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.

A CRISPR-based lateral flow assay for plant genotyping and pathogen diagnostics.

Efficient pathogen diagnostics and genotyping methods enable effective disease management and breeding, improve crop productivity and ensure food security. However, current germplasm selection and pathogen detection techniques are laborious, time-consuming, expensive and not easy to mass-scale application in the field. Here, we optimized a field-deployable lateral flow assay, Bio-SCAN, as a highly sensitive tool to precisely identify elite germplasm and detect mutations, transgenes and phytopathogens in <1 h, starting from sample isolation to result output using lateral flow strips. As a proof of concept, we genotyped various wheat germplasms for the Lr34 and Lr67 alleles conferring broad-spectrum resistance to stripe rust, confirmed the presence of synthetically produced herbicide-resistant alleles in the rice genome and screened for the presence of transgenic elements in the genome of transgenic tobacco and rice plants with 100% specificity. We also successfully applied this new assay to the detection of phytopathogens, including viruses and bacterial pathogens in Nicotiana benthamiana, and two destructive fungal pathogens (Puccinia striiformis f. sp. tritici and Magnaporthe oryzae Triticum) in wheat. Our results illustrate the power of Bio-SCAN in crop breeding, genetic engineering and pathogen diagnostics to enhance food security. The high sensitivity, simplicity, versatility and in-field deployability make the Bio-SCAN as an attractive molecular diagnostic tool for diverse applications in agriculture.

HIV pre-exposure prophylaxis: assessment of acceptability among members of HIV serodiscordant/serostatus unknown couples.

BACKGROUND: Pre-exposure prophylaxis (PrEP) is effective in preventing HIV infection but is not yet widely available in resource-limited settings such as the Dominican Republic. We aimed to ascertain PrEP acceptability among people living with HIV in the Dominican Republic who are part of HIV serodiscordant partnerships and understand relationships between PrEP acceptability, HIV stigma, and intimate partner violence.Methods: A cross-sectional survey of people in care for HIV infection included acceptability-related questions and assessments of HIV stigma and intimate partner violence. We also explored the expected impact of PrEP on HIV disclosure rates and fertility intentions.Results: Of the 100 participants, 74% had been in their current partnership for >1 year; 38% had not disclosed to their partner; 29% reported condomless sex, and 23% reported sex with multiple partners. PrEP was highly acceptable with 84% of participants saying they were "very likely" to offer PrEP to their partner if available and 21% stating it would allow them to have more children. Of those who had not disclosed to their partner, 71% stated PrEP would help them do so. No relationship was found between PrEP acceptability, HIV stigma, and intimate partner violence. However, higher than expected rates of PrEP acceptability limited the power of these analyses.Conclusion: Pre-exposure prophylaxis was considered to be highly acceptable among people living with HIV in the Dominican Republic who are part of serodiscordant partnerships.

Bio-SCAN: A CRISPR/dCas9-Based Lateral Flow Assay for Rapid, Specific, and Sensitive Detection of SARS-CoV-2.

Simple, rapid, specific, and sensitive point-of-care detection methods are needed to contain the spread of SARS-CoV-2. CRISPR/Cas9-based lateral flow assays are emerging as a powerful alternative for COVID-19 diagnostics. Here, we developed Bio-SCAN (biotin-coupled specific CRISPR-based assay for nucleic acid detection) as an accurate pathogen detection platform that requires no sophisticated equipment or technical expertise. Bio-SCAN detects the SARS-CoV-2 genome in less than 1 h from sample collection to result. In the first step, the target nucleic acid sequence is isothermally amplified in 15 min via recombinase polymerase amplification before being precisely detected by biotin-labeled nuclease-dead SpCas9 (dCas9) on commercially available lateral flow strips. The resulting readout is visible to the naked eye. Compared to other CRISPR-Cas-based pathogen detection assays, Bio-SCAN requires no additional reporters, probes, enhancers, reagents, or sophisticated devices to interpret the results. Bio-SCAN is highly sensitive and successfully detected a clinically relevant level (4 copies/µL) of synthetic SARS-CoV-2 RNA genome. Similarly, Bio-SCAN showed 100% negative and 96% positive predictive agreement with RT-qPCR results when using clinical samples (86 nasopharyngeal swab samples). Furthermore, incorporating variant-specific sgRNAs in the detection reaction allowed Bio-SCAN to efficiently distinguish between the α, ß, and δ SARS-CoV-2 variants. Also, our results confirmed that the Bio-SCAN reagents have a long shelf life and can be assembled locally in nonlaboratory and limited-resource settings. Furthermore, the Bio-SCAN platform is compatible with the nucleic acid quick extraction protocol. Our results highlight the potential of Bio-SCAN as a promising point-of-care diagnostic platform that can facilitate low-cost mass screening for SARS-CoV-2.

