Estudio de la citoqueratina- 18 como marcador no invasivo en pacientes con enfermedad de hígado graso no alcohólico

Introducción: La enfermedad por hígado graso no alcohólico es una de las principales causas de afección hepática. La citoqueratina 18 surge como marcador no invasivo para la valoración de fibrosis hepática. El objetivo del trabajo fue validar el uso de la citoqueratina 18 en sangre periférica en el diagnóstico y evolución de los pacientes con enfermedad por hígado graso no alcohólico. Metodología: Para validar la citoqueratina 18 en el diagnóstico se realizó un estudio de tipo caso-control. El grupo caso fueron los pacientes mayores de 18 años, de ambos sexos, con diagnóstico de enfermedad por hígado graso no alcohólico vinculado al síndrome metabólico, captados entre 2/2/2019 al 2/2/2020. El grupo control fueron personas donantes de sangre. Se parearon 1-1 por edad y sexo. Se cuantificó la citoqueratina 18 en sangre periférica de ambos grupos. Para validar la citoqueratina 18 en la evolución de los pacientes con enfermedad de hígado graso no alcohólico se realizó un trabajo prospectivo, longitudinal. El grupo de pacientes captados fueron seguidos durante un año bajo tratamiento estándar, finalizando el mismo se realizó la cuantificación de citoqueratina 18 en sangre periférica. Las variables continuas se expresan con la media y desvío estándar. Se analizó con test de t Student, error α < 5% Resultados: 13 pacientes integran el grupo caso (12 mujeres), de 53 ± 11 años, con IMC 35.01 ± 8.9 kg/m2. El valor de citoqueratina 18 pre-tratamiento fue de 1410 ± 120 UI, y el valor post-tratamiento fue de 117 ± 56, p < 0,005.El grupo control fueron 13 personas (12 mujeres), de 43,4 ± 8,1 años e IMC 28,10 ± 5,4 kg/m2 El valor de citoqueratina 18 fue de 193 ± 7.2 UI, p < 0.005 vs grupo caso pretratamiento. Conclusiones: La citoqueratina 18 es más elevada en los pacientes con enfermedad hígado graso no alcohólico, siendo estadísticamente significativa y disminuye con el tratamiento con significación estadística, pudiendo constituirse en un marcador útil en este grupo de pacientes.

Introduction: Nonalcoholic fatty liver disease is one of the main causes of liver disease. Cytokeratin 18 emerges as a non-invasive marker for the assessment of liver fibrosis. The objective of the work was to validate the use of cytokeratin 18 in peripheral blood in the diagnosis and evolution of patients with non-alcoholic fatty liver disease. Methodology: To validate cytokeratin 18 in the diagnosis, a case-control study was carried out. The case group was patients over 18 years of age, of both sexes, with a diagnosis of non-alcoholic fatty liver disease linked to metabolic syndrome, recruited between 2/2/2019 to 2/2/2020. The control group were blood donors. They were matched 1-1 for age and sex. Cytokeratin 18 was quantified in peripheral blood of both groups. To validate cytokeratin 18 in the evolution of patients with non-alcoholic fatty liver disease, a prospective, longitudinal study was carried out. The group of patients recruited were followed for one year under standard treatment, at the end of which cytokeratin 18 was quantified in peripheral blood. Continuous variables are expressed with the mean and standard deviation. It was analyzed with Student's t test, α error < 5%. Results: 13 patients make up the case group (12 women), 53 ± 11 years old, with BMI 35.01 ± 8.9 kg/m2. The pre-treatment cytokeratin 18 value was 1410 ± 120 IU, and the post-treatment value was 117 ± 56, p < 0.005. The control group was 13 people (12 women), 43.4 ± 8.1 years and BMI 28.10 ± 5.4 kg/m2 The cytokeratin 18 value was 193 ± 7.2 IU, p < 0.005 vs. pretreatment case group. Conclusions: Cytokeratin 18 is higher in patients with non-alcoholic fatty liver disease, being statistically significant, and decreases with treatment with statistical significance, and may become a useful marker in this group of patients.

