Presence and regulation of D1 and D2 deiodinases in rat white adipose tissue

Thyroid hormones regulate adipogenic differentiation, lipogenic and lipolytic metabolism, and mitochondrial activity in adipose tissue. Triiodothyronine (T3) levels in tissues are regulated by the deiodinase enzymes. The objective was to study the activity and messenger RNA (mRNA) expression of the 5′ outer-ring deiodinases (type 1 [D1] and type 2 [D2] deiodinase) and thyroid hormone concentrations in rat white adipose tissue (WAT), where only D1 activity had been described. Control, thyroidectomized, and thyroid hormone–treated rats were used. Type 1 and type 2 deiodinase mRNAs were determined in WAT by quantitative real-time polymerase chain reaction using Taqman probes; D1 and D2 activities were determined using reverse T3 and thyroxine (T4) as substrates. Thyroxine and T3 were measured by radioimmunoassay in plasma, liver, and adipose tissue. Type 1 and type 2 deiodinase mRNAs are present in epididymal rat WAT with similar abundance, which is 7% of the D2 mRNA levels in brown adipose tissue and 1% of D1 in liver. The Michaelis-Menten constants in WAT are 40 nmol/L T4 for D2 and 0.35 μmol/L reverse T3 for D1. Both D1 and D2 are regulated in rat epididymal WAT by thyroidal status. Thyroxine and T3 concentrations in plasma, liver, and WAT decreased after thyroidectomy and recovered after treatment with T4 + T3. Both D1 and D2 mRNAs increased in WAT from thyroidectomy rats; and T4 + T3 treatment inhibited them, especially D2 mRNA. Type 1 deiodinase activity did not change with thyroidal status, whereas D2 activity was inhibited by T4 + T3. The presence of both deiodinases in WAT suggests important roles in regulating T3 bioavailability for adipose tissue function and regulation of lipid metabolism and thermogenesis.Supported by SAF2006-01319 and SAF2009-2243 from MICINN and Fundacion Mutua Madrileña 2006.Peer Reviewe

Curriculum and teaching: what and how student at risk are thought?

En el presente artículo se analiza el currículo y la enseñanza de dos programas o medidas que se desarrollan en la Región de Murcia y en la Comunidad de Andalucía –Programa de Diversificación Curricular y Programa de Iniciación Profesional y/o Programa de Garantía Social- ambos destinados al alumnado con serias dificultades para continuar la enseñanza en las aulas regulares. Tras presentar diversos datos recogidos a través de cuestionarios y entrevistas con diferentes sujetos implicados, se analizan y valoran los resultados de la investigación realizada, procurando responder a la cuestión de en que grado el currículo diseñado en tales programas y la formación y aprendizajes logrados han contribuido a responder a las necesidades de este alumnadoThe article analyses curriculum and teaching of two programs in the Region of Murcia and in the Community of Andalusia - Program of Diversification Curricular and Program of Professional Initiation and / or Program of Social Guarantee – designed and implemented with students at risks, in serious difficulties to progress their learning in regular classrooms and teaching. After presenting different data gathered throw questionnaires and interviews carried out with different teachers, the outcomes are analyzed and valued in order to answer the question related to the degree in which de curriculum designed and its implementation in such programs respond properly to students needs and contributed to theirs expected learnin

Switching of Magnetic Moments of Nanoparticles by Surface Acoustic Waves

We report evidence of the magnetization reversal in nanoparticles by surface acoustic waves (SAWs). The experimental system consists of isolated magnetite nanoparticles dispersed on a piezoelectric substrate. Magnetic relaxation from a saturated state becomes significantly enhanced in the presence of the SAW at a constant temperature of the substrate. The dependence of the relaxation on SAW power and frequency has been investigated. The effect is explained by the effective ac magnetic field generated by the SAW in the nanoparticles.Comment: Accepted in Europhysics Letter

Detection of thyroid hormones in human embryonic cavities during the first trimester of pregnancy