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.

Managing the COVID-19 Pandemic Using Quality Improvement Principles: A New York City Pediatric Primary Care Experience.

In the setting of COVID-19, pediatric primary care in New York City faced multiple challenges, requiring large-scale practice reorganization. We used quality improvement principles to implement changes to care delivery rapidly. METHODS: Plan-do-study-act cycles were used, based on primary drivers of consolidation, reorganization of in-person and urgent care, telehealth expansion, patient outreach, mental health linkages, team communication, and safety. RESULTS: The average visit volume in pediatrics decreased from 662 per week to 370. Telehealth visits increased from 2 to 140 per week, whereas urgent in-person visits decreased from 350 to 8 per week. Adolescent visits decreased from 57 to 46 per week. Newborn Clinic visits increased from 37 per week to 54. Show rates increased significantly for pediatrics and adolescent (P = 0.003 and P = 0.038, respectively). CONCLUSIONS: Quality improvement methodology allowed for the consolidation of pediatric primary care practices during the first wave of the COVID-19 pandemic, ensuring care for patients while prioritizing safety, evidence-based practices, and available resources.

Design and implementation of an interactive, competency-based pilot pediatric telemedicine curriculum.

During the height of the COVID-19 pandemic, telemedicine visits surged to increase access and maintain continuity of care, while reducing transmission of disease. However, few curricula exist for training residents on how to care for patients via telemedicine, especially in pediatrics. We aimed to create and evaluate an interactive, competency-based pilot curriculum, to meet the urgent need to train residents in telemedicine. The curriculum was developed in 2020 and includes a didactic, cased-based discussions, and direct observation exercise. A model for precepting residents, adhering to new ACGME guidelines, was also created to further engage residents in telemedicine in the outpatient general pediatrics settings. To evaluate the curriculum, we assessed feasibility of a direct observation to provide feedback and we conducted pre and post surveys to assess for changes in residents' self-reported skills in performing telemedicine visits following implementation of the curriculum. 16 residents participated in the curriculum and 15 completed both the pre and post surveys (93%). Residents' self-reported efficacy in performing key components of telemedicine visits, including completion of telemedicine visit (p = 0.023), initiation of visits (p = 0.01), and documentation (p = 0.001) all improved significantly following implementation. Residents' perception of patient satisfaction with telemedicine and personal perception of ease of use of the telemedicine system increased, though neither were statistically significant. Uptake of the direct observation exercise was nearly universal, with all but one resident having a direct observation completed during their ambulatory month. This novel, interactive telemedicine pilot curriculum for residents addresses ACGME competencies and provides residents with a toolkit for engaging in telemedicine.

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).

Feynman Force Analysis of Chemical Processes in Terms of Topological Atomic Contributions.

The nature of the chemical bond is analyzed in terms of the atomic contributions to the Feynman forces using the Quantum Theory of Atoms in Molecules and the Interacting Quantum Atoms method. This approach provides a means for quantifying the relationship between the atomic electronic reorganization and the evolution of functional group interactions with the forces exerted on the nuclear framework during a chemical transformation. Using this decomposition scheme, the forces driving a chemical process are locally assigned to atoms or functional group contributions. The interatomic component of the forces can be ascribed as bonding forces; their exchange-correlation and electrostatic contributions reveal the nature of the interactions affecting the forces on the nuclei. This method is used to analyze the chemical interactions involved in the formation of ground and excited state diatomic molecules, the prototropism of formamide, the Diels-Alder cycloaddition of 1,3-butadiene with ethylene, and the Jahn-Teller effect of hydrated transition metal complexes.

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.

Variable processing and cross-presentation of HIV by dendritic cells and macrophages shapes CTL immunodominance and immune escape.

Dendritic cells (DCs) and macrophages (Møs) internalize and process exogenous HIV-derived antigens for cross-presentation by MHC-I to cytotoxic CD8⁺ T cells (CTL). However, how degradation patterns of HIV antigens in the cross-presentation pathways affect immunodominance and immune escape is poorly defined. Here, we studied the processing and cross-presentation of dominant and subdominant HIV-1 Gag-derived epitopes and HLA-restricted mutants by monocyte-derived DCs and Møs. The cross-presentation of HIV proteins by both DCs and Møs led to higher CTL responses specific for immunodominant epitopes. The low CTL responses to subdominant epitopes were increased by pretreatment of target cells with peptidase inhibitors, suggestive of higher intracellular degradation of the corresponding peptides. Using DC and Mø cell extracts as a source of cytosolic, endosomal or lysosomal proteases to degrade long HIV peptides, we identified by mass spectrometry cell-specific and compartment-specific degradation patterns, which favored the production of peptides containing immunodominant epitopes in all compartments. The intracellular stability of optimal HIV-1 epitopes prior to loading onto MHC was highly variable and sequence-dependent in all compartments, and followed CTL hierarchy with immunodominant epitopes presenting higher stability rates. Common HLA-associated mutations in a dominant epitope appearing during acute HIV infection modified the degradation patterns of long HIV peptides, reduced intracellular stability and epitope production in cross-presentation-competent cell compartments, showing that impaired epitope production in the cross-presentation pathway contributes to immune escape. These findings highlight the contribution of degradation patterns in the cross-presentation pathway to HIV immunodominance and provide the first demonstration of immune escape affecting epitope cross-presentation.

