Increased Natural Killer (NK)-cell cytotoxicity and Trypanosoma cruzi-specific memory B cells in subjects with discordant serology for Chagas disease.

The presence of memory T cell specific for Trypanosoma cruzi in subjects with discordant serology for Chagas disease supports a cleared infection in these subjects. Using high-dimensional flow cytometry, ELISPOT assays and quantitative PCR, antibody-secreting cells and memory B cells specific for T. cruzi, total B-cell phenotypes, innate immune responses and parasite DNA were evaluated in serodiscordant, seropositive and seronegative subjects for T. cruzi infection. T. cruzi-specific memory B cells but no antibody-secreting cells specific for T. cruzi, increased proportion of nonclassical monocytes and increased levels of polyfunctional NK cells were found in serodiscordant compared with seropositive subjects. None of the serodiscordant subjects evaluated showed detectable parasite DNA, most of them did not show cardiac abnormalities and a group of them had had confirmed positive serology for Chagas disease. The unique immune profiles in serodiscordant subjects support that T. cruzi infection was cleared or profoundly controlled in these subjects.

Comparison between the KARVI scale and the Child Development Evaluation test (EDI) as a screening tool for suspected neurodevelopmental delay.

BACKGROUND: Early detection of suspected neurodevelopmental delay allows for timely diagnosis and appropriate intervention, for which numerous screening tests have been developed. However, most are complex and impractical for health-care workers at the community level. This study aimed to validate the KARVI scale in the neurodevelopment assessment of children under 1 year of age. METHODS: We conducted an observational, longitudinal, comparative, inferential, and prospective study. Healthy children without risk factors for developing neurodevelopmental delay from 0 to 12 months of age were evaluated remotely using the Zoom® application. The Child Development Evaluation Test and the KARVI scale were applied once a month for four consecutive months. RESULTS: Fifty individuals were analyzed, with a predominance of males in 52%. Adequate percentages for a screening test were obtained in the first evaluation with a sensitivity of 70% (confidence interval [CI] 95% 34.75-93.33) and a specificity of 75% (CI 95% 58.8-87.31), and in the fourth evaluation with a sensitivity of 100% (CI 95% 29.4-100) and a specificity of 78.72% (CI 95% 64.34-89.3), being significant in both evaluations (p = 0.007 and p = 0.001, respectively). CONCLUSIONS: The KARVI scale has the elements to be an effective screening test for suspected neurodevelopmental delay, but more extensive studies are needed to obtain more reliable results.

INTRODUCCIÓN: La identificación temprana de retraso en el neurodesarrollo permite un diagnóstico oportuno y una intervención apropiada. Para ello, se han creado diversas pruebas de tamizaje; sin embargo, la mayoría son complejas y poco prácticas para el personal de la salud a nivel comunitario. El objetivo del estudio fue realizar la validación de la escala KARVI en la valoración del neurodesarrollo en niños menores de un año. MÉTODOS: Se realizó un estudio observacional, longitudinal, comparativo inferencial y prospectivo, en el cual se evaluaron, vía remota mediante la aplicación Zoom®, niños sanos de 0 a 12 meses de edad sin factores de riesgo para desarrollar retraso en el neurodesarrollo. Se aplicaron la prueba EDI (Evaluación del Desarrollo Infantil) y la escala KARVI una vez al mes por cuatro meses consecutivos. RESULTADOS: Se analizaron 50 individuos, con predominio del sexo masculino en el 52%. Se obtuvieron porcentajes adecuados para una prueba de tamizaje tanto en la primera evaluación, con sensibilidad de 70% (IC 95% 34.75-93.33) y especificidad de 75% (IC 95% 58.8-87.31), como en la cuarta, con sensibilidad de 100% (IC 95% 29.4-100) y especificidad de 78.72% (IC 95% 64.34-89.3), con significación estadística en ambas evaluaciones (p = 0.007 y p = 0.001, respectivamente). CONCLUSIONES: Se considera que la escala KARVI cuenta con los elementos para considerarla como una prueba de tamizaje efectiva para detectar retraso del neurodesarrollo, sin embargo. Sin requieren estudios más extensos para obtener resultados más confiables.

