Associations of externalizing polygenic scores with externalizing disorders among Mexican youth.

Several studies have examined the association of externalizing polygenic scores (PGS) with externalizing symptoms in samples of European ancestry. However, less is known about the associations of externalizing polygenic vulnerability in relation to phenotypic externalizing disorders among individuals of different ancestries, such as Mexican youth. Here, we leveraged the largest genome-wide association study on externalizing behaviors that included over 1 million individuals of European ancestry to examine associations of externalizing PGS with a range of externalizing disorders in Mexican adolescents, and investigated whether adversity exposure in childhood moderated these associations. Participants (N = 1064; age range 12-17 years old; 58.8% female) were adolescents recruited for a general population survey on adolescent mental health in the Mexico City Metropolitan region and were genotyped. Childhood adversity exposure and externalizing disorders, specifically attention-deficit hyperactivity disorder (ADHD), conduct disorder, oppositional defiant disorder, and substance use disorder, were assessed via the computer-assisted World Mental Health Composite International Diagnostic Interview for adolescents. A greater externalizing PGS was associated with a greater odds of any externalizing disorder (OR = 1.29 [1.12, 1.48]; p < 0.01) and ADHD (OR = 1.40 [1.15, 1.70]; p < 0.01) in the whole sample, and in females in particular. There were no main effects of the externalizing PGS on conduct disorder, oppositional defiant disorder, or substance use disorder, nor did adversity exposure moderate these associations. Our results suggest that greater genetic propensity for externalizing disorders is associated with increased odds of any externalizing disorders and ADHD among Mexican adolescents, furthering our understanding of externalizing disorder manifestation in this population.

Rethinking Benefits in Health Research, Reflections of an Ethics Committee.

The principle of beneficence in health research implies the effort of researchers to minimize risk to participants and maximize benefits to participants and society, which could be considered an abstract definition. Therefore, the benefits are not easily conceived by researchers who fail to achieve their goal, which is to privilege the well-being of participants. The purpose of this work was to describe and discuss the theoretical elements that support the principle of beneficence so that their knowledge allows designing and granting adequate benefits to participants. The present document defines the principle of beneficence. It also analyzes the maximization of benefits, the distinctions between different classifications of benefits, and the differentiation from compensations or incentives. With all this information, researchers must do a critical deliberation to select adequate benefits for participants of their studies, considering the type of study, potential participants, probability of risk, among others. These benefits should not be understood as a charity that researchers grant to the participant; they should be conceived as any form of action in favor of the well-being of participants. Participants must always be considered as moral agents, responsible for deciding whether the benefits would outweigh the possible negative unintended consequences of a particular study. Finally, no risk should be taken if it is not commensurate or proportional to the benefit of the research study.

After a disaster: Validation of PTSD checklist for DSM-5 and the four- and eight-item abbreviated versions in mental health service users.

Posttraumatic stress disorder (PTSD) is a common and disabling condition developing in one of four survivors after an earthquake. Brief and self-reported validated measures for assessing PTSD symptom severity are necessary to improve care access and assess disorder progress and treatment response. Therefore, we evaluated the psychometric properties of the PTSD-Checklist for the DSM-5 (PCL-5) of 20-, 8- and 4-item in patients that sought specialized mental health services after a catastrophic earthquake that stroke Mexico on September 19th, 2017. The internal consistency of 20-, 8- and 4-item PCL-5 was adequate (≥.7). Using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) as a reference, signal detection analyses revealed a PCL-5 score of 27 as optimal (sensitivity = .96, specificity = .73) for identifying probable PTSD cases. The shortened versions highly correlated with the full PCL-5 and had comparable diagnostic utility. Our results indicate that the 20-item PCL-5 and the abridged versions can effectively identify possible PTSD cases. The 8-item version has better psychometric properties and more consistent diagnostic utility across time and civil populations. These measures must be evaluated in independent samples to corroborate their utility in different populations and regarding diverse traumatic events.

Integrative DNA Methylation and Gene Expression Analysis in the Prefrontal Cortex of Mexicans Who Died by Suicide.

