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La depresión es uno de los trastornos más incapacitantes porque afecta todas las áreas de la vida y es dos veces más común en mujeres que en hombres. La rumiación se define como las ideas repetitivas sobre la propia tristeza, sus causas y posibles consecue ncias, es un predictor de algunas psicopatologías y es un factor fuertemente vinculado con la depresión. El propósito de este estudio fue evaluar las diferencias en rumiación por género en estudiantes universitarios. Participaron 500 estudiantes (250 hombr es y 250 mujeres) con una media 20.75 años (SD=1.84) de la Universidad Autónoma del Estado de Hidalgo. Se aplicaron la “Escala de Respuestas Rumiativas” ( ERR) y el “Inventario de Depresión de Beck” (BDI). Los resultados mostraron una correlación positiva entre rumiación y depresión, así como respuestas elevadas de rumiación y depresión en las mujeres, por lo que el factor género fue significativo en la correlación parcial.

The guidance and development of military law are needed and intended to guarantee the respect for human rights, rule of law and justice in the military environment, which among others are manifested through a system of law and order in the law number 25 of 2014 on the law of military discipline. Under the provisions of article 6 paragraph (1) of law number 25 0f 2014, then the law of military discipline should be imposed on any person who under the law equated with the military, including the citizens who are mobilized for their expertise in time of war. The enforcement is considered to be too early, given the sentencing of military discipline for offenders who have violated the law of military discipline must be performed by the Authorized adjudge (Ankum), but on the other hand, the law of number 25 of 2014 on the law military discipline does not provide any explicit and complete arrangements or provisions about the Ankum’s authority in enforcing discipline against citizen who are mobilized in time of war. Through the method of the normative legal research with an approach to the concept and approach to legislation, it can be concluded that assesment of vagueness of these arrangements is quite essential, considering that the vaqueness of these arrangements may result in legal uncertainty, therefore, it is needed more complete arrangement in order to implement the provisions of the law of military discipline against citizens who mobilized in time of war. Keywords : Authority, The Authorized adjudge, Citizens who are mobilized. Pembinaan dan pengembangan hukum militer diperlukan dan ditujukan untuk menjamin terciptanya penghormatan terhadap hak asasi manusia, kepastian hukum dan keadilan di lingkungan militer, yang diantaranya diwujudkan melalui suatu sistem dan tatanan hukum dalam Undang-Undang Nomor 25 Tahun 2014 tentang Hukum Disiplin Militer. Berdasarkan ketentuan Pasal 6 ayat (1) Undang-Undang Nomor 25 Tahun 2014, maka Hukum Disiplin Militer juga diberlakukan kepada setiap orang yang berdasarkan undang-undang dipersamakan dengan militer, diantaranya adalah warga negara yang dimobilisasi karena keahliannya pada waktu perang. Pemberlakuan ini dianggap terlampau dini, mengingat penjatuhan hukuman disiplin militer bagi pelaku yang melakukan pelanggaran hukum disiplin militer harus dilakukan oleh seorang Atasan Yang Berhak Menghukum (Ankum), namun di sisi lain, Undang-Undang Nomor 25 Tahun 2014 tentang Hukum Disiplin Militer tidak memberikan pengaturan secara tegas dan lengkap tentang kewenangan Ankum dalam menegakkan hukum disiplin terhadap warga negara yang dimobilisasi pada waktu perang. Melalui penelitian hukum normatif dengan pendekatan konsep hukum dan pendekatan perundangan-undangan, maka dapat disimpulkan bahwa pembahasan tentang kekaburan pengaturan ini merupakan hal yang cukup penting, mengingat kekaburan tersebut dapat menimbulkan ketidakpastian hukum, dan oleh karenanya diperlukan pengaturan lanjutan yang lebih lengkap dalam upaya menerapkan ketentuan hukum disiplin militer terhadap warga negara yang dimobilisasi pada waktu perang.

Abstract: INTRODUCTION: Leishmaniasis is a zoonotic disease caused by protozoa of the genus Leishmania . Cutaneous leishmaniasis is the most common form, with millions of new cases worldwide each year. Treatments are ineffective due to the toxicity of existing drugs and the resistance acquired by certain strains of the parasite. METHODS: We evaluated the activity of sodium nitroprusside in macrophages infected with Leishmania (Leishmania) amazonensis . Phagocytic and microbicidal activity were evaluated by phagocytosis assay and promastigote recovery, respectively, while cytokine production and nitrite levels were determined by ELISA and by the Griess method. Levels of iNOS and 3-nitrotyrosine were measured by immunocytochemistry. RESULTS: Sodium nitroprusside exhibited in vitro antileishmanial activity at both concentrations tested, reducing the number of amastigotes and recovered promastigotes in macrophages infected with L. amazonensis . At 1.5µg/mL, sodium nitroprusside stimulated levels of TNF-α and nitric oxide, but not IFN-γ. The compound also increased levels of 3-nitrotyrosine, but not expression of iNOS, suggesting that the drug acts as an exogenous source of nitric oxide. CONCLUSIONS: Sodium nitroprusside enhances microbicidal activity in Leishmania -infected macrophages by boosting nitric oxide and 3-nitrotyrosine.