et al.Transfer of maternal thyroxine (T4) to the human fetus near term has recently been demonstrated. We investigated whether maternal thyroid hormone is available to the conceptus during the first trimester of pregnancy as well. Transvaginal ultrasound-guided puncture of the embryonic cavities was performed during the first trimester of pregnancy to obtain coelomic fluid between 6 and 11 weeks, and amniotic fluid between 8 and 11 weeks of pregnancy. T4 was found in coelomic fluid with mean values (+/- SEM) being 961 +/- 193 pmol T4/L (747 +/- 150 pg/mL). Concentrations increased both with gestational age and with rising maternal serum T4. Concentrations of 3,5,3'-triiodothyronine (T3) were at least 30 times lower, and those of 3,3',5'-triiodothyronine (rT3) four times higher, than coelomic fluid T4. Thyroxine and rT3 in amniotic fluid (8-11 weeks) were markedly lower than in the coelomic fluid, and T3 was undetectable. These results show that maternal thyroxine can cross the placental barrier as early as the second month of pregnancy. T4 from the coelomic fluid may reach the embryo via the yolk sac. This finding raises the possibility that the increase in maternal T4 occurring during the first trimester may be functionally important for the developing embryo, when its thyroid is not yet functioning.This work was supported by grant 92 / 0888 of Fondo de Investigaciones Sanitarias (Spain) and grant nº 3.4530.93. from the “Fends de la Recherche Scientifique Médicale> (FRSM, Belgium).Peer Reviewe

Maternal diabetes mellitus, a rat model for nonthyroidal illness: Correction of hypothyroxinemia with thyroxine treatment does not improve fetal thyroid hormone status

Maintenance of normal maternal thyroxinemia prevents severe triiodothyronine (T3) deficiency of the fetus with primary thyroid failure (1). We have studied whether thyroxine (T4) would also protect the fetal brain when maternal hypothyroxinemia is caused by nonthyroidal illnesses. We have used the streptozotocin-induced diabetes mellitus pregnant rat as a model of maternal nonthyroidal illness. We measured the effects of diabetes mellitus, and of correction of the ensuing maternal hypothyroxinemia with T4 as compared to insulin, on maternal body weight, the outcome of pregnancy, glucose, insulin, T4, T3, reverse T3, and thyrotropin levels in the maternal and fetal circulation, as well as T4 and T3 concentrations in tissues, and iodothyronine deiodinases in liver, lung, and brain. The diabetic mothers showed changes in thyroid hormone status typical of nonthyroidal illnesses. Thyroid hormone status of the fetuses was severely affected: the total T4 and T3 pools decreased to one-third of normal values. T4 and T3 concentrations in the fetal brain were lower than normal and the expected increase in 5'-deiodinase activity was not observed. Although insulin treatment avoided or mitigated these changes, the low cerebral T3 did not improve with T4 treatment of the maternal hypothyroxinemia. Several findings indicated that treatment of the severely ill dams with T4 was actually harmful for the outcome of pregnancy. These negative effects were observed without the expected increase in the maternal or fetal T3 pools.This work was supported by Grant FISS (Fondo de Investigaciones Sanitarias) 92/0888, Spain.Peer Reviewe

Maternal nonthyroidal illness and fetal thyroid hormone status, as studied in the streptozotocin-induced diabetes mellitus rat model

11 pages, 9 figures, 1 table.We have used the streptozotocin-induced diabetes mellitus pregnant rat as a model of maternal nonthyroidal illness. We measured the effects of different degrees of diabetes mellitus on maternal body weight, the outcome of pregnancy, circulating glucose, insulin, T4, T3, rT3, and TSH in mother and fetus, T4 and T3 in maternal and fetal tissues, and iodothyronine deiodinases in liver, lung, and brain. All of the changes in thyroid hormone status typical of nonthyroidal illnesses were observed in the mothers and were related to the degree of the metabolic imbalances. Most were controlled with a daily insulin dose of 0.5 U/100 g BW. Normalization of maternal placental T4, however, required higher insulin doses than in other maternal tissues. The number and body weight of the fetuses, their pituitary GH contents, and their thyroid hormone status were severely affected. The total extrathyroidal T4 and T3 pools decreased to one third of normal fetal values. T4 and T3 concentrations in the fetal brain were lower than normal, and the expected increase in type II 5'deiodinase activity was not observed. The low cerebral T3 only improved with adequate insulin treatment of the dams. It is concluded that maternal diabetes mellitus, and possibly other nonthyroidal illnesses that impair the availability of intracellular energy stores, may affect fetal brain T3 when thyroid hormones are essential for normal development.This work was supported by Grant 92–08 88 from the Fondo de Investigaciones Sanitarias, Spain.Peer reviewe

El clima motivacional a les classes d’Educació Física: una aproximació pràctica des de la Teoria de Fites d’Assoliment

Al treball següent es fa una anàlisi dels processos motivacionals que es desenvolupen a les classes d’Educació Física. Prenent com a fonament la Teoria de les Fites d’Assoliment (Nicholls, 1989; Ames, 1992), s’expliquen cada un dels diferents constructes que formen la teoria esmentada (Orientacions, Climes i Implicacions Motivacionals) i la relació entre ells. També s’hi exposen diverses investigacions que han demostrat aquestes relacions, i de quina manera el desenvolupament d’un clima que implica vers la tasca pot millorar i fer més adaptatius els patrons conductuals dels alumnes. Finalment, es fa una proposta metodològica per desenvolupar un clima que impliqui vers la tasca per part del professorat d’Educació Física, amb els beneficis que això reporta

