Abstract Introduction. Cocoa cultivation in tropical areas is a commercially viable agroecological alternative that allows for productive diversification and sustainable soil management through the use of organic fertilization. Objective. To evaluate the development of four cocoa varieties (INIFAP 4, INIFAP 8, INIFAP 9, and Almendra Blanca) under the climatic conditions of the Úrsulo Galván region, Veracruz, Mexico. Materials and methods. An experiment was conducted between winter (December 2021) and summer (June 2022), using a completely randomized design with four treatments and ten replications. Conventional agronomic management was employed, with the addition of 10 kg of compost per tree, followed by 3 kg of vermicompost. At four months into the study, 50 g of urea, 50 g of ammonium diphosphate, and 50 g of potassium chloride were incorporated. The study included analysis of variance and Tukey’s tests (α 0.05). Results. Statistical equality was found for height, diameter, and number of branches. The cocoa’s response to temperature, precipitation, relative humidity, and wind showed that these factors influenced the expression of its productive potential, as well as its morphology and yield, without adapting to the climatic conditions under study. Conclusion. The development of the studied varieties was homogeneous based on the climatic conditions of the Ursulo Galvan region, with the Almendra Blanca variety standing out.

Resumen Introducción. El cultivo del cacao en las zonas tropicales es una alternativa comercial de interés agroecológico, que permite la diversificación productiva y el manejo sustentable de los suelos al emplear abonado orgánico. Objetivo. Evaluar el desarrollo de cuatro variedades de cacao (INIFAP 4, INIFAP 8, INIFAP 9 y Almendra Blanca) en las condiciones climatológicas de la región de Úrsulo Galván, Veracruz, México. Materiales y métodos. Se realizó un experimento, entre invierno (diciembre 2021) y verano (junio 2022), bajo un diseño completamente al azar, distribuido en cuatro tratamientos y diez repeticiones. El manejo agronómico fue convencional, se agregaron 10 kg de composta por árbol, seguidos de 3 kg de vermicompost. A los cuatro meses del estudio se incorporaron 50 g de urea, 50 g de difosfato de amonio y 50 g de cloruro de potasio. El estudio incluyó análisis de varianza y pruebas de Tukey (α 0,05). Resultados. Se encontró igualdad estadística para altura, diámetro y número de ramas. La respuesta del cacao a temperatura, precipitación, humedad relativa y viento, demostró que afectaron la expresión de su potencial productivo, así como su morfología y rendimiento, no adaptándose a las condiciones climáticas en estudio. Conclusión. El desarrollo de las variedades en estudio fue homogéneo, con base en las condiciones climatológicas de la región Úrsulo Galván, destacándose la variedad Almendra Blanca.

Abstract The exploration of the biodiversity of cyanobacteria and microalgae holds great promise for obtaining pigments of industrial interest. This study focused on the bioprospecting of these organisms to obtain pigments of industrial interest together with enriched biomass. We investigated the impact of photoperiod and concentration of C/N/P nutrient sources in heterotrophic cultures, controlling specific variables such as light intensity, volume, pH, temperature, air flow and time to produce phycobiliproteins in Arthrospira platensis UTEX1926 and total carotenoids in Scenedesmus sp. using a nonfactorial Plackett‒Burman design in STATISTICA 7.0 software. The biomass concentration was determined by dry weight, while the concentrations of phycocyanin and carotenoids were determined spectrophotometrically at specific wavelengths. Heterotrophic cultures demonstrated superior productivity, with phycocyanin and carotenoids achieving percentages of 7% and 0.4% (w/w), respectively, and an R2 value of 0.99. Among the influential parameters, potassium diphosphate and sodium bicarbonate played pivotal roles in the final deposition of carotenoids and phycocyanin, respectively, yielding concentrations of 96.5 mg/L phycocyanin and 6.5 mg/L carotenoids.

