Quantum dynamics of the internal motion of biphenyl-based molecular junctions.

Single molecule junctions based on selected 4,4'-biphenyldithiol and 4,4'-dicyanobiphenyl derivatives bonded to gold electrodes are analyzed from a dynamical point of view. A fully quantum mechanical description of the internal rotation of the biphenyl moiety is carried out in terms of the nuclear wavepacket dynamics obtained by the solution of the time-dependent Schrödinger equation expressed in terms of the torsion angle between the phenyl rings. The required potential energy surfaces are computed using ab initio electronic structure methods. The nature and positions of the substituents on the phenyl rings determine the features of the potential energy surfaces. The effect of the initial conditions on the time propagation of the nuclear wavepackets and, as a consequence, on the evolution of the conformational distribution is also analyzed. In addition, the conductances at zero bias for the nanojunctions were computed for different conformations of the biphenyl fragments. Weighted by the wavepacket amplitudes, non-stationary conductance expectation values, and time-averaged torsion angles and conductances for the entire simulation are obtained. The consequences of using the time-averaged values to perform a linear regression between the conductance and the square of the cosine of the dihedral angle between the phenyl rings are analyzed and compared to the usual static approach based only on the information for equilibrium geometries. The study of the time dependent conformational variations of the biphenyl moieties in the nanojunctions allows for a better understanding of the quantum chemical phenomena that affect their transport properties.

Experiencias etnográficas y preocupaciones éticas en espacios de atención a la salud en México

en México, la integración de estudiantes-investigadores de antropología en salud a espacios de atención a la salud es muy reciente, por lo que resulta relevante conocer el proceso histórico y de la misma forma problematizar la interacción de estos con los prestadores de salud, así como con sus usuarios, a fin de discutir sobre la posibilidad de acceso para realizar indagaciones sobre las prácticas etnográficas, funciones y consecuencias de la presencia del investigador social en dicho espacio, desde la visión del estudiante de posgrado. Por lo anterior, se realizaron grupos focales con diez alumnos del área de antropología en salud, en los que se averiguó sobre la experiencia de sus investigaciones en los ámbitos anteriormente mencionados, llegando a la conclusión de que son de relevancia tres ejes: en primer lugar, la preparación de trabajo antropológico para y en la institución, seguido de la performatividad en la institución y, por último, los conflictos tanto administrativos, como operativos en la práctica etnográfica. Estos ejes se desarrollaron en este trabajo, y a través de ellos se plantearon y describieron las tensiones de la práctica profesional antropológica en instituciones de salud, con base en el hecho de que la etnografía en estos espacios confronta a dos disciplinas y lógicas institucionales diferentes. Finalmente, se realizó una reflexión desde las implicaciones éticas del desarrollo de la etnografía en estos espacios, al abrigo de los derechos humanos del usuario-paciente.

in Mexico, the integration of anthropology students-researchers in health care spaces is very recent, so it is relevant to know the historical process and in the same way to problematize the interaction of these with health care providers, as well as with their users, in order to discuss the possibility of access to conduct research on ethnographic practices, functions, and consequences of the presence of the social researcher in this space, from the vision of the graduate student. Therefore, focus groups were conducted with ten students in the area of anthropology in health, in which they in-quired about the experience of their research in the aforementioned areas, reaching the conclusion that three axes are relevant: first, the preparation of anthropological work for and in the institution, followed by the performativity in the institution and, finally, both administrative and operational conflicts in ethnographic practice.Axes that were developed in this work, through which the tensions of the anthropological professional practice in health institutions were raised and described based on the fact that ethnography in these spaces confronts two dif-ferent disciplines and institutional logics. Finally, a reflection was made on the ethical implications of the development of ethnography in these spaces, under the protection of the human rights of the user-patient.

no México, a integração de estudantes-pesquisadores de antropologia em saúde a espaços de atenção à saúde é muito recente, portanto resulta relevante conhecer o processo histórico e, da mesma forma, problematizar a interação deles com os prestadores de saúde, bem como com seus usuários, a fim de discutir sobre a possibilidade de acesso para realizar questionamentos sobre as práticas etnográficas, funções e consequências da presença do pesquisador social nesse espaço, a partir da visão do estudante de pós-graduação. Por isso, foram realizados grupos focais com dez alunos da área de antropologia em saúde, nos quais se averiguou sobre a experiência de suas pesquisas nos contextos anteriormente mencionados, chegando à conclusão de que três eixos são de relevância: em primeiro lugar, a preparação de trabalho antropológico para e na instituição, seguido da performatividade na instituição e, por último, os conflitos tanto administrativos quanto operacionais na prática etnográfica. Eixos que são desenvolvidos neste trabalho por meio dos quais são descritas as tensões da prática profissional antropológica em instituições de saúde com base no fato de a etnografia nesses espaços confrontar duas disciplinas e lógicas institucionais diferentes. Finalmente, foi realizada uma reflexão a partir das implicações éticas do desenvolvimento da etnografia nesses espaços, sob a proteção de direitos humanos do usuário-paciente.

