The main objective of the present study was to evaluate the relative contribution of the intestine to glucose homeostasis in rainbow trout. In a first set of in vivo experiments trout were subjected to oral glucose treatments alone or in combination with insulin injections to assess changes in glucose-related enzymes activities, metabolite levels, and mRNA levels. Rainbow trout gut displays an important glucose metabolism that includes the ability to store glucose as glycogen (mostly in the muscle layers) and a large capacity to oxidize glucose. This constitutes a surprising result for a carnivorous fish. In a second set of in vivo experiments, trout received an oral amino acid solution alone or in combination with insulin injection to determine whether other factors besides fasting could regulate gluconeogenesis in intestine. The results confirm the absence of regulation of gluconeogenesis in trout gut, which does not respond to hormones, glucose, lactate, or amino acid changes, either in vivo or in vitro. We also fully characterized gut glucose metabolism in vitro. We observed that a large amount of glucose is oxidized to lactate, supporting the importance of glucose in gut metabolism. Moreover, we corroborated the minor actions of insulin in trout gut, whereas other hormones such as glucagon-like peptide-1 and C-peptide appear to be major hormonal regulators of glucose metabolism in fish gut. Finally, we obtained the first evidence for the existence of a glucosensing mechanism in the midgut of this carnivorous species.
SUMMARYTo assess the hypothesis that cortisol release in rainbow trout is modulated by glucose levels, we first evaluated cortisol release [basal and adrenocorticotropic hormone (ACTH)-regulated] by head kidney tissue superfused with medium reflecting hypoglycaemic, normoglycaemic or hyperglycaemic conditions. Next, cortisol release from head kidney fragments in static incubations was assessed in parallel with changes in parameters related to cortisol synthesis (mRNA abundance of StAR, P450scc, 3βHSD and 11βH) and the GK-mediated glucosensing mechanism (levels of glycogen and glucose, activities of GK, GSase and PK, and mRNA levels of GK, GLUT-2, Kir6.x-like and SUR-like). We then evaluated the effects of two inhibitors of glucose transport, cytochalasin B and phlorizin, on cortisol production and glucosensing mechanisms. The ACTH-induced release of cortisol proved to be modulated by glucose concentration such that increased release occurs under high glucose levels, and decreased ACTH-stimulated cortisol release occurs when glucose transport is inhibited by cytochalasin B. The release of cortisol can be associated with increased synthesis as enhanced mRNA abundance of genes related to cortisol synthesis was also noted in high glucose medium. Specific GK immunoreactivity in the cortisol-producing cells (not in chromaffin cells) further substantiates GK-mediated glucosensing in cortisol production. In contrast, no changes compatible with those of glucose levels and cortisol release/synthesis in the presence of ACTH were noted for any other putative glucosensor mechanisms based on LXR, SGLT-1 or Gnat3. These combined results are the first evidence for a mechanism in fish linking the synthesis and release of a non-pancreatic hormone like cortisol with circulating glucose levels. The relationship was evident for the regulated (ACTHdependent) pathway and this suggests that under acute stress conditions glucose is important for the regulation of cortisol synthesis and release.
Here we present the main findings of a study conducted at the Department of Teaching and School Organization of the University of Santiago de Compostela to explore the perceptions of teachers regarding didactic and music materials used and produced to facilitate teaching in early childhood education. This descriptive and interpretative study involved questionnaires sent to a sample of 560 early childhood teachers in public, private, private subsidized, and unitary schools in Galicia. In addition, interviews were conducted to better understand the questionnaire findings. A number of recommendations are included regarding measures to be taken by institutions and professionals involved in the process of design, selection, and use of didactic materials reflecting the analyses and opinions of the teachers in our study. Attention has been given to the comparative analysis of our findings with those in other studies carried out in Galicia and Spain over the past 10 years.