Comparison between the KARVI scale and the Child Development Evaluation test (EDI) as a screening tool for suspected neurodevelopmental delay / Comparación entre la escala KARVI y la prueba de Evaluación del Desarrollo Infantil (EDI) como tamizaje para la sospecha de retraso en el neurodesarrollo

Abstract Background: Early detection of suspected neurodevelopmental delay allows for timely diagnosis and appropriate intervention, for which numerous screening tests have been developed. However, most are complex and impractical for health-care workers at the community level. This study aimed to validate the KARVI scale in the neurodevelopment assessment of children under 1 year of age. Methods: We conducted an observational, longitudinal, comparative, inferential, and prospective study. Healthy children without risk factors for developing neurodevelopmental delay from 0 to 12 months of age were evaluated remotely using the Zoom® application. The Child Development Evaluation Test and the KARVI scale were applied once a month for four consecutive months. Results: Fifty individuals were analyzed, with a predominance of males in 52%. Adequate percentages for a screening test were obtained in the first evaluation with a sensitivity of 70% (confidence interval [CI] 95% 34.75-93.33) and a specificity of 75% (CI 95% 58.8-87.31), and in the fourth evaluation with a sensitivity of 100% (CI 95% 29.4-100) and a specificity of 78.72% (CI 95% 64.34-89.3), being significant in both evaluations (p = 0.007 and p = 0.001, respectively). Conclusions: The KARVI scale has the elements to be an effective screening test for suspected neurodevelopmental delay, but more extensive studies are needed to obtain more reliable results.

Resumen Introducción: La identificación temprana de retraso en el neurodesarrollo permite un diagnóstico oportuno y una intervención apropiada. Para ello, se han creado diversas pruebas de tamizaje; sin embargo, la mayoría son complejas y poco prácticas para el personal de la salud a nivel comunitario. El objetivo del estudio fue realizar la validación de la escala KARVI en la valoración del neurodesarrollo en niños menores de un año. Métodos: Se realizó un estudio observacional, longitudinal, comparativo inferencial y prospectivo, en el cual se evaluaron, vía remota mediante la aplicación Zoom®, niños sanos de 0 a 12 meses de edad sin factores de riesgo para desarrollar retraso en el neurodesarrollo. Se aplicaron la prueba EDI (Evaluación del Desarrollo Infantil) y la escala KARVI una vez al mes por cuatro meses consecutivos. Resultados: Se analizaron 50 individuos, con predominio del sexo masculino en el 52%. Se obtuvieron porcentajes adecuados para una prueba de tamizaje tanto en la primera evaluación, con sensibilidad de 70% (IC 95% 34.75-93.33) y especificidad de 75% (IC 95% 58.8-87.31), como en la cuarta, con sensibilidad de 100% (IC 95% 29.4-100) y especificidad de 78.72% (IC 95% 64.34-89.3), con significación estadística en ambas evaluaciones (p = 0.007 y p = 0.001, respectivamente). Conclusiones: Se considera que la escala KARVI cuenta con los elementos para considerarla como una prueba de tamizaje efectiva para detectar retraso del neurodesarrollo, sin embargo. Sin requieren estudios más extensos para obtener resultados más confiables.

Structural insights into the Smirnoff-Wheeler pathway for vitamin C production in the Amazon fruit camu-camu.

l-Ascorbic acid (AsA, vitamin C) is a pivotal dietary nutrient with multifaceted importance in living organisms. In plants, the Smirnoff-Wheeler pathway is the primary route for AsA biosynthesis, and understanding the mechanistic details behind its component enzymes has implications for plant biology, nutritional science, and biotechnology. As part of an initiative to determine the structures of all six core enzymes of the pathway, the present study focuses on three of them in the model species Myrciaria dubia (camu-camu): GDP-d-mannose 3',5'-epimerase (GME), l-galactose dehydrogenase (l-GalDH), and l-galactono-1,4-lactone dehydrogenase (l-GalLDH). We provide insights into substrate and cofactor binding and the conformational changes they induce. The MdGME structure reveals a distorted substrate in the active site, pertinent to the catalytic mechanism. Mdl-GalDH shows that the way in which NAD+ association affects loop structure over the active site is not conserved when compared with its homologue in spinach. Finally, the structure of Mdl-GalLDH is described for the first time. This allows for the rationalization of previously identified residues which play important roles in the active site or in the formation of the covalent bond with FAD. In conclusion, this study enhances our understanding of AsA biosynthesis in plants, and the information provided should prove useful for biotechnological applications.