Resumen La exploración de la biodiversidad de cianobacterias y microalgas es muy prometedora para la obtención de pigmentos de interés industrial. Este estudio se centra en la bioprospección de estos organismos para obtener pigmentos de interés industrial junto con biomasa enriquecida. Investigamos el impacto del fotoperiodo y la concentración de fuentes de nutrientes C/N/P en cultivos heterótrofos, controlando variables específicas como la intensidad luminosa, volumen, pH, temperatura, flujo de aire y tiempo para la producción de ficobiliproteínas en Arthrospira platensis UTEX1926 y carotenoides totales en Scenedesmus sp. Empleando un diseño Plackett‒Burman no factorial en el software STATISTICA 7.0. La concentración de biomasa fue determinada por peso seco, mientras que la concentración de ficocianinas y carotenoides fueron determinadas espectrofotométricamente a longitudes de onda específicas. Los cultivos heterótrofos demostraron una productividad superior, alcanzando las ficocianinas y los carotenoides porcentajes del 7% y el 0,4% (% p/p) respectivamente, y un notable valor R2 de 0,99. Entre los parámetros influyentes, el difosfato potásico y el bicarbonato sódico desempeñaron papeles fundamentales en la deposición final de carotenoides y ficocianinas, respectivamente, alcanzando concentraciones de 96,5 mg/L de ficocianinas y 6,5 mg/L de carotenoides.

Resumen Este trabajo presenta la síntesis de nanopartículas de difosfato de potasio-hierro, KFeP2O7, implantadas sobre carbón activado preparado a partir de restos de olote de maíz. La composición química y la estructura del compósito de carbono activado/difosfato de potasio-hierro (AC/KFP) se analizó mediante Difracción de Rayos X, Microscopía Electrónica de Barrido y Microscopía Electrónica de Transmisión. Se realizaron pruebas complementarias para determinar las características de la superficie, como el área de la superficie y el punto de carga cero (pHpzc). Además, la valoración ácido-base permitió determinar la densidad de sitios de superficie del compósito AC/KFP. Adicionalmente, las propiedades adsortivas del compósito AC/KFP frente a U (VI) fueron evaluadas utilizando el método de lotes.

Abstract This work deals with the synthesis of nanoparticles of iron-potassium diphosphate, KFeP2O7, implanted on activated carbon produced from corncob debris. The chemical composition and structure of activated carbon/potassium-iron diphosphate (AC/KFP) composite was analyzed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Complementary tests were conducted to determine surface characteristics such as surface area and point of zero charge (pHpzc). Further, the acid-base titration enabled to determine the surface sites density of AC/KFP composite. Adsorptive properties of AC/KFP composite vis à vis U(VI) was then tested using the batch method.

Terpenes are the most abundant class of natural product that exist in nature. They possess a myriad of industrial applications including pharmaceutical, perfumery and flavors, bulk chemicals, and fuel. Intriguingly, until today, the vast majority of characterized terpenoids have been isolated from plants and fungi, and only in recent years bacteria were found to generate a representative reservoir of terpenoids molecules. Mining Streptomyces sp. CBMAI 2042 genome data has revealed the presence of five terpene cyclase genes. Chemical analysis of mycelium extract of this bacteria strain has unveiled at least 28 volatile terpenes molecules, where three encoding sesquiterpene cyclase (STC) genes are apparently responsible for their biosynthesis. The cyclic products obtained by incubation of these three purified recombinant STCs with farnesyl diphosphate (FPP) were analyzed by gas chromatography-mass spectrometry (GC-MS) and identified using the Van den Dool and Kratz equation.

Abstract Ligustrazine is widely used for the treatment of cardiovascular diseases in traditional Chinese medication. It has been reported that Ligustrazine decreases the concentration of intracellular calcium ions (Ca2+); however, the underlying mechanism remains unknown. In the present study, the effect of Ligustrazine on adenosine diphosphate (ADP)-induced platelet aggregation was evaluated using a turbidimetric approach. The changes in concentration of intracellular Ca2+ stimulated by ADP was measured using fluo-4, a fluorescent Ca2+ indicator dye. The mRNA expression of stromal interaction molecule l (STIM1) and Orai1, calcium sensor, was determined using real-time PCR. In addition, the protein expression of STIM1, Orai1, and serum/glucocorticoid-regulated protein kinase 1 (SGK1) was determined using Western blot analysis. The data demonstrated that Ligustrazine significantly suppressed platelet aggregation in a dose-dependent manner and reduced the concentration of intracellular Ca2+ triggered by ADP. Our data showed that Ligustrazine treatment inhibited the expression of STIM1 and Orai1 induced by ADP at both mRNA and protein levels, and suppressed the protein expression of SGK1. Taken together, our data indicated that Ligustrazine suppressed platelet aggregation by partly inhibiting the activities of calcium sensors, thereby suggesting that Ligustrazine may be a promising candidate for the treatment of platelet aggregation.