ABSTRACT Background: The prevalence of Helicobacter pylori in obese candidates for bariatric surgery and its role in the emergence of inflammatory lesions after surgery has not been well established. Aim: To identify the incidence of inflammatory lesions in the stomach after bariatric surgery and to correlate it with H. pylori infection. Methods: This is a prospective study with 216 patients undergoing Roux-en-Y gastric bypass. These patients underwent histopathological endoscopy to detect H. pylori prior to surgery. Positive cases were treated with antibiotics and a proton inhibitor pump followed by endoscopic follow-up in the 6th and 12th month after surgery. Results: Most patients were female (68.1%), with grade III obesity (92.4%). Preoperative endoscopy revealed gastritis in 96.8%, with H. pylori infection in 40.7% (88/216). A biopsy was carried out in 151 patients, revealing H. pylori in 60/151, related to signs of inflammation in 90% (54/60). In the 6th and 12th month after surgery, the endoscopy and the histopathological exam showed a normal gastric pouch in 84% of patients and the incidence of H. pylori was 11% and 16%, respectively. The presence of inflammation was related to H. pylori infection (p

Meeting the target of 8000 steps/day, as recommended by many national governments and health authorities, can provide considerable physical and mental health benefits and is seen as a key target for reducing obesity levels and improving public health. However, to optimize the health benefits, walking should be performed at a “moderate” intensity. While there are numerous mobile fitness applications that monitor distance walked, none directly support walking at this cadence nor has there been any research into live feedback for walking cadence. We present a smartphone fitness application to help users learn how to walk at a moderate cadence and maintain that cadence. We apply real-time audio effects that diminish the audio quality of music when the target walking cadence is not being reached. This provides an immersive and intuitive application that can easily be integrated into everyday life as allows users to walk while listening to their own music and encourages eyes-free interaction. In this paper, we introduce our approach, design, initial lab evaluation and a controlled outdoor study. Results show that using music degradation decreases the number of below-cadence steps, that users felt they worked harder with our player and would use it while exercise walking.

The high cost of tuition and textbooks can have a negative impact on potential students from lower socioeconomic backgrounds. Open Educational Resources (OER) offers students a way to save educational costs while utilizing high-quality open textbooks. Up until now, there have been few studies focused on a specific provider of open textbooks. This study investigates open textbooks provided by OpenStax. Specifically, this study uses the COUP framework to examine: (1) cost reduction, (2) outcomes, (3) uses, and (4) the faculty perceptions of the quality of OpenStax textbooks. Additionally, we expanded the framework to address (5) the relationship between the perceived quality of the OpenStax textbook and the faculty perception of student performance, (6) the faculty’s intention to continue to adopt OpenStax textbooks, and (7) the perceived importance of accessibility to faculty who use OpenStax textbooks. Overall, the findings suggest that a significant amount of financial savings and a number of pedagogical shifts can be supported by the use of OpenStax textbooks.

Institutions of higher education are struggling to meet the growing demand for online courses and programs, partly because many faculty lack experience teaching online. The eCampus Quality Instruction Program (eQIP) is an online faculty development program developed to train faculty to design and teach fully online courses. The purpose of this article is to describe the eQIP (one institution’s multipronged approach to online faculty development), with a specific focus on how the overall success of the program is evaluated using surveys, analytics, and social network analysis. Reflections and implications for improving practice are discussed.

Resenha de PAUGAM, Serge (Org.) A pesquisa sociológica. Petrópolis: Editora Vozes, 2015.

Se encuentra por primera vez en el departamento de Antioquia (Colombia) y asociado al guayabo (Psidium guajava L.), la especie Greenidea ficicola Takahashi ( Hemiptera: Sternorrhyncha: Aphididae) colectada durante muestreos intensivos realizados durante el primer semestre de 2008 en el Valle de Aburrá y municipios aledaños. Dicha especie de áfido también fue colectada en falso laurel (Ficus benjamina). Dada la importancia que tienen los frutos de guayabo en la alimentación humana y de los animales domésticos en Colombia, es necesario registrar esta especie con el fin de tomar medidas en lo referente a programas de muestreo de sus poblaciones, estudio de su ciclo de vida y determinar los posibles controladores biológicos, que conduzcan al mejor conocimiento de este insecto y faciliten la toma de medidas de contención a su dispersión en el país.It is founded for the first time, the species of aphid Greenidea ficicola, Takahashi (Hemiptera: Sternorrhyncha: Aphididae) in the Antioquia Department (Colombia) associated to guava plants (Psidium guajava L.). The species was collected during intensive sampling done during the first semester of 2008, in the Aburra Valley and near municipalities. The species of aphid was also collected on "false laurel" (Ficus benjamina). Due to the importance of guava as food for humans as well as wild and domestic animals, it is considered important to report this species so that contention measures can be taken specially related with more sampling, life cycle and potential biological control agents to get to know better this pest and control its spread in the country.

