66 research outputs found
Evaluation of a Cryptococcal antigen Lateral Flow Assay in serum and cerebrospinal fluid for rapid diagnosis of cryptococcosis in Colombia
A Lateral Flow Assay to detect cryptococcal antigen (CrAgÂź LFA) in serum and cerebrospinal fluid for the rapid diagnosis of cryptococcosis was evaluated. A retrospective validation was performed. Sensitivity and specificity of the CrAgÂź LFA was 100%. High concordance (kappa index=1.0) between Cryptococcal Antigen Latex Agglutination System (CALASÂź) and CrAgÂź LFA was observed. CrAgÂź LFA showed higher analytical sensitivity for detecting low concentrations of cryptococcal antigen
The relationship between naturalized alien and native plant species: insights from oceanic islands of the south-east Pacific over the last 200 years
Aim: The relationship between native and naturalized alien species has been widely studied, particularly across large geographic scales. However, our knowledge of the spatial and temporal variations of their relationships is still limited, particularly for remote oceanic islands such as those of the south-east Pacific and across islands and archipelagos. In this study, we aim to assess the relationships between native and naturalized alien species by analyzing their current patterns of species-area relationships at different spatial scales, in addition to temporal variations in species richness, over the last 200 years. Area: One island (Rapa Nui) and two archipelagos (Juan Fernandez and Desventuradas Islands) comprising a total of 11 oceanic islands of the south-east Pacific (OISEP). Methods: We assembled the most comprehensive dataset of the vascular flora of the OISEP from currently available island flora checklists and updated with recent publications. Each plant species was classified as being native or naturalized alien. We examined temporal changes by estimating species richness, naturalization rates and naturalized-to-native ratios over time based on the first collection year of each naturalized alien species. Then, we determined the best shape of naturalized alien species richness accumulation over time by contrasting the fit of lineal, exponential, sigmoidal and Weibull regressions. Finally, we analyzed the relationships between native and naturalized species firstly at the inter-archipelagic scale by fitting island species-area relationship models and secondly at the island scale by performing ranged major axis regression analysis on residual values.Results: The OISEP flora dataset contained 674 species of which 282 were native and 392 were naturalized alien. Native island species-area relationships were similar to those of the naturalized alien species. Naturalized alien species richness increased notably through time with two clear peaks in 1950 and 2000. A Weibull regression and an exponential shape over time were the most appropriate fits for naturalized alien species richness accumulations at the inter-archipelagic scale, which further emphasizes the notable increase in naturalized alien species richness experienced in the timeframe examined here. Main conclusions: The relationship between naturalized alien species richness and native species richness was found to be independent of the geographic scale. The number of naturalized alien species clearly exceeded the number of native species on most islands but also for the whole OISEP. The accumulation of newly detected naturalized alien species does not show any sign of saturation and it is likely that new species will arrive in the future. Increased efforts on monitoring, prevention and biosecurity are needed to halt biological invasions on these unique island ecosystems
Los resultados adversos en el tratamiento de la tuberculosis resistente a mĂșltiples fĂĄrmacos sobrepasan la relaciĂłn fĂĄrmaco-microorganismo: resultados de un anĂĄlisis de correspondencia mĂșltiple
Introduction: Multidrug-resistant tuberculosis treatment is effective in 50% of patients due to several factors including antibiotic susceptibility of the microorganism, adverse treatment reactions, social factors, and associated comorbidities.Objectives: In this study, we describe the demographics, clinical characteristics, and factors associated with treatment outcomes in multidrug-resistant tuberculosis (MDR-TB) patients in MedellĂn, Colombia.Materials and methods: We conducted a retrospective analysis using data from patients diagnosed with MDR-TB attending Hospital La MarĂa in MedellĂn, Colombia, for treatment between 2010 and 2015. Patients were categorized as having successful (cured) or poor (failure, lost to follow-up, and death) treatment outcomes. Associations between demographic, clinical factors, laboratory results, treatment outcomes, and follow-up information were evaluated by univariate, multivariate, and multiple correspondence analyses.Results: Of the 128 patients with MDR-TB, 77 (60%) had successful outcomes. Of those with poor outcomes, 26 were lost to follow-up, 15 died, and 10 were treatment failures. Irregular treatment, the presence of comorbidities, and positive cultures after more than two