Manejo de las hipertirotropinemias en una consulta de endocrinología pediátrica

La hipertirotropinemia se define como la presencia de una elevación de TSH junto a concentraciones de T4 libre normales, sin síntomas o signos de hipotiroidismo. La prevalencia en la edad pediátrica es claramente inferior a la de la edad adulta (aproximadamente un 2%), siendo escasos los estudios epidemiológicos en la población infantil. Su etiología puede ser debida a procesos intercurrentes, ingesta de alimentos o fármacos, sobrepeso u obesidad, retraso del crecimiento intrauterino, patología psiquiátrica aguda, insuficiencia renal o suprarrenal no tratadas o errores de laboratorio. La causa más frecuente de diagnóstico de patología a partir de una hipertirotropinemia es la tiroiditis autoinmune. Para realizar el diagnóstico se debe confirmar la elevación de TSH en dos analíticas separadas al menos 3-4 meses, determinándose también la T4 libre y los anticuerpos antitiroideos. El objetivo principal de este trabajo es analizar los factores de riesgo de aparición de patología tiroidea en pacientes remitidos a una consulta de Endocrinología Pediátrica por hallazgo de hipertirotropinemia y de sus características epidemiológicas, así como realizar un algoritmo de manejo de las hipertirotropinemias infantiles. Concluyendo, la hipertirotropinemia en la edad pediátrica es con frecuencia, un proceso benigno que parece tener bajo riesgo de evolución hacia hipotiroidismo. Los factores de riesgo encontrados en este trabajo de evolución a patología tiroidea han sido el sexo femenino, la presencia de bocio o de alteraciones ecográficas tiroideas, una TSH al diagnóstico mayor o igual a 8.75 μUI/mL, la presencia de anticuerpos antitiroideos positivos y la presencia de síntomas sugestivos de hipotiroidismo

Síndrome De McKittrick-Wheelock Mediante Cirugía Transanal Mínimamente invasiva, dispositivo SILS.

Presentamos el caso de un paciente varón de 80 años de edad sin alergias conocidas y con antecedentes de riesgo cardiovascular, diabetes mellitus tipo II, insuficiencia renal (IR) crónica estadio III, nefropatía diabética, colon irritable de dos años de evolución e ingreso previo por insufiencia renal aguda de causa prerrenal, hiperpotasemia y acidosis metabólica que precisó diálisis

Condensin I Reveals New Insights on Mouse Meiotic Chromosome Structure and Dynamics

Chromosome shaping and individualization are necessary requisites to warrant the correct segregation of genomes in either mitotic or meiotic cell divisions. These processes are mainly prompted in vertebrates by three multiprotein complexes termed cohesin and condensin I and II. In the present study we have analyzed by immunostaining the appearance and subcellular distribution of condensin I in mouse mitotic and meiotic chromosomes. Our results demonstrate that in either mitotically or meiotically dividing cells, condensin I is loaded onto chromosomes by prometaphase. Condensin I is detectable as a fuzzy axial structure running inside chromatids of condensed chromosomes. The distribution of condensin I along the chromosome length is not uniform, since it preferentially accumulates close to the chromosome ends. Interestingly, these round accumulations found at the condensin I axes termini colocalized with telomere complexes. Additionally, we present the relative distribution of the condensin I and cohesin complexes in metaphase I bivalents. All these new data have allowed us to propose a comprehensive model for meiotic chromosome structure

A perikinetochoric ring defined by MCAK and Aurora-B as a novel centromere domain