Abstract Introduction: Sticky platelet syndrome (SPS) is a prothrombotic condition characterized by increased platelet aggregation that causes arterial and venous thrombosis. Its diagnosis is reached by identifying increased aggregation using low concentrations of adenosine diphosphate and epinephrine in platelet aggregation tests. Objectives: To identify common mutations through exome sequencing in two patients from the same family diagnosed with SPS and, thus, contribute to the molecular study of this disease. Materials and methods: Descriptive study. In January 2018, exome sequencing was performed in a 10-year-old patient treated at Fundación HOMI (Bogotá D.C., Colombia), index case, and in one of his adult first-degree relatives, both with a history of thrombotic disease and diagnosed with SPS. Exome sequencing was performed at the Complexo Hospitalario Universitario de Santiago de Compostela (Spain) using the SureSelect Clinical Research Exome V2 software by Agilent. Results: Exome sequencing led to detect genetic variants in both cases when compared with the reference sequence. The following variant was identified in the two samples: a cytosine to thymine transition at position c.236 (NM_000174.4) of the glycoprotein (GP)Ib-IX-V complex platelet membrane receptor, which causes a heterozygous transition of the amino acid threonine to isoleucine (i.e., a transition from hydrophilic amino acid to a hydrophobic amino acid) at position p. 79 of the extracellular leucine-rich repeat domain of GPIba subunit of the (GP)Ib-IX complex, involving a conformational change of the main receptor of ligands IB alpha, which might result in platelet hyperaggregation and thrombosis. This variant has not been described in patients with SPS to date. Conclusion: The mutation identified in both samples could be related to SPS considering the importance of glycoprotein IX in platelet function.

Resumen Introducción. El síndrome de plaqueta pegajosa (SPP) es una condición protrombótica caracterizada por un incremento de la agregabilidad plaquetaria que causa trombosis arterial y venosa. Su diagnóstico se realiza al identificar el aumento de la agregabilidad utilizando bajas concentraciones de adenosín difosfato y epinefrina en pruebas de agregación plaquetaria. Objetivos. Identificar mutaciones comunes mediante secuenciación del exoma en dos pacientes de una misma familia con diagnóstico de SPP y, de esta forma, contribuir al estudio molecular de esta enfermedad. Materiales y métodos. Estudio descriptivo en el que se realizó secuenciación del exoma en un paciente de 10 años atendido en la Fundación HOMI (Bogotá, Colombia), caso índice, y en uno de sus familiares adultos en primer grado, ambos con antecedente de enfermedad trombótica y diagnosticados con SPP. La secuenciación del exoma se realizó en el Complexo Hospitalario Universitario de Santiago de Compostela (España) con el programa SureSelect Clinical Research Exome V2 de Agilent. Resultados. En la secuenciación del exoma se detectaron variantes genéticas en ambos casos en comparación con la secuencia de referencia. En las muestras de ambos pacientes se identificó una variante heterocigota consistente en una transición de citosina a timina en la posición c.236 (NM_000174.4) que provoca el cambio del aminoácido treonina por isoleucina en la posición p.79 del dominio extracelular repetitivo rico en leucina (subunidad GPIba del complejo de la glicoproteína Ib-IX-V) y que podría provocar el cambio conformacional del receptor principal del ligando Ib alfa, así como hiperagregación plaquetaria y trombosis. Esta variante no ha sido descrita previamente en pacientes con SPP. Conclusión. La mutación identificada en las muestras estudiadas podría estar relacionada con el SPP considerando la importancia de la glicoproteína IX en las funciones plaquetarias.