Implementation of the interacting quantum atom energy decomposition using the CASPT2 method.

We present an implementation of the interacting quantum atom (IQA) energy decomposition scheme using the complete active space second-order perturbation theory (CASPT2). This combination yields a real-space interpretation tool with a proper account of the static and dynamic correlation that is particularly relevant for the description of processes in electronic excited states. The IQA/CASPT2 approach allows determination of the energy redistribution that takes place along a photophysical/photochemical deactivation path in terms of self- and interatomic contributions. The applicability of the method is illustrated by the description of representative processes spanning different bonding regimes: noble gas excimer and exciplex formation, the reaction of ozone with a chlorine atom, and the photodissociations of formaldehyde and cyclobutane. These examples show the versatility of using CASPT2 with the significant information provided by the IQA partition to describe chemical processes with a large multiconfigurational character.

Demographic variables associated with Covid-19 mortality.

Objectives: Covid-19 is a betacoronavirus that was initially transmitted to humans from an animal host. It enters the cell by binding its protein S with angiotensin-converted enzyme receptors. It is transmitted through direct contact and respiratory drops. The most affected population so far are older adults and people with chronic conditions. The objective of this research is to analyze the possible association between the structure of the population pyramid, the Gross Domestic Product, the type of isolation and screening used to detect Covid-19 in the countries with the highest and lowest mortality from this disease. Design and Methods: Some variables take part in the Covid- 19 mortality worldwide, such as the population structure, expressed in the population pyramid by country, the type of isolation adopted in each nation, the Gross Domestic Product (GDP) as well as the type of screening that is implemented in the different countries analyzed. Results: After analyzing the mean difference in the countries with a regressive and progressive population pyramid, an association was identified between the regressive population pyramid structure and the higher mortality rate (p<0.001). Conclusions: The countries with a progressive population pyramid are the most benefited by making their population more screened since the mortality rate decreases significantly compared to the countries with less attribution (p<0.036).

Reflejo trigémino cardíaco durante artroscopia de la articulación temporomandibular. Reporte de caso clínico / Trigeminocardiac reflex during arthroscopy of the temporomandibular joint. Clinical case report

Introducción: el reflejo trigémino cardíaco es una respuesta fisiológica parasimpática repentina, que ocasiona alteraciones cardiovasculares importantes durante la esti-mulación nerviosa en el trayecto del V par craneal, generalmente ocurre al realizar procedimientos quirúrgicos en cirugía oral y maxilofacial, neurocirugía, oftalmología y dermatología. La artroscopia de la articulación temporomandibular ha sido tradicional-mente considerada un procedimiento quirúrgico seguro, mínimamente invasivo, aun así, esta técnica no está exenta de complicaciones neuro y cardiovasculares. Objetivo:presentar un caso clínico que durante una artroscopia de la articulación temporo-mandibular en la fase de instrumentación del espacio articular superior, y que, bajo monitoreo continuo del anestesiólogo, reportó una bradicardia súbita. Conclusión: el diagnóstico intraoperatorio de reflejo trigémino cardíaco, fue descrito por el servicio de anestesiología recibiendo un tratamiento farmacológico temprano para esta condi-ción, lo que permitió obtener una adecuada evolución trans y postoperatoria

Background: Trigeminocardiac reflex is a sudden parasympathetic physiological response causing significant cardiovascular disturbances during nerve stimulation in the path of the fifth cranial nerve, generally during surgical procedures in oral and maxillofacial surgery, neurosurgery, ophthalmology, and dermatology. Arthroscopy of the temporomandibular joint has traditionally been considered a safe, minimally invasive surgical procedure, yet this technique is not without neuro and cardiovascular complications. Objective: To present a clinical case that during an arthroscopy of the temporomandibular joint in the instrumentation phase of the superior joint space, and under continuous monitoring by the anesthetist, report sudden bradycardia Conclusion: The intraoperative diagnosis of trigeminocardiac reflex was described by the anesthesiology service, receiving early pharmacological treatment of this condition, allowing an adequate trans and postoperative evolution.

