Modelamiento de presiones sobre la biodiversidad en la Guayana

Este artículo busca identificar los factores que han influido a que la transformación de ecosistemas y la deforestación avancen en 4 zonas del sector Guayanes de la Amazonía Colombiana (La Macarena, Nukak, Puinawai y Chiribiquete). Para la identificación de estos factores, se realizó un análisis en dos escalas: a nivel municipal y a nivel de píxel, los análisis con datos municipales sirvieron para dar un contexto de los aspectos sociales y demográficos para cada una de las zonas, adicionalmente se realizó un análisis de correlaciones. Los datos a nivel de píxel se utilizaron para la estimación de modelos de regresión logística para cada zona, de forma complementaria y para tener en cuenta la dinámica de cambio y los efectos de vecindad entre pixeles se realizó un ejercicio de simulación empleando el software DINAMICA (desarrollado por el centro de sensores remotos de la Universidad de Minas Gerais) para las dos zonas de mayor transformación. Los resultados del análisis de asociaciones, modelamiento y simulación evidencian que la facilidad de acceso terrestre (distancia a vías), el estado legal del territorio, la distancia a centros urbanos (distancia a cabeceras) son los factores relevantes que han impulsado la transformación de ecosistemas y la deforestación en el área de análisis.Ecosystem change and deforestation has advanced in four areas of the Guayanes region of the Colombian Amazon (La Macarena, Nukak, Puinawai and Chiribiquete). This paper aims to identify which factors have influenced these changes, by undertaking analyses on both municipal and pixel levels. The analyses of municipal data provide the social and demographic context for each area. In addition, a correlation analysis is carried out. Pixel level data is used to estimate logistic regression models for each area. Moreover, to take into account the dynamics of change and the effects of proximity between pixels, a simulation exercise is undertaken using DINAMICA software (developed at the Remote Sensor Centre of the Federal University of Minas Gerais) to analyse the two areas that underwent the most change. The results of the association, modelling and simulation analyses reveal that the following factors have driven ecosystem change and deforestation in the study area: ease of land access (distance from roads), the legal status of the territory and the distance from urban centres (the distance from administrative centres)

Systemic Th17 response in the presence of periodontal inflammation

The relationship between periodontitis and the pathogenesis of other inflammatory diseases, such as diabetes, rheumatoid arthritis and obesity has been an important topic of study in recent decades. The Th17 pathway plays a significant role in how local inflammation can influence systemic inflammation in the absence of systemic pathology. Objective: To determine Th17 biased-cells in systemically healthy patients in the presence of generalized chronic periodontitis. Methodology: A total of 28 patients were recruited without systemic inflammatory pathology, which was determined by clinical history, the Health Assessment Questionnaire (HAQ) and rheumatoid factor detection. Of these patients, 13 were diagnosed as healthy/gingivitis (H/G) and 15 as generalized chronic periodontitis (GCP). Th17 (CD4+CD161+) cells and Th17IL23R+ (CD4+CD161+IL-23R+) cells were quantified by flow cytometry, based on the total cells and on the lymphocyte region, termed the “enriched population” (50,000 events for each). Results: The percentages of Th17 cells of the H/G and periodontitis groups were similar on total cells and enriched population (19 vs 21.8; p=4.134 and 19.6 vs 21.8; p=0.55). However, Th17IL23R+ cells differ significantly between periodontally healthy patients and generalized chronic periodontitis patients in both total cell (0.22% vs 0.65%; p=0.0004) and enriched populations (0.2% vs 0.75%; p=0.0266). Conclusions: GCP patients (otherwise systemically healthy) were characterized by increased Th17-proinflammatory cell phenotype positive for the IL-23 receptor in peripheral blood. The proportion of Th17 cells that are negative for the IL-23 receptor in the peripheral blood of systemically healthy patients seemed to be unaffected by the presence or absence of chronic periodontitis

Factors affecting nectar sugar composition in chiropterophilic plants

AbstractMost pollinators prefer the sugars present in the nectar they consume, so it has been hypothesized that they have molded nectar trait evolution. However, nectar-feeding bats do not exhibit preferences for the sugars present in their diet. We analyzed the role that biochemical and ecological factors could play in shaping the nectar traits of chiropterophilic plants. We studied nectar traits and flower production in 49 plant species. We evaluated the relationship between nectar concentration and sugar composition using phylogenetically independent contrasts and if nectar traits were related to flower production using a Manova. We found that 42 species produced high hexoses nectars, and 7 species produced sucrose rich nectars. Phylogenetically independent contrasts showed that nectar concentration was negatively related to glucose content, positively related to fructose content, and was not related to sucrose content. A negative relationship was found from glucose and fructose contents to sucrose content, and glucose content was negatively related to fructose content. Finally, we did not found any relationship between nectar traits and the plants’ flowering strategies. We conclude that bat physiology and the relative low evolutionary time of the interaction between plants and bats may determine the lack of pattern in the nectar characteristics of chiropterophilic plants

Non-capsulated and capsulated Haemophilus influenzae in children with acute otitis media in Venezuela: a prospective epidemiological study

