Label-Free SERS of Urine Components: A Powerful Tool for Discriminating Renal Cell Carcinoma through Multivariate Analysis and Machine Learning Techniques.

The advent of Surface-Enhanced Raman Scattering (SERS) has enabled the exploration and detection of small molecules, particularly in biological fluids such as serum, blood plasma, urine, saliva, and tears. SERS has been proposed as a simple diagnostic technique for various diseases, including cancer. Renal cell carcinoma (RCC) ranks as the sixth most commonly diagnosed cancer in men and is often asymptomatic, with detection occurring incidentally. The onset of symptoms typically aligns with advanced disease, aggressive histology, and unfavorable prognosis, and therefore new methods for an early diagnosis are needed. In this study, we investigated the utility of label-free SERS in urine, coupled with two multivariate analysis approaches: Principal Component Analysis combined with Linear Discriminant Analysis (PCA-LDA) and Support Vector Machine (SVM), to discriminate between 50 RCC patients and 44 healthy donors. Employing LDA-PCA, we achieved a discrimination accuracy of 100% using 13 principal components, and an 88% accuracy in discriminating between different RCC stages. The SVM approach yielded a training accuracy of 100%, a validation accuracy of 99% for discriminating between RCC and controls, and an 80% accuracy for discriminating between stages. The comparative analysis of raw and normalized SERS spectral data shows that while raw data disclose relative concentration variations in urine metabolites between the two classes, the normalization of spectral data significantly improves the accuracy of discrimination. Moreover, the selection of principal components with markedly distinct scores between the two classes serves to alleviate overfitting risks and reduces the number of components employed for discrimination. We obtained the accuracy of the discrimination between the RCC patients cases and healthy donors of 90% for three PCs and a linear discrimination function, and a 88% accuracy of discrimination between stages using six PCs, mitigating practically the risk of overfitting and increasing the robustness of our analysis. Our findings underscore the potential of label-free SERS of urine in conjunction with chemometrics for non-invasive and early RCC detection.

Exploring Genomics and Microbial Ecology: Analysis of Bidens pilosa L. Genetic Structure and Soil Microbiome Diversity by RAD-Seq and Metabarcoding.

Bidens pilosa L., native to South America and commonly used for medicinal purposes, has been understudied at molecular and genomic levels and in its relationship with soil microorganisms. In this study, restriction site-associated DNA markers (RADseq) techniques were implemented to analyze genetic diversity and population structure, and metabarcoding to examine microbial composition in soils from Palmira, Sibundoy, and Bogotá, Colombia. A total of 2,984,123 loci and 3485 single nucleotide polymorphisms (SNPs) were identified, revealing a genetic variation of 12% between populations and 88% within individuals, and distributing the population into three main genetic groups, FST = 0.115 (p < 0.001) and FIT = 0.013 (p > 0.05). In the soil analysis, significant correlations were found between effective cation exchange capacity (ECEC) and apparent density, soil texture, and levels of Mg and Fe, as well as negative correlations between ECEC and Mg, and Mg, Fe, and Ca. Proteobacteria and Ascomycota emerged as the predominant bacterial and fungal phyla, respectively. Analyses of alpha, beta, and multifactorial diversity highlight the influence of ecological and environmental factors on these microbial communities, revealing specific patterns of clustering and association between bacteria and fungi in the studied locations.

Glomeromycota associations with bamboos (Bambusoideae) worldwide, a qualitative systematic review of a promising symbiosis.

Background: Around the world, bamboos are ecologically, economically, and culturally important plants, particularly in tropical regions of Asia, America, and Africa. The association of this plant group with arbuscular mycorrhizal fungi belonging to the phylum Glomeromycota is still a poorly studied field, which limits understanding of the reported ecological and physiological benefits for the plant, fungus, soil, and ecosystems under this symbiosis relationship. Methods: Through a qualitative systematic review following the PRISMA framework for the collection, synthesis, and reporting of evidence, this paper presents a compilation of the research conducted on the biology and ecology of the symbiotic relationship between Glomeromycota and Bambusoideae from around the world. This review is based on academic databases enriched with documents retrieved using different online databases and the Google Scholar search engine. Results: The literature search yielded over 6,000 publications, from which 18 studies were included in the present review after a process of selection and validation. The information gathered from the publications included over 25 bamboo species and nine Glomeromycota genera from eight families, distributed across five countries on two continents. Conclusion: This review presents the current state of knowledge regarding the symbiosis between Glomeromycota and Bambusoideae, while reflecting on the challenges and scarcity of research on this promising association found across the world.