Association of Polymorphisms in the Interleukin 6 Receptor Complex with Obesity and Hyperandrogenism

10 pages, 5 tables.Objective: Interleukin-6 (IL-6), is an inflammatory cytokine that may influence the pathogenesis of obesity and hyperandrogenism. IL-6 exerts its actions through a heterodimeric receptor consisting of two membrane-bound glycoproteins: an 80-kDa IL-6 binding unit (IL6R-alpha) and a 130-kDa IL-6 signal transducer (gp130). Genetic variability at these loci might contribute to explain the development of obesity and hyperandrogenism. Research Methods and Procedures: We have evaluated the possible association of several polymorphisms in the IL6R-alpha and gp130 genes with obesity and/or hyperandrogenism in a case-control study involving 143 hyperandrogenic patients and 45 healthy women from Spain. Results: A microsatellite CA-repeat polymorphism in the IL6R-alpha locus was associated with obesity. The frequency of the common 149-bp allele was markedly increased in obese women compared with controls when considering patients and controls as a whole (0.41 vs. 0.29, chi2 = 17.085, p < 0.050). On the other hand, the uncommon Arg148 allele of the Gly148Arg polymorphism in the gp130 gene was more frequent in controls compared with hyperandrogenic patients (0.17 vs. 0.08, chi2 = 5.605, p = 0.026). Controls carrying Arg148 alleles had lower 11-deoxycortisol and 17-hydroxyprogesterone concentrations, a lower response of androstenedione to 1–24 adrenocorticotropin, and an almost significant decrease in free testosterone levels, suggesting that Arg148 alleles in the gp130 gene have a protective effect against androgen excess and adrenal hyperactivity. Discussion: Polymorphisms in the gp130 and IL6R-alpha loci influence hyperandrogenism and obesity, respectively. Our present results further suggest that proinflammatory genotypes are involved in the pathogenesis of these common metabolic disorders.This work was supported by grants from the Consejería de Educación, Comunidad de Madrid, Spain (Proyectos 08.6/0022/1998, 08.6/0024.2/2000, and 08.6/0010/2001), and from the Fondo de Investigación Sanitaria, Ministerio de Sanidad y Consumo, Spain (Proyectos FIS 00/0414 and 02/0741 to H.F.E.-M.Peer reviewe

Verbal Memory and IQ Predict Adaptive Behavior in Children and Adolescents with High-Functioning Autism Spectrum Disorders

Adaptive deficits are commonly found in high functioning autism spectrum disorders (HF-ASD) despite of cognitive potential. Most studies have focused on the relationships between adaptive behavior and intellectual quotient (IQ) and have used correlations to study relationships between them. Few studies have analyzed cognitive variables other than IQ as potential predictors of adaptive behavior in HF-ASD using regression methods. This study aimed to analyze the impact of several cognitive variables on adaptive behavior in a sample of children and adolescents with HF-ASD. METHODS: Sample included 16 child and adolescent boys with HF-ASD (age between 7-17 years). Cognitive assessment included measures of general intelligence, visual memory, verbal memory, working memory and problem solving/flexibility tests. Vineland Adaptive Behavior Scales (VABS) was used to evaluate adaptive behavior. To establish the predictive capacity of the cognitive variables for adaptive functioning, linear regression models were fitted for each adaptive domain using a stepwise method. RESULTS: Verbal memory and IQ emerged as the main independent predictors for VABS adaptive scores. The 41% of the variance in Communication was predicted by IQ. The 35% of the variance in Daily Living Skills was predicted by verbal memory. Almost half of the variance in Socialization was predicted by both, verbal memory and IQ (49%). No other cognitive functions were associated with adaptive scores. CONCLUSIONS: The results highlight the strong impact of IQ and verbal memory on adaptive behavior in HF-ASD patients. These findings could contribute to identify potential targets of intervention

New Approach to Designing Functional Materials for Stealth Technology: Radar Experiment with Bilayer Absorbers and Optimization of the Reflection Loss

Microwave power absorption by a two-layer system deposited on a metallic surface is studied in the experimental setup emulating the response to a radar signal. Layers containing hexaferrite and iron powder in a dried paint of thickness under 1 mm are used. The data is analyzed within a theoretical model derived for a bilayer system from the transmission line theory. A good agreement between experimental and theoretical results is found. The advantage of using a bilayer system over a single-layer system is demonstrated. How the maximum microwave absorption (minimum reflection) can be achieved through the optimization of the filling factors and thicknesses of the two layers is shown