Mitotic Centromere-Associated Kinesin (MCAK) is a member of the kinesin-13 subfamily of kinesin-related proteins. In mitosis, this microtubule-depolymerising kinesin seems to be implicated in chromosome segregation and in the correction of improper kinetochore-microtubule interactions, and its activity is regulated by the Aurora-B kinase. However, there are no published data on its behaviour and function during mammalian meiosis. We have analysed by immunofluorescence in squashed mouse spermatocytes, the distribution and possible function of MCAK, together with Aurora-B, during both meiotic divisions. Our results demonstrate that MCAK and Aurora-B colocalise at the inner domain of metaphase I centromeres. Thus, MCAK shows a “cone”-like three-dimensional distribution beneath and surrounding the closely associated sister kinetochores. During the second meiotic division, MCAK and Aurora-B also colocalise at the inner centromere domain as a band that joins sister kinetochores, but only during prometaphase II in unattached chromosomes. During chromosome congression to the metaphase II plate, MCAK relocalises and appears as a ring below each sister kinetochore. Aurora-B also relocalises to appear as a ring surrounding and beneath kinetochores but during late metaphase II. Our results demonstrate that the redistribution of MCAK at prometaphase II/metaphase II centromeres depends on tension across the centromere and/or on the interaction of microtubules with kinetochores. We propose that the perikinetochoric rings of MCAK and Aurora-B define a novel transient centromere domain at least in mouse chromosomes during meiosis. We discuss the possible functions of MCAK at the inner centromere domain and at the perikinetochoric ring during both meiotic divisions

Sex chromosomes, synapsis, and cohesins: a complex affair

The final publication is available at http://link.springer.co

Involvement of synaptonemal complex proteins in sex chromosome segregation during marsupial male meiosis

Marsupial sex chromosomes break the rule that recombination during first meiotic prophase is necessary to ensure reductional segregation during first meiotic division. It is widely accepted that in marsupials X and Y chromosomes do not share homologous regions, and during male first meiotic prophase the synaptonemal complex is absent between them. Although these sex chromosomes do not recombine, they segregate reductionally in anaphase I. We have investigated the nature of sex chromosome association in spermatocytes of the marsupial Thylamys elegans, in order to discern the mechanisms involved in ensuring their proper segregation. We focused on the localization of the axial/lateral element protein SCP3 and the cohesin subunit STAG3. Our results show that X and Y chromosomes never appear as univalents in metaphase I, but they remain associated until they orientate and segregate to opposite poles. However, they must not be tied by a chiasma since their separation precedes the release of the sister chromatid cohesion. Instead, we show they are associated by the dense plate, a SCP3-rich structure that is organized during the first meiotic prophase and that is still present at metaphase I. Surprisingly, the dense plate incorporates SCP1, the main protein of the central element of the synaptonemal complex, from diplotene until telophase I. Once sex chromosomes are under spindle tension, they move to opposite poles losing contact with the dense plate and undergoing early segregation. Thus, the segregation of the achiasmatic T. elegans sex chromosomes seems to be ensured by the presence in metaphase I of a synaptonemal complex-derived structure. This feature, unique among vertebrates, indicates that synaptonemal complex elements may play a role in chromosome segregation

Sequential Loading of Cohesin Subunits during the First Meiotic Prophase of Grasshoppers

A previous version of this article appeared as an Early Online Release on January 2, 2007 (doi:10.1371/journal.pgen.0030028.eor).The cohesin complexes play a key role in chromosome segregation during both mitosis and meiosis. They establish sister chromatid cohesion between duplicating DNA molecules during S-phase, but they also have an important role during postreplicative double-strand break repair in mitosis, as well as during recombination between homologous chromosomes in meiosis. An additional function in meiosis is related to the sister kinetochore cohesion, so they can be pulled by microtubules to the same pole at anaphase I. Data about the dynamics of cohesin subunits during meiosis are scarce; therefore, it is of great interest to characterize how the formation of the cohesin complexes is achieved in order to understand the roles of the different subunits within them. We have investigated the spatio-temporal distribution of three different cohesin subunits in prophase I grasshopper spermatocytes. We found that structural maintenance of chromosome protein 3 (SMC3) appears as early as preleptotene, and its localization resembles the location of the unsynapsed axial elements, whereas radiation-sensitive mutant 21 (RAD21) (sister chromatid cohesion protein 1, SCC1) and stromal antigen protein 1 (SA1) (sister chromatid cohesion protein 3, SCC3) are not visualized until zygotene, since they are located in the synapsed regions of the bivalents. During pachytene, the distribution of the three cohesin subunits is very similar and all appear along the trajectories of the lateral elements of the autosomal synaptonemal complexes. However, whereas SMC3 also appears over the single and unsynapsed X chromosome, RAD21 and SA1 do not. We conclude that the loading of SMC3 and the non-SMC subunits, RAD21 and SA1, occurs in different steps throughout prophase I grasshopper meiosis. These results strongly suggest the participation of SMC3 in the initial cohesin axis formation as early as preleptotene, thus contributing to sister chromatid cohesion, with a later association of both RAD21 and SA1 subunits at zygotene to reinforce and stabilize the bivalent structure. Therefore, we speculate that more than one cohesin complex participates in the sister chromatid cohesion at prophase I.This work was supported by grants BFU2005–05668-C03–01, BFU2006–06655, BFU2005–01266, BFU2005–02431, and BFU2006–04406 from Ministerio de Educación y Ciencia, España, and grants 1001160016 and 11/BCB/013 from Universidad Autónoma de Madrid and Comunidad de Madrid. The Department of Immunology and Oncology was founded and is supported by the Spanish Council for Scientific Research (CSIC).Peer reviewe