Breast cancer is the leading cause of cancer death in Chilean women and worldwide. It is a heterogeneous disease and four different subtypes have been identified based on clinical, histological and molecular features, which correlate with different treatment tumor sensitivity. Triple negative breast cancer is characterized by its aggressiveness, early relapse, and a greater tendency to present in advanced stages. It frequently affects young women, with cancer family history, especially breast or ovarian cancer. The approved systemic therapy for triple negative breast cancer is chemotherapy; however, recently, targeted therapies with checkpoint inhibitors and polyadenosine diphosphate ribose polymerase inhibitors have been shown to be effective in selected patients and have been added to the therapeutic arsenal for triple negative breast cancer. Given the appearance of these new strategies, it seems relevant to understand the heterogeneity of this disease, the mechanisms of action behind new therapies, clinical results, and the criteria to select patients for molecular therapies. We present a review of the current systemic therapy of this breast cancer subtype.

Resumen El cáncer de mama (CM) es la principal causa de muerte por cáncer en mujeres chilenas. Es una enfermedad heterogénea, en la cual se han identificado cuatro subtipos básicos, determinados según características clínicas, histológicas y moleculares, los que se relacionan a estrategias terapéuticas. El CM triple negativo (CMTN) se caracteriza por su agresividad, recaída temprana y mayor tendencia a presentarse en etapas avanzadas. Frecuentemente afecta a mujeres jóvenes o con antecedentes familiares de CM u ovario. La única terapia sistémica aprobada para el CMTN es la quimioterapia; sin embargo, recientemente terapias moleculares con inhibidores de puntos de control inmune e inhibidores de la poli-adenosina difosfato ribosa polimerasa, han mostrado eficacia en pacientes seleccionados, y se han agregado al arsenal terapéutico para CMTN. Dada la aparición de estas nuevas estrategias, parece relevante entender la heterogeneidad de esta enfermedad, los mecanismos de acción de las nuevas terapias, resultados clínicos y criterios de selección de pacientes para terapias moleculares. Presentamos una revisión de la terapia sistémica actual del CMTN.

BACKGROUND An increasing amount of research has led to the positioning of nucleoside diphosphate kinases (NDPK/NDK) as key metabolic enzymes among all organisms. They contribute to the maintenance the intracellular di- and tri- phosphate nucleoside homeostasis, but they also are involved in widely diverse processes such as gene regulation, apoptosis, signal transduction and many other regulatory roles. OBJETIVE Examine in depth the NDPKs of trypanosomatid parasites responsible for devastating human diseases (e.g., Trypanosoma cruzi, Trypanosoma brucei and Leishmania spp.) which deserve special attention. METHODS The earliest and latest advances in the topic were explored, focusing on trypanosomatid NDPK features, multifunctionality and suitability as molecular drug targets. FINDINGS Trypanosomatid NDPKs appear to play functions different from their host counterparts. Evidences indicate that they would perform key roles in the parasite metabolism such as nucleotide homeostasis, drug resistance, DNA damage responses and gene regulation, as well as host-parasite interactions, infection, virulence and immune evasion, placing them as attractive pharmacological targets. MAIN CONCLUSIONS NDPKs are very interesting multifunctional enzymes. In the present review, the potential of trypanosomatid NDPKs was highlighted, raising awareness of their value not only with respect to parasite biology but also as molecular targets.

Abstract Mammals experience some degree of hypoxia during their lifetime. In response to hypoxic challenge, mammalian cells orchestrate specific responses at transcriptional and posttranslational level, which lead to changes in purine metabolites in order to cope with threatening conditions. The aim of this study was to evaluate the response of the enzymes involved in purine metabolism at human muscle cells under hypoxic conditions. Muscle cells in culture were exposed to hypoxia and the enzymatic activity of inosine monophosphate dehydrogenase (IMPDH), xanthine oxidase (XO), purine nucleoside phosphorylase (PNP) and hypoxanthine guanine phosphoribosyl transferase (HGPRT) as well as their transcript expression were quantified under normoxic and hypoxic conditions. Purine metabolite (hypoxanthine (HX), xanthine (X), uric acid (UA), inosine monophosphate (IMP), inosine, nicotinamide adenine dinucleotide (NAD+), adenosine, adenosine monophosphate (AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP), guanosine diphosphate (GDP) and guanosine triphosphate (GTP)) concentrations were also quantified. Significant reduction of IMPDH activity as well as in HX and IMP concentrations (p < 0.05) were observed after hypoxia, suggesting a decrease in the purines de novo synthesis. After hypoxia a global reduction of transcripts was observed, suggesting a reduction of the metabolic machinery of purine metabolism to new steady states that balance ATP demand and ATP supply pathways.