En cuatro localidades de la zona de influencia del embalse Porce II (Antioquia, Colombia), se observó el comportamiento de 23 taxones de abejas durante sus visitas a Aspilia tenella (Kunth) S. F. Blake; se registró el número de individuos y el tiempo total de visita y se midieron la temperatura y la humedad relativa. Los análisis de varianza indican que hubo una relación estadísticamente significativa en cuanto a los atributos considerados para las especies de abejas y una covariación significativa con las variables ambientales. Las pruebas de rangos múltiples muestran que Trigona nigerrima es la especie con los mayores valores promedio para el número de individuos y el tiempo de visita. En el estudio de las cargas polínicas se encontraron 30 tipos polínicos, dentro de los cuales A. tenella presentó el mayor porcentaje; Piper aduncum, Miconia minuti flora, Psidium guajava, Rapanea sp., Mimosa pudica y Psychotria sp., en su orden, son otras fuentes de polen importantes para varias de las especies de abejas. El análisis de agrupamiento para las abejas capturadas permitió diferenciar dos grupos: el primero incluye a 18 especies cuyas cargas polínicas que poseían una abundancia relativa de granos de polen de A. tenella por encima de 77%; el segundo grupo estaba conformado por cinco especies de abejas que recolectaron porcentajes mayores de otros tipos polínicos: Exomalopsis sp. 1 (90,4% de M. minuti flora); Lasioglossum sp. 1 y Coelioxys aff. mexicana (77,4% y 64,1% de P. aduncum, respectivamente); Exomalopsis sp. 2 (67,1% de P. guajava) y Auglochloropsis vesta (55,5% de Rapanea sp.). Trigona fulviventris y Apis mellifera presentaron los valores más altos de riqueza de tipos polínicos en las cargas de polen; ello evidencia sus nichos tróficos amplios y su comportamiento generalista de visita.We observed the behavior of 23 species of wild bees visiting Aspilia tenella (Kunth) S .F. Blake in four different localities of the Porce II dam influence zone ( Antioquia, Colombia ). We recorded number of individuals and total time spent per visit and we measured the temperature and relative humidity. The analyses of the pollen loads showed that out of the thirty pollen types, A. tenella represented the most common of all pollen types, followed by pollen types of Piper aduncum, Miconia minuti flora, Psidium guajava, Rapanea sp., Mimosa pudica y Psychotria sp., in that order. Grouping analyses for the collected bees produced two groups: first, a group of 18 species of bees whose pollen loads had more than 77% of A. tenella pollen grains; and the second group with five species of wild bees whose pollen loads were more abundant in other types of pollen: Exomalopsis sp. 2 (90,4% of M. minuti flora); Lasioglossum sp. 1 and Coelioxys aff. mexicana (77,4% and 64,1% of P. aduncum, respectively); Exomalopsis sp. 2 (67,1% of P. guajava) and Auglochloropsis vesta (55,5% of Rapanea sp.). Trigona fulviventris and Apis mellifera showed the highest richness of pollen types in their pollen loads; this is an evidence of their broad trophic niches and overall generalist feeding habits.

Parasites of the genus Leishmania are capable of inhibiting effector functions of macrophages. These parasites have developed the adaptive ability to escape host defenses; for example, they inactivate the NF-κB complex and suppress iNOS expression in infected macrophages, which are responsible for the production of the major antileishmanial substance nitric oxide (NO), favoring then its replication and successful infection. Metal complexes with NO have been studied as potential compounds for the treatment of certain tropical diseases, such as ruthenium compounds, known to be exogenous NO donors. In the present work, the compound cis-[Ru(bpy)2SO3(NO)]PF6, or RuNO, showed leishmanicidal activity directly and indirectly on promastigote forms of Leishmania (Leishmania) amazonensis. In addition, treatment with RuNO increased NO production by reversing the depletion of NO caused by Leishmania. We also found increased expression of Akt, iNOS, and NF-κB in infected and treated macrophages. These results demonstrated that RuNO was able to kill the parasite by NO release and modulate the transcriptional capacity of the cell.

The fact that drugs currently used in the treatment of Leishmania are highly toxic and associated with acquired resistance has promoted the search for new therapies for treating American tegumentary leishmaniasis (ATL). In this study, BALB/c mice were injected in the hind paw with Leishmania (Leishmania) amazonensis and subsequently treated with a combination of nitric oxide (NO) donor (cis-[Ru(bpy) 2imN(NO)](PF6)3) (Ru-NO), given by intraperitoneal injection, and oral Brazilian propolis for 30 days. Ru-NO reached the center of the lesion and increased the NO level in the injured hind paw without lesion exacerbation. Histological and immunological parameters of chronic inflammation showed that this combined treatment increased the efficacy of macrophages, determined by the decrease in the number of parasitized cells, leading to reduced expression of proinflammatory and tissue damage markers. In addition, these drugs in combination fostered wound healing, enhanced the number of fibroblasts, pro-healing cytokines and induced collagen synthesis at the lesion site. Overall, our findings suggest that the combination of the NO donor Ru-NO and Brazilian propolis alleviates experimental ATL lesions, highlighting a new therapeutic option that can be considered for further in vivo investigations as a candidate for the treatment of cutaneous leishmaniasis.

The neurons secreting gonadotropin-releasing hormone (GnRH) control fertility in all mammalian species. However, investigations of this neuronal population are difficult as the cell bodies of the approximately 800 GnRH neurons are scattered through the basal forebrain ranging from the olfactory bulbs through to the base of the hypothalamus. While acute brain slice preparations enable the electrophysiological characteristics of these cells to be determined in vitro, their topography has made investigations in vivo extremely difficult. We detail here a surgical approach that allows GnRH neurons at the base of the hypothalamus to be assessed in vivo in the anesthetized mouse (Figure 1). This procedure enables electrical recordings to be made from neurons located on the ventral surface of the mouse brain (Constantin et al., 2013).

