Antagonistic regulation of homeologous uncx.L and uncx.S genes orchestrates myotome and sclerotome differentiation in the evolutionarily divergent vertebral column of Xenopus laevis.

In anurans, the vertebral column diverges widely from that of other tetrapods; yet the molecular mechanisms underlying its morphogenesis remain largely unexplored. In this study, we investigate the role of the homeologous uncx.L and uncx.S genes in the vertebral column morphogenesis of the allotetraploid frog Xenopus laevis. We initiated our study by cloning the uncx orthologous genes in the anuran Xenopus and determining their spatial expression patterns using in situ hybridization. Additionally, we employed gain-of-function and loss-of-function approaches through dexamethasone-inducible uncx constructs and antisense morpholino oligonucleotides, respectively. Comparative analysis of the messenger RNA sequences of homeologous uncx genes revealed that the uncx.L variant lacks the eh1-like repressor domain. Our spatial expression analysis indicated that in the presomitic mesoderm and somites, the transcripts of uncx.L and uncx.S are located in overlapping domains. Alterations in the function of uncx genes significantly impact the development and differentiation of the sclerotome and myotome, resulting in axial skeleton malformations. Our findings suggest a scenario where the homeologous genes uncx.L and uncx.S exhibit antagonistic functions during somitogenesis. Specifically, uncx.S appears to be crucial for sclerotome development and differentiation, while uncx.L primarily influences myotome development. Postallotetraploidization, the uncx.L gene in X. laevis evolved to lose its eh1-like repressor domain, transforming into a "native dominant negative" variant that potentially competes with uncx.S for the same target genes. Finally, the histological analysis revealed that uncx.S expression is necessary for the correct formation of pedicles and neural arch of the vertebrae, and uncx.L is required for trunk muscle development.

Daily Intake of Smallanthus sonchifolius (Yacon) Roots Reduces the Progression of Non-alcoholic Fatty Liver in Rats Fed a High Fructose Diet.

High-fructose diet is associated with an increased risk of dyslipidemia, metabolic syndrome, and the development of non-alcoholic fatty liver disease (NAFLD) through chronic inflammation. The present study aimed to elucidate the potential benefit of daily consumption of Smallanthus sonchifolius (yacon) roots, rich in fructooligosaccharides (FOS), on the progression to liver fibrosis, in a rat model of NAFLD induced by a high-fructose diet. Male Wistar rats were fed a standard diet (CD, n = 6) or a standard diet plus 10% fructose solution (FD; n = 18). After 20 weeks, FD rats were randomly separated into the following groups (n = 6, each): FD; FD treated with yacon flour (340 mg FOS/body weight; FD + Y) and FD treated with fenofibrate (30 mg/kg body weight; FD + F), for 16 weeks. Daily intake of yacon flour significantly reduced body weight gain, plasma lipid levels, transaminase activities, and improved systemic insulin response in FD rats. In the liver, yacon treatment decreased fructose-induced steatosis and inflammation, and reduced total collagen deposition (64%). Also, yacon decreased TGF-ß1 mRNA expression (78%), followed by decreased nuclear localization of p-Smad2/3 in liver tissue. Yacon significantly reduced the expression of α-smooth muscle actin (α-SMA), Col1α1, and Col3α1 mRNAs (85, 44, and 47%, respectively), inhibiting the activation of resident hepatic stellate cells (HSCs). These results suggested that yacon roots have the potential to ameliorate liver damage caused by long-term consumption of a high-fructose diet, being a promising nutritional strategy in NAFLD management.

Lifestyle school-based intervention to increase the proportion of adolescents free of components of the metabolic syndrome in an andean region of Peru. / Intervención educativa basada en estilos de vida para incrementar la proporción de adolescentes libres de componentes del síndrome metabólico en una región altoandina del Perú.