The contents of dopamine (DA), noradrenaline (NA), serotonin (5HT), and some related metabolites were studied in different brain regions of rainbow trout at two different stages of sexual maturation (at the beginning of vitellogenesis), after naphthalene (NAP) administration. The effects of NAP varied according to duration of exposure, brain region and vitellogenesis stage of the trout, and were more significant during previtellogenesis. The changes observed in DA metabolism were generally stimulatory after exposure for 3 h, and either stimulatory or inhibitory (depending on the brain regions) after exposure for 3 days to NAP. NA levels were altered by NAP in various brain regions, but only during previtellogenesis. With respect to 5HT, treatment with NAP reduced levels of the amine and/or its main metabolite in most of the brain regions studied, particularly 3 h after treatment. The results suggest that NAP might interfere with the processes regulating brain monoamine metabolism, either locally or indirectly by altering steroid feedback to brain centres, and thus disrupt endocrine control of reproductive development through the brain-pituitary axis.
Background
Improved point-of-care diagnostic tests for tuberculosis (TB) in severe immune suppressed people living with HIV (PLWH) are needed to decrease morbidity and mortality outcomes. The aim of the study is to evaluate the performance of the lipoarabinomannan antigen test (LAM-test) with and without α-mannosidase pre-treated urine in a cohort of PLWH in primary care clinics in Guatemala. We further determined TB incidence, and mortality rates and its risk factors in PLWH with TB symptoms.
Methods
Prospective longitudinal study of PLWH with TB symptoms. Urine samples were collected at 2 HIV sites to test the sensitivity of the LAM-test in urine with and without α-mannosidase pre-treatment. A composite reference standard of either a positive Mycobacterium tuberculosis complex culture and/or GeneXpert® MTB/RIF (Xpert, Cepheid, Sunnyvale, CA, USA) results was used in the LAM-test diagnostic accuracy studies. Cox proportional hazards regression was used to study mortality predictors.
Results
The overall sensitivity of the LAM-test was of 56.1% with 95% CI of (43.3–68.3). There were no differences in the LAM-test sensitivity neither by hospital nor by CD4 T cell values. LAM-test sensitivity in PLWH with < 200 CD4 T cells/µl was of 62.2% (95% CI 46.5–76.2). There were no significant differences in sensitivity when comparing LAM-test results obtained from untreated vs. α-mannosidase treated urine [55.2% (95% CI 42.6–67.4) vs. 56.9% (95% CI 44–69.2), respectively]. TB incidence in our cohort was of 21.4/100 person years (PYs) (95% CI 16.6–27.6), and mortality rate was of 11.1/100 PYs (95% CI 8.2–15.0). Importantly, PLWH with a positive LAM-test result had an adjusted hazard ratio (aHR) of death of 1.98 (1.0–3.8) with a significant p value of 0.044 when compared to PLWH with a negative LAM-test result.
Conclusions
In this study, α-mannosidase treatment of urine did not significantly increase the LAM-test performance, however; this needs to be further evaluated in a large-scale study due to our study limitations. Importantly, high rates of TB incidence and mortality were found, and a positive LAM-test result predicted mortality in PLWH with TB clinical symptoms.
Los materiales didácticos forman parte de la realidad educativa. El docente los selecciona en función del alumnado, el centro educativo, características o finalidad. En consecuencia, el material condiciona el método y homogeniza el proceso de enseñanza y aprendizaje. La realidad española de los últimos 30 años, a través de la especialización docente, ha hecho posible la evolución de los materiales escolares en educación musical. Este artículo proporciona respuestas a algunas preguntas sobre los cambios que suscita la utilización de recursos tecnológicos y digitales en educación y reflexiona sobre particularidades de uso en el aula de música. La investigación parte del análisis de contenido de una muestra de materiales para 5º y 6º de Educación Primaria. El conocimiento de los materiales didácticos digitales y musicales y sus estrategias pedagógicas ha sido posible gracias a la elaboración minuciosa de instrumentos de análisis específicos. Este estudio permite conocer las características tecnológicas, las tareas específicas y el tipo de aprendizaje musical que ofrecen editoriales y administración pública a través de la tecnología educativa.
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