Circulating Cell Free DNA and DNA Double-Strand Breakage in Alzheimer's Disease.

Alzheimer's disease (AD) is an age-related neurodegenerative disease that is characterized by memory loss and multiple cognitive impairments. AD is pathologically characterized by age-dependent accumulation of amyloid-ß protein and the phosphorylation of tau protein in the brains of patients with AD. Clinically, manifestations of AD include cognitive decline, dementia, alterations of high-order brain functions, and movement disorders. Double-stranded DNA breaks are a lethal form of DNA damage and are typically repaired via non-homologous end joining and homologous recombination. However, in AD brain, repair mechanism is disrupted, leading to a cascade of events, cognitive dysfunction, organ failure and reduced lifespan. Increased circulating cell-free DNA in the blood, cerebrospinal fluid, and urine in patients with AD, can be used as early detectable biomarkers for AD. The purpose of our article is to explore the potential uses of cell-free DNA and double-stranded DNA breaks as prognostic markers for AD and examine the recent research on the application of these markers in studies.

Comparison of DNA quantity and quality from fecal samples of mammals transported in ethanol or lysis buffer.

Using fecal microbial community profiles through sequencing approaches helps to unravel the intimate interplay between health, wellness, and diet in wild animals with their environment. Ensuring the proper preservation of fecal samples before processing is crucial to ensure reliable results. In this study, we evaluated the efficiency of two different preservation methods, considering the following criteria: DNA yield, quality and integrity, and microbial community structure based on Oxford Nanopore amplicon sequencing of the V3-V4 region of bacterial 16S rRNA and protozoa 18S rRNA genes. Eighteen matched pairs of mammalian fecal samples were collected and transported in 99.8% ethanol and lysis buffer; processing occurred between 55 and 461 days post-collection. Wilcoxon signed-rank tests were used to analyze quantitative measurements for paired samples. The A260/280 ratio, a measure of nucleic acid purity, was assessed descriptively for each media, and the Bartlett test evaluated dispersion of this ratio. A Fisher test was performed to compare the number of positive reactions for DNA extraction or PCR amplification of the 16S and 18S rRNA genes between both media. The concentration of total DNA and amplicons, as well as the number of reads obtained in sequencing, was significantly higher in the samples preserved with lysis buffer compared to ethanol, with magnitudes up to three times higher. Electrophoretic analysis of total DNA and amplicons further confirmed superior DNA integrity in lysis buffer preserved samples. The A260/280 values  obtained using the lysis buffer were of optimal purity (mean: 1.92) and with little dispersion (SD: 0.27); on the other hand, the ethanol samples also presented an excellent average quality (mean: 1.94), but they were dispersed (SD: 1.10). For molecular studies using mammalian feces, the lysis buffer reagent proved to be a reliable solution for their collection, conservation, and storage.

Genomic epidemiology of SARS-CoV-2 δ sublineages of the second wave of 2021 in Antioquia, Colombia / Epidemiología genómica de los sublinajes δ del virus SARS-CoV-2 de la segunda ola de COVID en Antioquia en el 2021.

Introduction. During the development of the SARS-CoV-2 pandemic in Antioquia, we experienced epidemiological peaks related to the α, É£, ß, ƛ, and δ variants. δ had the highest incidence and prevalence. This lineage is of concern due to its clinical manifestations and epidemiological characteristics. A total of 253 δ sublineages have been reported in the PANGOLIN database. The sublineage identification through genomic analysis has made it possible to trace their evolution and propagation. Objective. To characterize the genetic diversity of the different SARS-CoV-2 δ sublineages in Antioquia and to describe its prevalence. Materials and methods. We collected sociodemographic information from 2,675 samples, and obtained 1,115 genomes from the GISAID database between July 12th, 2021, and January 18th, 2022. From the analyzed genomes, 515 were selected because of their high coverage values (>90%) to perform phylogenetic analysis and to infer allele frequencies of mutations of interest. Results. We characterized 24 sublineages. The most prevalent was AY.25. Mutations of interest as L452R, P681R, and P681H were identified in this sublineage, comprising a frequency close to 0.99. Conclusions. This study identified that the AY.25 sublineage has a transmission advantage compared to the other δ sublineages. This attribute may be related to the presence of the L452R and P681R mutations associated in other studies with higher evasion of the immune system and less efficacy of drugs against SARS-CoV-2.

