Assessing micro-macroparasite selective pressures and anthropogenic disturbance as drivers of immune gene diversity in a Neotropical wild cat.

Anthropogenic environmental change is reducing available habitat for wild species, providing novel selection pressures such as infectious diseases and causing species to interact in new ways. The potential for emerging infectious diseases and zoonoses at the interface between humans, domestic animals, and wild species is a key global concern. In vertebrates, diversity at the major histocompatibility complex MHC is critical to disease resilience, and its study in wild populations provides insights into eco-evolutionary dynamics that human activities alter. In natural populations, variation at MHC loci is partly maintained by balancing selection, driven by pathogenic selective pressures. We hypothesize that MHC genetic diversity differs between guigna populations inhabiting human-dominated landscapes (higher pathogen pressures) versus more natural habitats (lower pathogen pressures). We predict that MHC diversity in guignas would be highest in human-dominated landscapes compared with continuous forest habitats. We also expected to find higher MHC diversity in guignas infected with micro and macro parasites (higher parasite load) versus non infected guignas. We characterized for the first time the genetic diversity at three MHC class I and II exons in 128 wild guignas (Leopardus guigna) across their distribution range in Chile (32-46° S) and Argentina, representing landscapes with varying levels of human disturbance. We integrated MHC sequence diversity with multiple measures of anthropogenic disturbance and both micro and macro parasite infection data. We also assessed signatures of positive selection acting on MHC genes. We found significantly higher MHC class I diversity in guignas inhabiting landscapes where houses were present, and with lower percentage of vegetation cover, and also in animals with more severe cardiorespiratory helminth infection (richness and intensity) and micro-macroparasite co-infection. This comprehensive, landscape-level assessment further enhances our knowledge on the evolutionary dynamics and adaptive potential of vertebrates in the face of emerging infectious disease threats and increasing anthropogenic impacts.

Percepciones de riesgo respecto a la transmisión de VIH/sida en estudiantes de Universidad de Chile / Risk perception regarding HIV/AIDS transmission among students from the University of Chile

Fundamento: mantenerse informados es un mediador influyente en las conductas de riesgo, mas no determinante. Conocerlo no es suficiente para traducirlo en conductas preventivas ya que existen otros factores que podrían influir en el comportamiento sexual, como la percepción de riesgo. Objetivo: determinar la percepción sobre el riesgo de contraer y/o transmitir VIH/sida, en estudiantes de la Facultad de Medicina de la Universidad de Chile en el año 2020, desde una perspectiva de género. Métodos: se realizó una investigación cualitativa con enfoque fenomenológico, de tipo exploratorio descriptivo, a estudiantes de la Facultad de Medicina de la Universidad de Chile durante el año 2020. Se emplearon métodos teóricos: análisis-síntesis, inductivo-deductivo e histórico-lógico; y empíricos: entrevistas individuales semiestructuradas. Para obtener la información se aplicó el análisis narrativo de contenido. Resultados: los estudiantes demostraron tener conocimiento respecto a VIH/sida, sus mecanismos de transmisión, tratamiento y prevención. La mayoría dice usar métodos de barrera, aunque distinguen su uso entre relaciones casuales y estables. En las relaciones de pareja estable la percepción de riesgo parece ser menor, asociada el no uso de preservativo por confianza y placer, entre otros. Conclusiones: el manejo teórico del tema no logra ser suficiente para que la autopercepción de riesgo sea incrementada y se adopten conductas preventivas. Conocer los elementos que influyen en la percepción de riesgo es relevante para lograr programas de educación sexual efectivos, considerando factores socioculturales además de la entrega de información.

Background: being updated is an influencial mediator of risk behaviors, but it is not determinant. To know the risk is not enough to put in practice prevetive behaviors since there are others factors that could influence upon sexual behavior, as the risk perception. Objective: to determine the perception about the risk of getting and/or transmitting HIV / AIDS, among students from the University of Chile, Faculty of Medicine, 2020, and with a gender perspective. Methods: a qualitative research with a phenomenological approach of descriptive exploratory type, with students from the Faculty of Medicine of the University of Chile, was carried out in 2020. Theoretical methods were used: analysis-synthesis, inductive-deductive and historical-logical methods; and empirical ones: semi-structured individual interviews. To get the information, narrative content analysis was applied. Results: students showed their knowledge regarding HIV/AIDS, the mechanisms of transmission, treatment and prevention of it. Most of them refer using barrier methods, although they distinguish the use of it depending on what if it is a casual or stable relationship. In case of stable relationships, the perception of risk seems to be lower, associated with the non-use of condoms for trust and pleasure, among others. Conclusions: the theoretical management of the topic is not sufficient for the increase of self-perception risk and preventive behaviors be adopted. Knowing the elements that influence on risk perception is relevant to achieve effective sexual education programs, taking into account sociocultural factors in addition to the communication of information.

