Multifunctional Organometallic Compounds Active against Infective Trypanosomes: Ru(II) Ferrocenyl Derivatives with Two Different Bioactive Ligands.

Human African trypanosomiasis (HAT, sleeping sickness) and American trypanosomiasis (Chagas disease) are endemic zoonotic diseases caused by genomically related trypanosomatid protozoan parasites (Trypanosoma brucei and Trypanosoma cruzi, respectively). Just a few old drugs are available for their treatment, with most of them sharing poor safety, efficacy, and pharmacokinetic profiles. Only fexinidazole has been recently incorporated into the arsenal for the treatment of HAT. In this work, new multifunctional Ru(II) ferrocenyl compounds were rationally designed as potential agents against these pathogens by including in a single molecule 1,1'-bis(diphenylphosphino)ferrocene (dppf) and two bioactive bidentate ligands: pyridine-2-thiolato-1-oxide ligand (mpo) and polypyridyl ligands (NN). Three [Ru(mpo)(dppf)(NN)](PF6) compounds and their derivatives with chloride as a counterion were synthesized and fully characterized in solid state and solution. They showed in vitro activity on bloodstream T. brucei (EC50 = 31-160 nM) and on T. cruzi trypomastigotes (EC50 = 190-410 nM). Compounds showed the lowest EC50 values on T. brucei when compared to the whole set of metal-based compounds previously developed by us. In addition, several of the Ru compounds showed good selectivity toward the parasites, particularly against the highly proliferative bloodstream form of T. brucei. Interaction with DNA and generation of reactive oxygen species (ROS) were ruled out as potential targets and modes of action of the Ru compounds. Biochemical assays and in silico analysis led to the insight that they are able to inhibit the NADH-dependent fumarate reductase from T. cruzi. One representative hit induced a mild oxidation of low molecular weight thiols in T. brucei. The compounds were stable for at least 72 h in two different media and more lipophilic than both bioactive ligands, mpo and NN. An initial assessment of the therapeutic efficacy of one of the most potent and selective candidates, [Ru(mpo)(dppf)(bipy)]Cl, was performed using a murine infection model of acute African trypanosomiasis. This hit compound lacks acute toxicity when applied to animals in the dose/regimen described, but was unable to control parasite proliferation in vivo, probably because of its rapid clearance or low biodistribution in the extracellular fluids. Future studies should investigate the pharmacokinetics of this compound in vivo and involve further research to gain deeper insight into the mechanism of action of the compounds.

Exodoncia de premolar inferior supernumerario con posterior colocación de Fibrina Rica en Plaquetas y Leucocitos (L-PRF)

Los dientes supernumerarios son una anomalía odontogénica, consiste en aumento del número dentario con respecto a la cantidad normal. La Fibrina rica en Plaquetas y Leucocitos (L-PRF) es una matriz rica en plaquetas y glóbulos blancos, que promueve la curación y regeneración de los tejidos. La exodoncia de un tercer premolar inferior supernumerario con posterior colocación de membrana de L-PRF. Paciente de sexo masculino de 27 años de edad con un probable premolar supernumerario por lingual. Se programó la cirugía incluyendo L-PRF. Se realizó extracción de sangre para preparar la membrana de L-PRF, anestesia, incisión lineal, despegamiento mucoperióstico, osteotomía, exodoncia, tratamiento del lecho quirúrgico colocando la membrana de L-PRF y sutura interdental. Se prescribió medicación antibiótica, antiinflamatoria y analgésica. La técnica con L-PRF es sencilla y económica. Los resultados postoperatorios fueron favorables, observándose una buena cicatrización, ausencia de dolor, edema o infección.