Identification and distribution of a fungal endosymbiotic Alternaria species (Alternaria section Undifilum sp.) in Astragalus garbancillo tissues.

Plants belonging to the genera Astragalus, Oxytropis, Ipomoea, Sida, and Swainsona often contain the toxin swainsonine (SW) produced by an associated fungal symbiont. Consumption of SW-containing plants causes a serious neurological disorder in livestock, which can be fatal. In this study, a fungal endophyte, Alternaria section Undifilum, was identified in Astragalus garbancillo seeds, using polymerase chain reaction (PCR) followed by direct sequencing. In seeds, the SW concentrations were about 4 times higher than in other parts of the plant. Furthermore, microscopic examination demonstrated that the fungus mycelium grows inside the petioles and stems, on the outer surface and inside the mesocarp of the fruit, in the mesotesta and endotesta layers of the seed coat, and inside the endosperm of the seeds. Our results support the notion that the SW-producing fungus is vertically transmitted in the host plant A. garbancillo.

Interactions of variants of human apolipoprotein A-I with biopolymeric model matrices. Effect of collagen and heparin.

BACKGROUND: The extracellular matrix (ECM) is a complex tridimensional scaffold that actively participates in physiological and pathological events. The objective of this study was to test whether structural proteins of the ECM and glycosaminoglycans (GAGs) may favor the retention of human apolipoprotein A-I (apoA-I) variants associated with amyloidosis and atherosclerosis. METHODS: Biopolymeric matrices containing collagen type I (Col, a main macromolecular component of the ECM) with or without heparin (Hep, a model of GAGs) were constructed and characterized, and used to compare the binding of apoA-I having the native sequence (Wt) or Arg173Pro, a natural variant inducing cardiac amyloidosis. Protein binding was observed by fluorescence microscopy and unbound proteins quantified by a colorimetric assay. RESULTS: Both, Wt and Arg173Pro bound to the scaffolds containing Col, but the presence of Hep diminished the binding efficiency. Col-Hep matrices retained Arg173Pro more than the Wt. The retained protein was only partially removed from the matrices with saline solutions, indicating that electrostatic interactions may occur but are not the main driving force. Using in addition thermodynamic molecular simulations and size exclusion chromatography approaches, we suggest that the binding of apoA-I variants to the biopolymeric matrices is driven by many low affinity interactions. CONCLUSIONS: Under this scenario Col-Hep scaffolds contribute to the binding of Arg173Pro, as a cooperative platform which could modify the native protein conformation affecting protein folding. GENERAL SIGNIFICANCE: We show that the composition of the ECM is key to the protein retention, and well characterized biosynthetic matrices offer an invaluable in vitro model to mimic the hallmark of pathologies with interstitial infiltration such as cardiac amyloidosis.

Trypanosoma cruzi Secreted Cyclophilin TcCyP19 as an Early Marker for Trypanocidal Treatment Efficiency.

Cyclophilins (CyPs) are a family of enzymes involved in protein folding. Trypanosoma cruzi, the causative agent of Chagas disease, has a 19-kDa cyclophilin, TcCyP19, that was found to be secreted in parasite stages of the CL Brener clone and recognized by sera from T. cruzi-infected mice and patients. The levels of specific antibodies against TcCyP19 in T. cruzi-infected mice and subjects before and after drug treatment were measured by an in-house enzyme linked immunosorbent assay (ELISA). Mice in the acute and chronic phase of infection, with successful trypanocidal treatments, showed significantly lower anti-TcCyP19 antibody levels than untreated mice. In children and adults chronically infected with T. cruzi, a significant decrease in the anti-TcCyP19 titers was observed after 12 months of etiological treatment. This decrease was maintained in adult chronic patients followed-up 30-38 months post-treatment. These results encourage further studies on TcCyP19 as an early biomarker of trypanocidal treatment efficiency.