La trascendencia del dinero como institución en la sociedad actual, hace indispensable contar con una teoría que permita tanto explicar rigurosamente las razones por las cuales el dinero fiable tiene un valor positivo en equilibrio, como analizar la interacción de este con el resto del sistema económico. Claramente en los modelos del dinero exógeno reconciliar estos dos objetivos es imposible, debido a que por definición estos lo imponen exógenamente. Esta limitación ha dado origen al desarrollo de los modelos endógenos del dinero, los cuales suponen una fricción en el intercambio que solo el dinero puede evitar. Dentro de estos destacan los modelos de generaciones traslapadas, de autopista y de búsqueda. No obstante, estos últimos han probado ser los más útiles debido a la flexibilidad con que permiten introducir micro-fundamentos y analizar fenómenos conexos al dinero como la inflación, la oferta monetaria, la distribución optima de los acervos monetarios en equilibrio, entre otros.

En el mercado de acciones, una rgla de filtro se define como una herramienta técnica que le permite a los agentes involucados definir una estrategia sobre cuándo comprar o vender sus acciones, a partir de la determinación de ciertos parámetros. El asunto crucial radica en cómo seleccionar la combinación óptima de los parámetros dentro de un espacio de búsqueda suficientemente grande. En este artículo se aplica la técnica heurística de algoritmos genéticos, paa encontrar la combinación cuasi-óptima de parámetros que maximice las ganancias de capital en la transacción de acciones.

RESUMEN Se estudiaron las cargas polínicas de 13 taxones de abejas capturadas visitando a Mimosa pigra en la zona de influencia del Embalse Porce II (Antioquia, Colombia). De los 21 tipos polínicos encontrados, M. pigra presenta el mayor porcentaje acumulado de colecta; Mimosa pudica, Piper aduncum, Solanum diversifolium, Warszewiczia coccinea y Psidium guajava, en su orden, se pueden considerar fuentes alternativas de polen, para varias de las especies de abejas cuyas cargas polínicas fueron analizadas. Dentro de las especies de abejas capturadas visitando a M. pigra se pueden diferenciar varios grupos según el tipo y abundancia relativa de los tipos polínicos encontrados en sus cargas. Uno de ellos, incluye a siete especies de abejas con más del 85% de granos de polen de M. pigra; otro, con cuatro especies de abejas que colectaron más del 94,5% del polen en M. pigra y M. pudica. Adicionalmente, se encontraron especies como Trigona dorsalis con cargas de M. pigra (59,4%), de S. diversifolium (37,8%) y especies de abejas como Lasioglossum sp. 113, en cuyas cargas polínicas predominan los granos de polen de P. aduncum (61,8%) y de W.coccinea (36,4%), en contraste con los de M. pigra (1,3%). En cuanto a la riqueza de tipos polínicos colectados por las abejas sobresalen Trigona muzoensis (12 tipos polínicos) y T. dorsalis (10 tipos), lo cual refleja nichos tróficos más amplios para estas especies y deja duda sobre su constancia floral o hábitos de limpieza. Palabras clave: Mimosa pigra, cargas polínicas, tipos polínicos, abejas, polinización. ABSTRACT We studied the pollen loads of 13 taxa of wild bees visiting the flowers of Mimosa pigra on the influence zone of the Dam Project Porce II (Antioquia, Colombia). Out of 21 different pollen types, M. pigra represents the higuest percentage; Mimosa pudica, Piper aduncum, Solanum diversifolium, Warszewiczia coccinea and Psidium guajava, in that order, were also abundant, and are alternative sources of pollen for the different kinds of bees recorded. Among the species of bees collected, we differentiate several groups: one of them, includes seven species of bees whose pollen loads are in a high porcentaje of M. pigra (86% of pollen grains or above); another group of bees with high percentage (more than 94%) of pollen grains of Mimosa species (M. pigra and M. pudica); and the other two groups that include the bee species: Trigona dorsalis (who collected more than half of their pollen resources from M. pigra (59.4%) in addition to a high percentage of S. diversifolium (37.8%); the last kind of foragers includes Lasioglossum sp.113 who collected mostly pollen from species different to Mimosa (including P. aduncum with 61.8% of pollen grains, and W. coccinea with 36,4%) and only a small percentage of M. pigra (1,3%). In terms of the species of bees that collected a highest diversity of pollen grains, two species: Trigona muzoensis (12 pollen types) and T. dorsalis (10 pollen types) outstand other species of bees on on feeding niche and question either the bees capacity of cleaning or their floral constancy. Key words: Mimosa pigra, Pollen loads, Pollen types, Bees, Pollination.

El presente trabajo es un intento por identificar el legado deductivista (arraigado en el Círculo de Viena y en el pensamiento de Karl Popper) en la metodología de la economía positiva. Con este afán, se realiza una breve reseña del empirismo científico y del método inductivo para luego ahondar en el aporte del positivismo lógico y el racionalismo critico. Posteriormente, se pasa revista sobre las principales críticas a estos enfoques y se realiza un cuidadoso análisis de la función de los modelos en la economía, para terminar con algunas reflexiones sobre el desarrollo de la econometría como método de contrastación empírica, en donde se hace especial mención al aporte realizado por la Comisión Cowles.