Sequential Loading of Cohesin Subunits during the First Meiotic Prophase of Grasshoppers

The cohesin complexes play a key role in chromosome segregation during both mitosis and meiosis. They establish sister chromatid cohesion between duplicating DNA molecules during S-phase, but they also have an important role during postreplicative double-strand break repair in mitosis, as well as during recombination between homologous chromosomes in meiosis. An additional function in meiosis is related to the sister kinetochore cohesion, so they can be pulled by microtubules to the same pole at anaphase I. Data about the dynamics of cohesin subunits during meiosis are scarce; therefore, it is of great interest to characterize how the formation of the cohesin complexes is achieved in order to understand the roles of the different subunits within them. We have investigated the spatio-temporal distribution of three different cohesin subunits in prophase I grasshopper spermatocytes. We found that structural maintenance of chromosome protein 3 (SMC3) appears as early as preleptotene, and its localization resembles the location of the unsynapsed axial elements, whereas radiation-sensitive mutant 21 (RAD21) (sister chromatid cohesion protein 1, SCC1) and stromal antigen protein 1 (SA1) (sister chromatid cohesion protein 3, SCC3) are not visualized until zygotene, since they are located in the synapsed regions of the bivalents. During pachytene, the distribution of the three cohesin subunits is very similar and all appear along the trajectories of the lateral elements of the autosomal synaptonemal complexes. However, whereas SMC3 also appears over the single and unsynapsed X chromosome, RAD21 and SA1 do not. We conclude that the loading of SMC3 and the non-SMC subunits, RAD21 and SA1, occurs in different steps throughout prophase I grasshopper meiosis. These results strongly suggest the participation of SMC3 in the initial cohesin axis formation as early as preleptotene, thus contributing to sister chromatid cohesion, with a later association of both RAD21 and SA1 subunits at zygotene to reinforce and stabilize the bivalent structure. Therefore, we speculate that more than one cohesin complex participates in the sister chromatid cohesion at prophase I

Hospitalización a domicilio para pacientes quirúrgicos ante una pandemia por SARS-CoV-2: nuestra experiencia