Introducción. Durante el desarrollo de la pandemia por SARS-CoV-2 en Antioquia se presentaron picos epidemiológicos relacionados con las variantes α, É£, ß, ƛ y δ, donde δ tuvo la mayor incidencia y prevalencia. Este linaje se considera una variante de preocupación dadas las manifestaciones clínicas que desencadena y sus características epidemiológicas. Se han informado 253 sublinajes δ en la base de datos PANGOLIN. La identificación de estos sublinajes mediante análisis genómico ha permitido rastrear su evolución y propagación. Objetivo. Caracterizar la diversidad genética de los diferentes sublinajes δ de SARSCoV-2 en Antioquia y determinar su prevalencia. Materiales y métodos. Se recopiló información sociodemográfica de 2.675 muestras y de 1.115 genomas del repositorio GISAID entre el 12 de julio de 2021 y el 18 de enero de 2022. Se seleccionaron 501 por su alto porcentaje de cobertura (>90 %) para realizar análisis filogenéticos e inferencia de frecuencias alélicas de mutaciones de interés. Resultados. Se caracterizaron 24 sublinajes donde el más prevalente fue AY.25. En este sublinaje se identificaron mutaciones de interés como L452R, P681R y P681H, que comprendían una frecuencia cercana a 0,99. Conclusiones. Este estudio permitió identificar que el sublinaje AY.25 tiene una ventaja de transmisión en comparación con los otros sublinajes δ. Esto puede estar relacionado con la presencia de las mutaciones L452R y P681R que en otros estudios se han visto asociadas con una mayor transmisibilidad, evasión del sistema inmunitario y menor eficacia de los medicamentos contra SARS-CoV-2.

First teratological case of the ocular pattern in the brown recluse spider genus Loxosceles Heineken & Lowe (Araneae, Sicariidae)

An ocular malformation is described for the first time in the genus Loxosceles, specifically in a female of Loxosceles surca Gertsch. The specimen was collected at 3,540 m.a.s.l. in Tarapaca Region, Chile. It is the first record for this family and the first case of teratology described for spiders in this country

Toxicological Characterization and Phospholipase D Activity of the Venom of the Spider Sicarius thomisoides.

Envenomation by Loxosceles spiders (Sicariidae family) has been thoroughly documented. However, little is known about the potential toxicity of members from the Sicarius genus. Only the venom of the Brazilian Sicarius ornatus spider has been toxicologically characterized. In Chile, the Sicarius thomisoides species is widely distributed in desert and semidesert environments, and it is not considered a dangerous spider for humans. This study aimed to characterize the potential toxicity of the Chilean S. thomisoides spider. To do so, specimens of S. thomisoides were captured in the Atacama Desert, the venom was extracted, and the protein concentration was determined. Additionally, the venoms were analyzed by electrophoresis and Western blotting using anti-recombinant L. laeta PLD1 serum. Phospholipase D enzymatic activity was assessed, and the hemolytic and cytotoxic effects were evaluated and compared with those of the L. laeta venom. The S. thomisoides venom was able to hydrolyze sphingomyelin as well as induce complement-dependent hemolysis and the loss of viability of skin fibroblasts with a dermonecrotic effect of the venom in rabbits. The venom of S. thomisoides showed intraspecific variations, with a similar protein pattern as that of L. laeta venom at 32-35 kDa, recognized by serum anti-LlPLD1. In this context, we can conclude that the venom of Sicarius thomisoides is similar to Loxosceles laeta in many aspects, and the dermonecrotic toxin present in their venom could cause severe harm to humans; thus, precautions are necessary to avoid exposure to their bite.

Daily thermal preference variation of the sand recluse spider Sicarius thomisoides (Araneae: Sicariidae).

Preferential temperature as a physiological feature is crucial for spiders, since it determines the selection of key habitats for their survival and reproduction. In this work, we study the daily and geographical variation of the preferential temperature of the spider Sicarius thomisoides subjected to different degrees of daily thermal oscillation in their habitats. Preferred temperatures differ between coastal and inland populations, but in both cases, there is a marked bimodality in the daily pattern of temperature preference, with two peaks per day that would be given by the changes in the hours of activity. These nocturnal spiders select higher temperatures in the evening (active period) and select lower temperatures during late morning (resting period). In laboratory, spiders have preferred temperatures that differ from those found in their habitats, so they must tolerate or compensate non-preferred temperatures by active thermoregulation in natural conditions.

Alluvial and gypsum karst geological transition favors spreading arsenic contamination in Matehuala, Mexico.