BACKGROUND: Suicide represents a major health concern, especially in developing countries. While many demographic risk factors have been proposed, the underlying molecular pathology of suicide remains poorly understood. A body of evidence suggests that aberrant DNA methylation and expression is involved. In this study, we examined DNA methylation profiles and concordant gene expression changes in the prefrontal cortex of Mexicans who died by suicide. METHODS: In collaboration with the coroner's office in Mexico City, brain samples of males who died by suicide (n = 35) and age-matched sudden death controls (n = 13) were collected. DNA and RNA were extracted from prefrontal cortex tissue and analyzed with the Infinium Methylation480k and the HumanHT-12 v4 Expression Beadchips, respectively. RESULTS: We report evidence of altered DNA methylation profiles at 4430 genomic regions together with 622 genes characterized by differential expression in cases vs controls. Seventy genes were found to have concordant methylation and expression changes. Metacore-enriched analysis identified 10 genes with biological relevance to psychiatric phenotypes and suicide (ADCY9, CRH, NFATC4, ABCC8, HMGA1, KAT2A, EPHA2, TRRAP, CD22, and CBLN1) and highlighted the association that ADCY9 has with various pathways, including signal transduction regulated by the cAMP-responsive element modulator, neurophysiological process regulated by the corticotrophin-releasing hormone, and synaptic plasticity. We therefore went on to validate the observed hypomethylation of ADCY9 in cases vs control through targeted bisulfite sequencing. CONCLUSION: Our study represents the first, to our knowledge, analysis of DNA methylation and gene expression associated with suicide in a Mexican population using postmortem brain, providing novel insights for convergent molecular alterations associated with suicide.

Suicidal ideation and planning among Mexican adolescents are associated with depression polygenic risk scores.

Suicide is a major public health problem in Mexico and around the world. Genetic predisposition for major depressive disorder (MDD) has been associated with increased risk for suicidal behaviors (SB) in populations of European ancestry (EA). Here, we examine whether MDD polygenic risk scores (MDD PRS), derived from a genome-wide association study involving EA individuals, predict SB, including ideation, planning, and attempt, among Mexican youth using a longitudinal design. At baseline, participants (N = 1,128, 12-17 years, 55% women) were interviewed and genotyped as part of a general population survey on adolescent mental health. Eight years later, they were recontacted for a follow up visit (N = 437, 20-25 years, 63% women). At both assessments, individuals reported on their engagement in SB within the past year. MDD PRS were significantly positively associated with SB, particularly suicide ideation and planning during adolescence, accounting for ~4-5% of the variance in these outcomes. In contrast, associations between MDD PRS and SB during young adulthood did not reach statistical significance. Our results suggest that increased genetic liability for depression increased risk for SB, particularly during adolescence, expanding our knowledge of the genetic underpinnings of SB.

Disrupted maternal communication and attachment disorganization in children with autism spectrum disorder.

We examined whether disrupted maternal communication, which is associated with disorganized attachment in typically developing children, is also associated with disorganized attachment in children with ASD. The attachments of 45 boys with ASD and maternal disruption were assessed in the Strange Situation Procedure. Analyses revealed a link between low cognitive functioning and resistant/ambivalent and disorganized attachment, and children's functioning was therefore controlled. Contrary to expectations, mothers of children with disorganized attachments did not show more disrupted communication than mothers of children with organized attachments. However, the 4-way attachment breakdown showed that the mothers of disorganized and ambivalent/resistant children had higher disruption scores than mothers of secure and avoidant children. The findings suggest that the expected associations between maternal disruption and attachment disorganization apply to children with ASD as well, but raise questions whether disrupted behavior is a unique antecedent of disorganized attachment or also of resistant/ambivalent attachment.

The Trypanosoma brucei RNA-Binding Protein TbRRM1 is Involved in the Transcription of a Subset of RNA Pol II-Dependent Genes.

It has been long thought that RNA Polymerase (Pol) II transcriptional regulation does not operate in trypanosomes. However, recent reports have suggested that these organisms could regulate RNA Pol II transcription by epigenetic mechanisms. In this paper, we investigated the role of TbRRM1 in transcriptional regulation of RNA Pol II-dependent genes by focusing both in genes located in a particular polycistronic transcription unit (PTU) and in the monocistronic units of the SL-RNA genes. We showed that TbRRM1 is recruited throughout the PTU, with a higher presence on genes than intergenic regions. However, its depletion leads both to the decrease of nascent RNA and to chromatin compaction only of regions located distal to the main transcription start site. These findings suggest that TbRRM1 facilitates the RNA Pol II transcriptional elongation step by collaborating to maintain an open chromatin state in particular regions of the genome. Interestingly, the SL-RNA genes do not recruit TbRRM1 and, after TbRRM1 knockdown, nascent SL-RNAs accumulate while the chromatin state of these regions remains unchanged. Although it was previously suggested that TbRRM1 could regulate RNA Pol II-driven genes, we provide here the first experimental evidence which involves TbRRM1 to transcriptional regulation.