La literatura económica sobre los determinantes del ingreso y el consumo ha estado orientada primordialmente a la medición de la pobreza, por lo que se insiste poco en cuáles son las capacidades y potencialidades que ostentan los individuos en los estratos sociales más altos. A partir de la Encuesta de Ingresos y Gastos 2004, recogida por el Instituto Nacional de Estadística y Censos de Costa Rica, se realiza un análisis de regresión logit ordenado del consumo de los hogares, sobre potenciales variables explicativas. Los resultados muestran que la educación es un factor importante para no ocuparse en los estratos más bajos de la distribución, pero no garantiza ubicarse en la clase rica; que la concentración de la riqueza se da en la zona urbana de la Región Central, y que la estructura del ingreso de las familias más ricas está determinado fuertemente por un componente de renta.

OBJETIVO: Avaliar a mortalidade por mediastinite e sepse originadas por perfuração e ruptura do esôfago torácico, de acordo o tempo de evolução da doença. MÉTODO: Estudo retrospectivo de 14 anos (1992 a 2006), com pacientes portadores de ruptura e perfuração do esôfago. Foi avaliado sexo, idade, mecanismo de lesão, evolução ( 24 horas) e tratamento. RESULTADOS: Foram analisados 44 pacientes, sendo 10 do sexo feminino (22,73%) e 34 do sexo masculino (77,27%). A variação da idade foi de dois meses a 77 anos e a média de 33,2. Os ferimentos estiveram presentes em 19 casos (43,18%): Arma branca em cinco e projétil de arma de fogo 14. A instrumentação endoscópica foi detectada em nove casos (20,45%). Nos pacientes submetidos à esofagorrafia (diagnóstico precoce, menos de 24 horas) a mortalidade esteve presente três casos (20%). Em pacientes submetidos à esofagectomia (diagnóstico tardio, mais de 24 horas) a mortalidade ocorreu em oito casos (36,36%), e essa diferença não foi estatisticamente significante (p 0,05). No tratamento conservador, a mortalidade foi em cinco de sete casos a a diferença foi estatisticamente significativa quando comparado com o tratamento cirúrgico. CONCLUSÕES: O tratamento conservador para mediastinite por ruptura e perfuração do esôfago mostrou mortalidade alta quando comparada com tratamento cirúrgico. Entre os pacientes operados, a diferença não foi estatisticamente significante, confirmando a indicação de esofagectomia para casos de infecção avançada e a esofagorrafia para casos precoces.

BACKGROUND Zika virus (ZIKV) infections reported in recent epidemics have been linked to clinical complications that had never been associated with ZIKV before. Adaptive mutations could have contributed to the successful emergence of ZIKV as a global health threat to a nonimmune population. However, the causal relationships between the ZIKV genetic determinants, the pathogenesis and the rapid spread in Latin America and in the Caribbean remain widely unknown. OBJECTIVES The aim of this study was to characterise three ZIKV isolates obtained from patient samples during the 2015/2016 Brazilian epidemics. METHODS The ZIKV genomes of these strains were completely sequenced and in vitro infection kinetics experiments were carried out in cell lines and human primary cells. FINDINGS Eight nonsynonymous substitutions throughout the viral genome of the three Brazilian isolates were identified. Infection kinetics experiments were carried out with mammalian cell lines A549, Huh7.5, Vero E6 and human monocyte-derived dendritic cells (mdDCs) and insect cells (Aag2, C6/36 and AP61) and suggest that some of these mutations might be associated with distinct viral fitness. The clinical isolates also presented differences in their infectivity rates when compared to the well-established ZIKV strains (MR766 and PE243), especially in their abilities to infect mammalian cells. MAIN CONCLUSIONS Genomic analysis of three recent ZIKV isolates revealed some nonsynonymous substitutions, which could have an impact on the viral fitness in mammalian and insect cells.

Background: Platelet function is driven by the expression of specialized surface markers. The concept of distinct circulating subpopulations of platelets has emerged in recent years, but their exact nature remains debatable., Objectives: To design a spectral flow cytometry-based phenotyping workflow to provide a more comprehensive characterization, at a global and individual level, of surface markers in resting and activated healthy platelets, and to apply this workflow to investigate how responses differ according to platelet age., Methods: A 14-marker flow cytometry panel was developed and applied to vehicle- or agonist-stimulated platelet-rich plasma and whole blood samples obtained from healthy volunteers, or to platelets sorted according to SYTO-13 (Thermo Fisher Scientific) staining intensity as an indicator of platelet age. Data were analyzed using both user-led and independent approaches incorporating novel machine learning-based algorithms., Results: The assay detected differences in marker expression in healthy platelets, at rest and on agonist activation, in both platelet-rich plasma and whole blood samples, that are consistent with the literature. Machine learning identified stimulated populations of platelets with high accuracy (>80%). Similarly, machine learning differentiation between young and old platelet populations achieved 76% accuracy, primarily weighted by forward scatter, cluster of differentiation (CD) 41, side scatter, glycoprotein VI, CD61, and CD42b expression patterns., Conclusion: Our approach provides a powerful phenotypic assay coupled with robust bioinformatic and machine learning workflows for deep analysis of platelet subpopulations. Cleavable receptors, glycoprotein VI and CD42b, contribute to defining shared and unique subpopulations. This adoptable, low-volume approach will be valuable in deep characterization of platelets in disease., (© 2024 The Author(s).)