Engineering the catalytic activity of an Antarctic PET-degrading enzyme by loop exchange.

Several hydrolases have been described to degrade polyethylene terephthalate (PET) at moderate temperatures ranging from 25°C to 40°C. These mesophilic PET hydrolases (PETases) are less efficient in degrading this plastic polymer than their thermophilic homologs and have, therefore, been the subject of many protein engineering campaigns. However, enhancing their enzymatic activity through rational design or directed evolution poses a formidable challenge due to the need for exploring a large number of mutations. Additionally, evaluating the improvements in both activity and stability requires screening numerous variants, either individually or using high-throughput screening methods. Here, we utilize instead the design of chimeras as a protein engineering strategy to increase the activity and stability of Mors1, an Antarctic PETase active at 25°C. First, we obtained the crystal structure of Mors1 at 1.6 Å resolution, which we used as a scaffold for structure- and sequence-based chimeric design. Then, we designed a Mors1 chimera via loop exchange of a highly divergent active site loop from the thermophilic leaf-branch compost cutinase (LCC) into the equivalent region in Mors1. After restitution of an active site disulfide bond into this chimera, the enzyme exhibited a shift in optimal temperature for activity to 45°C and an increase in fivefold in PET hydrolysis when compared with wild-type Mors1 at 25°C. Our results serve as a proof of concept of the utility of chimeric design to further improve the activity and stability of PETases active at moderate temperatures.

Quantitative PCR-Based Diagnosis and Follow-up of Chagas Disease Primary Infection After Solid Organ Transplant: A Multicentre Study.

Chagas disease in solid organ transplant recipients may present as a primary infection (PI). Early detection is crucial for timely treatment. This is the largest observational multicentre study evaluating qPCR for early diagnosis and treatment monitoring of PI in seronegative recipients of organs from seropositive donors. Of 34 patients admitted at 5 health centers, PI was detected by qPCR in 8 (23.5%) within a posttransplant period of 40 days (interquartile range [IQR], 31-50 days). No PI was detected by the Strout test or clinical symptoms/signs. All patients had favorable treatment outcome with negative qPCR 31 days (IQR, 18-35 days) after treatment, with no posttreatment relapse episodes.

Cells immersed in collagen matrices show a decrease in plasma membrane fluidity as the matrix stiffness increases.

Cells are constantly adapting to maintain their identity in response to the surrounding media's temporal and spatial heterogeneity. The plasma membrane, which participates in the transduction of external signals, plays a crucial role in this adaptation. Studies suggest that nano and micrometer areas with different fluidities at the plasma membrane change their distribution in response to external mechanical signals. However, investigations linking fluidity domains with mechanical stimuli, specifically matrix stiffness, are still in progress. This report tests the hypothesis that the stiffness of the extracellular matrix can modify the equilibrium of areas with different order in the plasma membrane, resulting in changes in overall membrane fluidity distribution. We studied the effect of matrix stiffness on the distribution of membrane lipid domains in NIH-3 T3 cells immersed in matrices of varying concentrations of collagen type I, for 24 or 72 h. The stiffness and viscoelastic properties of the collagen matrices were characterized by rheometry, fiber sizes were measured by Scanning Electron Microscopy (SEM) and the volume occupied by the fibers by second harmonic generation imaging (SHG). Membrane fluidity was measured using the fluorescent dye LAURDAN and spectral phasor analysis. The results demonstrate that an increase in collagen stiffness alters the distribution of membrane fluidity, leading to an increasing amount of the LAURDAN fraction with a high degree of packing. These findings suggest that changes in the equilibrium of fluidity domains could represent a versatile and refined component of the signal transduction mechanism for cells to respond to the highly heterogeneous matrix structural composition. Overall, this study sheds light on the importance of the plasma membrane's role in adapting to the extracellular matrix's mechanical cues.