Introdução: A doença hepática gordurosa não alcoólica é uma das principais causas de doença hepática. A citoqueratina 18 surge como um marcador não invasivo para avaliação de fibrose hepática. O objetivo do trabalho foi validar o uso da citoqueratina 18 no sangue periférico no diagnóstico e evolução de pacientes com doença hepática gordurosa não alcoólica. Metodologia: Para validar a citoqueratina 18 no diagnóstico, foi realizado um estudo caso-controle. O grupo caso foi composto por pacientes maiores de 18 anos, de ambos os sexos, com diagnóstico de doença hepática gordurosa não alcoólica ligada à síndrome metabólica, recrutados entre 02/02/2019 a 02/02/2020. O grupo controle eram doadores de sangue. Eles foram comparados em 1 a 1 por idade e sexo. A citoqueratina 18 foi quantificada no sangue periférico de ambos os grupos. Para validar a citoqueratina 18 na evolução de pacientes com doença hepática gordurosa não alcoólica, foi realizado um estudo prospectivo e longitudinal. O grupo de pacientes recrutados foi acompanhado durante um ano sob tratamento padrão, ao final do qual a citoqueratina 18 foi quantificada no sangue periférico. As variáveis ​​contínuas são expressas com média e desvio padrão. Foi analisado com teste t de Student, erro α < 5%. Resultados: Compõem o grupo caso 13 pacientes (12 mulheres), 53 ± 11 anos, com IMC 35,01 ± 8,9 kg/m2. O valor de citoqueratina 18 pré-tratamento foi de 1410 ± 120 UI e o valor pós-tratamento foi de 117 ± 56, p < 0,005. O grupo controle foi de 13 pessoas (12 mulheres), 43,4 ± 8,1 anos e IMC 28,10 ± 5,4 kg/m2 O valor da citoqueratina 18 foi de 193 ± 7,2 UI, p < 0,005 vs. grupo de casos pré-tratamento. Conclusões: A citoqueratina 18 é maior em pacientes com doença hepática gordurosa não alcoólica, sendo estatisticamente significativa, e diminui com o tratamento com significância estatística, podendo se tornar um marcador útil neste grupo de pacientes.

Quantifying the contribution of environmental variables to cyclists' exposure to PM2.5 using machine learning techniques.

Cyclists are particularly vulnerable to travel-related exposure to air pollution. Understanding the factors that increase exposure is crucial for promoting healthier urban environments. Machine learning models have successfully predicted air pollutant concentrations, but they tend to be less interpretable than classical statistical ones, such as linear models. This study aimed to develop a predictive model to assess cyclists' exposure to fine particulate matter (PM2.5) in urban environments. The model was generated using geo-temporally referenced data and machine learning techniques. We explored several models and found that the gradient boosting machine learning model best fitted the PM2.5 predictions, with a minimum root mean square error value of 5.62 µg m-3. The variables with greatest influence on cyclist exposure were the temporal ones (month, day of the week, and time of the day), followed by meteorological variables, such as temperature, relative humidity, wind speed, wind direction, and atmospheric pressure. Additionally, we considered relevant attributes, which are partially linked to spatial characteristics. These attributes encompass street typology, vegetation density, and the flow of vehicles on a particular street, which quantifies the number of vehicles passing a given point per minute. Mean PM2.5 concentration was lower in bicycle paths away from vehicular traffic than in bike lanes along streets. These outcomes underscore the need to thoughtfully design public transportation routes, including bus routes, concerning the network of bicycle pathways. Such strategic planning attempts to improve the air quality in urban landscapes.

Inverse priority effects: A role for historical contingency during species losses.

Communities worldwide are losing multiple species at an unprecedented rate, but how communities reassemble after these losses is often an open question. It is well established that the order and timing of species arrival during community assembly shapes forthcoming community composition and function. Yet, whether the order and timing of species losses can lead to divergent community trajectories remains largely unexplored. Here, we propose a novel framework that sets testable hypotheses on the effects of the order and timing of species losses-inverse priority effects-and suggests its integration into the study of community assembly. We propose that the order and timing of species losses within a community can generate alternative reassembly trajectories, and suggest mechanisms that may underlie these inverse priority effects. To formalize these concepts quantitatively, we used a three-species Lotka-Volterra competition model, enabling to investigate conditions in which the order of species losses can lead to divergent reassembly trajectories. The inverse priority effects framework proposed here promotes the systematic study of the dynamics of species losses from ecological communities, ultimately aimed to better understand community reassembly and guide management decisions in light of rapid global change.