Guadua angustifolia Kunth leaves as a source for bioactive phenolic compounds: Optimization of ultrasound-assisted extraction using response surface methodology and antioxidant activities.

This study evaluated the ultrasound-assisted extraction of phenolic compounds from Guadua angustifolia leaves, along with their optimization using response surface methodology. The effects of two sonication process conditions were determined using a central composite experimental design, with three levels (low, medium, and high) evaluated for time (10, 20, and 30 min) and temperature (20 °C, 35 °C, and 50 °C). A total of 12 experiments with four replicates were conducted at the central point, with the total phenol and flavonoid contents determined using the Folin-Ciocalteu colorimetric method and complexation with AlCl3, respectively. The optimized extract was analyzed using ultra-performance liquid chromatography (UPLC), and the antioxidant capacity of the optimized extract was determined by DPPH• (2,2-Diphenyl-1-Picrylhydrazyl) and ABTS•+ (2,2'-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) assays. Extraction at 50 °C for 20 min was found to favor the extraction of phenol and total flavonoids. The experimental validation of the total phenol and flavonoid content produced values of 7.39 mg gallic acid equivalents per gram of dry matter and 1.55 mg quercetin equivalents per gram of dry matter, respectively. These values suggest that the extraction process is reproducible, with a relative standard deviation of 22.9 % and 14.1 %, respectively. The chromatographic profile showed that optimization favored the visualization of phenolic compounds compared to the non-optimized extract. The optimized extract had higher antioxidant capacity than the non-optimized extract, with values of 209.23 and 144.76 µmol Trolox per gram extract for the DPPH• and ABTS•+ techniques, respectively. Thus, the conditions evaluated in the ultrasound-assisted extraction were an efficient technique capable of extracting the maximum amount of phenolic compounds with antioxidant activity from the leaves of G. angustifolia, showing its potential application in various industries.

River widening in mountain and foothill areas during floods: Insights from a meta-analysis of 51 European Rivers.

River widening, defined as a lateral expansion of the channel, is a critical process that maintains fluvial ecosystems and is part of the regular functioning of rivers. However, in areas with high population density, channel widening can cause damage during floods. Therefore, for effective flood risk management it is essential to identify river reaches where abrupt channel widening may occur. Despite numerous efforts to predict channel widening, most studies have been limited to single rivers and single flood events, which may not be representative of other conditions. Moreover, a multi-catchment scale approach that covers various settings and flood magnitudes has been lacking. In this study, we fill this gap by compiling a large database comprising 1564 river reaches in several mountain regions in Europe affected by floods of varying magnitudes in the last six decades. By applying a meta-analysis, we aimed to identify the types of floods responsible for more extensive widening, the river reach types where intense widening is more likely to occur, and the hydraulic and morphological variables that explain widening and can aid in predicting widening. Our analysis revealed seven groups of reaches with significantly different responses to floods regarding width ratios (i.e., the ratio between channel width after and before a flood). Among these groups, the river reaches located in the Mediterranean region and affected by extreme floods triggered by short and intense precipitation events showed significantly larger widening than other river reaches in other regions. Additionally, the meta-analysis confirmed valley confinement as a critical morphological variable that controls channel widening but showed that it is not the only controlling factor. We proposed new statistical models to identify river reaches prone to widening, estimate potential channel width after a flood, and compute upper bound width ratios. These findings can inform flood hazard evaluations and the design of mitigation measures.

Ethnobotanical Insights: Qualitative Analysis of Medicinal Plants in Colón Putumayo for Traditional Knowledge Preservation.

The ancestral knowledge of the community of Colón Putumayo unfolds in several dimensions that allow us to recognise the ethnomedicinal properties of plants. The research focused on systematising ethnobotanical and ethnomedicinal knowledge on the use of plants as alternatives for treating illnesses. A cross-sectional study was carried out through semi-structured questionnaires to 100 inhabitants of the community of Colón. We found 38 plant species catalogued in 18 botanical families where 10 species of medicinal plants were prioritised by the community for the treatment of illnesses. The use value (UV) evaluation showed that Chamaemelum nobile equals 0.18 compared to Cymbopogon citratus and Lippia alba with 0.04. The Informant Consensus Factor (ICF) for the cited medicinal use categories equivalent to 1.00 are for the treatment of six types of ailments, however, the plants can treat 16 types of ailments. The Fidelity Level (LF) found identified that four plants are used for the treatment of one type of ailment while three are used to alleviate several ailments. The local knowledge of the community of Colón Putumayo is linked to the ancestry of the territory, culture, and family farming practices.