Introduction: The HaDQ is an alternative to conventional hospitalization for clinically stable surgical patients who require complex nursing procedures due to intensity, frequency or characteristics, and control by a surgical specialist at home. Method: Cross-sectional, descriptive and retrospective study of the HADQ activity of our hospital during the first six months of 2020, to analyze the impact of the SARSCov2 pandemic in the unit. Three periods are distinguished: pre-pandemic (Jan-Feb), lockdown (Mar-Apr), post-lockdown (May-Jun). Two groups are differentiated: A (conventional HaD) and B (COVID19 preoperative screening). Various variables were collected: month, type, stay (HaD and hospital), procedures, readmissions, address, type of visits, covid+. A quantitative and qualitative descriptive statistical analysis of the results obtained was carried out. Results: 345 patients were admitted, 225 in group A (phase Pre (34%), Phase C (40%), and phase Post (25%)), and 120 in group B (Phase C (75%), phase Post (25%)). %)). The confinement (phase C) was the most active period of the HADQ, both due to the number of admissions (53%), and the complexity of group A, which required more procedures (71%) and more home visits (52%). There was also an increase in patients from the non-coverage area (42%), which involved medical and nursing visits at the Day Hospital (HD) (21%), and an increase in medical telephone consultations (36%). In the phase Post, the income of group A decreased by 37%. Conclusions: The HaDQ was reorganized due to the pandemic to care for more surgical patients, being an essential care resource, especially during confinement.Introducción: La hospitalización a domicilio para pacientes quirúrgicos (HaDQ) es una alternativa a la hospitalización convencional para pacientes quirúrgicos estables clínicamente, que precisen procedimientos de enfermería complejos por intensidad, frecuencia o características, y control por especialista quirúrgico en el domicilio. Método: Estudio transversal, descriptivo y retrospectivo de la actividad de la HADQ de nuestro hospital durante los primeros seis meses del 2020, para analizar la repercusión de la pandemia por SARS-CoV-2 en la unidad. Se distinguen tres periodos: prepandemia (enero-febreo), confinamiento (marzo-abril), posconfinamiento (mayo-junio). Se diferencian dos grupos: A (HaD convencional) y B (despistaje preoperatorio COVID19). Se recogieron diversas variables: mes, tipo, estancia (HaD y hospital), procedimientos, reingresos, domicilio, tipo visitas, COVID+. Se realizó un análisis estadístico descriptivo cuantitativo y cualitativo de los resultados obtenidos Resultados: Ingresaron 345 pacientes, 225 en el grupo A (fase Pre (34%), fase C (40%), y fase Pos (25%)), y 120 en el B (fase C (75%), fase Pos (25%)). El confinamiento (fase C) fue el período más activo de la HADQ, tanto por número de ingresos (53%), como por la complejidad del grupo A que requería más procedimientos (71%) y más visitas domiciliarias (52%). También aumentaron los pacientes de zona de no cobertura (42%), que implicaron visitas médicas y de enfermería en Hospital de Día (HD) (21%), y aumento de consultas telefónicas médicas (36%). En la fase Pos disminuyeron un 37% los ingresos del grupo A. Conclusiones: La HaDQ se reorganizó por la pandemia para atender a más pacientes quirúrgicos, siendo un recurso asistencial esencial, especialmente durante el confinamiento

Meiotic Pairing and Segregation of Achiasmate Sex Chromosomes in Eutherian Mammals: The Role of SYCP3 Protein

In most eutherian mammals, sex chromosomes synapse and recombine during male meiosis in a small region called pseudoautosomal region. However in some species sex chromosomes do not synapse, and how these chromosomes manage to ensure their proper segregation is under discussion. Here we present a study of the meiotic structure and behavior of sex chromosomes in one of these species, the Mongolian gerbil (Meriones unguiculatus). We have analyzed the location of synaptonemal complex (SC) proteins SYCP1 and SYCP3, as well as three proteins involved in the process of meiotic recombination (RAD51, MLH1, and γ-H2AX). Our results show that although X and Y chromosomes are associated at pachytene and form a sex body, their axial elements (AEs) do not contact, and they never assemble a SC central element. Furthermore, MLH1 is not detected on the AEs of the sex chromosomes, indicating the absence of reciprocal recombination. At diplotene the organization of sex chromosomes changes strikingly, their AEs associate end to end, and SYCP3 forms an intricate network that occupies the Y chromosome and the distal region of the X chromosome long arm. Both the association of sex chromosomes and the SYCP3 structure are maintained until metaphase I. In anaphase I sex chromosomes migrate to opposite poles, but SYCP3 filaments connecting both chromosomes are observed. Hence, one can assume that SYCP3 modifications detected from diplotene onwards are correlated with the maintenance of sex chromosome association. These results demonstrate that some components of the SC may participate in the segregation of achiasmate sex chromosomes in eutherian mammals