Aproximación crítica a las políticas públicas en salud indígena, medicina tradicional e interculturalidad en México (1990-2016) / A critical examination of public policies related to indigenous health, traditional medicine, and interculturality in Mexico (1990-2016)

RESUMEN En los últimos 26 años, el gobierno mexicano desarrolló múltiples discursos y actividades sobre la denominada "salud intercultural" dirigidos, en especial, a los pueblos originarios de México (alrededor de 62, de acuerdo al criterio lingüístico), y construyó establecimientos de salud (puestos de salud, clínicas y hospitales) en los que propuso la aplicación de indicadores de pertinencia cultural en algunos estados como Puebla, Nayarit, Oaxaca, Chiapas, Querétaro y Jalisco (mínimos e insuficientes). Sin embargo, la salud indígena y la atención médica institucional siguen siendo precarias en cuanto a recursos humanos y materiales (personal sanitario, medicamentos, etc.), y discriminatorios con relación a la forma y al contenido de la atención que se brinda. En este artículo, detallamos algunas de las intervenciones del gobierno que suponen un avance institucional sobre el tema de interculturalidad en salud pero que, en el fondo, significan la continuidad de políticas arbitrarias y excluyentes.

ABSTRACT Over the last 26 years, the Mexican government has developed a number of activities and discourses around what has been called "intercultural health," directed especially at indigenous peoples in Mexico (some 62, according to linguistic criteria). In this way, the government has built health care institutions (rural centers, clinics, and hospitals) in states like Puebla, Nayarit, Oaxaca, Chiapas, Queretaro, and Jalisco, proposing the implementation of cultural pertinence indicators (which are minimal and inadequate). Nevertheless, the health conditions among indigenous populations and the quality of health care provided by public institutions continue to be precarious in terms of human and material resources (health personnel, drugs, etc.) and discriminatory with respect to the form and content of the provided services. This paper describes some of the governmental interventions that purport to be institutional improvements in the field of interculturality, but that actually represent the continuity of arbitrary and exclusive policies.

[A critical examination of public policies related to indigenous health, traditional medicine, and interculturality in Mexico (1990-2016)]. / Aproximación crítica a las políticas públicas en salud indígena, medicina tradicional e interculturalidad en México (1990-2016).

Over the last 26 years, the Mexican government has developed a number of activities and discourses around what has been called "intercultural health," directed especially at indigenous peoples in Mexico (some 62, according to linguistic criteria). In this way, the government has built health care institutions (rural centers, clinics, and hospitals) in states like Puebla, Nayarit, Oaxaca, Chiapas, Queretaro, and Jalisco, proposing the implementation of cultural pertinence indicators (which are minimal and inadequate). Nevertheless, the health conditions among indigenous populations and the quality of health care provided by public institutions continue to be precarious in terms of human and material resources (health personnel, drugs, etc.) and discriminatory with respect to the form and content of the provided services. This paper describes some of the governmental interventions that purport to be institutional improvements in the field of interculturality, but that actually represent the continuity of arbitrary and exclusive policies.

En los últimos 26 años, el gobierno mexicano desarrolló múltiples discursos y actividades sobre la denominada "salud intercultural" dirigidos, en especial, a los pueblos originarios de México (alrededor de 62, de acuerdo al criterio lingüístico), y construyó establecimientos de salud (puestos de salud, clínicas y hospitales) en los que propuso la aplicación de indicadores de pertinencia cultural en algunos estados como Puebla, Nayarit, Oaxaca, Chiapas, Querétaro y Jalisco (mínimos e insuficientes). Sin embargo, la salud indígena y la atención médica institucional siguen siendo precarias en cuanto a recursos humanos y materiales (personal sanitario, medicamentos, etc.), y discriminatorios con relación a la forma y al contenido de la atención que se brinda. En este artículo, detallamos algunas de las intervenciones del gobierno que suponen un avance institucional sobre el tema de interculturalidad en salud pero que, en el fondo, significan la continuidad de políticas arbitrarias y excluyentes.