TbRRM1 knockdown produces abnormal cell morphology and apoptotic-like death in the bloodstream form of T. brucei.

TbRRM1, an SR-related protein, is involved in transcriptional and post-transcriptional gene expression regulation in procyclic T. brucei. In previous work, we found that TbRRM1 is essential and its depletion leads to cell cycle impairment, aberrant phenotypes and cell loss by apoptotic-like death. Here, we report the findings obtained after TbRRM1 knockdown in bloodstream parasites. Depletion of TbRRM1 in this cell stage led also to growth arrest and cell loss by apoptosis-like death. However, microscopic analysis showed aberrant cell morphology with parasites displaying flagellum detachment and cytokinesis impairment after RNAi induction, suggesting that TbRRM1 could play different roles depending on parasite stage.

The protein family TcTASV-C is a novel Trypanosoma cruzi virulence factor secreted in extracellular vesicles by trypomastigotes and highly expressed in bloodstream forms.

TcTASV-C is a protein family of about 15 members that is expressed only in the trypomastigote stage of Trypanosoma cruzi. We have previously shown that TcTASV-C is located at the parasite surface and secreted to the medium. Here we report that the expression of different TcTASV-C genes occurs simultaneously at the trypomastigote stage and while some secreted and parasite-associated products are found in both fractions, others are different. Secreted TcTASV-C are mainly shedded through trypomastigote extracellular vesicles, of which they are an abundant constituent, despite its scarce expression on culture-derived trypomastigotes. In contrast, TcTASV-C is highly expressed in bloodstream trypomastigotes; its upregulation in bloodstream parasites was observed in different T. cruzi strains and was specific for TcTASV-C, suggesting that some host-molecules trigger TcTASV-C expression. TcTASV-C is also strongly secreted by bloodstream parasites. A DNA prime-protein boost immunization scheme with TcTASV-C was only partially effective to control the infection in mice challenged with a highly virulent T. cruzi strain. Vaccination triggered a strong humoral response that delayed the appearance of bloodstream trypomastigotes at the early phase of the infection. Linear epitopes recognized by vaccinated mice were mapped within the TcTASV-C family motif, suggesting that blockade of secreted TcTASV-C impacts on the settlement of infection. Furthermore, although experimental and naturally T. cruzi-infected hosts did not react with antigens from extracellular vesicles, vaccinated and challenged mice recognized not only TcTASV-C but also other vesicle-antigens. We hypothesize that TcTASV-C is involved in the establishment of the initial T. cruzi infection in the mammalian host. Altogether, these results point towards TcTASV-C as a novel secreted virulence factor of T. cruzi trypomastigotes.

Inflammatory Profiles in Depressed Adolescents Treated with Fluoxetine: An 8-Week Follow-up Open Study.

Changes in cytokine levels in major depression and during treatment have been reported in adults. However, few studies have examined cytokine levels in an adolescent sample despite this being a common age of onset. Methods. We measured proinflammatory (IL-2, IFN-γ, IL-1ß, TNF-α, IL-6, IL-12, and IL-15) and anti-inflammatory (IL-4, IL-5, IL-13, IL-1Ra, and IL-10) cytokine serum levels in 22 adolescents with major depression and 18 healthy volunteers. Cytokines were measured by multiplex bead-based immunoassays at baseline, and 4 and 8 weeks after commencement of fluoxetine administration in the clinical group. Results. Compared to healthy volunteers, adolescents with major depression at baseline showed significant increases in all pro- and anti-inflammatory cytokines, except IL-1Ra and IL-10. Significant changes were observed in fluoxetine treatment compared to baseline: proinflammatory cytokines IFN-γ, IL-1ß, TNF-α, IL-6, IL-12, and IL-15 were decreased only at week 4 whereas IL-2 was increased only at week 8; anti-inflammatory cytokines IL-4 and IL-5 were increased at week 8 while IL-1Ra was reduced only at week 4. There were no significant correlations between cytokine levels and symptomatic improvement in HDRS. Discussion. The results suggest a significant interplay between cytokine levels, the depressive state, and the stage of treatment with an SSRI. To the best of our knowledge, this is the first report in depressed adolescents with elevated IL-12, IL-13, and IL-15 levels. Further studies are necessary to clarify the role and mechanisms of altered cytokine levels in the pathogenesis and physiopathology of major depressive disorder.

