Comparable diagnostic accuracy of SARS-CoV-2 Spike RBD and N-specific IgG tests to determine pre-vaccination nation-wide baseline seroprevalence in Mexico.

A major challenge for developing countries during the COVID-19 pandemic is affordable and adequate monitoring of disease progression and population exposure as the primary source relevant epidemiological indicators. Serology testing enables assessing population exposure and to guide vaccination strategies but requires rigorous accuracy validation before population-wide implementation. We adapted a two-step ELISA protocol as a single-step protocol for detection of IgG against the Receptor Binding Domain (RBD) of SARS-CoV-2 spike protein and compared its diagnostic accuracy with a commercial immunoassay anti-nucleoprotein IgG. Both methods yielded adequate and comparable diagnostic accuracy after 3 weeks post-symptom onset and were implemented in a nation-wide population based serological survey during August-November 2020. Anti-RBD National seroprevalence was 23.6%, 1.3% lower, but not significantly, than for anti-N. Double positive seroprevalence was 19.7%. Anti-N single-positive seroprevalence was 3.72% and anti-RBD single-positive seroprevalence was 1.98%. Discrepancies in the positivity to either single marker may be due to different kinetics of each antibody marker as well as the heterogeneity of the sampling time in regards to local epidemic waves. Baseline single positivity prevalence will be useful to assess the serological impact of vaccination and natural infection in further serosurveillance efforts.

Evaluation of respiratory anatomical-functional sequelae in patients who recovered from COVID-19.

INTRODUCTION: Coronavirus disease 19 (COVID-19) has been a global public health emergency, with 209.89 million cases of infection with SARS-CoV-2 recorded, resulting in 4,401,675 deaths. After recuperation, it is probable that COVID-19 patients have sequelae of the disease. This study aimed to evaluate the respiratory anatomical-functional sequelae in Mexican patients who recovered from COVID-19. METHODOLOGY: This study included twenty-four patients who recovered from COVID-19 and eight non-infected patients (controls). Participants were screened for SARS-CoV-2 and the presence of IgM/IgG antibodies. Pulmonary function and lung anatomical abnormalities were evaluated by spirometry and computerized tomography. RESULTS: A total of 45.8% of the patients had pulmonary function with obstructive patterns: 70.8% of recovered cases had COVID-19 Reporting and Data System (CO-RADS) 1, 20.8% CO-RADS 3 and 16.7% CO-RADS 4. A total of 35.3% of patients with CO-RADS 1 also showed bilateral nodal growth; 70.8% of patients tested positive for IgG and 8.4% for IgG/IgM, and 20.8% tested negative for both antibodies. CONCLUSIONS: There were respiratory anatomical and functional sequelae in Mexican patients who recovered from COVID-19, with a high occurrence of pulmonary obstructive patterns in the study population. These observations indicate the importance of the routine evaluation of sequelae in Mexican patients who recovered from COVID-19 and the need for strict follow-up to improve the quality of life of these patients.

Phylogenomics of Salvia L. subgenus Calosphace (Lamiaceae).

The evolutionary relationships of Salvia have been difficult to estimate. In this study, we used the Next Generation Sequencing method Hyb-Seq to evaluate relationships among 90 Lamiaceae samples, including representatives of Mentheae, Ocimeae, Salvia subgenera Audibertia, Leonia, Salvia, and 69 species of subgenus Calosphace, representing 32 of Epling's sections. A bait set was designed in MarkerMiner using available transcriptome data to enrich 119 variable nuclear loci. Nuclear and chloroplast loci were assembled with hybphylomaker (HPM), followed by coalescent approach analyses for nuclear data (ASTRAL, BEAST) and a concatenated Maximum Likelihood analysis of chloroplast loci. The HPM assembly had an average of 1,314,368 mapped reads for the sample and 527 putative exons. Phylogenetic inferences resolved strongly supported relationships for the deep-level nodes, agreeing with previous hypotheses which assumed that subgenus Audibertia is sister to subgenus Calosphace. Within subgenus Calosphace, we recovered eight monophyletic sections sensu Epling, Cardinalis, Hastatae, Incarnatae, and Uricae in all the analyses (nDNA and cpDNA), Biflorae, Lavanduloideae, and Sigmoideae in nuclear analyses (ASTRAL, BEAST) and Curtiflorae in ASTRAL trees. Network analysis supports deep node relationships, some of the main clades, and recovers reticulation within the core Calosphace. The chloroplast phylogeny resolved deep nodes and four monophyletic Calosphace sections. Placement of S. axillaris is distinct in nuclear evidence and chloroplast, as sister to the rest of the S. subg. Calosphace in chloroplast and a clade with "Hastatae clade" sister to the rest of the subgenus in nuclear evidence. We also tested the monophyly of S. hispanica, S. polystachia, S. purpurea, and S. tiliifolia, including two samples of each, and found that S. hispanica and S. purpurea are monophyletic. Our baits can be used in future studies of Lamiaceae phylogeny to estimate relationships between genera and among species. In this study, we presented a Hyb-Seq phylogeny for complex, recently diverged Salvia, which could be implemented in other Lamiaceae.