Mecanismos de atención materno infantiles en dos contextos comparativos: México-Beijing / Maternal and child care mechanisms in two comparative contexts: Mexico-Beijing

Los mecanismos de atención realizados por la madre de familia forman parte dele proceso salud-enfermedad-atención para resolver problemas de salud presentados en el ámbito doméstico. Estos mecanismos emplean recursos de los diferentes sistemas de atención y varían de acuerdo al conocimiento de la enfermedad o padecimento, la consulta de los profesionales de salud, el acceso a recursos terapéuticos, la solución del problema o la reformulación de una nueva búsqueda de atención; todo esto integrado a un contexto cultural en donde interactúan la madre y el infante. A partir de la perspectiva antropológica, el presente estudio pretende analizar los componentes, las barreras y estrategias que fueron utilizados por cinco mujeres mexicanas migrantes, habitantes de Beijing, durante episodios de enfermedad infantil. La metodología empleada es de corte etnográfico a través de entrevistas estructuradas con las informantes y observación participante de los casos. La información se integra en cuatro categorías base asociadas a los mecanismos de atención: percepción materna del problema, accesibilidad a los recursos terapéuticos, su eficacia y el surgimiento de nuevos problemas. Los resultados describen las adaptaciones de los cuidados maternos en los mecanismos de atención durante padecimientos infantiles respiratorios a causa de las importantes barreras culturales presentadas dada la condición de migrantes.(AU)

Application of water quality index to evaluate groundwater quality (temporal and spatial variation) of an intensively exploited aquifer (Puebla valley, Mexico).

The spatial and temporal variation of water quality in the urban area of the Puebla Valley aquifer was evaluated using historical and present data obtained during this investigation. The current study assessed water quality based on the Water Quality Index developed by the Canadian Council of Ministers of the Environment (CCME-WQI), which provides a mathematical framework to evaluate the quality of water in combination with a set of conditions representing quality criteria, or limits. This index is flexible regarding the type and number of variables used by the evaluation given that the variables of interest are selected according to the characteristics and objectives of development, conservation and compliance with regulations. The CCME-WQI was calculated using several variables that assess the main use of the wells in the urban area that is public supply, according to criteria for human use and consumption established by Mexican law and international standards proposed by the World Health Organization. The assessment of the index shows a gradual deterioration in the quality of the aquifer over time, as the amount of wells with excellent quality have decreased and those with lower index values (poor quality) have increased throughout the urban area of the Puebla Valley aquifer. The parameters affecting groundwater quality are: total dissolved solids, sulfate, calcium, magnesium and total hardness.

Conocimientos y actitudes sobre estimulación temprana que tienen las madres de niños menores de 3 años del AA.HH. Los Rosales, San Juan de Miraflores - 2013 / Knowledge and attitudes about early stimulation that have the mothers of children under 3 years at the AA.HH. Los Rosales, San Juan de Miraflores - 2013

El presente estudio titulado "Conocimientos y actitudes sobre estimulación temprana que tienen las madres de niños menores de 3 años del AA.HH. "Los Rosales" San Juan de Miraflores - 2013” tuvo como objetivo determinar el nivel de conocimientos y actitudes sobre estimulación temprana que tienen las madres de niños menores de 3 años; siendo el propósito proporcionar información actualizada a la enfermera del Centro de Salud de la jurisdicción señalada, para que pueda implementar y/o establecer estrategias de intervención educativa más acordes a las necesidades individuales de las madres, de tal modo que las prepare para promover un normal desarrollo del niño, con prácticas efectivas de estimulación temprana en sus hogares que contribuyan a mejorar su calidad de vida y los prepare para el futuro. Esta investigación es de tipo cuantitativo, de nivel aplicativo y de método descriptivo de corte transversal. La población estuvo constituida por el total de madres con niños menores de 3 años que viven en el AA.HH. "Los Rosales" que corresponde a 50 madres. La técnica que se utilizó fue la encuesta y los instrumentos un cuestionario y una escala de Likert. Entre los principales resultados se encontró que de un total de 50 (100 por ciento) madres encuestadas, 39 (78 por ciento) tienen conocimiento bajo, 11 (22 por ciento) conocimiento medio y ninguna madre tiene conocimiento alto sobre estimulación temprana y respecto a actitudes 34 (68 por ciento) madres tienen actitud de indiferencia, 12 (24 por ciento) tienen una actitud de aceptación y 4 (8 por ciento) actitud de rechazo hacia la estimulación temprana, concluyendo que la mayoría de madres de niños menores de 3 años del AA.HH. "Los Rosales" tiene nivel bajo de conocimientos y actitud de indiferencia hacia la estimulación de los niños menores de 3 años.