OBJECTIVE.: To estimate the impact of a school-based nutritional and healthy lifestyle intervention to increase the proportions of adolescents free of components of the metabolic syndrome. MATERIALS AND METHODS.: We conducted a pre-experimental study in a representative sample of adolescents from two schools in a high Andean district of Peru (Cajamarca city); 388 students completed the intervention and the baseline and post-intervention measurement. The intervention had nine thematic modules; each module was developed in an educational session of 45 minutes every two weeks. We used the National Cholesterol Education Program Expert Panel and Adult Treatment Panel III criteria for metabolic syndrome. We used paired proportions comparison (McNemar test) to determine the impact of the intervention. RESULTS.: At baseline, 20.4% (95% CI: 16.2 to 24.5) students had no metabolic syndrome components, post-intervention this proportion increased to 32,5% (95% CI: 27.7 to 37.3), the difference in proportions was 12.1% (95% CI: 7.5 to 16.8; p<0.001). The prevalence of metabolic syndrome was 4.6% (95% CI: 2.4 to 6.9) at baseline, while post-intervention was 2.3% (95%CI: 0.7 to 3.9). During the analysis of components, the greatest reduction was observed in the proportion of hypertriglyceridemia (difference in proportions: 21.9%, 95%CI: 16.9 to 26.9, p <0.001); we also found a significant reduction in arterial hypertension (difference in proportions: 3.1%, 95% CI: 0.6 to 5.6, p=0.025). In the other components, there were no significant differences. CONCLUSIONS.: The school-based intervention increased in 59.3% the proportion of students free of any component of the metabolic syndrome.

OBJETIVO.: Estimar el efecto de una intervención educativa basada en nutrición y estilos de vida saludables para incrementar la proporción de adolescentes libres de componentes del síndrome metabólico. MATERIALES Y MÉTODOS.: Se realizó un estudio preexperimental en una muestra representativa de adolescentes de dos escuelas de un distrito altoandino del Perú (ciudad de Cajamarca); 388 estudiantes completaron la intervención, así como la medición basal y la posintervención. La intervención tuvo nueve ejes temáticos, cada uno fue desarrollado en una sesión educativa de 45 min cada dos semanas. Se usó los criterios del National Cholesterol Education Program Expert Panel and Adult Treatment Panel III para el síndrome metabólico. Se realizó la comparación de proporciones pareadas (prueba de McNemar) para determinar el impacto de la intervención. RESULTADOS.: En la medición basal, el 20,4% (IC95%: 16,2 a 24,5) no tenía componentes de SM, posintervención dicha proporción se incrementó a 32,5% (IC95%: 27,7 a 37,3), la diferencia de proporciones fue 12,1% (IC95%: 7,5 a 16,8; p<0,001). La prevalencia de síndrome metabólico fue 4,6% (IC95%: 2,4 a 6,9) basalmente; posintervención fue 2,3% (IC95%: 0,7 a 3,9). La diferencia de proporciones fue 2,3%, (IC95%: 0,3 a 3,2; p=0,022). Entre los componentes, la mayor reducción fue en la proporción de hipertrigliceridemia (diferencia de proporciones: 21,9%, IC95%: 16,9 a 26,9; p<0,001), también se observó una reducción significativa de la hipertensión arterial (diferencia de proporciones: 3,1%, IC95%: 0,6 a 5,6; p=0,025). En los demás componentes no hubo diferencias significativas. CONCLUSIONES.: La intervención educativa incrementó en un 59,3% la proporción de estudiantes libres de algún componente del síndrome metabólico.

Intervención educativa basada en estilos de vida para incrementar la proporción de adolescentes libres de componentes del síndrome metabólico en una región altoandina del Perú / Lifestyle school-based intervention to increase the proportion of adolescents free of components of the metabolic syndrome in an andean region of Peru

RESUMEN Objetivo. Estimar el efecto de una intervención educativa basada en nutrición y estilos de vida saludables para incrementar la proporción de adolescentes libres de componentes del síndrome metabólico. Materiales y métodos. Se realizó un estudio preexperimental en una muestra representativa de adolescentes de dos escuelas de un distrito altoandino del Perú (ciudad de Cajamarca); 388 estudiantes completaron la intervención, así como la medición basal y la posintervención. La intervención tuvo nueve ejes temáticos, cada uno fue desarrollado en una sesión educativa de 45 min cada dos semanas. Se usó los criterios del National Cholesterol Education Program Expert Panel and Adult Treatment Panel III para el síndrome metabólico. Se realizó la comparación de proporciones pareadas (prueba de McNemar) para determinar el impacto de la intervención. Resultados. En la medición basal, el 20,4% (IC95%: 16,2 a 24,5) no tenía componentes de SM, posintervención dicha proporción se incrementó a 32,5% (IC95%: 27,7 a 37,3), la diferencia de proporciones fue 12,1% (IC95%: 7,5 a 16,8; p<0,001). La prevalencia de síndrome metabólico fue 4,6% (IC95%: 2,4 a 6,9) basalmente; posintervención fue 2,3% (IC95%: 0,7 a 3,9). La diferencia de proporciones fue 2,3%, (IC95%: 0,3 a 3,2; p=0,022). Entre los componentes, la mayor reducción fue en la proporción de hipertrigliceridemia (diferencia de proporciones: 21,9%, IC95%: 16,9 a 26,9; p<0,001), también se observó una reducción significativa de la hipertensión arterial (diferencia de proporciones: 3,1%, IC95%: 0,6 a 5,6; p=0,025). En los demás componentes no hubo diferencias significativas. Conclusiones. La intervención educativa incrementó en un 59,3% la proporción de estudiantes libres de algún componente del síndrome metabólico.