Resumen Los mamíferos experimentan cierto grado de hipoxia durante su vida. Como respuesta al reto de hipoxia, las células de mamíferos orquestan respuestas específicas a nivel transcripcional y postraduccional que conducen a cambios en los metabolitos de purinas para hacer frente a las condiciones amenazantes. El objetivo de este estudio fue evaluar la respuesta de las enzimas involucradas en el metabolismo de las purinas de células musculares humanas a condiciones hipóxicas. Las células musculares en cultivo se expusieron a hipoxia y la actividad enzimática de la inosina monofosfato deshidrogenasa (IMPDH), la xantina oxidasa (XO), la purina nucleósido fosforilasa (PNP) y la hipoxantina guanina fosforribosil transferasa (HGPRT), así como su expresión de transcripción, se cuantificaron bajo condiciones de normoxia e hipoxia. Los metabolitos de purina (hipoxantina (HX), xantina (X), ácido úrico (UA), monofosfato de inosina (IMP), inosina, dinucleótido de nicotinamida y adenina (NAD+), adenosina, monofosfato de adenosina (AMP), difosfato de adenosina (ADP), trifosfato de adenosina (ATP), difosfato de guanosina (GDP) y trifosfato de guanosina (GTP)) también se cuantificaron. Se observó una reducción significativa de la actividad de IMPDH y de las concentraciones de HX e IMP (p < 0.05) después de la hipoxia, lo que sugiere una disminución de la síntesis de novo de purinas. Después de la hipoxia, se observó una reducción global de la expresión transcripcional, lo que sugiere una reducción de la maquinaria metabólica del metabolismo de las purinas a nuevos estados estacionarios que equilibran la demanda de ATP y las vías de suministro de ATP.

ABSTRACT Introduction: Platelets contribute to hemostasis and inherited or acquired interruption; in its biochemical processes it can alter platelet function. These aggregation disorders have been associated with genetic diseases with connective tissue involvement such as Ehlers-Danlos syndrome, whose differential diagnosis with the spectrum of joint hypermobility is clinically and molecularly difficult. These entities with involvement of the collagen fibers and different clinical repercussions require differentials in their clinical diagnosis. Methods: 353 medical records of patients attended in the Genetics service of the William Soler Pediatric Hospital from September 2009 to 2012, with a diagnosis of joint hypermobility by Beighton and Ehlers-Danlos criteria according to Villefranche (1997) were reviewed. Patients aged 5-18 years were included with documented results of the platelet aggregation study, assessed by specialists in hematology. Results: Platelet aggregation disorders were found in 79 of 86 patients (92%). In 7 cases with hypermobility of 65 with this diagnosis (10%), the results were negative. The 21 with Ehlers-Danlos syndrome had affectations with platelet phospholipids. Joint hypermobility was associated with the combination adenosine diphosphate (ADP) -epinephrine and the Ehlers-Danlos with the combination ADP-epinephrine-collagen-phospholipids. Conclusions: Patients with joint hypermobility showed an association to granule release defects with agonists such as ADP-epinephrine and Ehlers-Danlos with the availability of phospholipids, related to platelet shape change. This result can be a tool to know the platelet functional endophenotype as a differential element in collagen fiber disorders.