This study entitled "Knowledge and attitudes about early stimulation with mothers of children under three years of AA.HH. “Los Rosales” San Juan de Miraflores - 2013” was to determine the level of knowledge and attitudes about early intervention with mothers of children under three years, is intended to provide updated information to the Health Center nurse's jurisdiction marked, so you can implement and/or develop educational intervention strategies more suited to the individual needs of mothers, so to prepare them to promote normal development of the child, early learning effective practices in their homes that contribute to improve their quality of life and prepare them for the future. Present study applied court transversal's, method descriptive. The population was constituted by all mothers with children under three years living in the AA.HH. "Los Rosales" corresponding to 50 mothers. The technique used was the survey, the instruments were a questionnaire and Likert scale. Among the main results, we find that out of 50 (100 per cent) mothers surveyed, 39 (78 per cent) have low knowledge, 11 (22 per cent) average knowledge and no mother has high knowledge about early stimulation, we found that attitudes regarding 34 (68 per cent) have an attitude of indifference, 12 (24 per cent) have an attitude of acceptance and 4 (8 per cent) negative attitude towards early stimulation. Finally, most mothers with children under three years living in the AA.HH. "Los Rosales" have low levels of knowledge and attitude of indifference to the stimulation of children under 3 years.

The acute response of the amygdalar TRH system to psychogenic stressors varies dependent on the paradigm and circadian condition.

Central administration of thyrotropin releasing hormone (TRH) reduces anxiety; amygdalar TRH expression is inversely proportional to the anxious behavior displayed in the elevated plus maze performed during the dark phase (EPM-D). To better understand the role of TRH in amygdala function, we evaluated the expression of TRH and the elements involved in its transmission in various stressful paradigms and how they associated with behavior. Wistar male rats were exposed to restraint (RES), EPM, or the open field test (OFT) and sacrificed 0-60 min afterwards; OFT, RES and EPM were performed during the light (L), and OFT during the dark phase. Restraint increased amygdalar levels of proCRH mRNA, without change in proTRH. All paradigms augmented corticosterone release, highest after OFT-L that also enhanced proCRH mRNA levels and decreased those of proTRH. OFT-D activated the TRH system. Levels of anxiety or locomotion were similar in animals tested in light or dark phases but their association with biochemical parameters differed. ProTRH expression and TRH release correlated positively with decreased anxiety in EPM-L and in OFT-D. No association with anxiety was detected in OFT-L where proCRH and proTRH expression correlated with locomotion supporting their involvement in arousal. The responses of TRH amygdalar systems appeared modulated by the extent of the stress response and by the circadian conditions. Increased proTRH expression of animals exposed to OFT-D was specifically observed in the cortical nucleus of the amygdala, area involved in processing fear stimuli; these TRH neurons may thus be part of a circuit with anxiolytic properties.

Prevalencia de hemoglobinopatía Sy perfil hematológico de individuos con malaria, Quibdó-Chocó, 2011 / Prevalence of hemoglobinopathy S and hematological profile of individuals with malaria, Quibdó-Chocó, 2011

La malaria constituye un problema de salud pública grave en los países del trópico y se cree que la hemoglobina S podría conferir protección contra la malaria grave. Objetivo: determinar la prevalencia de la hemoglobina S y el perfil hematológico en individuos con malaria, Quibdó-Chocó. Materiales y métodos: estudio descriptivo transversal en 177 sujetos con malaria; se empleó fuente primaria de información basada en una encuesta estructurada, la determinación del perfil hematológico, el diagnóstico de malaria, la prueba de ciclaje y la electroforesis dehemoglobina para identificar la hemoglobina S. Se calcularon las medidas de frecuencia y de resumen, los intervalos de confianza para proporciones y las pruebas de estadística paramétrica y no paramétrica. Resultados: el 59% de los casos correspondieron a malaria por Plasmodium falciparum, el 35% a Plasmodium vivax y el 6% a malaria mixta; la prevalencia de anemia fue del52% y de hemoglobinopatía S del 1,1%. Adicionalmente, se hallaron diferencias estadísticas en la prevalencia de anemia según la raza, el sexo y la edad, mientras que la frecuencia de anemiano presentó diferencias en el análisis de la densidad parasitaria y el tipo de infección malárica. Conclusión: la prevalencia de hemoglobinopatía S fue menor de la esperada para esta población; la prevalencia de anemia fue muy alta, lo que evidencia un elevado riesgo para la salud individual y la calidad de vida en general.