Supernumerary teeth are an odontogenic anomaly, involving an increase in the number of teeth compared to the normal amount. Platelet-Rich Fibrin (L-PRF) is a matrix rich in platelets and white blood cells that promotes tissue healing and regeneration. The Extraction of a supernumerary lower third premolar followed by placement of L-PRF membrane. A 27-year-old male patient with a probable lingual supernumerary premolar. Surgery was scheduled, including L-PRF. Blood was extracted to prepare the L-PRF membrane, followed by anesthesia, linear incision, mucoperiosteal detachment, osteotomy, extraction, treatment of the surgical site with L-PRF membrane placement, and interdental suturing. Antibiotic, anti-inflammatory, and analgesic medication was prescribed. The L-PRF technique is simple and cost-effective. Postoperative results were favorable, with good healing, absence of pain, swelling, or infection was observed.

Hybrid Controller Based on Numerical Methods for Chemical Processes with a Long Time Delay.

A hybrid control framework is proposed as an alternative for long time delays in chemical processes. The hybrid approach mixes the numerical methods in an internal mode control (IMC) structure, which uses the particle swarm optimization (PSO) algorithm to improve the adjustment of the controller parameters. Simulation tests are carried out on linear systems of high order and inverse response, both with dominant delay, and tests on a nonlinear process (chemical reactor). The performance of the proposed controller is stable and satisfactory despite nonlinearities in various operating conditions, set-point changes, process disturbances, and modeling errors. In addition, experimental tests were performed on a setup composed of two heaters and two temperature sensors mounted on an Arduino microcontroller-based board called the Temperature Control Laboratory (TCLab), with an additional software delay introduced. The merits and drawbacks of each scheme are analyzed using radar charts, comparing the control methods with different performance measures for set-point and disturbance changes. Furthermore, the new controller uses PSO to improve the tuning parameters.

Mode of action of p-quinone derivatives with trypanocidal activity studied by experimental and in silico models.

Quinones are attractive pharmacological scaffolds for developing new agents for the treatment of different transmissible and non-transmissible human diseases due to their capacity to alter the cell redox homeostasis. The bioactivity and potential mode of action of 19 p-quinone derivatives fused to different aromatic rings (carbo or heterocycles) and harboring distinct substituents were investigated in infective Trypanosoma brucei brucei. All the compounds, except for a furanequinone (EC50=38 µM), proved to be similarly or even more potent (EC50 = 0.5-5.5 µM) than the clinical drug nifurtimox (EC50 = 5.3 µM). Three furanequinones and one thiazolequinone displayed a higher selectivity than nifurtimox. Two of these selective hits resulted potent inhibitors of T. cruzi proliferation (EC50=0.8-1.1 µM) but proved inactive against Leishmania infantum amastigotes. Most of the p-quinones induced a rapid and marked intracellular oxidation in T. b. brucei. DFT calculations on the oxidized quinone (Q), semiquinone (Q•-) and hydroquinone (QH2) suggest that all quinones have negative ΔG for the formation of Q•-. Qualitative and quantitative structure-activity relationship analyses in two or three dimensions of different electronic and biophysical descriptors of quinones and their corresponding bioactivities (killing potency and oxidative capacity) were performed. Charge distribution over the quinone ring carbons of Q and Q.- and the frontier orbitals energies of SUMO (Q.-) and LUMO (Q) correlate with their oxidative and trypanocidal activity. QSAR analysis also highlighted that both bromine substitution in the p-quinone ring and a bulky phenyl group attached to the furane and thiazole rings (which generates a negative charge due to the π electron system polarized by the nearby heteroatoms) are favorable for activity. By combining experimental and in silico procedures, this study disclosed important information about p-quinones that may help to rationally tune their electronic properties and biological activities.

Gonococci resistant to current antimicrobial management standards: a new threat to global public health.