Untargeted metabolomics approach and molecular networking analysis reveal changes in chemical composition under the influence of altitudinal variation in bamboo species.

Bamboo species have traditionally been used as building material and potential source of bioactive substances, as they produce a wide variety of phenolic compounds, including flavonoids and cinnamic acid derivatives that are considered biologically active. However, the effects of growth conditions such as location, altitude, climate, and soil on the metabolome of these species still need to be fully understood. This study aimed to evaluate variations in chemical composition induced by altitudinal gradient (0-3000 m) by utilizing an untargeted metabolomics approach and mapping chemical space using molecular networking analysis. We analyzed 111 samples from 12 bamboo species collected from different altitudinal ranges using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). We used multivariate and univariate statistical analyses to identify the metabolites that showed significant differences in the altitude environments. Additionally, we used the Global Natural Products Social Molecular Networking (GNPS) web platform to perform chemical mapping by comparing the metabolome among the studied species and the reference spectra from its database. The results showed 89 differential metabolites between the altitudinal ranges investigated, wherein high altitude environments significantly increased the profile of flavonoids. While, low altitude environments significantly boosted the profile of cinnamic acid derivatives, particularly caffeoylquinic acids (CQAs). MolNetEnhancer networks confirmed the same differential molecular families already found, revealing metabolic diversity. Overall, this study provides the first report of variations induced by altitude in the chemical profile of bamboo species. The findings may possess fascinating active biological properties, thus offering an alternative use for bamboo.

Use of biochar and a post-coagulation effluent as an adsorbent of malachite green, beneficial bacteria carrier, and seedling substrate for plants belonging to the poaceae family.

Wastewater treatment plants produce solid and semi-solid sludge, which treatment minimises secondary environmental pollution because of wastewater treatment and obtaining new bioproducts. For this reason, in this paper, the co-pyrolysis of biogenic biomasses recovered from a biological reactor with immobilised fungal and bacterial biomass and a tertiary reactor with Chlorella sp. used for dye-contaminated wastewater treatment was carried out. Biogenic biomasses mixed with pine bark allowed the production and characterisation of two types of biochar. The raw material and biochar were on the "in vitro" germination of Lolium sp. seeds, followed by adsorption studies for malachite green (MG) dye using the raw material and the biochar. Results showed that using 60 mg L-1 of a cationic coagulant at pH 6.5 allowed for the recovery of more than 90% of the microalgae after 50 min of processing. Two biochar resulted: BC300, at pH 5.08 ± 0.08 and BC500, at pH 6.78 ± 0.01. The raw material and both biochars were co-inoculated with growth-promoting bacteria; their viabilities ranged from 1.7 × 106 ± 1.0 × 101 to 7.5 × 108 ± 6.0 × 102 CFU g-1 for total heterotrophic, nitrogen-fixing and phosphate-solubilising bacteria. Re-use tests on Lolium sp. seed germination showed that with the post-coagulation effluent, the germination was 100%, while with the biochar, with and without beneficial bacteria, the germination was 98 and 99%, respectively. Finally, BC500 adsorbed the highest percentage of malachite green at pH 4.0, obtaining qecal values of 0.5249 mg g-1 (R2: 0.9875) with the pseudo-second-order model. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03766-x.

Evaluation of a Lyophilized CRISPR-Cas12 Assay for a Sensitive, Specific, and Rapid Detection of SARS-CoV-2.

We evaluated a lyophilized CRISPR-Cas12 assay for SARS-CoV-2 detection (Lyo-CRISPR SARS-CoV-2 kit) based on reverse transcription, isothermal amplification, and CRISPR-Cas12 reaction. From a total of 210 RNA samples extracted from nasopharyngeal swabs using spin columns, the Lyo-CRISPR SARS-CoV-2 kit detected 105/105 (100%; 95% confidence interval (CI): 96.55-100) positive samples and 104/105 (99.05%; 95% CI: 94.81-99.97) negative samples that were previously tested using commercial RT-qPCR. The estimated overall Kappa index was 0.991, reflecting an almost perfect concordance level between the two diagnostic tests. An initial validation test was also performed on 30 nasopharyngeal samples collected in lysis buffer, in which the Lyo-CRISPR SARS-CoV-2 kit detected 20/21 (95.24%; 95% CI: 76.18-99.88) positive samples and 9/9 (100%; 95% CI: 66.37-100) negative samples. The estimated Kappa index was 0.923, indicating a strong concordance between the test procedures. The Lyo-CRISPR SARS-CoV-2 kit was suitable for detecting a wide range of RT-qPCR-positive samples (cycle threshold range: 11.45-36.90) and dilutions of heat-inactivated virus (range: 2.5-100 copies/µL); no cross-reaction was observed with the other respiratory pathogens tested. We demonstrated that the performance of the Lyo-CRISPR SARS-CoV-2 kit was similar to that of commercial RT-qPCR, as the former was highly sensitive and specific, timesaving (1.5 h), inexpensive, and did not require sophisticated equipment. The use of this kit would reduce the time taken for diagnosis and facilitate molecular diagnosis in low-resource laboratories.