ABSTRACT Objective. To estimate the impact of a school-based nutritional and healthy lifestyle intervention to increase the proportions of adolescents free of components of the metabolic syndrome. Materials and methods. We conducted a pre-experimental study in a representative sample of adolescents from two schools in a high Andean district of Peru (Cajamarca city); 388 students completed the intervention and the baseline and post-intervention measurement. The intervention had nine thematic modules; each module was developed in an educational session of 45 minutes every two weeks. We used the National Cholesterol Education Program Expert Panel and Adult Treatment Panel III criteria for metabolic syndrome. We used paired proportions comparison (McNemar test) to determine the impact of the intervention. Results. At baseline, 20.4% (95% CI: 16.2 to 24.5) students had no metabolic syndrome components, post-intervention this proportion increased to 32,5% (95% CI: 27.7 to 37.3), the difference in proportions was 12.1% (95% CI: 7.5 to 16.8; p<0.001). The prevalence of metabolic syndrome was 4.6% (95% CI: 2.4 to 6.9) at baseline, while post-intervention was 2.3% (95%CI: 0.7 to 3.9). During the analysis of components, the greatest reduction was observed in the proportion of hypertriglyceridemia (difference in proportions: 21.9%, 95%CI: 16.9 to 26.9, p <0.001); we also found a significant reduction in arterial hypertension (difference in proportions: 3.1%, 95% CI: 0.6 to 5.6, p=0.025). In the other components, there were no significant differences. Conclusions. The school-based intervention increased in 59.3% the proportion of students free of any component of the metabolic syndrome.

Early and late stages of Developmental Biology in Argentina.

The history of science in Argentina is based on the enormous contribution that the great immigration of the 19th and 20th centuries produced in the country. The scientific and philosophical ideas and the role played especially by Italian scientists who arrived in the country produced a great impact on the different disciplines including Development Biology in emerging universities. The University of Tucumán pioneered the study of experimental biology, making important contributions to reproductive biology and to the early development of amphibians. The contribution of the Italian embryologist Armando Pisanó and the Argentinian Francisco D. Barbieri expanded the field to other universities and research centers located in Córdoba, La Plata, Bahía Blanca and Rosario. Given its strategic position, laboratories located in the city of Buenos Aires reached technological advances faster than others. Indeed, these laboratories saw the evolution from experimental biology to developmental genetics, renewing interest in this area. Currently, Developmental Biology brings together young researchers eager to consolidate regional and global collaboration networks that seek to help solve specific problems such as fertility, epigenetics, stem cells and tissue engineering.

Delineating the anuran axial skeleton.

The axial skeleton of the anurans has undergone an evolutionary reduction of its bone elements. This structural plan is strongly preserved throughout the order and would have emerged as a highly specialized anatomical adaptation to its locomotor jumping pattern. The development programs that direct the vertebral morphogenesis of the anurans are poorly described and the molecular bases that have caused their pattern to differ from other tetrapods are completely unknown. In this work, we review the ontogeny of the spinal column of the anurans and explore the genetic mechanisms that could explain the morphological difference and the maintenance of the body plan during evolution. Here, we propose that the absence of caudal osseous elements, as a consequence of the inability of sclerotomes to form cartilaginous condensations in frogs, could be due to changes in both pattern and expression levels of Hox, Pax1, Pax9 and Uncx4.1 genes along the anteroposterior axis. The anteriorised expression of the Hox genes together with the reduction in the expression levels of Pax1, Pax9 and Uncx4 in the posterior somites could explain, at least partly, the loss of caudal vertebrae in the anurans during evolution.