Omega-3-Supplemented Fat Diet Drives Immune Metabolic Response in Visceral Adipose Tissue by Modulating Gut Microbiota in a Mouse Model of Obesity.

Obesity is a chronic, relapsing, and multifactorial disease characterized by excessive accumulation of adipose tissue (AT), and is associated with inflammation mainly in white adipose tissue (WAT) and an increase in pro-inflammatory M1 macrophages and other immune cells. This milieu favors the secretion of cytokines and adipokines, contributing to AT dysfunction (ATD) and metabolic dysregulation. Numerous articles link specific changes in the gut microbiota (GM) to the development of obesity and its associated disorders, highlighting the role of diet, particularly fatty acid composition, in modulating the taxonomic profile. The aim of this study was to analyze the effect of a medium-fat-content diet (11%) supplemented with omega-3 fatty acids (D2) on the development of obesity, and on the composition of the GM compared with a control diet with a low fat content (4%) (D1) over a 6-month period. The effect of omega-3 supplementation on metabolic parameters and the modulation of the immunological microenvironment in visceral adipose tissue (VAT) was also evaluated. Six-weeks-old mice were adapted for two weeks and then divided into two groups of eight mice each: a control group D1 and the experimental group D2. Their body weight was recorded at 0, 4, 12, and 24 weeks post-differential feeding and stool samples were simultaneously collected to determine the GM composition. Four mice per group were sacrificed on week 24 and their VAT was taken to determine the immune cells phenotypes (M1 or M2 macrophages) and inflammatory biomarkers. Blood samples were used to determine the glucose, total LDL and HDL cholesterol LDL, HDL and total cholesterol, triglycerides, liver enzymes, leptin, and adiponectin. Body weight measurement showed significant differences at 4 (D1 = 32.0 ± 2.0 g vs. D2 = 36.2 ± 4.5 g, p-value = 0.0339), 12 (D1 = 35.7 ± 4.1 g vs. D2 = 45.3 ± 4.9 g, p-value = 0.0009), and 24 weeks (D1 = 37.5 ± 4.7 g vs. D2 = 47.9 ± 4.7, p-value = 0.0009). The effects of diet on the GM composition changed over time: in the first 12 weeks, α and ß diversity differed considerably according to diet and weight increase. In contrast, at 24 weeks, the composition, although still different between groups D1 and D2, showed changes compared with previous samples, suggesting the beneficial effects of omega-3 fatty acids in D2. With regard to metabolic analysis, the results did not reveal relevant changes in biomarkers in accordance with AT studies showing an anti-inflammatory environment and conserved structure and function, which is in contrast to reported findings for pathogenic obesity. In conclusion, the results suggest that the constant and sustained administration of omega-3 fatty acids induced specific changes in GM composition, mainly with increases in Lactobacillus and Ligilactobacillus species, which, in turn, modulated the immune metabolic response of AT in this mouse model of obesity.

Mixed T Helper1/T Helper2/T Cytotoxic Profile in Subjects with Chronic Chagas Disease with Hypersensitivity Reactions to Benznidazole.

Dermatitis is the most common adverse event during treatment with benznidazole in chronic Chagas disease and is probably mediated by T cells. A set of molecules representative of the different type IV hypersensitivity reactions was evaluated in the circulation and skin biopsies of Trypanosoma cruzi-infected subjects presenting dermatitis during benznidazole administration. Through cytometric bead assays and enzyme-linked immunosorbent assay capture techniques, the serum levels of cytokines, chemokines, proapoptotic molecules, and mediators of the activation and migration of eosinophils and T cells were measured in subjects infected with Trypanosoma cruzi who exhibited skin adverse events (n = 22) and compared with those without adverse events (n = 37) during benznidazole therapy. Serum levels of interleukin- 5 (IL-5), soluble Fas cell surface death receptor ligand (FAS-L), and interferon γ-induced protein (IP-10) significantly increased at 7 to 30 days posttreatment with benznidazole and decreased thereafter in subjects with dermatitis but not in those without dermatitis. Circulating eotaxin levels were lower in subjects with dermatitis than in those without. Two patterns emerged in the skin biopsies: a T helper 1/T cytotoxic profile and a T helper 2/T cytotoxic profile with the presence of CD4+ and CD8+ T cells. Increased low-density lipoprotein (LDL), glutamic-oxaloacetic transaminase (GOT), uremia, and T cell activation emerged as risk factors for the development of dermatitis during benznidazole administration. These results support a delayed-type hypersensitivity reaction to benznidazole, involving CD4+ and CD8+ T cells and eosinophils, and a mixed cytokine profile. This study provides new insights for better management of adverse drug reactions to benznidazole. IMPORTANCE This study identified the risk factors for the development of adverse reactions to benznidazole and identified a set molecule to monitor the appearance of these reactions. This knowledge might improve the safety of benznidazole administration.