Background: Assessment of platelet function is key in diagnosing bleeding disorders and evaluating antiplatelet drug efficacy. However, there is a prevailing "one-size-fits-all" approach in the interpretation of measures of platelet reactivity, with arbitrary cutoffs often derived from healthy volunteer responses., Objectives: Our aim was to compare well-used platelet reactivity assays., Methods: Blood and platelet-rich plasma obtained from the Framingham Heart Study ( N  = 3429) were assayed using a range of agonists in 5 platelet assays: light transmission aggregometry, Optimul aggregometry, Multiplate impedance aggregometry (Roche Diagnostics), Total Thrombus-Formation Analysis System, and flow cytometry. Using linear mixed-effect models, we determined the contribution of preanalytical and technical factors that modulated platelet reactivity traits., Results: A strong intra-assay correlation of platelet traits was seen in all assays, particularly Multiplate velocity ( r  = 0.740; ristocetin vs arachidonic acid). In contrast, only moderate interassay correlations were observed ( r  = 0.375; adenosine diphosphate Optimul E max vs light transmission aggregometry large area under the curve). As expected, antiplatelet drugs strongly reduced platelet responses, with aspirin use primarily targeting arachidonic acid-induced aggregation, and explained substantial variance (β = -1.735; P  = 4.59 × 10 -780 ; variance proportion = 46.2%) and P2Y 12 antagonists blocking adenosine diphosphate responses (β = -1.612; P  = 6.75 × 10 -27 ; variance proportion = 2.1%). Notably, female sex and older age were associated with enhanced platelet reactivity. Fasting status and deviations from standard venipuncture practices did not alter platelet reactivity significantly. Finally, the agonist batch, phlebotomist, and assay technician (more so for assays that require additional sample manipulation) had a moderate to large effect on measured platelet reactivity., Conclusion: Caution must be exercised when extrapolating findings between assays, and the use of standard ranges must be medication-specific and sex-specific at a minimum. Researchers should also consider preanalytical and technical variables when designing experiments and interpreting platelet reactivity measures.

Background: Major trauma results in dramatic changes in platelet behavior. Newly formed platelets are more reactive than older platelets, but their contributions to hemostasis and thrombosis after severe injury have not been previously evaluated., Objectives: To determine how immature platelet metrics and plasma thrombopoietin relate to clinical outcomes after major injury., Methods: A prospective observational cohort study was performed in adult trauma patients. Platelet counts and the immature platelet fraction (IPF) were measured at admission and 24 hours, 72 hours, and 7 days after injury. Thromboelastometry was performed at admission. Plasma thrombopoietin, c-Mpl, and GPIbα were quantified in a separate cohort. The primary outcome was in-hospital mortality; secondary outcomes were venous thromboembolic events and multiple organ dysfunction syndrome (MODS)., Results: On admission, immature platelet counts (IPCs) were significantly lower in nonsurvivors (n = 40) than in survivors (n = 236; 7.3 × 10 9 /L vs 10.6 × 10 9 /L; P = .009), but IPF did not differ. Similarly, impaired platelet function on thromboelastometry was associated with lower admission IPC (9.1 × 10 9 /L vs 11.9 × 10 9 /L; P < .001). However, at later time points, we observed significantly higher IPF and IPC in patients who developed venous thromboembolism (21.0 × 10 9 /L vs 11.1 × 10 9 /L; P = .02) and prolonged MODS (20.9 × 10 9 /L vs 11 × 10 9 /L; P = .003) than in those who did not develop complications. Plasma thrombopoietin levels at admission were significantly lower in nonsurvivors (P < .001), in patients with MODS (P < .001), and in those who developed venous thromboembolism (P = .04)., Conclusion: Lower levels of immature platelets in the acute phase after major injury are associated with increased mortality, whereas higher immature platelet levels at later time points may predispose to thrombosis and MODS., Competing Interests: Declaration of competing interests There are no competing interests to disclose., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Research into the natural aging process of platelets has garnered much research interest in recent years, and there have long been associations drawn between the proportion of newly formed platelets in the circulation and the risk of thrombosis. However, these observations have largely been demonstrated in patient groups in which there may be underlying systemic changes that effect platelet function. Recent advances in technology have allowed in-depth analysis of differently aged platelets isolated from the peripheral blood of healthy individuals and have demonstrated that aged platelets, often referred to as senescent platelets, undergo extensive changes in the transcriptome and proteome. Ultimately, these changes result in platelets whose functions have deteriorated such that they cannot partake in hemostatic responses to the same extent as newly formed platelets. Here, we review transcriptomic and proteomic research in platelet aging in the context of health and how this research sheds light upon alterations in platelet structure and function.