RESUMEN Introducción: Las plaquetas contribuyen a la hemostasia y la interrupción heredada o adquirida; en sus procesos bioquímicos pueden alterar la función plaquetaria. Estos trastornos de agregación se han asociado a enfermedades genéticas con afectación del tejido conectivo como el síndrome Ehlers-Danlos, cuyo diagnóstico diferencial con el espectro de hipermovilidad articular resulta difícil clínica y molecularmente. Estas entidades con afectación en las fibras colágenas y diferente repercusión clínica precisan diferenciales en su diagnóstico clínico. Métodos: Se revisaron 353 historias clínicas de pacientes atendidos en el Servicio de Genética del Hospital Pediátrico William Soler desde septiembre del 2009 al 2012, con diagnóstico de hipermovilidad articular por criterios de Beighton y de Ehlers-Danlos según Villefranche (1997). Se incluyó a los pacientes de 5-18 años con resultados documentados del estudio de agregación plaquetaria, valorados por especialistas en hematología. Resultados: Se encontraron trastornos de agregación plaquetaria en 79 de 86 pacientes (92 %). En 7 casos con hipermovilidad de 65 con este diagnóstico (10 %), los resultados fueron negativos. Los 21 con síndrome Ehlers-Danlos tuvieron afectaciones con los fosfolípidos plaquetarios. La hipermovilidad articular estuvo asociada a la combinación difosfato de adenosina (ADP)-epinefrina y el Ehlers-Danlos a la combinación ADP-epinefrina-colágeno-fosfolípidos. Conclusiones: Los pacientes con hipermovilidad articular mostraron asociación a defectos de liberación de gránulos con agonistas como el ADP-epinefrina y los Ehlers-Danlos con la disponibilidad de los fosfolípidos, relacionados con el cambio de forma plaquetaria. Este resultado puede ser una herramienta para conocer el endofenotipo funcional plaquetario como elemento diferencial en los trastornos de la fibra colágena.

RESUMO Em pacientes com fibrilação atrial, a anticoagulação padrão com antagonista da vitamina K mais terapia antiplaquetária dupla (DAPT) com inibidor de P2Y12 e aspirina é o padrão de tratamento após intervenção coronária percutânea (ICP). Enquanto essa terapia reduz o risco de trombose e derrame, aumenta o risco de sangramento. Não está claro se o efeito antiplaquetário da aspirina e do clopidogrel pode piorar a fibrilação atrial (FA). OBJETIVO Analisar a resistência à aspirina plaquetária (AR) e ao clopidogrel (CR) em pacientes coronarianos agudos (SCA) com base no ritmo sinusal (SR) e na FA. MÉTODOS Neste estudo prospectivo, foram incluídos 543 pacientes (idade média: 62±12 anos; intervalo: 26-89 anos) em uso de aspirina e clopidogrel após o diagnóstico de síndrome coronariana aguda. AR e CR foram analisados por um dispositivo Multiplate® MP-0120, utilizando o método de agregometria de sangue total. RESULTADOS Os pacientes com FA apresentaram valores significativamente maiores para idade, volume médio de plaquetas e proteína C reativa de alta sensibilidade (p<0,01 para cada parâmetro). Da mesma forma, a agregação induzida por ácido araquidônico (Aspi) foi maior nos pacientes com FA em comparação com os pacientes com SR (666±218 vs. 187±179, p<0,001). Entre os pacientes com SCA, significativamente mais pacientes do sexo feminino apresentaram FA (p<0,001). A incidência de hipertensão no grupo FA foi maior em comparação com o grupo SR (p<0,001). No entanto, os níveis de difosfato de adenosina não foram expressivamente significativos nos dois grupos. CONCLUSÃO Nossos achados indicam que o efeito inibitório plaquetário da aspirina foi pior em pacientes com FA, sugerindo que a eficácia da aspirina pode ser menor na profilaxia do tromboembolismo, com maior risco de sangramento.