Steaming and Toasting Reduce the Nutrimental Quality, Total Phenols and Antioxidant Capacity of Fresh Kabuli Chickpea (Cicer arietinum L.).

Kabuli chickpea is traditionally consumed in Mexico. It is currently exported to countries including United States where its demand has recently increased. In order to demonstrate the effect of thermal processes on the quality of fresh chickpea, the objective of the present work was to evaluate some nutrimental and functional characteristics of raw, steamed and toasted chickpea. The partial chemical composition, total phenols, oligosaccharides, and antioxidant capacities were measured in five genotypes of chickpea. Steamed and toasted chickpea showed up to 8.4 and 25.8% less protein, respectively, than that of raw samples. Oligosaccharides, in general decreased in steamed and toasted fresh grain; however, verbascose increased on average 30.6 and 37.9% in steamed and toasted samples, respectively. Minor changes in total phenolic content were observed a result of the process. Trolox equivalent antioxidant capacity increased up to 3.5 times compared to that of antioxidant capacity of raw samples. Fresh chickpea grain, raw or processed, shows attractive nutritional and antioxidant properties that can contribute to the diet and health of the person who consumes it.

Biomarcadores para la evaluación y diagnóstico del síndrome de ojo seco: una revisión / Biomarkers for the evaluation and diagnosis of the dry eye syndrome: a review

Resumen Introducción: El síndrome de ojo seco es una enfermedad en la que se generan signos y síntomas que conducen a alteraciones oculares prolongadas, por lo tanto, es relevante establecer con precisión la etiología de la enfermedad con la finalidad de establecer el tratamiento más efectivo, de allí, la importancia del desarrollo de exámenes innovadores como son los biomarcadores, los cuales permiten identificar con mayor precisión el cuadro clínico. Por esta razón, el presente trabajo pretende describir los principales avances de los biomarcadores de la superficie ocular y reconocer su aplicación clínica para el diagnóstico de ojo seco entre los años 2013 a 2018. Metodología: Se analizó literatura sobre biomarcadores empleados para el diagnóstico del ojo seco, mediante una revisión sistemática tipo narrativa de 2013 a 2018 por medio de los descriptores controlados "Dry Eye Syndrome" "biomarkers" "tear proteins" "eye proteins" seleccionados en DeCS y Pubmed; la búsqueda arrojó 48 estudios, de los cuales seleccionamos 21 para el análisis. Resultados: Son diversas las proteínas lagrimales que pueden ser relacionadas con la presencia y ausencia de la enfermedad, es vital que los biomarcadores sean valorados como una herramienta alternativa para diagnosticar con facilidad y precisión la enfermedad del ojo seco. Discusión: Los biomarcadores permiten reconocer los procesos patógenos y biológicos del síndrome de ojo seco, al reflejar el estado de la superficie ocular en presencia o ausencia de signos y síntomas, facilitando el diagnóstico precoz, seguimiento, tratamiento y control de la enfermedad.

Abstract Introduction: Dry eye syndrome is a disease in which signs and symptoms that lead to prolonged ocular alterations occur, therefore, it is relevant to accurately establish the etiology of the disease with the configuration of establishing the most effective treatment, hence the development of innovative exams such as biomarkers selected with greater precision the clinical picture. For this reason, the present work aims to describe the main advances of biomarkers of the ocular surface and to recognize their clinical application for the diagnosis of dry eye between 2013 and 2018. Metodology: Literature on biomarkers used for the diagnosis of dry eye was analyzed, by means of a systematic narrative review from 2013 to 2018 by means of the controlled descriptors "Dry Eye Syndrome" "biomarkers" "tear proteins" "eye proteins" selected in DeCS and Pubmed; The search yielded 48 studies and 21 studies were selected for the analysis. Results: There are several tear proteins that can be related to the presence and absence of the disease, it is vital that biomarkers are evaluated as an alternative tool to easily and accurately diagnose dry eye disease. Discussion: Biomarkers allow to recognize the pathogenic and biological processes of dry eye syndrome, reflecting the state of the ocular surface in the presence or absence of signs and symptoms, facilitating early diagnosis, monitoring, treatment and control of the disease.

Smallanthus sonchifolius (Yacon) Flour Improves Visceral Adiposity and Metabolic Parameters in High-Fat-Diet-Fed Rats.