months of treatment were associated with poor outcomes compared to successful ones (p<0.05 for all). The multiple correspondence analyses grouped patients who were lost to follow-up, had HIV, and drug addiction, as well as patients with treatment failure, irregular treatment, and chronic obstructive pulmonary disease.Conclusion: The recognition of factors affecting treatment is essential and was associated with treatment outcomes in this series of patients. Early identification of these factors should increase the rates of treatment success and contribute to MDR-TB control.IntroducciĂłn. El tratamiento de la tuberculosis multirresistente tiene una efectividad del 50 %, afectado por mĂșltiples factores como la sensibilidad del microorganismo, las reacciones secundarias, los factores sociales y las comorbilidades existentes.Objetivos. Describir la demografĂa, las caracterĂsticas clĂnicas y los factores pronĂłsticos asociados con los resultados del tratamiento en pacientes multirresistentes (TB-MDR) de MedellĂn, Colombia.MĂ©todos. Se hizo un anĂĄlisis retrospectivo de los datos de los pacientes con TB-MDR atendidos en el Hospital La MarĂa de MedellĂn, Colombia, que fueron tratados entre el 2010 y el 2015. Los pacientes se categorizaron con tratamiento exitoso (curados) o con tratamiento fallido (falla en el tratamiento, pĂ©rdida durante el seguimiento y muerte). Se determinĂł la asociaciĂłn entre las caracterĂsticas demogrĂĄficas y clĂnicas, los resultados de los exĂĄmenes de laboratorio, los desenlaces del tratamiento y la informaciĂłn del seguimiento, utilizando anĂĄlisis univariado, multivariado y de correspondencia mĂșltiple.Resultados. De 128 pacientes con TB-MDR, 77 (60 %) tuvieron un tratamiento exitoso. De los que tuvieron un tratamiento fallido, 26 pacientes se perdieron en el seguimiento, 15 murieron y 10 tuvieron falla en el tratamiento. El tratamiento irregular, las comorbilidades y los cultivos positivos mĂĄs allĂĄ de 2 meses de tratamiento se asociaron significativamente con los tratamientos fallidos (p<0,05). El anĂĄlisis de correspondencia mĂșltiple agrupĂł los pacientes con pĂ©rdida en el seguimiento, con HIV y tratamientos irregulares, y los pacientes con tratamientos irregulares y enfermedad pulmonar obstructiva crĂłnica con falla en el tratamiento y muerte.ConclusiĂłn. El reconocimiento temprano de los factores que afectan el desenlace del tratamiento de los pacientes con TB-MDR es esencial; la identificaciĂłn de dichos factores deberĂa incrementar el Ă©xito del tratamiento y contribuir al adecuado control de la TB-MDR
The fight against HIV-associated disseminated histoplasmosis in the Americas: Unfolding the different stories of four centers
Disseminated histoplasmosis is a major opportunistic infection of HIV-infected patients, killing thousands in Latin America each year. Yet, it remains a neglected disease that is often confused with tuberculosis, for lack of simple, affordable, and rapid diagnostic tools. There is great heterogeneity in the level of histoplasmosis awareness. The purpose of this report was to describe how the historical âawakeningâ to the threat of histoplasmosis came to be in four different centers that have actively described this disease: In Brazil, the Sao JosĂ© hospital in Fortaleza; in Colombia, the CorporaciĂłn para Investigaciones BiolĂłgicas inMedellin; in French Guiana, Cayenne Hospital; and in Guatemala, the Association de Salud Integral in Guatemala city. In Brazil and French Guiana, the search for leishmaniasis on the buffy coat or skin smears, respectively, led to the rapid realization that HIV patients were suffering from disseminated histoplasmosis. With time and progress in fungal culture, the magnitude of this problem turned it into a local priority. In Colombia and Guatemala, the story is different because for these mycology centers, it was no surprise to find histoplasmosis in HIV patients. In addition, collaborations with the CDC to evaluate antigen-detection tests resulted in researchers and clinicians developing the capacity to rapidly screen most patients and to demonstrate the very high burden of disease in these countries. While the lack of awareness is still a major problem, it is instructive to review the ways through which different centers became histoplasmosis-aware. Nevertheless, as new rapid diagnostic tools are becoming available, their implementation throughout Latin America should rapidly raise the level of awareness in order to reduce the burden of histoplasmosis deaths. © 2019 by the authors
EstandarizaciĂłn y validaciĂłn de un mĂ©todo de cromatografĂa lĂquida de alta eficiencia con detector de arreglo de diodos (HPLC-DAD) para la determinaciĂłn de niveles sanguĂneos de voriconazol
