysed using mitochondrial DNA and geometric morphometrics. Although genetic and phenotypic differentiation patterns were congruent between lineages, no fine-scale association was found, suggesting adaptive divergence. Connectivity among Pacific foraging grounds found here suggests that temperatures of ocean surface currents may influence the genetic structure of\ua0C. mydas\ua0on a broad scale. Our results suggest that vicariance, dispersal, life-history traits and ecological conditions operating in foraging grounds have shaped the intraspecific morphology and genetic diversity of this species. Considering a range of geographic and temporal scales is useful when management strategies are required for cosmopolitan species. Integrating morphological and genetic tools at different spatial scales, conservation management is proposed based on protection of neutral and adaptive diversity. This approach opens new questions and challenges, especially regarding conservation genetics in cosmopolitan species

Lenguajes, sociedades y culturas.

Lenguajes, Sociedades y Culturas como obra que trasciende lo escritural, encarna los senti-pensamientos de quienes decidimos darnos cita en el Simposio para asumirlo como un escenario vital y dar a conocer nuestros avances y resultados de las trayectorias en investigación. Un entramado de realidades que asistieron y nos asistieron en la co-construcción de relaciones y de lenguajes disímiles, paradójicos, literarios, científicos, en los que nos encontramos y desencontramos, en los que nos reconocimos como comunidad científica rigurosa, sin perder la calidez de la condición humana, en los que se vivió intensamente y al debate las caleidoscópicas miradas de la investigación, primando siempre el respecto por el lugar de observación de quien habla. Habitan en estas páginas leves reflejos de los momentos vividos, sin pretensión alguna de congelarlos o encerrarlos en el tiempo, sino como una reminiscencia de aquellas conversaciones sostenidas no solo en los auditorios o en los salones, sino en todos aquellos espacios en los que ponentes y asistentes encontrábamos posibilidades para intercambiar ideas, sensaciones, emociones, contradicciones, entre otras