Smallanthus sonchifolius (yacon), a native plant of South America, was observed to improve lipid profile in rodents and humans. This study aimed to investigate the antiobesity properties of yacon roots in a high-fat-diet (HFD) model and the underlying mechanisms. A total of 30 Wistar male rats were divided into five groups (n=6): the standard chow diet (SD) group was fed a SD; the HFD group was fed a HFD; and the HFD Y340 and HFD Y680 groups were fed a HFD plus yacon flour (340 and 680 mg FOS/kg b. w./day, respectively). HFD Y340 and HFD Y680 rats exhibited marked attenuation of weight gain, a decrease in visceral fat pad weight, a restoration of the serum lipid profile and atherogenic index in a dose-dependent manner, being the higher dose more effective (p < 0.05). In addition, we found that HFD Y680 rats showed lower glucose and insulin levels, improved glucose tolerance, and insulin sensitivity (p < 0.5). A downregulation of several adipocyte specific-transcription factors, including peroxisome proliferator-activated receptor gamma2 (PPAR-γ2), CCAAT/enhancer binding protein a (C/EBP-a) and activating protein (aP2) mRNA levels, was determined in the visceral adipose tissue of HFD Y680 rats (p < 0.05). An improvement of adipokine profile in HFD Y680 rats and decreased serum proinflammatory cytokine levels (p < 0.05) were determined by ELISA. Decreased macrophage infiltration and F4/80 and MCP-1 expression in the visceral adipose tissue of HFD Y680 rats (p < 0.5), together with a higher pAkt/Akt expression (p < 0.05) were also observed by immunofluorescence and immunoblotting. A significant increase in glucagon (Gcg) and PYY mRNA levels in distal ileum of HFD Y680 rats (p < 0.05) were also detected. In the second approach, we determined that yacon supplementation potentiates the effects of the HFD reversion to a standard diet. In conclusion, yacon showed antiobesity properties by inhibiting adipogenesis and improving the visceral adipose tissue function.

Contenido de ácidos grasos saturados y trans en materias primas grasas empleadas en algunas panaderías de Medellín / Content of Saturated and Trans Fatty Acids in Margarines Used in Some Bakeries in Medellín

Resumen Antecedentes: estudios previos reportan la presencia de grasas saturadas y grasas trans en productos de panadería, relacionadas con enfermedades crónicas no transmisibles. Sin embargo, se desconoce la procedencia y calidad de las materias primas grasas utilizadas por los panaderos en Medellín. Objetivo: caracterizar las materias primas grasas utilizadas para la preparación de productos de panadería. Materiales y métodos: estudio descriptivo transversal, de tipo exploratorio, con 24 muestras. Por cada muestra se realizó una encuesta a los panaderos para evaluar la calidad de las grasas y un análisis por cromatografía de gases para cuantificar 17 grasas saturadas y grasas trans. Resultados: el promedio de grasas trans en las materias primas grasas fue de 0,46 g en 100 g, mientras la normatividad permite 5 g en 100 g (Resolución 2508 de 2012, del Ministerio de Salud y Protección Social); el 42,1 % del contenido graso proviene de grasas saturadas; y algunas materias primas grasas no cumplen con la normatividad vigente para el etiquetado de alimentos envasados, pues no tienen rotulado nutricional. Conclusiones: en ninguna de las 24 materias primas grasas evaluadas cromatográficamente se cuantificó un contenido de grasas trans superior a lo permitido por la Resolución 2508, lo cual evidencia el esfuerzo de la industria de alimentos. Es necesario mantener la vigilancia del etiquetado para asegurar su cumplimiento.

Abstract Background: Previous studies have reported the presence of saturated and trans fatty acids in bakery products, which are related with chronic non-communicable diseases. Currently, the origin and quality of the primary fat ingredients and products used by bakers in the city of Medellin is currently unknown. Objective: The aim of this paper is to characterize the primary fat ingredients used for the preparation of bakery products. Materials and Methods: An exploratory transversal descriptive study, with 24 bakery samples belonging to three groups according to socioeconomic level. For each sample, a survey was conducted to evaluate the quality of fat and an analysis by gas chromatography was done to quantify 17 saturated and trans fatty acids was. Results: The average trans fatty acid content in the margarines is 0.46 g per 100 g, however regulatory entities allow 5 g per 100 g (Resolución 2508 de 2012, del Ministerio de Salud y Protección Social); 42.1% of fat content comes from saturated fatty acids and some primary fat ingredients do not comply with current regulations for packaged foods. Conclusions: None of the 24 fat ingredient chromatographic evaluations was quantified with trans fatty acids content higher than that allowed by Resolution 2508. This proves the effort of the food industry, however it is necessary to maintain the surveillance of the labeling to ensure compliance.