SUMMARY In patients with atrial fibrillation, standard anticoagulation with a vitamin K antagonist plus dual antiplatelet therapy with a P2Y12 inhibitor and aspirin is the standard of care after percutaneous coronary intervention (PCI). While this therapy reduces the risk of thrombosis and stroke, it increases the risk of bleeding. It is unclear whether the antiplatelet effect of aspirin and clopidogrel may worsen atrial fibrillation (AF). OBJECTIVE Thus we aimed to analyze platelet aspirin resistance (AR) and clopidogrel resistance (CR) in acute coronary (ACS) patients based on sinus rhythm (SR) and AF. METHODS In this prospective trial, we included 543 patients (mean age: 62± 12 years; range: 26 - 89 years) who were on aspirin and clopidogrel therapy after the diagnosis of acute coronary syndrome. AR and CR were analyzed by a Multiplate® MP-0120 device by using the method of whole blood aggregometry. RESULTS AF patients had significantly higher age, mean platelet volume, and High-Sensitivity C-Reactive Protein (p< 0.01 for each parameter). Similarly, Arachidonic-acid induced (ASPI) aggregation was higher in AF patients compared to SR patients (666±218 vs. 187±179, p<0.001). Among the ACS patients, significantly more female patients had AF (p<0.001). The incidence of hypertension in the AF group was higher compared to the SR group (p<0.001). However, adenosine diphosphate levels were not at a significant level in the two groups. CONCLUSION Our findings indicate that the platelet inhibitory effect of Aspirin was worse for patients with AF, suggesting that the effectiveness of aspirin may be less in the prophylaxis of thromboembolism and more a bleeding risk.

Abstract The poly (adenosine diphosphate (ADP)-ribosyl) polymerase inhibitors (PARPi) selectively kill cancer cells with BRCA1 or BRCA2 (BRCA)-mutations. It has been proposed that cell death induction after PARPi depends on unrepaired double strand breaks (DSBs) that accumulate due to the homologous recombination deficiency of BRCA-mutated cells. Such accumulation of DSBs is inferred mainly from the high levels of DNA damage markers like phosphorylated histone H2AX. Herein, we developed a model of isogenic cell lines to show that depletion of BRCA causes PARPi-triggered cell death, replication stress (phosphorylated-H2AX and 53BP1 foci), and genomic instability. However, persistent DSBs accumulation was not detected under the same experimental conditions. Hence, at least in this cellular model, the trigger for cell death in PARPi-treated BRCA-depleted samples is not the accumulation of unrepaired DSBs. Instead, cell death better correlates with a rapid and aberrant resolution of DSBs by error-prone pathways that leads to severe chromosomic aberrations. Therefore, our results suggest that in PARPi-treated BRCA-deficient cells, chromosome aberrations may dually trigger both genomic instability and cell death.

BACKGROUND NME23/NDPKs are well conserved proteins found in all living organisms. In addition to being nucleoside diphosphate kinases (NDPK), they are multifunctional enzymes involved in different processes such as DNA stability, gene regulation and DNA repair among others. TcNDPK1 is the canonical NDPK isoform present in Trypanosoma cruzi, which has nuclease activity and DNA-binding properties in vitro. OBJECTIVES In the present study we explored the role of TcNDPK1 in DNA damage responses. METHODS TcNDPK1 was expressed in mutant bacteria and yeasts and over-expressed in epimastigotes. Mutation frequencies, tolerance to genotoxic agents and activity of DNA repair enzymes were evaluated. FINDINGS Bacteria decreased about 15-folds the spontaneous mutation rate and yeasts were more resistant to hydrogen peroxide and to UV radiation than controls. Parasites overexpressing TcNDPK1 were able to withstand genotoxic stresses caused by hydrogen peroxide, phleomycin and hidroxyurea. They also presented less genomic damage and augmented levels of poly(ADP)ribose and poly(ADP)ribose polymerase, an enzyme involved in DNA repair. MAIN CONCLUSION These results strongly suggest a novel function for TcNDPK1; its involvement in the maintenance of parasite’s genome integrity.