Gonorrhea is the second most common sexually transmitted bacterial infection on the planet and is caused by a Gram-negative cocco, Neisseria gonorrhoeae. Currently, the preferred regimen for the management of this disease in Brazil is a combination of antimicrobials, in this case, ceftriaxone and azithromycin. However, over time, the gonococcus developed a decrease in susceptibility to the regimen used, which resulted in frank resistance to antimicrobials, progressively reducing the therapeutic options available. Thus, the study presented here aims to analyze and discuss the current scenario of resistance of N. gonorrhoeae to the antimicrobials used to date, to encourage discussion on the subject in the academic environment. For this purpose, 47 articles indexed in the Bireme, PubMed, Scielo and UpToDate platforms were selected.

A Simple Bioluminescent Assay for the Screening of Cytotoxic Molecules Against the Intracellular Form of Leishmania infantum.

This chapter describes a viability assay for the intracellular (amastigote) and clinically relevant form of Leishmania infantum that is based on the detection of bioluminescence (BL) signal. The assay uses a reporter cell line of L. infantum that expresses constitutively a redshifted luciferase from Photinus pyralis and murine macrophages (cell line J774.A1) as host cells for infection. The host cell line was selected because it is a differentiated cell line, easy to manipulate in vitro, and advantageous for ethical reasons. This chapter introduces an assay designed for the screening of bioactive compounds/molecules employing a 96-well microplate and a 24 h treatment. The assay setup shows excellent balance between simplicity (cell culture manipulation/infection and timing) and quality parameters, as well as potential to detect drug-like molecules acting in a fast and cytotoxic manner.

A Simple, Robust, and Affordable Bioluminescent Assay for Drug Screening Against Infective African Trypanosomes.

This chapter introduces a simple and robust in vitro viability assay to screen bioactive small molecules (e.g., natural, synthetic) against the monomorphic and infective (bloodstream) form of Trypanosoma brucei brucei. The assay relies on a bioluminescent transgenic parasite harboring a genetically encoded copy of a thermostable redshifted firefly luciferase from Photinus pyralis.The major advantages of the assay are simplicity and cost efficiency, along with excellent quality parameters. The bioassay allows estimating parasite numbers and viability (and metabolic state) as a function of bioluminescence (BL) signal. Parasites are grown in the presence of the molecules of interest in a 96-well microplate, and 24 h later, BL is determined with a simple protocol lacking washing steps, using cost-efficient reagents with a reasonable readout time for high-throughput applications.

Caracterización clínica de la peritonitis secundaria en una institución de tercer nivel y factores relacionados con mortalidad / Clinical characterization of secondary peritonitis in a tertiary level of care institution and factors related to mortality

Introducción. La peritonitis secundaria es una enfermedad con altos índices de mortalidad, por lo que se considera de gran importancia identificar los factores que inciden en ella. Método. Se realizó un estudio analítico entre 2019 y 2020 en el que se incluyeron pacientes con peritonitis secundaria, se caracterizaron las variables más relacionadas con el pronóstico, como aspectos demográficos y clínicos, y se analizó la asociación entre la mortalidad y estas variables. Resultados. La mortalidad hospitalaria fue del 30,7 %, encontrando como condiciones relacionadas con la mortalidad la ubicación de la fuente séptica en abdomen superior, la presencia de dolor en abdomen superior, atención en UCI, control del foco en la primera intervención, pacientes que cursaron con falla renal, edad del paciente y valores de hemoglobina. Conclusiones. En la cohorte estudiada se encontraron índices de mortalidad dos veces superiores a los reportados en Suramérica y 1,5 veces a los del resto del país. El mayor poder predictivo de mortalidad en el análisis bivariado fue dado por la presencia de falla renal y el valor de la hemoglobina.

Introduction. Secondary peritonitis is a disease with high mortality rates, so it is considered of great importance to identify the factors that affect it. Methods. An analytical study was carried out between 2019 and 2020 in which patients with secondary peritonitis were included, the variables most related to prognosis were characterized, such as demographic and clinical aspects, and the association between mortality and these variables was analyzed. Results. Hospital mortality was 30.7%, finding conditions related to mortality to be the location of the septic source in the upper abdomen, the presence of pain in the upper abdomen, care in the ICU, control of the focus in the first intervention, patients who underwent kidney failure, patient age, and hemoglobin values. Conclusion. Mortality rates were found in the studied cohort twice higher than those reported in South America and 1.5 times higher than those of the rest of the country. The greatest predictive power of mortality in the bivariate analysis was given by the presence of kidney failure and hemoglobin.