N-(4-Methoxyphenyl)Pentanamide, a Simplified Derivative of Albendazole, Displays Anthelmintic Properties against the Nematode Toxocara canis.

Infections caused by parasitic helminths have enormous health, social, and economic impacts worldwide. The treatment and control of these diseases have been dependent on a limited set of drugs, many of which have become less effective, necessitating the search for novel anthelmintic agents. In this study, a simplified compound, N-(4-methoxyphenyl)pentanamide (N4MP), based on the structure of the most widely used anthelmintic (albendazole), was chemically prepared using 4-anisidine and pentanoic acid. N-(4-Methoxyphenyl)pentanamide was evaluated in vitro against the nematode Toxocara canis, an ascarid roundworm of animals that can infect humans. Similar to albendazole, bioassays showed that N-(4-methoxyphenyl)pentanamide affected the viability of parasites in a time- and concentration-dependent manner. Interestingly, N-(4-methoxyphenyl)pentanamide showed a profile of lower cytotoxicity to human and animal cell lines than albendazole. Pharmacokinetic, drug-likeness, and medicinal chemistry friendliness studies demonstrated an excellent drug-likeness profile for N-(4-methoxyphenyl)pentanamide as well as an adherence to major pharmaceutical companies' filters. Collectively, the results of this study demonstrate that the molecular simplification of albendazole to give N-(4-methoxyphenyl)pentanamide may be an important pipeline in the discovery of novel anthelmintic agents. IMPORTANCE Infections caused by parasitic helminths have enormous health, social, and economic impacts worldwide. The treatment and control of these diseases have been dependent on a limited set of drugs, many of which have become less effective, necessitating the search for novel anthelmintic agents. Considering this scenario, the present study reports the preparation of N-(4-methoxyphenyl)pentanamide (N4MP), a simplified molecule based on the structure of the most widely used anthelmintic (albendazole). N4MP was evaluated in vitro against the nematode Toxocara canis, a common ascarid roundworm of domestic animals that can infect humans. Similar to albendazole, bioassays showed that N4MP affected the viability of parasites in a time- and concentration-dependent manner but displayed a profile of lower cytotoxicity to human and animal cell lines than albendazole. Therefore, this study demonstrates that the molecular simplification of albendazole to give N4MP may be an important pipeline in the discovery of novel anthelmintic agents.

Caracterización in situ de poblaciones de Aloysia gratissima var. gratissima recolectadas del noreste de la provincia de San Luis, Argentina / In situ characterization of populations of Aloysia gratissima var. gratissima collected from the northeast of the province of San Luis, Argentina

Abstract: The aerial part of Aloysia gratissima (Gil lies & Hook. ex Hook.) Tronc., "Usillo", is used as aromatic and medicinal. It is a shrub of up to 3 meters, distributed in North America, from the south of the USA to the north of Mexico, and in South America up to the 37th parallel. As in other native sp ecies, the demand is covered by harvesting in wild populations, which brings about the deterioration of the resource and lack of homogeneity of the harvested product. The variability was characterized in nine populations of A. gratissima var. gratissima fr om the northeast of San Luis, Argentina, based on morphological and phytochemical characters. It was found that the species in the region presents considerable heterogeneity. Diversity was detected in the chemical characteristics of the essential oils anal yzed and the prevalence of mono and sesquiterpenes was related to the olfactory identities identified. The main components were the sesquiterpene spatulenol and the monoterpene 1,8 cineole