Different antigen-processing activities in dendritic cells, macrophages, and monocytes lead to uneven production of HIV epitopes and affect CTL recognition.

Dendritic cells (DCs), macrophages (MPs), and monocytes are permissive to HIV. Whether they similarly process and present HIV epitopes to HIV-specific CD8 T cells is unknown despite the critical role of peptide processing and presentation for recognition and clearance of infected cells. Cytosolic peptidases degrade endogenous proteins originating from self or pathogens, exogenous Ags preprocessed in endolysosomes, thus shaping the peptidome available for endoplasmic reticulum translocation, trimming, and MHC-I presentation. In this study, we compared the capacity of DCs, MPs, and monocyte cytosolic extracts to produce epitope precursors and epitopes. We showed differences in the proteolytic activities and expression levels of cytosolic proteases between monocyte-derived DCs and MPs and upon maturation with LPS, R848, and CL097, with mature MPs having the highest activities. Using cytosol as a source of proteases to degrade epitope-containing HIV peptides, we showed by mass spectrometry that the degradation patterns of long peptides and the kinetics and amount of antigenic peptides produced differed among DCs, MPs, and monocytes. Additionally, variable intracellular stability of HIV peptides prior to loading onto MHC may accentuate the differences in epitope availability for presentation by MHC-I between these subsets. Differences in peptide degradation led to 2- to 25-fold differences in the CTL responses elicited by the degradation peptides generated in DCs, MPs, and monocytes. Differences in Ag-processing activities between these subsets might lead to variations in the timing and efficiency of recognition of HIV-infected cells by CTLs and contribute to the unequal capacity of HIV-specific CTLs to control viral load.

Acute response of hypophysiotropic thyrotropin releasing hormone neurons and thyrotropin release to behavioral paradigms producing varying intensities of stress and physical activity.

The activity of the hypothalamus-pituitary-thyroid (HPT) axis is essential for energy homeostasis and is differentially modulated by physical and by psychological stress. Contradictory effects of stressful behavioral paradigms on TSH or thyroid hormone release are due to type, length and controllability of the stressor. We hypothesized that an additional determinant of the activity of the HPT axis is the energy demand due to physical activity. We thus evaluated the response of thyrotropin releasing hormone (TRH) neurons of the hypothalamic paraventricular nucleus (PVN) in Wistar male rats submitted to the elevated plus maze (EPM), the open field test (OFT), or restraint, and sacrificed within 1h after test completion; the response to OFT was compared during light (L) or dark (D) phases. Locomotion and anxiety behaviors were similar if animals were tested in L or D phases but their relation to the biochemical parameters differed. All paradigms increased serum corticosterone concentration; the levels of corticotropin releasing hormone receptor 1 and of glucocorticoid receptor (GR) mRNAs in the PVN were enhanced after restraint or OFT-L. Levels of proTRH mRNA increased in the PVN after exposure to EPM-L or OFT-D; serum levels of thyrotropin (TSH) and T(4) only after OFT-D. In contrast, restraint decreased TRH mRNA and serum TSH levels, while it increased TRH content in the mediobasal hypothalamus, implying reduced release. Expression of proTRH in the PVN varied proportionally to the degree of locomotion in OFT-D, while inversely to anxiety in the EPM-L, and to corticosterone in EPM-L and OFT-D. TRH mRNA levels were analyzed by in situ hybridization in the rostral, middle and caudal zones of the PVN in response to OFT-D; they increased in the middle PVN, where most TRH hypophysiotropic neurons reside; levels correlated positively with the velocity attained in the periphery of the OF and negatively, with anxiety. Variations of serum TSH levels correlated positively with locomotor activity in EPM-L and OFT-L or -D, while negatively to serum corticosterone levels in all paradigms. These results support the proposal that the hypophysiotropic PVN TRH neurons are activated by short term physical activity but that this response may be blunted by the inhibitory effect of stress.