Guillain-Barré syndrome in a COVID-19 patient / Síndrome de Guillain-Barré en paciente con COVID-19

Abstract Coronavirus type 2 is a P-coronavirus whose infection is characterized by a predominantly respiratory clinical picture. However, neurological symptoms are garnering great interest related to pulmonary infection and direct viral invasion of the central nervous system, with a possible association between Guillain-Barré syndrome and SARS-CoV-2 infection. This report describes this relationship in a 44-year-old female patient with classical Guillain-Barré syndrome signs and symptoms on admission, and respiratory signs and symptoms six days prior to the onset of neurological symptoms. There were positive SARS-CoV IgG and IgM blood tests and an epidemiological link of direct contact with people infected with SARS-CoV-2. She required ICU care due to the risk of respiratory failure, along with immunoglobulin treatment, but did not need mechanical ventilation; she improved and was discharged. One month later she consulted again and was thought to have had a Guillain-Barré relapse. She was hospitalized and treated until she progressed and her symptoms resolved. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2204).

Resumen El coronavirus tipo 2 es un P-coronavirus cuya infección se caracteriza por clínica de predominio respiratorio; sin embargo, la sintomatologia neurológica está cobrando gran interés asociada a la infección pulmonar e invasión directa del virus al sistema nervioso central. Siendo posible la aso ciación entre el síndrome de Guillain-Barré y la infección por virus SARS-CoV-2. En este reporte se describe dicha asociación en una paciente femenina de 44 años de edad, con clínica clásica de síndrome de Guillain-Barré al ingreso y clínica respiratoria seis días previos a la instalación de los síntomas neurológicos. Reportándose serologías IgG e IgM para SARS-CoV-positivas y nexo epidemiológico de contacto directo con personas infectadas por SARS-CoV-2. Requirió manejo en UCI por riesgo de falla respiratoria, manejo con inmunoglobulinas, sin requerimiento de ventilación mecánica, presentando mejoría y otorgándose salida. Un mes después reconsulta, se considera recaída de Guillain-Barré, se hospitaliza, se inicia manejo hasta evolución y resolución de síntomas. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2204).

Drug-like molecules with anti-trypanothione synthetase activity identified by high throughput screening.

Trypanothione synthetase (TryS) catalyses the synthesis of N1,N8-bis(glutathionyl)spermidine (trypanothione), which is the main low molecular mass thiol supporting several redox functions in trypanosomatids. TryS attracts attention as molecular target for drug development against pathogens causing severe and fatal diseases in mammals. A drug discovery campaign aimed to identify and characterise new inhibitors of TryS with promising biological activity was conducted. A large compound library (n = 51,624), most of them bearing drug-like properties, was primarily screened against TryS from Trypanosoma brucei (TbTryS). With a true-hit rate of 0.056%, several of the TbTryS hits (IC50 from 1.2 to 36 µM) also targeted the homologue enzyme from Leishmania infantum and Trypanosoma cruzi (IC50 values from 2.6 to 40 µM). Calmidazolium chloride and Ebselen stand out for their multi-species anti-TryS activity at low µM concentrations (IC50 from 2.6 to 13.8 µM). The moieties carboxy piperidine amide and amide methyl thiazole phenyl were identified as novel TbTryS inhibitor scaffolds. Several of the TryS hits presented one-digit µM EC50 against T. cruzi and L. donovani amastigotes but proved cytotoxic against the human osteosarcoma and macrophage host cells (selectivity index ≤ 3). In contrast, seven hits showed a significantly higher selectivity against T. b. brucei (selectivity index from 11 to 182). Non-invasive redox assays confirmed that Ebselen, a multi-TryS inhibitor, induces an intracellular oxidative milieu in bloodstream T. b. brucei. Kinetic and mass spectrometry analysis revealed that Ebselen is a slow-binding inhibitor that modifies irreversible a highly conserved cysteine residue from the TryS's synthetase domain. The most potent TbTryS inhibitor (a singleton containing an adamantine moiety) exerted a non-covalent, non-competitive (with any of the substrates) inhibition of the enzyme. These data feed the drug discovery pipeline for trypanosomatids with novel and valuable information on chemical entities with drug potential.