Effect of temperature and moisture contents on dielectric properties at 2.45 GHz of fruit and vegetable processing by-products.

Microwave heating is a part of several food processing unit-operations, while also emerging as a processing technology for by-products. Process efficiency depends on dielectric properties; however, data of these by-products are scarce in literature. The present study is focused on the effect of temperature and moisture content (M) on the dielectric constant (ε') and loss (ε'') of carrot waste, apple pomace, pineapple peel and spent coffee grounds at 2.45 GHz. Results on ε' showed moisture-dependent temperature effect with an inflection point at M = 50.3%. The ε'' increased with increasing M up to 60% and decreased at higher moisture levels. Results at different temperatures were significantly affected by the composition of the studied materials and thus the calculated power penetration depth. Although fresh food dielectric properties are available in literature, the data is not always suitable to estimate food waste properties as processing may cause compositional changes. The obtained results support microwave process optimization in the field of food-waste valorization.

CRISPR-based platform for carbapenemases and emerging viruses detection using Cas12a (Cpf1) effector nuclease.

CRISPR-Cas12a (also called Cpf1) has been commonly used for genomic editing, based on its ability to generate precise double-stranded DNA (dsDNA) breaks. Recently, it was demonstrated that Cas12a exhibits unspecific ssDNAse activity upon target recognition. This feature allows CRISPR-Cas to be coupled with a ssDNA reporter and generate a fast, accurate and ultrasensitive molecular detection method. Here, we demonstrate that Cas12a was able to detect DNA target sequences corresponding to carbapenemases resistance genes such as KPC, NDM and OXA. Also, with the addition of a reverse-transcription step, we were able to detect viral RNA sequences from DENV, ZIKV and HANTV genomes. In all cases, assay run time was less than two hours. Additionally, we report attomolar levels of detection. This methodology was validated using clinical samples from patients infected with Dengue virus. Reactions were visualized by detection of a fluorescent signal, as well as by the use of a simple lateral flow strip. These results indicate that Cas12a is able to detect both DNA and RNA targets, making it an appropriate and convenient tool to detect all types of pathogens.

Planform changes and large wood dynamics in two torrents during a severe flash flood in Braunsbach, Germany 2016.

This work presents a post-event survey study, addressing the geomorphic response and large wood budget of two torrents, Grimmbach and Orlacher Bach, in southwestern Germany that were affected by a flash flood on May 29, 2016. During the event, large amounts of wood clogged and damaged a bridge of a cycling path at the outlet of the Grimmbach, while the town of Braunsbach was devastated by discharge and material transported along the Orlacher Bach. The severity of the event in these two small catchments (30.0 km2 and 5.95 km2, respectively) is remarkable in basins with a relatively low average slope (10.7 and 12.0%, respectively). In order to gain a better understanding of the driving forces during this flood event an integrated approach was applied including (i) an estimate of peak discharges, (ii) an analysis of changes in channel width by comparing available aerial photographs before the flood with a post-flood aerial surveys with an Unmanned Aerial Vehicle and validation with field observations, (iii) a detailed mapping of landslides and analysis of their connectivity with the channel network and finally (iv) an analysis of the amounts of large wood recruited and deposited in the channel. The morphological changes in the channels can be explained by hydraulic parameters, such as stream power and unit stream power, and by morphological parameters such as the valley confinement. This is similar for LW recruitment amounts and volume of exported LW since most of it comes from the erosion of the valley floor. The morphological changes and large wood recruitment and deposit are in the range of studied mountain rivers. Both factors thus need to be considered for mapping and mitigating flash flood hazards also in this kind of low range mountains.