The COVID-19 pandemic is intricately linked to biodiversity loss and ecosystem health.

The ongoing COVID-19 pandemic, caused by zoonotic SARS-CoV-2, has important links to biodiversity loss and ecosystem health. These links range from anthropogenic activities driving zoonotic disease emergence and extend to the pandemic affecting biodiversity conservation, environmental policy, ecosystem services, and multiple conservation facets. Crucially, such effects can exacerbate the initial drivers, resulting in feedback loops that are likely to promote future zoonotic disease outbreaks. We explore these feedback loops and relationships, highlighting known and potential zoonotic disease emergence drivers (eg, land-use change, intensive livestock production, wildlife trade, and climate change), and discuss direct and indirect effects of the ongoing pandemic on biodiversity loss and ecosystem health. We stress that responses to COVID-19 must include actions aimed at safeguarding biodiversity and ecosystems, in order to avoid future emergence of zoonoses and prevent their wide-ranging effects on human health, economies, and society. Such responses would benefit from adopting a One Health approach, enhancing cross-sector, transboundary communication, as well as from collaboration among multiple actors, promoting planetary and human health.

Rabdomiólisis asociada al tratamiento con telbivudina: a propósito de un caso / Rhabdomyolysis associated with telbivudin therapy: report of a case

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Biofilm Forming Lactobacillus: New Challenges for the Development of Probiotics.

Probiotics are live bacteria, generally administered in food, conferring beneficial effects to the host because they help to prevent or treat diseases, the majority of which are gastrointestinal. Numerous investigations have verified the beneficial effect of probiotic strains in biofilm form, including increased resistance to temperature, gastric pH and mechanical forces to that of their planktonic counterparts. In addition, the development of new encapsulation technologies, which have exploited the properties of biofilms in the creation of double coated capsules, has given origin to fourth generation probiotics. Up to now, reviews have focused on the detrimental effects of biofilms associated with pathogenic bacteria. Therefore, this work aims to amalgamate information describing the biofilms of Lactobacillus strains which are used as probiotics, particularly L. rhamnosus, L. plantarum, L. reuteri, and L. fermentum. Additionally, we have reviewed the development of probiotics using technology inspired by biofilms.

Biofilm and Helicobacter pylori: from environment to human host.

Helicobacter pylori (H. pylori) is a Gram negative pathogen that selectively colonizes the human gastric epithelium. Over 50% of the world population is infected with H. pylori reaching up to 90% of infected individuals in developing countries. Nonetheless the increased impact upon public health care, its reservoir and the transmission pathway of the species has not been clearly established yet. Molecular studies allowed the detection of H. pylori in various aquatic environments, even forming biofilm in tap water distribution systems in several countries, suggesting a role of water as a possible reservoir of the pathogen. The persistence of human infection with H. pylori and the resistance of clinical isolates to commonly used antibiotics in eradication therapy have been related to the genetic variability of the species and its ability to develop biofilm, demonstrated both in vivo and in vitro experiments. Thus, during the last years, experimental work with this pathogen has been focused in the search for biofilm inhibitors and biofilm destabilizing agents. However, only two anti- H. pylori biofilm disrupting agents have been successfully used: Curcumin - a natural dye - and N-acetyl cysteine - a mucolytic agent used in respiratory diseases. The main goal of this review was to discuss the evidences available in the literature supporting the ability of H. pylori to form biofilm upon various surfaces in aquatic environments, both in vivo and in vitro. The results published and our own observations suggest that the ability of H. pylori to form biofilm may be important for surviving under stress conditions or in the spread of the infection among humans, mainly through natural water sources and water distribution systems.