A simple, robust, and affordable bioluminescent assay for drug discovery against infective African trypanosomes.

African trypanosomiasis is a major problem for human and animal health in endemic countries, where it threatens millions of people and affects economic development. New drugs are needed to overcome the toxicity, administration, low efficacy, and resistance issues of the current chemotherapy. Robust, simple, and economical high-throughput, whole-cell-based assays are required to accelerate the identification of novel chemical entities. With this aim, we generated a bioluminescent cell line of the bloodstream stage of Trypanosoma brucei brucei and established a screening assay. Trypanosomes were stably transfected to constitutively express a thermostable red-shifted luciferase. The growth phenotype and drug sensitivity of the reporter cell line were essentially identical to that of the parental cell line. The endogenous luciferase activity, measured by a simple bioluminescence assay, proved to be proportional to parasite number and metabolic status. The assay, optimized to detect highly potent compounds in a 96-well-plate format, was validated by screening a small compound library (inter-assay values for Z' factor and coefficient variation were 0.77 and 5.8%, respectively). With a hit-confirmation ratio of ~97%, the assay was potent enough to identify several hits with EC50 ≤ 10 µM. Preliminary tests indicated that the assay can be scaled up to a 384-well-plate format without compromising its robustness. In summary, we have generated reporter trypanosomes and a simple, robust, and affordable bioluminescence screening assay with great potential to speed up the early-phase drug discovery against African trypanosomes.

Nox2-derived superoxide radical is crucial to control acute Trypanosoma cruzi infection.

Trypanosoma cruzi is a flagellated protozoan that undergoes a complex life cycle between hematophagous insects and mammals. In humans, this parasite causes Chagas disease, which in thirty percent of those infected, would result in serious chronic pathologies and even death. Macrophages participate in the first stages of infection, mounting a cytotoxic response which promotes massive oxidative damage to the parasite. On the other hand, T. cruzi is equipped with a robust antioxidant system to repeal the oxidative attack from macrophages. This work was conceived to explicitly assess the role of mammalian cell-derived superoxide radical in a murine model of acute infection by T. cruzi. Macrophages derived from Nox2-deficient (gp91phox-/-) mice produced marginal amounts of superoxide radical and were more susceptible to parasite infection than those derived from wild type (wt) animals. Also, the lack of superoxide radical led to an impairment of parasite differentiation inside gp91phox-/- macrophages. Biochemical or genetic reconstitution of intraphagosomal superoxide radical formation in gp91phox-/- macrophages reverted the lack of control of infection. Along the same line, gp91phox-/- infected mice died shortly after infection. In spite of the higher lethality, parasitemia did not differ between gp91phox-/- and wt animals, recapitulating an observation that has led to conflicting interpretations about the importance of the mammalian oxidative response against T. cruzi. Importantly, gp91phox-/- mice presented higher and disseminated tissue parasitism, as evaluated by both qPCR- and bioimaging-based methodologies. Thus, this work supports that Nox2-derived superoxide radical plays a crucial role to control T. cruzi infection in the early phase of a murine model of Chagas disease.

Ensemble learning application to discover new trypanothione synthetase inhibitors.