Underexplored and growing economic costs of invasive alien trees.

The high ecological impacts of many invasive alien trees have been well documented. However, to date, we lacked synthesis of their economic impacts, hampering management actions. Here, we summarize the cost records of invasive trees to (I) identify invasive trees with cost information and their geographic locations, (II) investigate the types of costs recorded and sectors impacted by invasive trees and (III) analyze the relationships between categories of uses of invasive trees and the invasion costs attributed to these uses. We found reliable cost records only for 72 invasive trees, accumulating a reported total cost of $19.2 billion between 1960 and 2020. Agriculture was the sector with the highest cost records due to invasive trees. Most costs were incurred as resource damages and losses ($3.5 billion). Close attention to the ornamental sector is important for reducing the economic impact of invasive trees, since most invasive trees with cost records were introduced for that use. Despite massive reported costs of invasive trees, there remain large knowledge gaps on most invasive trees, sectors, and geographic scales, indicating that the real cost is severely underestimated. This highlights the need for further concerted and widely-distributed research efforts regarding the economic impact of invasive trees.

Identifying Priorities, Targets, and Actions for the Long-term Social and Ecological Management of Invasive Non-Native Species.

Formulating effective management plans for addressing the impacts of invasive non-native species (INNS) requires the definition of clear priorities and tangible targets, and the recognition of the plurality of societal values assigned to these species. These tasks require a multi-disciplinary approach and the involvement of stakeholders. Here, we describe procedures to integrate multiple sources of information to formulate management priorities, targets, and high-level actions for the management of INNS. We follow five good-practice criteria: justified, evidence-informed, actionable, quantifiable, and flexible. We used expert knowledge methods to compile 17 lists of ecological, social, and economic impacts of lodgepole pines (Pinus contorta) and American mink (Neovison vison) in Chile and Argentina, the privet (Ligustrum lucidum) in Argentina, the yellow-jacket wasp (Vespula germanica) in Chile, and grasses (Urochloa brizantha and Urochloa decumbens) in Brazil. INNS plants caused a greater number of impacts than INNS animals, although more socio-economic impacts were listed for INNS animals than for plants. These impacts were ranked according to their magnitude and level of confidence on the information used for the ranking to prioritise impacts and assign them one of four high-level actions-do nothing, monitor, research, and immediate active management. We showed that it is possible to formulate management priorities, targets, and high-level actions for a variety of INNS and with variable levels of available information. This is vital in a world where the problems caused by INNS continue to increase, and there is a parallel growth in the implementation of management plans to deal with them.

Invasive trees rely more on mycorrhizas, countering the ideal-weed hypothesis.

The ideal-weed hypothesis predicts that invasive plants should be less dependent on mutualisms. However, evidence in favor of or against this hypothesis comes mainly from observational studies. Here, we experimentally tested this hypothesis using a two-factor greenhouse experiment, comparing the seedling growth response of different Pinus species (varying in invasiveness) to ectomycorrhizal fungal inoculation. Most species showed no response until they were 6 mo old, at which point inoculation increased growth between 10 and 260% among the different species. This growth response was higher for species with lower seed mass, higher dispersal ability, higher Z score (a proxy for invasiveness) and higher number of naturalized regions, all of which correspond to higher invasiveness. Our results show that timing is a crucial factor when comparing mycorrhizal dependency of different species. Dependence on mutualistic microorganisms could be part of a strategy in which invasive species produce smaller seeds, in greater number, which can disperse further, but where seedlings are more reliant on mycorrhizas to improve access to water, nutrients, and protection from pathogens. Our results suggest that reliance on mutualisms may enhance, rather than limit, nonnative species in their ability to spread, establish, and colonize.

Sheep feeding preference as a tool to control pine invasion in Patagonia: influence of foliar toughness, terpenoids and resin content.