Platelet ageing is an area of research which has gained much interest in recent years. Newly formed platelets, often referred to as reticulated platelets, young platelets or immature platelets, are defined as RNA-enriched and have long been thought to be hyper-reactive. This latter view is largely rooted in associations and observations in patient groups with shortened platelet half-lives who often present with increased proportions of newly formed platelets. Evidence from such groups suggests that an increased proportion of newly formed platelets is associated with an increased risk of thrombotic events and a reduced effectiveness of standard anti-platelet therapies. Whilst research has highlighted the existence of platelet subpopulations based on function, size and age within patient groups, the common intrinsic changes which occur as platelets age within the circulation are only just being explored. By understanding the changes that occur during the natural ageing processes of platelets, we may be able to identify the triggers for alterations in platelet life span and platelet reactivity. Here we review research on platelet ageing in the context of health and disease, paying particular attention to the experimental approaches taken and the robustness of conclusions that can be drawn., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Thrombosis of the lung microvasculature is a characteristic of COVID-19 disease, which is observed in large excess compared to other forms of acute respiratory distress syndrome and thus suggests a trigger for thrombosis that is endogenous to the lung. Our recent work has shown that the SARS-CoV-2 Spike protein activates the cellular TMEM16F chloride channel and scramblase. Through a screening on >3,000 FDA/EMA approved drugs, we identified Niclosamide and Clofazimine as the most effective molecules at inhibiting Spike-induced TMEM16 activation. As TMEM16F plays an important role in stimulating the procoagulant activity of platelets, we investigated whether Spike directly affects platelet activation and pro-thrombotic function and tested the effect of Niclosamide and Clofazimine on these processes. Here we show that Spike, present either on the virion envelope or on the cell plasma membrane, promotes platelet activation, adhesion and spreading. Spike was active as a sole agonist or, even more effectively, by enhancing the function of known platelet activators. In particular, Spike-induced a marked procoagulant phenotype in platelets, by enhancing Ca 2+ flux, phosphatidylserine externalization on the platelet outer cell membrane, and thrombin generation. Eventually, this increased thrombin-induced clot formation and retraction. Both Niclosamide and Clofazimine blocked this Spike-induced procoagulant response. These findings provide a pathogenic mechanism to explain lung thrombosis-associated with severe COVID-19 infection. We propose that Spike, present in SARS-CoV-2 virions or exposed on the surface of infected cells in the lungs, enhances the effects of inflammation and leads to local platelet stimulation and subsequent activation of the coagulation cascade. As platelet TMEM16F is central in this process, these findings reinforce the rationale of repurposing Niclosamide for COVID-19 therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Cappelletto, Allan, Crescente, Schneider, Bussani, Ali, Secco, Vodret, Simeone, Mascaretti, Zacchigna, Warner and Giacca.)

The proportion of young platelets, also known as newly formed or reticulated, within the overall platelet population has been clinically correlated with adverse cardiovascular outcomes. However, our understanding of this is incomplete because of limitations in the technical approaches available to study platelets of different ages. In this study, we have developed and validated an in vivo temporal labeling approach using injectable fluorescent antiplatelet antibodies to subdivide platelets by age and assess differences in functional and molecular characteristics. With this approach, we found that young platelets (<24 hours old) in comparison with older platelets respond to stimuli with greater calcium flux and degranulation and contribute more to the formation of thrombi in vitro and in vivo. Sequential sampling confirmed this altered functionality to be independent of platelet size, with distribution of sizes of tracked platelets commensurate with the global platelet population throughout their 5-day lifespan in the circulation. The age-associated decrease in thrombotic function was accompanied by significant decreases in the surface expression of GPVI and CD31 (PECAM-1) and an increase in CD9. Platelet messenger RNA (mRNA) content also decreased with age but at different rates for individual mRNAs indicating apparent conservation of those encoding granule proteins. Our pulse-chase-type approach to define circulating platelet age has allowed timely reexamination of commonly held beliefs regarding size and reactivity of young platelets while providing novel insights into the temporal regulation of receptor and protein expression. Overall, future application of this validated tool will inform age-based platelet heterogeneity in physiology and disease., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Background: Platelets circulate in the blood of healthy individuals for approximately 7-10 days regulated by finely balanced processes of production and destruction. As platelets are anucleate we reasoned that their protein composition would change as they age and that this change would be linked to alterations in structure and function., Objective: To isolate platelets of different ages from healthy individuals to test the hypothesis that changes in protein content cause alterations in platelet structure and function., Methods: Platelets were separated according to thiazole orange fluorescence intensity as a surrogate indicator of mRNA content and so a marker of platelet age and then subjected to proteomics, imaging, and functional assays to produce an in-depth analysis of platelet composition and function., Results: Total protein content was 45 ± 5% lower in old platelets compared to young platelets. Predictive proteomic pathway analysis identified associations with 28 biological processes, notably higher hemostasis in young platelets whilst apoptosis and senescence were higher in old platelets. Further studies confirmed platelet ageing was linked to a decrease in cytoskeletal protein and associated capability to spread and adhere, a reduction in mitochondria number, and lower calcium dynamics and granule secretion., Conclusions: Our findings demonstrate changes in protein content are linked to alterations in function as platelets age. This work delineates physical and functional changes in platelets as they age and serves as a base to examine differences associated with altered mean age of platelet populations in conditions such as immune thrombocytopenia and diabetes., (© 2021 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis.)