Depletion of the SR-Related Protein TbRRM1 Leads to Cell Cycle Arrest and Apoptosis-Like Death in Trypanosoma brucei.

Arginine-Serine (RS) domain-containing proteins are RNA binding proteins with multiple functions in RNA metabolism. In mammalian cells this group of proteins is also implicated in regulation and coordination of cell cycle and apoptosis. In trypanosomes, an early branching group within the eukaryotic lineage, this group of proteins is represented by 3 members, two of them are SR proteins and have been recently shown to be involved in rRNA processing as well as in pre-mRNA splicing and stability. Here we report our findings on the 3rd member, the SR-related protein TbRRM1. In the present study, we showed that TbRRM1 ablation by RNA-interference in T. brucei procyclic cells leads to cell-cycle block, abnormal cell elongation compatible with the nozzle phenotype and cell death by an apoptosis-like mechanism. Our results expand the role of the trypanosomal RS-domain containing proteins in key cellular processes such as cell cycle and apoptosis-like death, roles also carried out by the mammalian SR proteins, and thus suggesting a conserved function in this phylogenetically conserved protein family.

Genetic and epigenetic regulation of the brain-derived neurotrophic factor in the central nervous system.

The BDNF is required for the development and proper function of the central nervous system, where it is involved in a variety of neural and molecular events relevant to cognition, learning, and memory processes. Although only a functional mature protein is synthesized, the human BDNF gene possesses an extensive structural complexity, including the presence of multiple promoters, splicing events, and 3´UTR poly-adenylation sites, resulting in an intricate transcriptional regulation and numerous messengers RNA. Recent data support specific cellular roles of these transcripts. Moreover, a central role of epigenetic modifications on the regulation of BDNF gene transcription is also emerging. The present essay aims to summarize the published information on the matter, emphasizing their possible implications in health and disease or in the treatment of different neurologic and psychiatric disorders.

BDNF Met66 modulates the cumulative effect of psychosocial childhood adversities on major depression in adolescents.

BACKGROUND: The interplay among lifetime adversities and the genetic background has been previously examined on a variety of measures of depression; however, only few studies have focused on major depression disorder (MDD) in adolescence. METHODS: Using clinical data and DNA samples from mouthwash gathered from an epidemiological study on the prevalence of mental disorders in youths between 12 and 17 years old, we tested the statistical interaction between a set of psychosocial adversities experienced during childhood (CAs) with two common polymorphisms in the brain-derived neurotrophic factor (BDNF) (Val66Met) and SLC6A4 (L/S) genes on the probability of suffering MDD in adolescence. RESULTS: Genotype or allele frequencies for both polymorphisms were similar between groups of comparison (MDD N = 246; controls N = 270). The CAs factors: Abuse, neglect, and family dysfunctions; parental maladjustment, parental death, and to have experienced a life-threatening physical illness were predictors of clinical depression in adolescents. Remarkably, the cumulative number of psychosocial adversities was distinctly associated with an increase in the prevalence of depression but only in those Val/Val BDNF individuals; while the possession of at least a copy of the BDNF Met allele (i.e., Met +) was statistically linked with a "refractory" or resilient phenotype to the noticeable influence of CAs. CONCLUSION: Liability or resilience to develop MDD in adolescence is dependent of a complex interplay between particular environmental exposures and a set of plasticity genes including BDNF. A better understanding of these factors is important for developing better prevention and early intervention measures.

TcTASV-C, a protein family in Trypanosoma cruzi that is predominantly trypomastigote-stage specific and secreted to the medium.