Herbivores modulate the structure and composition of plant communities, including plant invasions. This is conditioned by plant palatability which can be reduced by its chemical or physical traits. The effects that ungulates browsing has on pine invasions are variable and the empirical evidence on the causes of this variability is scarce. We experimentally explored how sheep browsing preference varies between seedlings of pine species with different invasiveness; Pinus contorta (high invasiveness), P. ponderosa (medium invasiveness), P. radiata (medium invasiveness) and P. jeffreyi (low invasiveness). Secondly, we quantified anti-herbivory chemical compounds and physical traits of these species and related them with sheep preference observed. The browsing incidence of P. contorta was 68%, P. ponderosa 58%, P. radiata 29%, and P. jeffreyi 84%. Among anti-herbivory traits analyzed, α-pinene concentration had a negative effect on the probability of a terminal bud being browsed and on browsing intensity. Meanwhile, foliar toughness was negatively related to browsing intensity and water concentration was positively related to browsing intensity. Also, the most invasive species, P. contorta, was highly damaged. Thus, sheep herbivory could be slowing pine invasion rate; suggesting that could be considered a tool to control early invasions, especially for this particular species.

Highly invasive tree species are more dependent on mutualisms.

Why some species become invasive while others do not remains an elusive question. It has been proposed that invasive species should depend less on mutualisms, because their spread would then be less constrained by the availability of mutualistic partners. We tested this idea with the genus Pinus, whose degree of invasiveness is known at the species level (being highly and negatively correlated with seed size), and which forms obligate mutualistic associations with ectomycorrhizal fungi (EMF). Mycorrhizal dependence is defined as the degree to which a plant needs the mycorrhizal fungi to show the maximum growth. In this regard, we use plant growth response to mycorrhizal fungi as a proxy for mycorrhizal dependence. We assessed the responsiveness of Pinus species to EMF using 1,206 contrasts published on 34 species, and matched these data with data on Pinus species invasiveness. Surprisingly, we found that species that are more invasive depend more on mutualisms (EMF). Seedling growth of species with smaller seeds benefited more from mutualisms, indicating a higher dependence. A higher reliance on EMF could be part of a strategy in which small-seeded species produce more seeds that can disperse further, and these species are likely to establish only if facilitated by mycorrhizal fungi. On the contrary, big-seeded species showed a lower dependence on EMF, which may be explained by their tolerance to stressful conditions during establishment. However, the limited dispersal of larger seeds may limit the spread of these species. We present strong evidence against a venerable belief in ecology that species that rely more on mutualisms are less prone to invade, and suggest that in certain circumstances greater reliance on mutualists can increase spread capacity.

Indoor persistent organic pollutants in agricultural areas from Argentina.

Persistent Organic Pollutants (POPs) are anthropogenic chemicals extensively used in the past for industrial and agricultural purposes, characterized by their lipophilicity, ubiquity, volatility and environmental persistence. By other hand, chlorpyrifos is the most widely used current pesticide (CUPs) being the main insecticide used for crops in Argentina. The aim of this work was to assess levels of POPs and CUPs in different fractions of airborne particles collected indoor in agricultural areas from Argentina. Particles higher than 2.5 µm were trapped in polyurethane foams (PUF) while particles smaller than 1 µm and volatile compounds were adsorbed on activated charcoal. Compounds were analyzed by gas chromatograph with electron capture detector (GC-ECD). Endosulfans, chlordanes, PCBs, and HCHs were detected in all PUF samples, while endosulfans, chlorpyrifos, PCBs, and HCHs were the most abundant in smaller particles. Majority of pesticides showed higher concentrations during the summer season (1397.7 vs 832.5 pg/m3 ). Even adding up all measured organic compounds, no sample reaches the threshold limit value for indoor pesticides levels (0.1 pg/m3 ), neither in the large or small particle fraction. However, the fact that chronic exposure to POPs has been linked to several diseases raises concern for human health.

Seed predation does not explain pine invasion success.