Trypanosomatid-caused diseases are among the neglected infectious diseases with the highest disease burden, affecting about 27 million people worldwide and, in particular, socio-economically vulnerable populations. Trypanothione synthetase (TryS) is considered one of the most attractive drug targets within the thiol-polyamine metabolism of typanosomatids, being unique, essential and druggable. Here, we have compiled a dataset of 401 T. brucei TryS inhibitors that includes compounds with inhibitory data reported in the literature, but also in-house acquired data. QSAR classifiers were derived and validated from such dataset, using publicly available and open-source software, thus assuring the portability of the obtained models. The performance and robustness of the resulting models were substantially improved through ensemble learning. The performance of the individual models and the model ensembles was further assessed through retrospective virtual screening campaigns. At last, as an application example, the chosen model-ensemble has been applied in a prospective virtual screening campaign on DrugBank 5.1.6 compound library. All the in-house scripts used in this study are available on request, whereas the dataset has been included as supplementary material.

Automatic ladybird beetle detection using deep-learning models.

Fast and accurate taxonomic identification of invasive trans-located ladybird beetle species is essential to prevent significant impacts on biological communities, ecosystem functions, and agricultural business economics. Therefore, in this work we propose a two-step automatic detector for ladybird beetles in random environment images as the first stage towards an automated classification system. First, an image processing module composed of a saliency map representation, simple linear iterative clustering superpixels segmentation, and active contour methods allowed us to generate bounding boxes with possible ladybird beetles locations within an image. Subsequently, a deep convolutional neural network-based classifier selects only the bounding boxes with ladybird beetles as the final output. This method was validated on a 2, 300 ladybird beetle image data set from Ecuador and Colombia obtained from the iNaturalist project. The proposed approach achieved an accuracy score of 92% and an area under the receiver operating characteristic curve of 0.977 for the bounding box generation and classification tasks. These successful results enable the proposed detector as a valuable tool for helping specialists in the ladybird beetle detection problem.

New Pd-Fe ferrocenyl antiparasitic compounds with bioactive 8-hydroxyquinoline ligands: a comparative study with their Pt-Fe analogues.

In the search for a more effective chemotherapy for the treatment of Human African Trypanosomiasis, a disease caused by the parasite Trypanosoma brucei, the development of ferrocenyl compounds has arisen as a promising strategy. In this work, five new Pd-Fe heterobimetallic [PdII(L)(dppf)](PF6) compounds, including 8-hydroxyquinolyl derivatives HL1-HL5 as bioactive ligands and dppf = 1,1'-bis(diphenylphosphino)ferrocene as the organometallic co-ligand, were synthesized and fully characterized in the solid state and in solution. Molecular structures of three compounds were solved by single crystal X-ray diffraction methods. The compounds displayed submicromolar or micromolar IC50 values against bloodstream T. brucei (IC50: 0.33-1.2 µM), and good selectivity towards the pathogen (SI: 4-102) with respect to mammalian macrophages (cell line J774). The new Pd complexes proved to be 2-fold to 45-fold more potent than the drug nifurtimox but most of them are less active than their Pt analogues. Potential molecular targets were studied. The complexes interact with DNA but they do not alter the intracellular thiol-redox homeostasis of the parasite. In order to understand and predict the main structural determinants on the anti-T. brucei activity, a search of quantitative structure-activity relationships (QSAR) was performed including all the [M(L)(dppf)](PF6) complexes, where M = Pd(ii) or Pt(ii), currently and previously developed by us. The correlation obtained shows the relevance of the electronic effects, the lipophilicity and the type of metal. According to the QSAR study, compounds with electron-withdrawing ligands, higher lipophilicity and harboring Pt would result in higher T. brucei cytotoxicity. From the whole series of [M(L)(dppf)](PF6) compounds developed, where M = Pt(ii) or Pd(ii) and HL = 8-hydroxyquinolyl derivatives, Pt-dppf-L4 (IC50 = 0.14 µM, SI = 48) was selected to perform an exploratory pre-clinical study in infected mice. This hit compound lacks acute toxicity when applied to animals in the dose/regimen described and exerts an anti-proliferative effect on parasites, which extends animal survival but is not curative.