<p>Abstract</p> <p>Background</p> <p>Non-typeable <it>Haemophilus influenzae </it>(NTHi) and <it>Streptococcus pneumoniae </it>are major causes of bacterial acute otitis media (AOM). Data regarding AOM are limited in Latin America. This is the first active surveillance in a private setting in Venezuela to characterize the bacterial etiology of AOM in children < 5 years of age.</p> <p>Methods</p> <p>Between December 2008 and December 2009, 91 AOM episodes (including sporadic, recurrent and treatment failures) were studied in 87 children enrolled into a medical center in Caracas, Venezuela. Middle ear fluid samples were collected either by tympanocentesis or spontaneous otorrhea swab sampling method. Standard laboratory and microbiological techniques were used to identify bacteria and test for antimicrobial resistance. The results were interpreted according to Clinical Laboratory Standards Institute (CLSI) 2009 for non-meningitis isolates. All statistical analyses were performed using SAS 9.1 and Microsoft Excel (for graphical purposes).</p> <p>Results</p> <p>Overall, bacteria were cultured from 69.2% (63 of the 91 episodes); at least one pathogen (<it>S. pneumoniae, H. influenzae, S. pyogenes </it>or <it>M. catarrhalis</it>) was cultured from 65.9% (60/91) of episodes. <it>H. influenzae </it>(55.5%; 35/63 episodes) and <it>S. pneumoniae </it>(34.9%; 22/63 episodes) were the most frequently reported bacteria. Among <it>H. influenzae </it>isolates, 62.9% (22/35 episodes) were non-capsulated (NTHi) and 31.4% (11/35 episodes) were capsulated including types d, a, c and f, across all age groups. Low antibiotic resistance for <it>H. influenzae </it>was observed to amoxicillin/ampicillin (5.7%; 2/35 samples). NTHi was isolated in four of the six <it>H. influenzae </it>positive samples (66.7%) from recurrent episodes.</p> <p>Conclusions</p> <p>We found <it>H. influenzae </it>and <it>S. pneumoniae </it>to be the main pathogens causing AOM in Venezuela. Pneumococcal conjugate vaccines with efficacy against these bacterial pathogens may have the potential to maximize protection against AOM.</p

Integrative multi-omics analysis identifies a prognostic miRNA signature and a targetable miR-21-3p/TSC2/ mTOR axis in metastatic pheochromocytoma/ paraganglioma

Rationale: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that present variable outcomes. To date, no effective therapies or reliable prognostic markers are available for patients who develop metastatic PPGL (mPPGL). Our aim was to discover robust prognostic markers validated through in vitro models, and define specific therapeutic options according to tumor genomic features. Methods: We analyzed three PPGL miRNome datasets (n=443), validated candidate markers and assessed them in serum samples (n=36) to find a metastatic miRNA signature. An integrative study of miRNome, transcriptome and proteome was performed to find miRNA targets, which were further characterized in vitro. Results: A signature of six miRNAs (miR-21-3p, miR-183-5p, miR-182-5p, miR-96-5p, miR-551b-3p, and miR-202-5p) was associated with metastatic risk and time to progression. A higher expression of five of these miRNAs was also detected in PPGL patients’ liquid biopsies compared with controls. The combined expression of miR-21-3p/miR-183-5p showed the best power to predict metastasis (AUC=0.804, P=4.67·10-18), and was found associated in vitro with pro-metastatic features, such as neuroendocrine-mesenchymal transition phenotype, and increased cell migration rate. A pan-cancer multi-omic integrative study correlated miR-21-3p levels with TSC2 expression, mTOR pathway activation, and a predictive signature for mTOR inhibitor-sensitivity in PPGLs and other cancers. Likewise, we demonstrated in vitro a TSC2 repression and an enhanced rapamycin sensitivity upon miR-21-3p expression. Conclusions: Our findings support the assessment of miR-21-3p/miR-183-5p, in tumors and liquid biopsies, as biomarkers for risk stratification to improve the PPGL patients’ management. We propose miR-21-3p to select mPPGL patients who may benefit from mTOR inhibitors

WHO global research priorities for antimicrobial resistance in human health

The WHO research agenda for antimicrobial resistance (AMR) in human health has identified 40 research priorities to be addressed by the year 2030. These priorities focus on bacterial and fungal pathogens of crucial importance in addressing AMR, including drug-resistant pathogens causing tuberculosis. These research priorities encompass the entire people-centred journey, covering prevention, diagnosis, and treatment of antimicrobial-resistant infections, in addition to addressing the overarching knowledge gaps in AMR epidemiology, burden and drivers, policies and regulations, and awareness and education. The research priorities were identified through a multistage process, starting with a comprehensive scoping review of knowledge gaps, with expert inputs gathered through a survey and open call. The priority setting involved a rigorous modified Child Health and Nutrition Research Initiative approach, ensuring global representation and applicability of the findings. The ultimate goal of this research agenda is to encourage research and investment in the generation of evidence to better understand AMR dynamics and facilitate policy translation for reducing the burden and consequences of AMR

Parasitosis en la ciudad de Villavicencio

Como parte de la programación de adiestramiento de personal en Saneamiento ambiental, se realizó una encuesta parasitológica en ocho barrios de la ciudad de Villavicencio, como sistema de control, para evaluar más tarde los resultados de las modificaciones ambientales. La encuesta parasitológica señala la intensidad del parasitismo de estas comunidades para cada uno de los protozoarios y helmintos y la relación que tienen con respecto a las condiciones sanitarias de la vivienda

Parasitosis en la ciudad de villavicencio

Como parte de la programación de adiestramiento de personal en Saneamiento ambiental, se realizó una encuesta parasitológica en ocho barrios de la ciudad de Villavicencio, como sistema de control, para evaluar más tarde los resultados de las modificaciones ambientales. La encuesta parasitológica señala la intensidad del parasitismo de estas comunidades para cada uno de los protozoarios y helmintos y la relación que tienen con respecto a las condiciones sanitarias de la vivienda