We describe an on-flow zonal affinity-based chromatography assay to screen ligands for the nucleoside diphosphate kinase B enzyme (NME2) from Homo sapiens. For the first time, we have covalently immobilized NME2 on the surface of an open fused silica capillary reactor (NME2-ICER) and placed the reactor before the analytical column, which resulted in a two-dimensional liquid chromatography-based system. We evaluated the pH effect on immobilized NME2 activity and carried out steady-state kinetic studies to compare free and immobilized NME2. Steady-state kinetic studies with the substrates adenosine 5’-triphosphate di(tris) salt dihydrate (ATP) and guanosine 5’-diphosphate sodium salt (GDP) resulted in apparent Michaelis-Menten constant values of 1136 and 713 mmol L-1, respectively. The ping-pong catalysis mechanism and substrate specificity were preserved after NME2 immobilization. By employing a reference inhibitor, (-)-epicatechin gallate (ECG), we verified the potential application of this method in NME2 ligand screening and NME2 inhibitor identification. The half maximum inhibitory concentration (IC50) for ECG was 161.3 ± 1.0 μmol L-1.

RESUMO OBJETIVO O objetivo deste estudo foi investigar os efeitos da síndrome do baixo triiodotironina (LT3S) na função plaquetária e nos fatores de coagulação em pacientes com síndrome nefrótica (SN). MÉTODOS Pacientes com síndrome nefrótica primária foram divididos em dois grupos, função tireoidiana normal (grupo A) e LT3S (grupo B), com base na presença ou não de LT3S. Indivíduos saudáveis foram selecionados como grupo de controle (grupo C). A função de coagulação do sangue foi analisada em cada grupo. A função de ativação plaquetária (CD62P, CD63) foi determinada por citometria de fluxo. A taxa de agregação plaquetária foi detectada por um método óptico usando adenosina difosfato e ácido araquidônico como indutores. RESULTADOS A proporção de síndrome nefrótica primária com LT3S foi de 23,2% (69/298). Em comparação com o grupo C, o grupo A apresentou níveis mais altos de CD62P e PAgTADP, e o grupo B apresentou maiores CD62P, CD63, PAgTAA e PAgTADP; a diferença teve significância estatística (P < 0,05). Não houve diferença significativa na patologia renal entre o grupo A e o grupo B (X2 = 4,957, P = 0,421). Em comparação com o grupo A, a proteína em urina de 24 horas, CD63, PAgTAA e PAgTADP foram maiores no grupo B, já APTT e Alb foram mais baixos. A diferença apresentou significância estatística (P < 0,05). A análise de regressão logística mostrou uma associação entre LT3S e CD36 (OR: 3,516; 95% IC: 1,742~8,186; P = 0,004) e PAgTAA (OR: 0,442; 95% IC: 1,001~1,251; P = 0,037). CONCLUSÃO Pacientes com síndrome nefrótica estão propensos à síndrome do baixo triiodotironina (LT3S). Pacientes com LT3S podem ter ativação plaquetária anormal e aumento da agregação plaquetária.

SUMMARY OBJECTIVE The objective of this study was to investigate the effects of low triiodothyronine syndrome (LT3S) on platelet function and clotting factors in patients with nephrotic syndrome(NS). METHODS Patients with primary nephrotic syndrome were divided into two groups, normal thyroid function (group A) and LT3S (group B), based on whether they had LT3S or not. Healthy subjects were selected as the control group (group C). Blood coagulation function was detected in each group. The platelet activation function (CD62P, CD63) was determined by flow cytometry. The platelet aggregation rate was detected by an optical method using adenosine diphosphate and arachidonic acid as inducers. RESULTS The proportion of primary nephrotic syndrome with LT3S was 23.2% (69/298). Compared with group C, group A had higher CD62P and PAgTADP, and group B had higher CD62P, CD63, PAgTAA, and PAgTADP; the difference was statistically significant (all P < 0.05). There was no significant difference in renal pathology between group A and group B (X2 = 4.957, P = 0.421). Compared with group A, the 24-hour urine protein, CD63, PAgTAA, and PAgTADP were higher in group B, and APTT and Alb were lower. The difference was statistically significant (P < 0.05). Logistic regression analysis showed that LT3S was associated with CD36 (OR: 3.516; 95% CI: 1.742~8.186; P = 0.004) and PAgTAA (OR: 0.442; 95% CI: 1.001~1.251; P = 0.037). CONCLUSION NS patients are prone to LT3S. Patients with LT3S may have abnormal platelet activation and increase of platelet aggregation.