We have identified a rare missense variant on chromosome 9, position 125145990 (GRCh37), in exon 8 in PTGS1 (the gene encoding cyclo-oxygenase 1, COX-1, the target of anti-thrombotic aspirin therapy). We report that in the homozygous state within a large consanguineous family this variant is associated with a bleeding phenotype and alterations in platelet reactivity and eicosanoid production. Western blotting and confocal imaging demonstrated that COX-1 was absent in the platelets of three family members homozygous for the PTGS1 variant but present in their leukocytes. Platelet reactivity, as assessed by aggregometry, lumi-aggregometry and flow cytometry, was impaired in homozygous family members, as were platelet adhesion and spreading. The productions of COX-derived eicosanoids by stimulated platelets were greatly reduced but there were no changes in the levels of urinary metabolites of COX-derived eicosanoids. The proband exhibited additional defects in platelet aggregation and spreading which may explain why her bleeding phenotype was slightly more severe than those of other homozygous affected relatives. This is the first demonstration in humans of the specific loss of platelet COX-1 activity and provides insight into its consequences for platelet function and eicosanoid metabolism. Notably despite the absence of thromboxane A2 (TXA2) formation by platelets, urinary TXA2 metabolites were in the normal range indicating these cannot be assumed as markers of in vivo platelet function. Results from this study are important benchmarks for the effects of aspirin upon platelet COX-1, platelet function and eicosanoid production as they define selective platelet COX-1 ablation within humans.

Aspirin prevents thrombosis by inhibiting platelet cyclooxygenase (COX)-1 activity and the production of thromboxane (Tx)A 2 , a pro-thrombotic eicosanoid. However, the non-platelet actions of aspirin limit its antithrombotic effects. Here, we used platelet-COX-1-ko mice to define the platelet and non-platelet eicosanoids affected by aspirin. Mass-spectrometry analysis demonstrated blood from platelet-COX-1-ko and global-COX-1-ko mice produced similar eicosanoid profiles in vitro: for example, formation of TxA 2 , prostaglandin (PG) F 2α , 11-hydroxyeicosatraenoic acid (HETE), and 15-HETE was absent in both platelet- and global-COX-1-ko mice. Conversely, in vivo, platelet-COX-1-ko mice had a distinctly different profile from global-COX-1-ko or aspirin-treated control mice, notably significantly higher levels of PGI 2 metabolite. Ingenuity Pathway Analysis (IPA) predicted that platelet-COX-1-ko mice would be protected from thrombosis, forming less pro-thrombotic TxA 2 and PGE 2 . Conversely, aspirin or lack of systemic COX-1 activity decreased the synthesis of anti-aggregatory PGI 2 and PGD 2 at non-platelet sites leading to predicted thrombosis increase. In vitro and in vivo thrombosis studies proved these predictions. Overall, we have established the eicosanoid profiles linked to inhibition of COX-1 in platelets and in the remainder of the cardiovascular system and linked them to anti- and pro-thrombotic effects of aspirin. These results explain why increasing aspirin dosage or aspirin addition to other drugs may lessen antithrombotic protection., (© 2020 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Trauma hemorrhage is a leading cause of death and disability worldwide. Platelets are fundamental to primary hemostasis, but become profoundly dysfunctional in critically injured patients by an unknown mechanism, contributing to an acute coagulopathy which exacerbates bleeding and increases mortality. The objective of this study was to elucidate the mechanism of platelet dysfunction in critically injured patients. We found that circulating platelets are transformed into procoagulant balloons within minutes of injury, accompanied by the release of large numbers of activated microparticles which coat leukocytes. Ballooning platelets were decorated with histone H4, a damage-associated molecular pattern released in massive quantities after severe injury, and exposure of healthy platelets to histone H4 recapitulated the changes in platelet structure and function observed in trauma patients. This is a report of platelet ballooning in human disease and of a previously unrecognized mechanism by which platelets contribute to the innate response to tissue damage., Competing Interests: The authors declare no conflict of interest., (Copyright © 2019 the Author(s). Published by PNAS.)

Objectives: The liver X receptors (LXRs) and farnesoid X receptor (FXR) have been identified in human platelets. Ligands of these receptors have been shown to have nongenomic inhibitory effects on platelet activation by platelet agonists. This, however, seems contradictory with the platelet hyper-reactivity that is associated with several pathological conditions that are associated with increased circulating levels of molecules that are LXR and FXR ligands, such as hyperlipidemia, type 2 diabetes mellitus, and obesity., Approach and Results: We, therefore, investigated whether ligands for the LXR and FXR receptors were capable of priming platelets to the activated state without stimulation by platelet agonists. Treatment of platelets with ligands for LXR and FXR converted platelets to the procoagulant state, with increases in phosphatidylserine exposure, platelet swelling, reduced membrane integrity, depolarization of the mitochondrial membrane, and microparticle release observed. Additionally, platelets also displayed features associated with coated platelets such as P-selectin exposure, fibrinogen binding, fibrin generation that is supported by increased serine protease activity, and inhibition of integrin αIIbβ3. LXR and FXR ligand-induced formation of coated platelets was found to be dependent on both reactive oxygen species and intracellular calcium mobilization, and for FXR ligands, this process was found to be dependent on cyclophilin D., Conclusions: We conclude that treatment with LXR and FXR ligands initiates coated platelet formation, which is thought to support coagulation but results in desensitization to platelet stimuli through inhibition of αIIbβ3 consistent with their ability to inhibit platelet function and stable thrombus formation in vivo., (© 2017 The Authors.)