Genetic diversity of Fusarium pseudocircinatum in the central western region of Mexico: the case of big-leaf mahogany malformation disease.

Fusarium pseudocircinatum is the main causal agent of big-leaf mahogany malformation disease (BLMMD) of mahogany (Swietenia macrophylla) in Mexico. Although, BLMMD is the most important disease for this high-value timber species, there is a lack of information on the genetic variation present in geographically diverse isolates of F. pseudocircinatum. The objective of this study was to determine the genetic diversity of populations of F. pseudocircinatum causing BLMMD in the central western region of Mexico. A total of 611 big-leaf mahogany trees were inspected at eight sites in four states (Colima, Guerrero, Jalisco and Michoacán); of these, 42.7% showed malformation symptoms similar to those of BLMMD. Of 374 Fusarium isolates that were recovered, 277 were identified as F. pseudocircinatum, 56 were F. mexicanum, and 41 were Fusarium spp. An ISSR analysis of the F. pseudocircinatum isolates generated 51 bands of which 38 were polymorphic (76.8%) with a mean of 17 bands per primer. A total of 87 multilocus genotypes (MLGs) were identified. Nei's genetic diversity analysis showed that the isolates had a high genetic diversity average (0.147), with values ranging from 0.070 to 0.365 depending of the geographical location. An analysis of molecular variance revealed that the variation within the populations was low (27.36%), while the variation within MLGs was significant (72.64%), indicating genetic flow. Overall, the genetic variability of F. pseudocircinatum populations was high and the MLGs from Colima (Colima) and Gabriel Zamora (Michoacán) were placed centrally, which possibly is evidence of ancestry and indicates its dispersion routes in the central western region of Mexico.

Correlation between protein concentration and bacterial cell size can reveal mechanisms of gene expression.

Classically, gene expression is modeled as a chemical process with reaction rates dependent on the concentration of the reactants (typically, DNA loci, plasmids, RNA, enzymes, etc). Other variables like cell size are in general ignored. Size dynamics can become an important variable due to the low number of many of these reactants, imperfectly symmetric cell partitioning and molecule segregation. In this work we measure the correlation between size and protein concentration by observing the gene expression of the RpOD gene from a low-copy plasmid in Escherichia coli during balanced growth in different media. A positive correlation was found, and we used it to examine possible models of cell size dynamics and plasmid replication. We implemented a previously developed model describing the full gene expression process including transcription, translation, loci replication, cell division and molecule segregation. By comparing with the observed correlation, we determine that the transcription rate must be proportional to the size times the number of plasmids. We discuss how fluctuations in plasmid segregation, due to the low copy number, can impose limits in this correlation.

Cost-effectiveness Analysis of Viscosupplementation versus Conventional Supportive Therapy for Knee Osteoarthritis in Colombia.

BACKGROUND: Treatment goals for knee osteoarthritis (OA) include preservation of mobility, control of pain, and delaying total knee replacement (TKR). OBJECTIVE: To estimate the cost-effectiveness of viscosupplementation (hylan G-F 20) alone compared with conventional supportive therapy (CST) in the treatment of knee OA in Colombia. METHODS: Microsimulation in patients with knee OA, modeling of clinical outcomes (disease progression, symptom improvement, TKR), and estimation of associated costs were performed (drugs, diagnostic tests, procedures, and hospitalizations). The probabilities for disease progression and clinical events were correlated with patients' characteristics. Clinical outcome information was obtained from the literature. The costs were drawn from institutional databases from health maintenance organizations and the Colombian standard tariffs handbook (ISS 2001. Agreement No. 256 of 2001. Tariffs for the health promoter Social Security EPS-ISS. Social Insurance Board of Directors. December 19, 2001). Sensitivity analyses were performed for costs and transition probabilities. RESULTS: Monte-Carlo simulation for 1000 patients with knee OA showed that viscosupplementation with hylan G-F 20 delayed the occurrence of TKR by 3 years compared with CST. Western Ontario and McMaster Universities Arthritis Index scores indicate improvement in symptoms and function with hylan G-F 20. The incremental cost-effectiveness ratio for viscosupplementation is dominant, with reduction of US $576 in treatment cost in favor of hylan G-F 20, with more cost-effectiveness per quality-adjusted life-year during the first 10 years of treatment compared with CST. CONCLUSIONS: The results of mathematical simulation indicate that in comparison to conventional support therapies, viscosupplementation with hylan G-F 20 improved disease symptoms, joint function, and quality of life, reduced direct treatment costs, delayed TKR by 3 years, and was cost-effective in Colombia.