Variante protrombótica C677T del gen metilenotetrahidrofolato reductasa es un biomarcador molecular de fallas de implantación en mujeres chilenas sometidas a protocolos de reproducción asistida / Prothrombotic variant C677T at the methylenetetrahydrofolate reductase gene is a molecular biomarker of implantation failure in chilean women undergoing assisted reproductive protocols

Las fallas de implantación son consideradas una importante causa de infertilidad en mujeres sometidas a protocolos de Fecundación Asistida. Evidencia reciente sugiere que la presencia de variantes protrombóticas está asociada a diversos defectos obstétricos y falla reproductiva. Sin embargo, los resultados en diversas poblaciones son contradictorios. De acuerdo a esta evidencia, se evaluó la potencial asociación entre variantes protrombóticas y fallas de implantación en mujeres chilenas incluidas en protocolos de fecundación asistida. Un total de 180 mujeres, 80 pacientes sometidas a protocolos de reproducción asistida y 100 controles fueron incluidas en este estudio. La genotipificación molecular de variantes protrombóticas en genes candidatos fue realizada por PCR-RFLP. Observamos una paciente heterocigota para la variante F5 G1691A y ausencia total del polimorfismo F2 G20210A en pacientes y controles. La distribución genotípica y la distribución relativa de alelos del polimorfismo MTHFR C677T fueron significativamente diferentes entre pacientes y controles. Odds Ratio para fallas de implantación asociadas al genotipo homocigoto fue 2,78 (95 por ciento IC 1,147 - 6,755; p= 0,0199). En resumen, nuestros resultados sugieren que la variante MTHFR C677T constituye un biomarcador molecular de susceptibilidad a fallas de implantación población chilena.

Implantation failures are considered an important cause of infertility in women undergoing assisted reproductive protocols. Recent evidence suggests that the presence of prothrombotic variants is associated with obstetric defects and reproductive failure. However, results between several populations are contradictory. According this evidence, we evaluated the potential association between prothrombotic variants and implantation failure susceptibility in Chilean women undergoing Assisted Reproductive protocols. 180 women, 80 patients undergoing assisted reproductive protocols and 100 controls were included in this study. Molecular genotyping of prothrombotic variants in candidate genes was realized by PCR-RFLP. We observed one patient heterozygote for factor V G1691A variant, and total absence to prothrombin G20210A polymorphism in patients and controls. Genotype distribution and allelic frequencies of MTHFR C677T polymorphism were significantly different between patients and controls (p<0.05). Odss Ratio for implantation failure associated to homozygote genotype was 2.78 (95 percent IC 1.147 ¡ 6.755; p= 0.0199). In summary, our data suggest that the MTHFR C677T polymorphism constituted a molecular biomarker of implantation failure susceptibility in Chilean population.

Efecto de la medicación contra la parasitosis intestinal sobre el bruxismo en niños / Effect of the medication against intestinal parasitosis over bruxism in children

El propósito de este estudio fue relacionar a la parasitosis intestinal como un agente específico en el desarrollo del bruxismo. El estudio fue de tipo descriptivo y de corte transversal. El grupo de estudio estuvo conformado por 21 pre-escolares entre 4 y 6 años de edad matriculados durante el año 2001 en el Centro Educativo Inicial N° 301 del distrito de Buenos Aires, provincia de Morropón, departamento de Piura. Las variables que se evaluaron fueron el bruxismo y el efecto de la medicación antiparasitaria; y las covariables fueron género y edad. Los datos se analizaron mediante un análisis univariado. La distribución del grupo de estudio por género fue de 57%para el género masculino y 43% para el género femenino. Se encontró que de los 21 sujetos evaluados la medicación antiparasitaria tuvo efecto sobre la eliminación del bruxismo en siete sujetos correspondiendo en mayoría al género masculino. Y al evaluar el desgaste dental se encontró que éste comprendíaen su mayoría solo esmalte.

The purpose of the study was to relate the intestinal parasitosis as an specific agent in the development of bruxism.The study was descriptive and transversal. The study group included 21 children between 4 and 6 years of age matriculated during 2001 in the Preschool N° 301 of the district of Buenos Aires - Morropón, department of Piura. The variables evaluated were bruxism and the effect of the medication against parasitosis; and the covariables were gender and age. The distribution of the group by gender was 57% males and 43% females.We found that of the 21 children evaluated the medication against intestinal parasitosis had effect in 7 children eliminating the bruxism, who were most males. And the tooth wear evaluated were most in enamel.