Extracellular matrix remodeling and TGF-ß1/Smad signaling in diabetic colon mucosa.

Diabetes is associated with metabolic and functional alterations in the gut. Using an experimental model of streptozotocin (STZ)-induced diabetes in rodents, we analyzed the extracellular matrix (ECM) and TGF-ß/Smad signaling in the colon mucosa. Male rats were divided into normal control, diabetic and insulin treated diabetic groups during 4 and 9 weeks. Sirius red staining showed marked increase in the extracellular matrix deposition in diabetic mucosa. High levels of fibrillar collagen (I and III) and fibronectin mRNAs were also detected with an imbalance between MMPs/TIMPs activities. Moreover, an increased mesenchymal cell proliferation together with an enhanced expression of myofibroblasts markers vimentin and α-SMA were observed. TGF-ß/Smad signaling-related genes were determined using RT-PCR, Western blotting, and immunohistochemistry. Diabetic rats showed a significant up-regulation of TGF-ß1, TGF-ß receptors and the effectors p-Smad2/3 in the mucosa compared with control rats. Insulin treatment attenuated the stimulating effect of diabetes on colon ECM deposition and TGF-ß/Smad signaling. In conclusion, the overall results showed a deregulation of the TGFß1 pathway associated with the appearance of myofibroblasts and the accumulation of ECM in the mucosa of diabetic colon. These data provide the first in vivo evidence that TGF-ß1/Smad is a key component of intestinal tissue remodeling in diabetes.

Polymatin A from Smallanthus macroscyphus leaves: A safe and promising antidiabetic compound.

Smallanthus macroscyphus is an herb native to South America whose leaves are a source of antidiabetic compounds, although complete information about their safe use is not available yet. This study was developed to evaluate the toxicity profile of both 10% decoction and the sesquiterpene lactone polymatin A from S. macroscyphus leaves through in vitro cytotoxicity assays and in vivo subchronic oral toxicity. Cell viability of Hep-G2, COS1, CHO-K1 and Vero cell lines decreased in a concentration-dependent manner when cells were incubated with 0.4-200 µg ml(-1) of dry extract or 0.12-60 µg ml(-1) of polymatin A. In subchronic studies, decoction was orally administered to Wistar rats for 90 days at daily doses of 70, 140 and 280 mg kg(-1) of dry extract, whereas polymatin A was administered in the same way at doses of 7, 14 and 28 mg kg(-1) . No toxicity signs or deaths were observed. There were no changes in the behavior, body or organ weights, hematological, biochemical or urine parameters of the rats. No histopathological lesions were observed in the examined organs. The results indicate that the 10% decoction and polymatin A from S. macroscyphus leaves may be considered as non-toxic substances at a wide range of doses, including the effective hypoglycemic dose. Copyright © 2016 John Wiley & Sons, Ltd.

Paraxis is required for somite morphogenesis and differentiation in Xenopus laevis.

BACKGROUND: In most vertebrates, the segmentation of the paraxial mesoderm involves the formation of metameric units called somites through a mesenchymal-epithelial transition. However, this process is different in Xenopus laevis because it does not form an epithelial somite. Xenopus somitogenesis is characterized by a complex cells rearrangement that requires the coordinated regulation of cell shape, adhesion, and motility. The molecular mechanisms that control these cell behaviors underlying somite formation are little known. Although the Paraxis has been implicated in the epithelialization of somite in chick and mouse, its role in Xenopus somite morphogenesis has not been determined. RESULTS: Using a morpholino and hormone-inducible construction approaches, we showed that both gain and loss of function of paraxis affect somite elongation, rotation and alignment, causing a severe disorganization of somitic tissue. We further found that depletion or overexpression of paraxis in the somite led to the downregulation or upregulation, respectively, of cell adhesion expression markers. Finally, we demonstrated that paraxis is necessary for the proper expression of myotomal and sclerotomal differentiation markers. CONCLUSIONS: Our results demonstrate that paraxis regulates the cell rearrangements that take place during the somitogenesis of Xenopus by regulating cell adhesion. Furthermore, paraxis is also required for somite differentiation.