Um estudo sobre jovens e violência no espaço escolar / Un estudio sobre juventud y violencia en la escuela / A study on youth and violence at school

Este texto é resultado de um projeto de pesquisa sobre a temática do jovem, violência e escola. O objetivo desse projeto foi investigar a interpretação dos jovens sobre a violência na sociedade, na escola e na sua própria vida. O pressuposto é o de que conhecer a perspectiva de agressores e vítimas sobre as suas experiências de violência contribui para esclarecer os universos simbólicos e normativos que regulam as condutas violentas e as possíveis formas de reduzir sua incidência. Os dados foram coletados por meio de grupos focais. Um dos grupos foi constituído por alunos qualificados pela escola como protagonistas de situações de violência. O outro grupo foi constituído por jovens considerados bons alunos. A análise dos dados mostra uma diferença entre a lógica da violência à escola e da escola, e a violência na escola.

Este texto es el resultado de un proyecto de investigación sobre el tema de la violencia juvenil y la escuela. El objetivo de este proyecto fue investigar la interpretación de los jóvenes sobre la violencia en la sociedad, en la escuela y en su propia vida. El supuesto es que el conocimiento de la perspectiva de los agresores y de las víctimas acerca de sus experiencias de violencia ayuda a clarificar los universos normativos y simbólicas que regulan el comportamiento violento y las posibles maneras de reducir su incidencia. Los datos fueron recolectados a través de grupos de enfoque. Un grupo fue formado por la escuela calificada como protagonistas de los estudiantes situaciones de violencia. El otro grupo estaba formado por los jóvenes considerados buenos estudiantes. Análisis de los datos muestra una diferencia entre la lógica de la violencia hacia y desde la escuela y la violencia escolar.

This paper is the result of a research project on the subject of youth, violence and school. The purpose of this project was to investigate the understanding of the young people on the violence in society, at school and in their own lives. The assumption is that knowing the aggressors' and victims' perspective about their experiences of violence helps to clarify the symbolic and the normative universes that rule violent conducts and the possible ways to reduce the incidence of violence. Data were collected through focus groups. One of the groups was composed by students qualified by their school's board as protagonists in situations of violence. The other group was consisted by those considered as good students. Data analysis shows the differences between the logic of violence at school, the school violence and violence against the school.

Um estudo sobre jovens e violência no espaço escolar / Un estudio sobre juventud y violencia en la escuela / A study on youth and violence at school

Este texto é resultado de um projeto de pesquisa sobre a temática do jovem, violência e escola. O objetivo desse projeto foi investigar a interpretação dos jovens sobre a violência na sociedade, na escola e na sua própria vida. O pressuposto é o de que conhecer a perspectiva de agressores e vítimas sobre as suas experiências de violência contribui para esclarecer os universos simbólicos e normativos que regulam as condutas violentas e as possíveis formas de reduzir sua incidência. Os dados foram coletados por meio de grupos focais. Um dos grupos foi constituído por alunos qualificados pela escola como protagonistas de situações de violência. O outro grupo foi constituído por jovens considerados bons alunos. A análise dos dados mostra uma diferença entre a lógica da violência à escola e da escola, e a violência na escola.

Este texto es el resultado de un proyecto de investigación sobre el tema de la violencia juvenil y la escuela. El objetivo de este proyecto fue investigar la interpretación de los jóvenes sobre la violencia en la sociedad, en la escuela y en su propia vida. El supuesto es que el conocimiento de la perspectiva de los agresores y de las víctimas acerca de sus experiencias de violencia ayuda a clarificar los universos normativos y simbólicas que regulan el comportamiento violento y las posibles maneras de reducir su incidencia. Los datos fueron recolectados a través de grupos de enfoque. Un grupo fue formado por la escuela calificada como protagonistas de los estudiantes situaciones de violencia. El otro grupo estaba formado por los jóvenes considerados buenos estudiantes. Análisis de los datos muestra una diferencia entre la lógica de la violencia hacia y desde la escuela y la violencia escolar.