Why some non-native plant species invade, and others fail remains an elusive question. Plant invasion success has been associated with specific species traits. Yet, we have limited knowledge of the mechanisms relating these traits to invasion potential. General patterns of biotic resistance by seed predation may provide a mechanism that helps separate invasive from non-invasive plants. Seed predation is an important barrier against plant establishment for many plant species. It may, therefore, create a selective filter against non-native plant establishment based on plant traits related to seed predation rate. In two cafeteria-style seed predation experiments in a steppe ecosystem in Patagonia (Argentina) we provided seeds of 16 non-native Pinaceae covering a 300-fold variation in seed mass, a 200-fold variation in seed volume and 75-fold variation in seed toughness. Seed removal decreased with seed mass and seed volume. Seed toughness was not a significant predictor while seed volume was the best predictor of predators' preference. However, for species of this family small seed size is the most important predictor of species invasiveness. Our results show that seed predation does not explain Pinaceae invasive success. In our system, species that have smaller seeds (i.e., more invasive) are preferentially consumed by seed predators. Seed mass was not the best predictor of granivory rates, despite being the seed trait on which most studies have been focused. Our ability to predict future invasion and understand invasion success could benefit from other studies that focus on the mechanisms behind invasive traits.

Suilloid fungi as global drivers of pine invasions.

Belowground biota can deeply influence plant invasion. The presence of appropriate soil mutualists can act as a driver to enable plants to colonize new ranges. We reviewed the species of ectomycorrhizal fungi (EMF) that facilitate pine establishment in both native and non-native ranges, and that are associated with their invasion into nonforest settings. We found that one particular group of EMF, suilloid fungi, uniquely drive pine invasion in the absence of other EMF. Although the association with other EMF is variable, suilloid EMF are always associated with invasive pines, particularly at early invasion, when invasive trees are most vulnerable. We identified five main ecological traits of suilloid fungi that may explain their key role at pine invasions: their long-distance dispersal capacity, the establishment of positive biotic interactions with mammals, their capacity to generate a resistant spore bank, their rapid colonization of roots and their long-distance exploration type. These results suggest that the identity of mycorrhizal fungi and their ecological interactions, rather than simply the presence of compatible fungi, are key to the understanding of plant invasion processes and their success or failure. Particularly for pines, their specific association with suilloid fungi determines their invasion success in previously uninvaded ecosystems.

How are monospecific stands of invasive trees formed? Spatio-temporal evidence from Douglas fir invasions.

Invasive plant species can produce many impacts on native communities. Impacts can be especially important when the non-natives reach high densities, producing monospecific stands where little grows besides the non-native species. We propose three basic pathways by which monospecific stands of invasive tree species are formed: (i) gradually from the propagule source, (ii) via synchronous establishment and (iii) following several pulses of synchronous establishment. Different patterns can produce different impacts through time and may require different management techniques. This study aims to further our understanding of how monotypic stands of invasive species arise. We documented how monospecific stands are formed during invasion processes by studying patterns of spatio-temporal establishment of several monospecific stands of Douglas fir in Patagonia. We obtained data on tree density, year of establishment, size, distance to the seed source and other related measurements for this tree species along transects from the original seed source (80-year-old plantations) to the edge of the monospecific stand. We found that these monospecific stands arose in a more complex way than expected. While individuals established on average simultaneously over all distances from the seed source, there was substantial variation in time of establishment at all distances. Also, tree density was higher near the source than far from it. Different factors can account for the observed pattern of tree establishment, including seed dispersal, mycorrhizal facilitation and herbivory. Our results elucidate the complexities of spatio-temporal pattern of formation in monospecific stands. This understanding can improve management strategies and techniques for this invasion and other plant invasions in different regions.

Potential problems of removing one invasive species at a time: a meta-analysis of the interactions between invasive vertebrates and unexpected effects of removal programs.

Although the co-occurrence of nonnative vertebrates is a ubiquitous global phenomenon, the study of interactions between invaders is poorly represented in the literature. Limited understanding of the interactions between co-occurring vertebrates can be problematic for predicting how the removal of only one invasive-a common management scenario-will affect native communities. We suggest a trophic food web framework for predicting the effects of single-species management on native biodiversity. We used a literature search and meta-analysis to assess current understanding of how the removal of one invasive vertebrate affects native biodiversity relative to when two invasives are present. The majority of studies focused on the removal of carnivores, mainly within aquatic systems, which highlights a critical knowledge gap in our understanding of co-occurring invasive vertebrates. We found that removal of one invasive vertebrate caused a significant negative effect on native species compared to when two invasive vertebrates were present. These unexpected results could arise because of the positioning and hierarchy of the co-occurring invasives in the food web (e.g., carnivore-carnivore or carnivore-herbivore). We consider that there are important knowledge gaps to determinate the effects of multiple co-existing invaders on native ecosystems, and this information could be precious for management.