Las espacialidades en la investigación clínica médica. El Instituto de Investigaciones Médicas de la Universidad de Buenos Aires, 1957-1976 / The Role of Space in Clinical Medical Research. The Instituto de Investigaciones Médicas of the Buenos Aires University, 1957-1976 / As espacialidades na investigação clínica médica. O Instituto de Investigações Médicas da Universidade de Buenos Aires, 1957-1976

Objetivo: este trabajo trata sobre la configuración de prácticas de transmisión, producción y uso de conocimiento científico en términos del establecimiento de diferentes espacialidades en la investigación clínica médica. Desarrollo: se reconstruyen las actividades desarrolladas en el Instituto de Investigaciones Médicas (IIM) de la Universidad de Buenos Aires, durante la dirección de Alfredo Lanari entre 1957 y 1976, por medio del uso de material documental y de archivo y del análisis de entrevistas realizadas a protagonistas de la época. Conclusiones: (i) la diferenciación y a la vez la interconexión de espacialidades fueron elementos centrales de la ideología y cultura institucional del Instituto de Investigaciones Médicas Lanari; (ii) los distintos espacios tales como la sección trasplantes y el servicio de diálisis hicieron del Instituto un lugar con reputación nacional e internacional al tiempo que otorgaron identidad y autoridad hacia su interior; (iii) la construcción de autoridad y jerarquía cognitiva implicó la puesta en juego de un conjunto de espacialidades tales como el ateneo y las residencias médicas y (iv) las formas de enseñanza y reclutamiento implementadas supusieron una nueva ecología común.

Objective: this paper study how scientific knowledge is, transmitted, produced and used in terms of the establishment of different spaces, in clinical and medical research. Content: we analyze the way research activities developed at the Instituto de Investigaciones Médicas de la Universidad de Buenos Aires, during Alfredo Lanari was its director, between 1957 and 1976, using data from documental archives and form personal interviews. Conclusions: (i) differentiation and interconnection of spaces were central issues of the institutional culture and ideology of the Instituto de Investigaciones Médicas Lanari; (ii) different spaces such as transplant section and dialysis service help the Institute to build itself as a place with national and international reputation as well as to reinforce internal authority and identity; (iii) cognitive authority and hierarchies construction mobilized a set of spaces such as medical residencies and seminars (the ateneo) and (iv) teaching and recruitment reforms involved a new common ecology.

Objetivo: este trabalho trata sobre a configuração de práticas de transmissão, produção e uso de conhecimento científico em termos do estabelecimento de diferentes espacialidades na investigação clínica médica. Desenvolvimento: reconstroem-se as atividades desenvolvidas no Instituto de Investigações médicas (IIM) da Universidade de Buenos Aires, durante a direção de Alfredo Lanari entre 1957 e 1976, através do uso de material documental e de arquivo e da análise de entrevistas realizadas a protagonistas da época. Conclusões: (i) a diferenciação e ao mesmo tempo a interconexão de espacialidades foram elementos centrais da ideologia e cultura institucional do Instituto de Investigações Médicas Lanari, (ii) os distintos espaços tais como a seção transplantes e o serviço de dialise fizeram do Instituto um lugar com reputação nacional e internacional ao tempo que outorgaram identidade e autoridade a seu interior, (iii) a construção de autoridade e hierarquia cognitiva implicou a posta em jogo de um conjunto de espacialidades tais como o ateneu e as residências médicas e (iv) as formas de ensino e recrutamento implementadas supuseram uma nova ecologia comum.

[To treat or not to treat? Scientific controversy about the treatment for chronic Chagas' disease patients.]. / ¿Tratar o no tratar? La controversia científica sobre el tratamiento para los enfermos de Chagas crónico.

Chagas disease is one of the main endemic illnesses in Latin America. Since 1969 up to the present, the treatment of chronic Chagas patients has been the object of a scientific-medical controversy mobilizing several bodies of knowledge and actors. The resolution of the controversy has direct effects on the health of patients; however, they have been systematically excluded of public debates. In this paper we identified and specified four different steps of the controversy, showing the different positions adopted by the actors implicated, analyzing their statements, the scientific knowledge mobilized during the debates and the consequences for the establishment of norms for the treatment. We conclude showing that what makes up the central issue of the controversy is not what the actors implicated explicitly state as it but the criteria (technical and cognitive) through which are measured and defined "illness" and "cure" states. This research is about a case study in Argentina.