Malaria is a serious public health issue worldwide, especially in tropical countries;it is believed that hemoglobin S could protect against severe malaria. Objective: to determine theprevalence of hemoglobin S and assess the hematological profile of individuals with malaria, inQuibdó-Chocó. Materials and methods: cross-sectional study of 177 patients with malaria. Theprimary source of information was based on a structured survey, determination of the completeblood count, malaria diagnosis, a sickle cell test, and a hemoglobin electrophoresis to identifyhemoglobin S. The measures of frequency and summary, the confidence intervals for proportions and the tests of parametric and nonparametric statistics were calculated. Results: 59% of thecases were positive for Plasmodium falciparum malaria, 35% for Plasmodium vivax malaria and 6%for mixed malaria; the prevalence of anemia was 52% and the hemoglobinopathy S prevalencewas 1,1%. Furthermore, statistical differences in the prevalence of anemia were found accordingto race, sex, and age, whereas the frequency of anemia did not show differences in the analysisin relation to parasite density and the type of malaria infection. Conclusion: for this population theprevalence of hemoglobin S was lower than expected. However, the prevalence of anemia was very high, which shows a high risk for individual health and for quality of life in general.

La sangre de cerdo y de vaca como substitutos de la sangre de oveja o de caballo en medios de cultivo para campylobacters termotolerantes / The pig's blood and cow's blood substitutes sheep or horse culture media for thermotolerant campylobacters

En la ciudad de Iquitos (ubicada en la Amazonía peruana), la sangre de oveja y de caballo, uno de los suplementos recomendados para los medios de cultivo de campylobacters termotolerantes, no son tan disponibles como la sangre de cerdo y de vaca. Por ello, se estudió la capacidad de crecimiento de 60 cepas de Campylobacter termotolerantes (37 C. jejuni y 23 C. coli), usando sangre de vaca y de cerdo como potenciales substitutos de la sangre de oveja o de caballo. Estas cepas fueron aisladas de vacas, cerdos, pollos y patos (15 cepas de cada tipo de animal). Recuentos viables fueron realizados empleando el método de Miles y Misra, modificado. Las cepas de Campylobacter mostraron mayor crecimiento en presencia de sangre de cerdo o de oveja que con sangre de vaca; por lo que se sugiere el uso de sangre de cerdo como un suplemento de los medios de cultivo para Campylobacter, cuando no existe disponibilidad de sangre de oveja o de caballo.

In Iquitos (capital city of the Peruvian Amazon), sheep and horse blood, one of the recommended supplements for thermo tolerant campylobacters in growing environments, are difficult to obtain in comparison to pig and cow blood. Therefore, the growing capacity of 60 thermo tolerant Campylobacter strains (37 C. jejuni and 23 C. coli) using cow and pig blood as potential substitutes for sheep or horse blood, was studied. The strains were isolated from cows, pigs, chickens and ducks (15 strains of each animal). Accountable measure were used applying a modified Miles and Misra method. Compylobacter strains showed better growth in presence of pig or sheep blood in comparison with cow blood, so, we suggest the use of pig blood as a supplemet in the Campylobacter growing environment, when there is no availability of sheep or horse blood.

Paracrine signaling by glial cell-derived triiodothyronine activates neuronal gene expression in the rodent brain and human cells.

Hypothyroidism in humans is characterized by severe neurological consequences that are often irreversible, highlighting the critical role of thyroid hormone (TH) in the brain. Despite this, not much is known about the signaling pathways that control TH action in the brain. What is known is that the prohormone thyroxine (T4) is converted to the active hormone triiodothyronine (T3) by type 2 deiodinase (D2) and that this occurs in astrocytes, while TH receptors and type 3 deiodinase (D3), which inactivates T3, are found in adjacent neurons. Here, we modeled TH action in the brain using an in vitro coculture system of D2-expressing H4 human glioma cells and D3-expressing SK-N-AS human neuroblastoma cells. We found that glial cell D2 activity resulted in increased T3 production, which acted in a paracrine fashion to induce T3-responsive genes, including ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2), in the cocultured neurons. D3 activity in the neurons modulated these effects. Furthermore, this paracrine pathway was regulated by signals such as hypoxia, hedgehog signaling, and LPS-induced inflammation, as evidenced both in the in vitro coculture system and in in vivo rat models of brain ischemia and mouse models of inflammation. This study therefore presents what we believe to be the first direct evidence for a paracrine loop linking glial D2 activity to TH receptors in neurons, thereby identifying deiodinases as potential control points for the regulation of TH signaling in the brain during health and disease.