This paper is the result of a research project on the subject of youth, violence and school. The purpose of this project was to investigate the understanding of the young people on the violence in society, at school and in their own lives. The assumption is that knowing the aggressors' and victims' perspective about their experiences of violence helps to clarify the symbolic and the normative universes that rule violent conducts and the possible ways to reduce the incidence of violence. Data were collected through focus groups. One of the groups was composed by students qualified by their school's board as protagonists in situations of violence. The other group was consisted by those considered as good students. Data analysis shows the differences between the logic of violence at school, the school violence and violence against the school.

Cementado indirecto de brackets: sistema de doble cubeta termoformada / Indirect bracket bonding: doble transfer tray system

El cementado indirecto de la aparatología ortodóntica, conlleva una curva de aprendizaje para efectuar correctamente la técnica, siendo necesario tomar en cuenta varios factores para poder aplicar dicha técnica satisfactoriamente. Se puede dividir el cementado en tres etapas: clínica inicial, de laboratorio y la clínica final. En la etapa clínica inicial, es necesario regularizar la anatomía de las piezas dentarias, dejándolas con una antomía lo más próxima al ideal que debe tener al finalizar el tratamiento. Se deben realizar las impresiones de las arcadas para obtener modelos de trabajo (preferentemente de yeso densita). En la etapa de laboratorio se realizará la ubicación de los brackets y tubos molares en los modelos de yeso, verificando la posición de éstos desde diferentes ángulos para poder así evitar errores de posicionamiento vertical, horizontal, de angulación y excesivo grosor del adhesivo en los brackets. En este punto se confeccionan los medios de transferencia, en este caso doble cubeta de silicona. En la etapa final se procederá a cementar los brackets en boca, ubicándolos en la posición correcta a través de la doble cubeta de transferencia. Una vez cementado el aparato ortodóntico, se colocarán los arcos iniciales del tratamiento.(AU)

Cementado indirecto de brackets: sistema de doble cubeta termoformada / Indirect bracket bonding: doble transfer tray system

El cementado indirecto de la aparatología ortodóntica, conlleva una curva de aprendizaje para efectuar correctamente la técnica, siendo necesario tomar en cuenta varios factores para poder aplicar dicha técnica satisfactoriamente. Se puede dividir el cementado en tres etapas: clínica inicial, de laboratorio y la clínica final. En la etapa clínica inicial, es necesario regularizar la anatomía de las piezas dentarias, dejándolas con una antomía lo más próxima al ideal que debe tener al finalizar el tratamiento. Se deben realizar las impresiones de las arcadas para obtener modelos de trabajo (preferentemente de yeso densita). En la etapa de laboratorio se realizará la ubicación de los brackets y tubos molares en los modelos de yeso, verificando la posición de éstos desde diferentes ángulos para poder así evitar errores de posicionamiento vertical, horizontal, de angulación y excesivo grosor del adhesivo en los brackets. En este punto se confeccionan los medios de transferencia, en este caso doble cubeta de silicona. En la etapa final se procederá a cementar los brackets en boca, ubicándolos en la posición correcta a través de la doble cubeta de transferencia. Una vez cementado el aparato ortodóntico, se colocarán los arcos iniciales del tratamiento.

Estudio comparativo in vitro de la transportación del canal radicular, utilizando tres sistemas rotatorios de níquel-titanio: HERO Shaper, Protaper Universal y RaCe / Comparative in vitro study of root canal transportation, using three nickeltitanium rotary systems: HERO Shaper, ProTaper Universal, and RaCe

Introducción: el objetivo de este estudio in vitro fue comparar el grado de transportación de los canales radicularesutilizando tres técnicas de instrumentación rotatoria: HERO Shaper, ProTaper Universal y RaCe. Métodos: se seleccionó una muestrade treinta canales vestibulares de molares humanos superiores con ángulo de curvatura entre 25 y 35° con conductos finos y formación radicular completa que fue dividida en tres grupos arbitrarios de diez conductos cada uno, los que fueron preparados por los sistemas de instrumentación rotatoria HERO Shaper, ProTaper Universal y Race respectivamente, todos hasta el diámetro # 30 a la longitud de trabajo,utilizando el motor Endo-Mate TC NSK con control de torque y velocidad controlada. Se tomaron radiografías previas y posteriores a la instrumentación, las que fueron digitalizadas con escáner Agfa Duoscan T1200 a resolución de 2.400 dpi en escala de grises, luego mediante el método de morfometría lineal utilizando el sistema computacional para imágenes digitales NIH ImageJ se hicieron un totalde 12 mediciones por canal, 4 para el ancho total radicular, 4 para la pared cóncava y 4 para la pared convexa, todos a 1, 2, 4 y 6 mm, respectivamente, desde el vértice radiográfico del conducto. Los datos obtenidos fueron analizados mediante el análisis estadístico no paramétrico Mann Whitney Rank Sum y Kruskal Wallis para muestras independientes. Resultados: se observa transportación del canal radicular hacia la pared cóncava al utilizar el sistema ProTaper Universal, siendo estadísticamente significativa. (p = 0,01). Conclusión:el sistema rotatorio ProTaper Universal produce mayor número de transportaciones al compararlo con los sistemas RaCe y HERO Shaper.