Resumen: La parte aérea de Aloysia gratissima (Gillies & Hook. ex Hook.) Tronc., "usillo", es utilizada como aromática y medicinal. Es un arbusto de hasta 3 metros, distribuido en Norteamerica, desde e l sur de EEUU hasta el norte de México, y en Sudamerica hasta el paralelo 37°. Al igual que en otras especies nativas, la demanda es cubierta por recolección en poblaciones silvestres, lo cual trae aparejado el deterioro del recurso y falta de homogeneidad del producto cosechado. Se caracterizó la variabilidad en nueve poblaciones de A. gratissima var. gratissima del noreste de San Luis, Argentina, en base a caracteres morfológicos y fitoquímicos. Se encontró que la especie en la región presenta una conside rable heterogeneidad. Se detectó diversidad en las características químicas de los aceites esenciales analizados y se relacionó la prevalencia de mono y sesquiterpenos con las identidades olfativas identificadas. Los componentes mayoritarios fueron el sesq uiterpeno espatulenol y el monoterpeno 1,8 cineol.

Loop-Mediated Isothermal Amplification of Trypanosoma cruzi DNA for Point-of-Care Follow-Up of Anti-Parasitic Treatment of Chagas Disease.

A loop-mediated isothermal amplification assay was evaluated as a surrogate marker of treatment failure in Chagas disease (CD). A convenience series of 18 acute or reactivated CD patients who received anti-parasitic treatment with benznidazole was selected-namely, nine orally infected patients: three people living with HIV and CD reactivation, five chronic CD recipients with reactivation after organ transplantation and one seronegative recipient of a kidney and liver transplant from a CD donor. Fifty-four archival samples (venous blood treated with EDTA or guanidinium hydrochloride-EDTA buffer and cerebrospinal fluid) were extracted using a Spin-column manual kit and tested by T. cruzi Loopamp kit (Tc-LAMP, index test) and standardized real-time PCR (qPCR, comparator test). Of them, 23 samples were also extracted using a novel repurposed 3D printer designed for point-of-care DNA extraction (PrintrLab). The agreement between methods was estimated by Cohen's kappa index and Bland-Altman plot analysis. The T. cruzi Loopamp kit was as sensitive as qPCR for detecting parasite DNA in samples with parasite loads higher than 0.5 parasite equivalents/mL and infected with different discrete typing units. The agreement between qPCR and Tc-LAMP (Spin-column) or Tc-LAMP (PrintrLab) was excellent, with a mean difference of 0.02 [CI = -0.58-0.62] and -0.04 [CI = -0.45-0.37] and a Cohen's kappa coefficient of 0.78 [CI = 0.60-0.96] and 0.90 [CI = 0.71 to 1.00], respectively. These findings encourage prospective field studies to validate the use of LAMP as a surrogate marker of treatment failure in CD.

Synthesis, Structural Characterization, and In Vitro and In Silico Antifungal Evaluation of Azo-Azomethine Pyrazoles (PhN2(PhOH)CHN(C3N2(CH3)3)PhR, R = H or NO2).

The azo-azomethine imines, R1-N=N-R2-CH=N-R3, are a class of active pharmacological ligands that have been prominent antifungal, antibacterial, and antitumor agents. In this study, four new azo-azomethines, R1 = Ph, R2 = phenol, and R3 = pyrazol-Ph-R' (R = H or NO2), have been synthesized, structurally characterized using X-ray, IR, NMR and UV-Vis techniques, and their antifungal activity evaluated against certified strains of Candida albicans and Cryptococcus neoformans. The antifungal tests revealed a high to moderate inhibitory activity towards both strains, which is regulated as a function of both the presence and the location of the nitro group in the aromatic ring of the series. These biological assays were further complemented with molecular docking studies against three different molecular targets from each fungus strain. Molecular dynamics simulations and binding free energy calculations were performed on the two best molecular docking results for each fungus strain. Better affinity for active sites for nitro compounds at the "meta" and "para" positions was found, making them promising building blocks for the development of new Schiff bases with high antifungal activity.