Type 2 iodothyronine deiodinase is highly expressed in germ cells of adult rat testis.

The testis has been classically described as a thyroid hormone unresponsive tissue, but recent studies indicate that these hormones might play an important role in developing testes. We have previously demonstrated that type 2 iodothyronine deiodinase (D2), a thyroid hormone-activating enzyme, is expressed in adult rodent testis and that its activity is induced by hypothyroidism. Nevertheless, the precise location of D2 in testis is not known. The aim of the present work was to determine the testicular cell types in which D2 is expressed using real-time PCR analysis, in situ hybridization histochemistry, and determination of D2 activity in cell fractions isolated from adult euthyroid and/or hypothyroid rat testis. The D2 mRNA levels in germ cells were higher than those from somatic cells (6.94 +/- 1.49 vs 2.32 +/- 0.79 arbitrary units (au); P = 0.017). Hypothyroidism increased D2 expression in germ cells (6.94 +/- 1.49 vs 8.78 +/- 5.43 au, P = 0.002) but did not change D2 transcripts in somatic cells significantly (2.12 +/- 0.79 vs 2.88 +/- 1.39 au, P = 0.50). In situ hybridization analysis showed that D2 mRNA is specifically present in elongated spermatids undergoing differentiation, whereas other germ cell types and Sertoli cells of seminiferous epithelium and the interstitial cells were virtually negative for this enzyme. The enzyme activity measured in germ and somatic isolated cell fractions (0.23 +/- 0.003 vs 0.02 +/- 0.013 fmol/min per mg protein respectively; P < 0.001) further confirmed the real-time PCR and in situ hybridization results. Hence, our findings demonstrated that D2 is predominantly expressed in elongated spermatids, suggesting that thyroid hormone might have a direct effect on spermatogenesis in the adult rats.

Hábitos de estudio y rendimiento académico de estudiantes del programa de profesionalización para técnicos de laboratorio de la Escuela de Tecnología Médica de la Facultad de Medicina Alberto Hurtado de la UPCH - 1998 / Study habits and the students' of the professionalization program academic yield for technicians of laboratory of the Escuela de Tecnología Médica de Facultad de Medicina Alberto Hurtado de la UPCH - 1998

El presente trabajo es un estudio descriptivo de corte transversal, realizado en los estudiantes del II Ciclo del Programa de Profesionalización para Técnicos de Laboratorio, de la Escuela de Tecnología Médica de la Facultad de Medicina Alberto Hurtado de la Universidad Peruana Cayetano Heredia, durante los meses de febrero y marzo de 1998. Tuvo como objetivo determinar la relación de hábitos de estudio y rendimiento académico, así como identificar si el interés en obtener el Título profesional y la actividad que realiza actualmente influyen en ambas variables. La recolección de datos se realizó en forma directa a través de dos instrumentos: el primero un cuestionario, para la obtención de datos personales; el segundo fue el inventario de Hábitos de estudio de Wilbert Wrenn. La población de estudio estuvo constituída por 257 estudiantes, los cuales fueron sometidos a criterios de inclusión y exclusión, obteniéndose de ellos una muestra de 139 estudiantes, cuyas edades fluctuaban entre 21 y 30 años, cabe resaltar que el número de mujeres supera al de varones en una proporción de 2 a 1, siendo la mayoría solteros, que estudian y trabajan actualmente. Para evaluar el rendimiento académico de los estudiantes se consideraron las notas del I ciclo, proporcionadas según Código del Alumno por la Secretaría Académica de la Escuela de Tecnología Médica, asegurándose así la confidencialidad de la información. Para el análisis estadístico se utilizó la prueba de chi cuadrado y el analísis de correlación de Pearson. Se encontró relación significativa entre hábitos de estudio y la nota final obtenida en cada uno de los cursos que conforman el promedio general. Así mismo los resultados obtenidos demuestran que, el interés por obtener el Título Profesional y la actividad que realizan actualmente se relaciona con el rendimiento académico, expresado como promedio general.