Yacon roots (Smallanthus sonchifolius) improve oxidative stress in diabetic rats.

CONTEXT: Smallanthus sonchifolius (Poepp. and Endl.) H. Robinson, Asteraceae (yacon) roots are a natural product recognized by the traditional medicine to treat diabetes-related problems. There are no reports concerning the potential of yacon roots to reduce oxidative stress and ameliorate diabetes complications in diabetic animals. OBJECTIVE: This work analyzes the in vivo antioxidant activity and beneficial effects of yacon roots, using a model of streptozotocin-induced diabetes in rats. MATERIALS AND METHODS: Lipid peroxidation and other indicators of oxidative stress were determined in liver and kidney homogenates from non-diabetic rats, untreated diabetic rats, and diabetic rats treated orally with yacon flour (340 mg fructooligosaccharide/kg/d) as a diet supplement for 90 d. Biochemical parameters were determined in liver, kidney, and blood at the end of the experimental period. RESULTS: Yacon supplementation to diabetic rats produced a significant decrease in malondialdehyde levels in both liver (-30.97%) and kidney (-19.15%). Hepatic superoxide dismutase and catalase activities were significantly lower in diabetic-treated rats (-13.46 and -64.33%, respectively) compared with diabetic controls. Similar results were observed in kidney. The treatment of diabetic rats produced an increase of glutathione peroxidase and glutathione levels in liver (172.50 and 35.91%, respectively) and kidney (177.78 and 57.76%, respectively). Plasma cholesterol and triacylglycerol levels and liver fatty acid composition, which were altered in diabetic rats, reverted back to nearly normal with yacon treatment. CONCLUSIONS: These results indicate that yacon root flour is a potential diet supplement with high in vivo antioxidant activity.

Xepac protein and IP3/Ca2+ pathway implication during Xenopus laevis vitellogenesis.

The objective of this study was to elucidate the signalling pathways initiated by cAMP once inside the Xenopus laevis oocyte, where it triggers and maintains vitellogenin endocytic uptake. Our results showed the presence of Xepac transcripts at all stages of oogenesis and we demonstrated that a cAMP analogue that exclusively activates Xepac, 8-CPT, was able to rescue the endocytic activity in oocytes with uncoupled gap junctions. Inhibition experiments for the IP3/Ca2+ signalling pathway showed either a complete inhibition or a significant reduction of the vitellogenic process. These results were confirmed with the rescue capability of the A-23187 ionophore in those oocyte batches in which the IP3/Ca2+ pathway was inhibited. Taking our findings into account, we propose that the cAMP molecule binds Xepac protein enabling it to activate the IP3/Ca2+ pathway, which is necessary to start and maintain X. laevis vitellogenin uptake.

Smallanthus macroscyphus: a new source of antidiabetic compounds.

The aim of the present study was to analyze the in vivo hypoglycaemic effects of both decoction of Smallanthus macroscyphus leaves and pure crystalline polymatin A isolated from its leaves. Phytochemical analysis of the leaf decoction showed that its major constituents were caffeic, chlorogenic and three dicaffeoilquinic acids, together with the sesquiterpene lactone polymatin A. Oral glucose tolerance test in normal rats was performed to evaluate the hypoglycemic activity and to choose the minimum effective dose of the decoction and polymatin A. They have effective hypoglycemic activity at the minimum dose of 140 mg dry extract and 14 mg crystalline powder/kg body weight, respectively, and were selected for the following experiments. Oral administration of a single-dose of decoction produced a moderate lowering effect in fasting glycemia of normal rats, whereas polymatin A had no significant effect. We also assessed the effect of a single-dose on post-prandial blood glucose, resulting in an inhibition of the hyperglycemic peak after sucrose overload. Daily administration of decoction or polymatin A for 4 weeks produced an effective glycemic control in diabetic animals, with a decrease in urinary glucose excretion and a significant reduction in the HbA1c levels. Although there were no significant increases in plasma insulin levels, both treatments improved the fasting blood glucose/insulin ratio. In vivo acute toxicity studies were performed in adult Wistar rats. There were no deaths or signs of toxicity observed after oral administration of decoction or polymatin A at any dose level up to the highest dose tested (14.0 and 2.8 g/kg, respectively). The results presented here strongly support the notion that S. macroscyphus represents a new source of antidiabetic compounds that could help to manage diabetes more efficiently and safely.