Introduction. A specialized service for the determination of antifungal blood levels is not available in Colombia, this service is essential for the proper follow-up of the antifungal therapy.Objective. The aim of this study was to standardize and validate a simple, sensitive, and specific protocol, based on High Performance Liquid Chromatography with Diode Array Detector (HPLC-DAD) for the quantification of voriconazole blood levels. Materials and methods. An Agilent HPLC-series-1200 equipment with UV-DAD detector was used. Analytical column-Eclipse XDB-C18 and pre- column Eclipse-XDB-C18, Agilent were also used. We used voriconazole as the primary control, and posaconazole as an internal control. The validation was done following the Food and Drug Administration (FDA) recommendations.Results. Best chromatographic conditions were: Column temperature of 25°C, UV variable wavelength detectors (VWD) detection at 256 nm for voriconazole, and 261 nm for Posaconazole (internal standard), 50 ÎŒL of injection volume, flow of volume 0,8mL/min, time of run of 10 min, mobile phase of acetonitrile:water (60:40). Finally, retention times were 3.13 and 5.16 min for the voriconazole and posaconazole, respectively. Range of quantification ranging from 0.125 ÎŒg/mL to 16 ÎŒg/mL. Conclusion. The selectivity and chromatographic purity of the obtained signal as well as the limits of detection and quantification standardized make this method an excellent tool for therapeutic monitoring of patients treated with voriconazole.IntroducciĂłn. Hasta la fecha en Colombia no contĂĄbamos con un servicio especializado de mediciĂłn de niveles sĂ©ricos de antifĂșngicos, procedimiento esencial para el adecuado manejo del tratamiento de las Infecciones FĂșngicas Invasoras (IFI). Objetivo. Estandarizar y validar un protocolo, simple, sensible y especĂfico, basado en CromatografĂa LĂquida de Alta Eficiencia con detector de arreglo de diodos (HPLC-DAD) para la cuantificaciĂłn de los niveles sĂ©ricos de voriconazol. Materiales y mĂ©todos. Se usĂł un equipo HPLC-Agilent, serie-1200, con detector UV-DAD columna analĂtica Eclipse-XDB-C18 y una pre-columna Eclipse-XDB-C18, ambas de la marca Agilent. Como control primario se utilizĂł voriconazol, y como control interno posaconazol. La validaciĂłn se hizo cumpliendo todos los criterios de aceptaciĂłn de los parĂĄmetros recomendados por la Food and Drug Administration (FDA). Resultados. Las mejores condiciones cromatogrĂĄficas se obtuvieron bajo los siguientes parĂĄmetros: temperatura de la columna de 25°C, detecciĂłn UV-VWD de 261 nm, volumen de inyecciĂłn de 50 ÎŒL, flujo de 0,8mL/min y un tiempo de corrido de 10 min. La fase mĂłvil usada fue acetonitrilo:agua (40:60), obteniendo finalmente unos tiempos de retenciĂłn de 3,13 y 5,16 min para el voriconazol y posaconazol respectivamente. El rango de cuantificaciĂłn fue desde 0,125 ÎŒg/mL hasta 16 ÎŒg/mL. Conclusiones. La selectividad y pureza de la señal cromatogrĂĄfica obtenida, asĂ como los lĂmites de detecciĂłn y cuantificaciĂłn estandarizados, hacen de esta metodologĂa una excelente herramienta para el seguimiento terapĂ©utico de los pacientes bajo tratamiento o profilaxis con voriconazol
Valuing natureâs contributions to people: the IPBES approach
Nature is perceived and valued in starkly different and often conflicting ways. This paper presents the rationale for the inclusive valuation of natureâs contributions to people (NCP) in decision making, as well as broad methodological steps for doing so. While developed within the context of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), this approach is more widely applicable to initiatives at the knowledgeâpolicy interface, which require a pluralistic approach to recognizing the diversity of values. We argue that transformative practices aiming at sustainable futures would benefit from embracing such diversity, which require recognizing and addressing power relationships across stakeholder groups that hold different values on human nature-relations and NCP
MAP1B Regulates Axonal Development by Modulating Rho-GTPase Rac1 Activity
This article shows a novel function for the MAP1B protein, related to the control of actin dynamics through interaction with Tiam1
State of the climate in 2018
In 2018, the dominant greenhouse gases released into Earthâs atmosphereâcarbon dioxide, methane, and nitrous oxideâcontinued their increase. The annual global average carbon dioxide concentration at Earthâs surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W mâ2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the yearâs end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981â2010 average, tying for third highest in the 118-year record, following 2016 and 2017. Juneâs Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°â0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000â18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decadeâ1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981â2010 average of 82. Eleven tropical cyclones reached SaffirâSimpson scale Category 5 intensity. North Atlantic Major Hurricane Michaelâs landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and 6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and RĂ©union Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at WaipÄ Gardens (Kauai) on 14â15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000â10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)
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