Arsenic transport in alluvial aquifers is usually constrained due to arsenic adsorption on iron oxides. In karstic aquifers, however, arsenic contamination may spread to further extensions mainly due to favorable hydrogeochemical conditions. In this study, we i) determined the spatial and temporal behavior of arsenic in water in an alluvial-karstic geological setting using field and literature data, ii) established whether a contaminated aquifer exists using field and literature piezometric data and geophysical analysis, iii) studied the local geology and associated arsenic contaminated water sources to specific aquifers, iv) revealed and modeled subsoil stratigraphy, and v) established the extent of arsenic exposure to the population. We found arsenic contamination (up to 91.51 mg/l) in surface and shallow groundwater (<15 m), where water flows from west to east through a shallow aquifer, paleochannels and a qanat within an alluvial-karst transition that favors the spreading and transport of arsenic along 8 km as well as the increase of arsenic exposure to the population (up to 3.6 mgAs/kghair). Results from this study contribute to understanding arsenic transport in semi-arid, mining-metallurgical, and urban environments, where the presence of karst could favor arsenic transport to remote places and exacerbate arsenic exposure and impact in the future.

The Influence of Solar Power Plants on Microclimatic Conditions and the Biotic Community in Chilean Desert Environments.

The renewable energy sector is growing at a rapid pace in northern Chile and the solar energy potential is one of the best worldwide. Therefore, many types of solar power plant facilities are being built to take advantage of this renewable energy resource. Solar energy is considered a clean source of energy, but there are potential environmental effects of solar technology, such as landscape fragmentation, extinction of local biota, microclimate changes, among others. To be able to minimize environmental impacts of solar power plants, it is important to know what kind of environmental conditions solar power plants create. This study provides information about abiotic and biotic conditions in the vicinity of photovoltaic solar power plants. Herein, the influence of these power plants as drivers of new microclimate conditions and arthropods diversity composition in the Atacama Desert was evaluated. Microclimatic conditions between panel mounts was found to be more extreme than in the surrounding desert yet beneath the panels temperature is lower and relative humidity higher than outside the panel area. Arthropod species composition was altered in fixed-mount panel installations. In contrast, solar tracking technology showed less influence on microclimate and species composition between Sun and Shade in the power plant. Shady conditions provided a refuge for arthropod species in both installation types. For example, Dipterans were more abundant in the shade whereas Solifugaes were seldom present in the shade. The presented findings have relevance for the sustainable planning and construction of solar power plants.

Evaluación de la herramienta SaTScan-Whonet para la detección precoz de brotes en infecciones bacterianas en una institución de tercer nivel de atención en Colombia / Evaluation of the SaTScan-Whonet tool for detecting outbreaks of bacterial infection in a tertiary healthcare institution in Colombia

Introducción: Las infecciones asociadas al cuidado de la salud representan un problema de salud pública y la transmisión horizontal supone un incremento en la morbimortalidad y los costos en la atención. La vigilancia activa es costosa y tiene alto riesgo de omitir la detección de brotes, mientras que la virtual (modelos matemáticos) permite la búsqueda sistemática de alertas de brotes. El objetivo de este estudio es evaluar la relación costo-efectividad del uso de la herramienta SaTScan-Whonet para la detección temprana de infecciones bacterianas, comparada con la vigilancia tradicional en una institución de alta complejidad de Colombia. Metodología: En un hospital universitario de alta complejidad se realizó un estudio retrospectivo, se identificó un brote bacteriano, se caracterizó clínicamente y por biología molecular. Se extrajeron las bases de datos de los sistemas automatizados de identificación y susceptibilidad microbiológica. Se realizaron análisis retrospectivos de SaTScan-Whonet, así como simulaciones diarias para el primer semestre de 2011 de manera prospectiva; también se identificó la fecha para la alerta de detección de brote, tanto en la vigilancia activa como en la virtual. Resultados: Se aislaron 4.584 microorganismos en los servicios de hospitalización tanto UCI como no UCI entre 2010 y 2011 (2.288 y 2.296 respectivamente). Por vigilancia activa se notificó un brote por Enterococcus faecium el 28 de marzo de 2011, que fue caracterizado por biología molecular con la presencia del gen Van A, que confiere resistencia a glucopéptidos. Se identificó de manera retrospectiva una alerta de brote para E. faecium entre el 14 de marzo y el 10 de mayo de 2011 con un intervalo de recurrencia de 609.384. En los análisis prospectivos simulados se identificó la primera alerta de brote de esta bacteria el 13 de abril de 2011 con un intervalo de recurrencia de 3.897 (p = 0,0002655). Conclusión: La utilización de dicha herramienta de manera prospectiva no fue superior a la vigilancia activa en cuanto a oportunidad en la detección. Los análisis retrospectivos tuvieron un alto rendimiento diagnóstico y podrían ser de utilidad para los sistemas de vigilancia y control de los entes reguladores.