Plants and Natural Products with Activity against Various Types of Coronaviruses: A Review with Focus on SARS-CoV-2.

COVID-19 is a pandemic disease caused by the SARS-CoV-2 virus, which is potentially fatal for vulnerable individuals. Disease management represents a challenge for many countries, given the shortage of medicines and hospital resources. The objective of this work was to review the medicinal plants, foods and natural products showing scientific evidence for host protection against various types of coronaviruses, with a focus on SARS-CoV-2. Natural products that mitigate the symptoms caused by various coronaviruses are also presented. Particular attention was placed on natural products that stabilize the Renin-Angiotensin-Aldosterone System (RAAS), which has been associated with the entry of the SARS-CoV-2 into human cells.

Transcription Landscape of the Early Developmental Biology in Pigs.

Since pre- and postnatal development are programmed during early prenatal life, studies addressing the complete transcriptional landscape during organogenesis are needed. Therefore, we aimed to disentangle differentially expressed (DE) genes between fetuses (at 35 days old) and embryos (at 25 days old) through RNA-sequencing analysis using the pig as model. In total, 1705 genes were DE, including the top DE IBSP, COL6A6, HBE1, HBZ, HBB, and NEUROD6 genes, which are associated with developmental transition from embryos to fetuses, such as ossification, skeletal muscle development, extracellular matrix organization, cardiovascular system, erythrocyte differentiation, and neuronal system. In pathway analysis, embryonic development highlighted those mainly related to morphogenic signaling and cell interactions, which are crucial for transcriptional control during the establishment of the main organs in early prenatal development, while pathways related to myogenesis, neuronal development, and cardiac and striated muscle contraction were enriched for fetal development, according to the greater complexity of organs and body structures at this developmental stage. Our findings provide an exploratory and informative transcriptional landscape of pig organogenesis, which might contribute to further studies addressing specific developmental events in pigs and in other mammals.

Comparison of Argentinean microbiota with other geographical populations reveals different taxonomic and functional signatures associated with obesity.

Accumulating evidence suggests that various genetic and environmental factors contribute to the development of obesity. Among the latter, the gut microbiota has emerged as a critical player in the regulation of human metabolism and health and the development of non-communicable chronic diseases. Considering that no information on this matter is available in Argentina, our aim was to identify the microorganisms associated with obesity as well as their potential functionality. Using high throughput sequencing of 16SrRNA bacterial gene and diverse bioinformatics tools, we observed that the gut microbiota of obese and overweight individuals differs qualitatively and quantitatively from that from their lean counterparts. The comparison of the gut microbiota composition in obese subjects from Argentina, US and UK showed that the beta diversity significantly differs among the three countries, indicating that obesity-associated microbiota composition changes according to the geographical origin of the individuals. Moreover, four distinct microbiotypes were identified in obese individuals, whose prevalence and metabolic pathway signature differed according to the country, indicating that obesity associated dysbiosis would comprise several structures. In summary, identification of distinct taxonomic signatures associated with obesity might be a novel promising tool to stratify patients based on their microbiome configuration to design strategies for managing obesity.

Higher Cognitive Reserve Is Associated with Better Working Memory Performance and Working-Memory-Related P300 Modulation.

This study aims to examine how two levels of cognitive reserve, as evidenced by reading syntactic skill, modify performance and neural activity in a two-load-level (high vs. low) working memory (WM) task. Two groups of participants with different reading skills, high and low, were obtained from clustering analysis. We collected the P300 event-related potential component during the performance of the WM Sternberg task. The high reading performance (HRP) group showed a higher percentage of correct answers than the low reading performance (LRP) group in the negative probes of the WM task, which were probe stimuli not included in the memory set presented immediately before. Both groups showed P300 amplitude modulations, that is, larger WM-related P300 amplitudes for low than for high WM loads. Following the behavioral results, the HRP group displayed smaller WM-related amplitude modulations than the LRP group in the negative probes. The findings together suggest that higher levels of reading skill are associated with improved neural efficiency, which reflects in a better working memory performance.