An approach to automatic classification of Culicoides species by learning the wing morphology.

Fast and accurate identification of biting midges is crucial in the study of Culicoides-borne diseases. In this work, we propose a two-stage method for automatically analyzing Culicoides (Diptera: Ceratopogonidae) species. First, an image preprocessing task composed of median and Wiener filters followed by equalization and morphological operations is used to improve the quality of the wing image in order to allow an adequate segmentation of particles of interest. Then, the segmentation of the zones of interest inside the biting midge wing is made using the watershed transform. The proposed method is able to produce optimal feature vectors that help to identify Culicoides species. A database containing wing images of C. obsoletus, C. pusillus, C. foxi, and C. insignis species was used to test its performance. Feature relevance analysis indicated that the mean of hydraulic radius and eccentricity were relevant for the decision boundary between C. obsoletus and C. pusillus species. In contrast, the number of particles and the mean of the hydraulic radius was relevant for deciding between C. foxi and C. insignis species. Meanwhile, for distinguishing among the four species, the number of particles and zones, and the mean of circularity were the most relevant features. The linear discriminant analysis classifier was the best model for the three experimental classification scenarios previously described, achieving averaged areas under the receiver operating characteristic curve of 0.98, 0.90, and 0.96, respectively.

Mechanistic and biological characterisation of novel N5-substituted paullones targeting the biosynthesis of trypanothione in Leishmania.

Trypanothione synthetase (TryS) produces N1,N8-bis(glutathionyl)spermidine (or trypanothione) at the expense of ATP. Trypanothione is a metabolite unique and essential for survival and drug-resistance of trypanosomatid parasites. In this study, we report the mechanistic and biological characterisation of optimised N5-substituted paullone analogues with anti-TryS activity. Several of the new derivatives retained submicromolar IC50 against leishmanial TryS. The binding mode to TryS of the most potent paullones has been revealed by means of kinetic, biophysical and molecular modelling approaches. A subset of analogues showed an improved potency (EC50 0.5-10 µM) and selectivity (20-35) against the clinically relevant stage of Leishmania braziliensis (mucocutaneous leishmaniasis) and L. infantum (visceral leishmaniasis). For a selected derivative, the mode of action involved intracellular depletion of trypanothione. Our findings shed light on the molecular interaction of TryS with rationally designed inhibitors and disclose a new set of compounds with on-target activity against different Leishmania species.

Elongator Subunit 3 (Elp3) Is Required for Zebrafish Trunk Development.

Transfer RNAs (tRNAs) are the most post-transcriptionally modified RNA species. Some of these modifications, especially the ones located in the anti-codon loop, are required for decoding capabilities of tRNAs. Such is the case for 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U), synthetized by the Elongator complex. Mutants for its sub-units display pleiotropic phenotypes. In this paper, we analyze the role of elp3 (Elongator catalytic sub-unit) in zebrafish development. We found that it is required for trunk development; elp3 knock-down animals presented diminished levels of mcm5s2U and sonic hedgehog (Shh) signaling activity. Activation of this pathway was sufficient to revert the phenotype caused by elp3 knockdown, indicating a functional relationship between Elongator and Shh through a yet unknown molecular mechanism.

Cellular Dynamics during Spinal Cord Regeneration in Larval Zebrafish.