Background: Healthcare-associated infections represent a public health problem, and horizontal transmission has led to an increase in morbidity and mortality as well as higher health care costs. Active surveillance is expensive and carries high risk of failing to detect outbreaks. Virtual surveillance (mathematical models) allows a systematic search for alerts to outbreaks. The objective of this study is to evaluate the cost-effectiveness of the SaTScan-Whonet tool for the early detection of outbreaks of bacterial infection, compared with traditional surveillance, in an institution of high complexity in Colombia. Methodology: In a university hospital of high complexity a retrospective study was performed, identifying a bacterial outbreak that was characterised clinically and by molecular biology techniques. Databases of automated systems of identification and microbiological susceptibility were extracted. Retrospective analyses were performed using SaTScan-Whonet and daily simulations during the first semester of 2011 in a prospective manner. The date for the alert to the detection of the outbreak for both active and virtual surveillance was also identified. Results: A total of 4,584 microorganisms were isolated both inside and outside the ICU bet-ween 2010 and 2011 (2,288 and 2,296, respectively). An outbreak of Enterococcus faecium was identified by active surveillance on March 28, 2011. Using molecular biology techniques, the outbreak was characterised, showing the presence of the vanA gene, which confers resistance to glycopeptides. An alert to an Enterococcus faecium outbreak was retrospectively identified between March 14 and May 10, 2011 with a recurrence interval of 609,384. The first alert to outbreak for this bacterium was identified in a prospective simulated analysis on April 13, 2011 with a recurrence interval of 3,897 (P=.0002655). Conclusion: The use of such a tool prospectively is not superior to active surveillance in regard to timely detection of bacterial outbreaks. Retrospective analyses have high diagnostic ability and could be very helpful in systems of surveillance and control of regulatory entities.

On chilean loxosceles (Araneae: Sicariidae): first description of the males of L. surca and L. coquimbo, new records of L. laeta and three remarkable new species from coastal deserts

Loxosceles Heineken & Lowe, 1832 spiders are infamous for their medical importance, but a taxonomic picture of the genus is still far from complete. In this study, the Chilean species of Loxosceles are described and mapped. The males of Loxosceles surca Gertsch, 1967 and L. coquimbo Gertsch, 1967 are described for the first time. Three new species with narrow distributions are described from central and northern Chile: Loxosceles diaguita sp. nov. from the Antofagasta Region, L. pallalla sp. nov. from Coquimbo and L. vallenar sp. nov. from Atacama. The first two species are remarkable in their morphology and do not fit into any of Gertsch’s species groups, suggesting that Chile still harbours an undiscovered phylogenetic diversity of the genus. New distribution records for Loxosceles laeta (Nicolet, 1849) are provided throughout Chile.

Using Global and Regional Species Distribution Models (SDM) to Infer the Invasive Stage of Latrodectus geometricus (Araneae: Theridiidae) in the Americas.

The brown widow spider, Latrodectus geometricus C. L. Koch, 1841, is a large spider of the family Theridiidae that belongs to a genus of medical interest owing to its potent neurotoxic venom, which causes severe pain in humans. In America, this alien spider has been found in virtually all countries in the region, mainly associated with human dwellings, but also in agricultural sectors. However, the invasive process and potential distribution of this invasive species across the American continent are completely unknown. In this context, using a combination of both global and regional niche models, it is possible to hypothesize the invasive phase of the species as well as the geographic space where these different phases occur. By comparing the global and regional niches of L. geometricus, we examined its invasive process and potential distribution across the American continent. This work is an innovative approach to understanding the invasion of the brown widow spider in this area and the ecological processes that underlie this invasion. In this context, the global and regional niche comparison constitutes an appropriate tool to account for the complexities of the invasive process, generating different hypotheses amenable to being tested in future studies.

La araña cangrejo gigante Heteropoda venatoria (Linnaeus, 1767) (Araneae: Sparassidae:Heteropodinae) en Chile

Se reporta por primera vez la presencia de la araña sinantropica Heteropoda venatoria (Linnaeus, 1767) paraChile. Los ejemplares fueron colectados en la ciudad de Iquique (20°13'10.78"S 70° 8'16.14"O), Región de Tarapacá, en un ambiente peridomiliciario. Se entrega una breve diagnosis para reconocer la especie y se discute respecto de las posibles vías de ingreso de este arácnido a Chile.