Introduction: the objective of this in vitro study was to compare the degree of transportation of root canals using three rotary systems: HERO Shaper, ProTaper Universal, and Race. Methods: a sample of thirty buccal root canals of upper molars with curvatures between 25 and 35º was divided into three random groups of ten canals each, which were then instrumented by using the rotary systems HERO Shaper, ProTaper Universal, and Race respectively, all to a diameter # 30 to the working length, using the motor NSK Endo-Mate TCto control torque and speed. Radiographs were taken before and after mechanical instrumentation, and they were scanned with DuoScanAgfa T1200 scanner at a resolution of 2400 dpi gray scale. Afterwards, by the method of lineal morphometry and using the computer system for digital images NIH imageJ, a total of 12 measurements per root canal were done: 4 for the total root width, 4 for the concave wall and 4for the convex wall, all at 1, 2, 4 and 6 mm respectively from the radiographic apex of the canal. The data were analyzed by using the Mann Whitney Rank Sum and Kruskal Wallis nonparametric statistical analysis for independent samples. Results: Transportation was observed fromthe root canal to the concave wall when the ProTaper Universal system was used, being statistically significant (p = 0,01). Conclusion: the ProTaper Universal rotary system produced the greatest number of transportations when compared with HERO Shaper and RaCe systems.

Plasmodium falciparum genetic diversity maintained and amplified over 5 years of a low transmission endemic in the Peruvian Amazon.

Plasmodium falciparum entered into the Peruvian Amazon in 1994, sparking an epidemic between 1995 and 1998. Since 2000, there has been sustained low P. falciparum transmission. The Malaria Immunology and Genetics in the Amazon project has longitudinally followed members of the community of Zungarococha (N = 1,945, 4 villages) with active household and health center-based visits each year since 2003. We examined parasite population structure and traced the parasite genetic diversity temporally and spatially. We genotyped infections over 5 years (2003-2007) using 14 microsatellite (MS) markers scattered across ten different chromosomes. Despite low transmission, there was considerable genetic diversity, which we compared with other geographic regions. We detected 182 different haplotypes from 302 parasites in 217 infections. Structure v2.2 identified five clusters (subpopulations) of phylogenetically related clones. To consider genetic diversity on a more detailed level, we defined haplotype families (hapfams) by grouping haplotypes with three or less loci differences. We identified 34 different hapfams identified. The F(st) statistic and heterozygosity analysis showed the five clusters were maintained in each village throughout this time. A minimum spanning network (MSN), stratified by the year of detection, showed that haplotypes within hapfams had allele differences and haplotypes within a cluster definition were more separated in the later years (2006-2007). We modeled hapfam detection and loss, accounting for sample size and stochastic fluctuations in frequencies overtime. Principle component analysis of genetic variation revealed patterns of genetic structure with time rather than village. The population structure, genetic diversity, appearance/disappearance of the different haplotypes from 2003 to 2007 provides a genome-wide "real-time" perspective of P. falciparum parasites in a low transmission region.

Carcinoma escamocelular intracerebral originario de un quiste epidermoide: reporte de un caso / Sgnamous carcinoma arising in a intracerebral epidermoid cyst

La frecuencia del quiste epidermoide es baja, su transformación maligna lo es aún más. Se presenta el caso de un quiste epidermoide parcialmente resecado que ocho años mas tarde cursó como carcinoma escamocelular

El conflicto y la psicología social / Conflict and Social Psichology

El estudio del conflicto es un área en expansión de la Psicología Social en la actualidad. Por ello es importante en este momento realizar una revisión de los desarrollos más importantes que ha conocido la Psicología Social en su relación con el conflicto. En líneas generales, la transición más importante ha sido el paso del estudio del conflicto intrapsíquico -desde el psicoanálisis, las teorías conductistas y la teoría del campo- al conflicto social, ya sea interpersonal o, sobre todo, intergrupal...(AU)