El Instituto de Investigaciones Médicas y Alfredo Lanari: Una tradición de investigación clínica médica (1957-1976) / The Institute of Medical Research and Alfredo Lanari: A tradition of medical clinical research (1957-1976)

La investigación clínica médica en la Argentina sin dudas, tuvo sus desarrollos más centrales ysignificativos a partir de la segunda mitad del siglo XX, con la conformación y el desarrollo de la tradición de Alfredo Lanari. Lejos de ser una disciplina o especialidad, la investigación clínica médica se constituyó históricamente como un ámbito compuesto, donde los objetos y métodos de la medicina experimental2I fueron colocados al servicio de los conocimientos e intereses de la práctica clínica médica, orientada a brindar soluciones a los problemas de la salud humana. Esta articulación epistémica y cognitiva se dio con el desarrollo de específicos modelos institucionales y estilos profesionales

Efecto de la inoculación de Azospirillum brasilense y Glomus sp: en Gmelina arborea durante su germinación y manejo en vivero / Response of gmelina arborea to glomus sp. and azospirillum brasilense Inoculation in greenhouse conditions

Se realizó la inoculación de Azospirillum brasilense inmovilizado en microperlas de alginato y de los hongos Glomus manihotis y Glomus occultum en semillas de Gmelina arborea en tres grados de madurez. Las semillas inoculadas se sembraron en suelo y en turba compactada. Cuarenta y un días después de la siembra se determinó el efecto de los sistemas de siembra y de los microorganismos sobre la germinación. Cuarenta y siete días después del transplante a bolsa se determinaron las variables de micorrización y altura de las plantas. El sustrato de siembra (p<0.01) y la inoculación de A. brasilense (p<0.01) influyeron en la germinación de las semillas de G. arborea. Se presentó correlación positiva entre micorrización y la altura de las plantas durante el establecimiento en vivero (0.61 p=0.03). Además se presentó un efecto sinérgico de los microorganismos sobre la micorrización.

Seeds of Gmelina arborea at three different maturity degrees were inoculated with Glomus manihotis,Glomus occultum and Azospirillum brasilense immobilized in alginate microbeads. Inoculated seeds were sown in two different growing systems: soil and compacted- peat-Jiffy®. Forty-one days after sowing (das), the effects of growing system and microorganism application on seed germination were determined. Forty-seven das, mycorrhization percentages and plant height were evaluated. Results showed that the growing system and the inoculation of A. brasilense have a significant effect (p<0.01) on the germination of G. arborea seeds. A positive correlation between mycorrhization and plantheight was found during the initial stage of establishment in greenhouse conditions (0.61 p=0.03). In addition, there is a synergic effect of both types of microorganisms on mycorrhization.

¿Tratar o no tratar? la controversia científica sobre el tratamiento para los enfermos de chagas crónico / To treat or not to treat? scientific controversy about the treatment for chronic chagas´disease patients

La enfermedad de Chagas es una de las principales endemias de América Latina. Desde 1969 yhasta la actualidad, el tratamiento de los enfermos que cursan la etapa crónica es objeto de unacontroversia científica y médica que moviliza diferentes conocimientos, es motorizada por diversosactores y tiene consecuencias sobre los propios enfermos, quienes, sin embargo, carecen de voz yvisibilidad. En este trabajo identificamos y diferenciamos cuatro momentos centrales de esta controversia,analizando los posicionamientos de los distintos actores, los conocimientos científicospuestos en cuestión y sus consecuencias en la confección de normativas sobre el tratamiento. Finalmente,mostramos que el objeto central de controversia no es lo que los actores implicadosexplicitan como tal sino los criterios (técnicos y cognitivos) mediante los cuales se miden y definenlos estados de «enfermedad» y de «cura». Este trabajo trata de un estudio de caso en la Argentina(AU)

Chagas disease is one of the main endemic illnesses in Latin America. Since 1969 up to the present,the treatment of chronic Chagas patients has been the object of a scientific-medical controversymobilizing several bodies of knowledge and actors. The resolution of the controversy has direct effectson the health of patients; however, they have been systematically excluded of public debates. Inthis paper we identified and specified four different steps of the controversy, showing the differentpositions adopted by the actors implicated, analyzing their statements, the scientific knowledge mobilizedduring the debates and the consequences for the establishment of norms for the treatment. Weconclude showing that what makes up the central issue of the controversy is not what the actors implicated explicitly state as it but the criteria (technical and cognitive) through which are measured anddefined «illness» and «cure» states. This research is about a case study in Argentina(AU)