The presence of the synanthropic spider Heteropoda venatoria (Linnaeus, 1767) is recorded for the first time in Chile. Specimens were collected in Iquique city (20°13'10.78"S 70° 8'16.14"O), Tarapaca Region in a peridomestic environment. A brief diagnosis to recognize the species is delivered, and the possible ways of entry of this spider to Chile are discussed.

Biotic vs abiotic resistance: the case of urban spiders in Chile / Resistencia biótica vs resistencia abiótica: el caso de las arañas urbanas en Chile

Biological invasions are a major threat that affects negatively to biodiversity. Several hypotheses have been generated to explain why some species can naturalize in invaded areas. The hypothesis of biotic resistance is one of the best known, wich describe the ability of native communities to repel invaders; however it has been poorly studied in urban environments. Urban habitats are currently the most common ecosystem on the planet but have been poor studied. In this study, we do not found effect of communities on exotic species, but a negative and significant effect of climate was found. In conclusion, we can point out that is the abiotic resistance that is conditioning the naturalization of exotic species in urban environments, while the role of the biotic competition to repel the invasion is not important, rejecting the hypothesis of biotic resistance.

Body type and performance of elite cuban baseball players.

Introduction Appropriate stature and adequate somatotype are not the only attributes determining athletic performance, but they are important prerequisites for sports participation and success. However, there is scant literature on baseball players' kinanthropometric profiles and their association with performance. Given that Cuban baseball players have been among the world's top performers in recent decades, characterization of their morphological features linked to their performance may contribute to developing the evidence base in this area. Objective Describe the kinanthropometric profile related to sports performance of elite Cuban baseball players, classified by playing position. Methods Body composition, somatotype, proportionality, and performance were measured in 100 elite baseball players grouped by playing position and performance. Data from the 2002-2003 baseball season was gathered for players participating in the 43rd Cuban National Baseball Series (November 2003-May 2004). Slugging percentage (SLG) was used to measure performance of all players except pitchers, whose performance was measured as end-of-season win-loss record. Mean and standard deviation values were calculated for anthropometric and performance results, presented in tables for comparison. ANOVA and MANOVA analyses were applied to determine magnitudes of difference between the variables studied, as well as statistical significance of the differences established (p≤0.05 and p≤0.01). Results Performance and body type varied by playing position, and statistically significant differences were found in performance, body composition and somatotype variables between some positions. No significant differences in proportionality were found. First basemen and outfielders (center, left, and right fielders) were the best offensive players with the highest mean SLG, body weight and muscle mass values. Infielders (second basemen, shortstops, and third basemen) had the lowest mean body weight and adipose tissue mass values, as well as the lowest mean SLG. Catchers had similar mean weight, height, muscle mass, and adipose tissue mass values as first basemen, outfielders and infielders, but a low mean SLG similar to that of infielders. Pitchers were morphologically similar to players in all positions, but significant morphological differences were found among pitchers with different performance levels. Better-performing pitchers (≥.600 winning percentage (Wpct)) were significantly heavier and more mesomorphic than lower-performing pitchers (<.600 Wpct). All players were predominantly mesoendomorphic, but mean somatotype values varied between players in different positions, and between pitchers with different performance levels. Conclusions The kinanthropometric profile of high-performance baseball players described in this study generally coincides with the available literature. Further research on comparative samples is needed to validate the relationship between players' body type and performance. Nevertheless, the results of this study may be applied to criteria for selection and training of high-performance baseball players in Cuba. Key words: Body composition, somatotypes, anthropometry, sports, baseball, athletic performance, sports performance.

Enfermedad de Chagas en caninos, bovinos y equidos sinantrópicos de la Provincia del Limari, Chile / Chagas's disease in synantropic dogs, cattle and equines of the Limarí Province, Chile

En la Provincia del Limarí (Chile) existe una alta prevalencia de la enfermedad de Chagas en humanos. El objetivo de este estudio fue estimar el rol de caninos, bovinos y equinos sinantrópicos en la mantención de la infección en la Provincia. Docientos dos caninos, 202 bovinos, 101 equinos y 101 asnales, de diferentes edades y sexos se estudiaron mediante Hemoaglutinación indirecta para detectar la presencia de anticuerpos contra T. cruzi. Los animales fueron seleccionados al azar muestrados en relación directa al número de habitaciones de cada comuna. La prevalencia obtenida fue un 19,8% en caninos, 13,4% en bovinos, 15,8% en equinos y 17,8% en asnales, no observándose diferencias estadísticamente significativas en relación al sexo y edad de los animales