Lesiones talámicas: un desafío semiológico / Thalamic lesions

RESUMEN: El tálamo es un núcleo gris de la base que sirve como punto de entrecruzamiento de múltiples vías neuronales. Las manifestaciones clínicas producidas por lesiones talámicas son muy diversas, poco sistematizables y relativamente poco conocidas por el médico clínico. A su vez, dichas lesiones responden a variadas etiologías, dentro de las cuales predomina la vascular. En el presente artículo se describen dos casos clínicos de lesiones talámicas que difieren en su presentación y naturaleza: el primero se manifestó con una sintomatología de la esfera neurológica muy variada y correspondía a una lesión de origen vascular, mientras que el segundo se presentó como el clásico síndrome sensitivo de Déjerine-Roussy correspondiendo a una lesión de origen infeccioso.

ABSTRACT: The thalamus is a basal grey nuclei which serves as a cross-linking point for multiple neural networks. Clinical manifestations of thalamic lesions are varied, non-systematized and relatively not familiar to physicians. Moreover, these lesions are associated with numerous disorders, among which vascular lesions are by far the more frequent. Two cases of thalamic lesions that differ in their presentation and nature are described in this article: the first one showed varied neurologic symptoms and was caused by a vascular disease, while the second one presented itself as the classic Déjerine-Roussy sensitive syndrome and was caused by an infectious disease

Replacement of native by non-native animal communities assisted by human introduction and management on Isla Victoria, Nahuel Huapi National Park.

One of the possible consequences of biological invasions is the decrease of native species abundances or their replacement by non-native species. In Andean Patagonia, southern Argentina and Chile, many non-native animals have been introduced and are currently spreading. On Isla Victoria, Nahuel Huapi National Park, many non-native vertebrates were introduced ca. 1937. Records indicate that several native vertebrates were present before these species were introduced. We hypothesize that seven decades after the introduction of non-native species and without appropriate management to maintain native diversity, non-native vertebrates have displaced native species (given the known invasiveness and impacts of some of the introduced species). We conducted direct censuses in linear transects 500 m long (n = 10) in parallel with camera-trapping (1,253 camera-days) surveys in two regions of the island with different levels of disturbance: high (n = 4) and low (n = 6) to study the community of terrestrial mammals and birds and the relative abundances of native and non-native species. Results show that currently non-native species are dominant across all environments; 60.4% of census records and 99.7% of camera trapping records are of non-native animals. We detected no native large mammals; the assemblage of large vertebrates consisted of five non-native mammals and one non-native bird. Native species detected were one small mammal and one small bird. Species with the highest trapping rate were red and fallow deer, wild boar, silver pheasant (all four species are non-native) and chucao (a native bird). These results suggest that native species are being displaced by non-natives and are currently in very low numbers.

Impact of Non-Native Birds on Native Ecosystems: A Global Analysis.

Introduction and naturalization of non-native species is one of the most important threats to global biodiversity. Birds have been widely introduced worldwide, but their impacts on populations, communities, and ecosystems have not received as much attention as those of other groups. This work is a global synthesis of the impact of nonnative birds on native ecosystems to determine (1) what groups, impacts, and locations have been best studied; (2) which taxonomic groups and which impacts have greatest effects on ecosystems, (3) how important are bird impacts at the community and ecosystem levels, and (4) what are the known benefits of nonnative birds to natural ecosystems. We conducted an extensive literature search that yielded 148 articles covering 39 species belonging to 18 families -18% of all known naturalized species. Studies were classified according to where they were conducted: Africa, Asia, Australasia, Europe, North America, South America, Islands of the Indian, of the Pacific, and of the Atlantic Ocean. Seven types of impact on native ecosystems were evaluated: competition, disease transmission, chemical, physical, or structural impact on ecosystem, grazing/ herbivory/ browsing, hybridization, predation, and interaction with other non-native species. Hybridization and disease transmission were the most important impacts, affecting the population and community levels. Ecosystem-level impacts, such as structural and chemical impacts were detected. Seven species were found to have positive impacts aside from negative ones. We provide suggestions for future studies focused on mechanisms of impact, regions, and understudied taxonomic groups.