The study of spinal cord regeneration using diverse animal models, which range from null to robust regenerative capabilities, is imperative for understanding how regeneration evolved and, eventually, to treat spinal cord injury and paralysis in humans. In this study, we used electroablation to fully transect the spinal cord of zebrafish larvae (3 days postfertilization) and examined regeneration of the tissue over time. We used transgenic lines to follow immune cells, oligodendrocytes, and neurons in vivo during the entire regenerative process. We observed that immune cells are recruited to the injury site, oligodendrocytes progenitor cells (olig2-expressing cells) invade, and axons cross the gap generated upon damage from anterior to reinnervate caudal structures. Together with the recovery of cell types and structures, a complete reversal of paralysis was observed in the lesioned larvae indicating functional regeneration. Finally, using transplantation to obtain mosaic larvae with single-labeled neurons, we show that severed spinal axons exhibited varying regenerative capabilities and plasticity depending on their original dorsoventral position in the spinal cord.

Factores de riesgo cardiovascular y anomalías electrocardiográficas en estudiantes universitarios de Itá, Paraguay / Cardiovascular risk factors and electrocardiographic anomalies in university students from Itá, Paraguay

Introducción: La determinación de los factores de riesgo cardiovascular debe realizarse en etapas precoces como en la edad universitaria. Esto tiene como propósito identificar los factores modificables, sobre todo en edades tempranas de la vida. Objetivos: Determinar la frecuencia de alteraciones antropométricas, hipertensión arterial, hiperglicemia, hábito de fumar, sedentarismo, ingesta de alcohol y alteraciones electrocardiográficas en los alumnos de la Universidad Gran Asunción (Itá, Paraguay) en los años 2017 y 2018. Materiales y métodos: Estudio observacional prospectivo realizado en varones y mujeres, mayores de 18 años, estudiantes de todas las carreras universitarias, que acudieron en los años 2017 y 2018. Se realizó examen clínico y electrocardiográfico previo consentimiento informado. Se aplicó estadística descriptiva para la descripción de las variables. Resultados: Se incluyeron 121 mujeres (edad media 21±4 años) y 62 varones (edad media 20±3 años). Se hallaron las siguientes frecuencias: sobrepeso 27%, obesidad 14%, circunferencia abdominal aumentada 26%, índice de conicidad aumentado 45%, hipertensión arterial 18%, sedentarismo 80%, hábito de fumar 0,5% e ingesta de alcohol 15%. Las anomalías electrocardiográficas se detectaron en 19% siendo la más frecuente la bradicardia sinusal. Se detectaron dos casos de síndrome QTc prolongado en pacientes asintomáticos. Conclusión: Los factores de riesgo cardiovascular más frecuentes fueron el sedentarismo, el sobrepeso y la hipertensión arterial. Las anomalías electrocardiográficas se detectaron en 19% siendo la bradicardia sinusal la más frecuente.

Introduction: The determination of cardiovascular risk factors should be carried out in early life stages such as university age. The purpose of this is to identify modifiable factors, especially at early ages of life. Objectives: To determine the frequency of anthropometric alterations, arterial hypertension, hyperglycemia, smoking habit, sedentary lifestyle, alcohol intake and electrocardiographic alterations in the students of the Gran Asunción University (Itá, Paraguay) in the years 2017 and 2018. Materials and methods: Prospective observational study carried out in males and females, over 18 years old, students of all university careers, who attended the university in the years 2017 and 2018. A clinical and electrocardiographic examination was performed with informed consent. Descriptive statistics was applied for the description of the variables. Results: One hundred twenty one women were included (average age 21±4 years) and 62 men (average age 20±3 years). The following frequencies were found: overweight 27%, obesity 14%, increased abdominal circumference 26%, conicity index increased 45%, hypertension 18%, sedentary lifestyle 80%, smoking habit 0.5% and alcohol intake 15%. The electrocardiographic anomalies were detected in 19%, with sinus bradycardia being the most frequent. Two cases of prolonged QTc syndrome were detected in asymptomatic patients. Conclusion: The most frequent cardiovascular risk factors were sedentary lifestyle, overweight and high blood pressure. Electrocardiographic abnormalities were detected in 19%, with sinus bradycardia being the most frequent.