Among the several multigene families codified by the genome of T. cruzi, the TcTASV family was the latest discovered. The TcTASV (Trypomastigote, Alanine, Serine, Valine) family is composed of ∼40 members, with conserved carboxi- and amino-termini but with a variable central core. According to the length and sequence of the central region the family is split into 3 subfamilies. The TcTASV family is conserved in the genomes of - at least - lineages TcI and TcVI and has no orthologues in other trypanosomatids. In the present work we focus on the study of the TcTASV-C subfamily, composed by 16 genes in the CL Brener strain. We determined that TcTASV-C is preferentially expressed in trypomastigotes, but it is not a major component of the parasite. Both immunoflourescence and flow cytometry experiments indicated that TcTASV-C has a clonal expression, i.e. it is not expressed by all the parasites of a certain population at the same time. We also determined that TcTASV-C is phosphorylated and glycosylated. TASV-C is attached to the parasite surface by a GPI anchor and is shed spontaneously into the medium. About 30% of sera from infected hosts reacted with TcTASV-C, confirming its exposition to the immune system. Its superficial localization and secretory nature suggest a possible role in host-parasite interactions.

Estudio de la variabilidad genética del DRD4 y del DAT1 en individuos habitantes de la Ciudad de México / Genetic variability study of DRD4 and DAT1 in the urban population of Mexico City

Family, twin and adoption studies suggest that genetics plays an important role in the etiology of many psychiatric disorders. It has been proposed that the dopaminergic brain system could be affected in schizophrenia, substance abuse and attention deficit hyperactivity disorder. The most studied genes are two VNTR polymorphic systems; one located in the exon 3 of the dopamine D4 receptor (DRD4) gene, and the other in the 3' untranslated region of the dopamine transporter (DAT1 or SCLA6A3) gene. It has been reported that allele frequencies of these polymorphisms varied between populations and this could affect the results in the association studies. Due to the previous findings, the objective of the present study was to determine the allele frequencies of DRD4 and DAT1 in an epidemiological sample of the adolescent population of México City. We found that the frequencies presented in our study were in between those reported for Caucasians and those reported for the American Indigenous population, this result are consistent with Euro-Indigenous inbreeding that has occurred in Mexico. Moreover, the results presented in the present study could explain the lack of consistency in the association analysis and make necessary to develop these investigations in our population.

Existe evidencia fehaciente de la influencia genética en los trastornos psiquiátricos y se ha propuesto que el sistema dopáminergico cerebral puede ser uno de los afectados en diversos trastornos como la esquizofrenia, el abuso de sustancias y el trastorno por déficit de atención e hiperactividad. En este sentido, los sistemas genéticos más estudiados son 2 VNTRs; uno localizado en el exón 3 del gen del Receptor a dopamina D4 (DRD4) y el otro en la región 3' no traducida del transportador a dopamina (DAT1 o SCL6A3). Se ha reportado que las frecuencias alélicas de estos polimorfismos difieren significativamente entre poblaciones y que esto puede afectar los resultados en los estudios de asociación. Debido a lo anterior, el objetivo del presente trabajo fue determinar las frecuencias alélicas del DRD4 y del DAT1 a partir de una muestra epidemiológica de la población adolescente de la Ciudad de México. Las frecuencias alélicas reportadas en el presente estudio son intermedias a las reportadas en caucásicos y poblaciones indígenas de América, lo que concuerda con la historia de mestizaje ocurrida en México. Estás diferencias pueden ayudar a explicar la falta de consistencia en diferentes estudios de asociación y hacen necesario realizarlos en población mexicana.

Antibodies against the Trypanosoma cruzi ribosomal P proteins induce apoptosis in HL-1 cardiac cells.

High levels of antibodies (Abs) against the C-terminal end of the Trypanosoma cruzi ribosomal P2ß protein, defined by the R13 peptide, are detected in sera from patients with chronic Chagas heart disease (cChHD). These Abs can cross-react with the ß1-adrenergic receptor (ß1-AR), inducing a functional response in cardiomyocytes. In this study, we report that a monoclonal Ab against the R13 peptide, called mAb 17.2, and its single-chain Fv fragment (scFv), C5, caused apoptosis of murine adult cardiac HL-1 cells, and this effect was inhibited by pre-incubation with the ß-blocker, propranolol. In addition, apoptosis induced by mAb 17.2 might involve the mitochondrial pathway evidenced by an increase in pro-apoptotic molecule, Bax/anti-apoptotic molecule, Bcl(XL), mRNA levels. HL-1 cells also underwent apoptosis after incubation with nine of 23 IgGs from cChHD patients (39.1%) that presented reactivity against R13 peptide and ß1-AR. The apoptotic effect caused by these IgGs was partially abolished by pre-incubation with R13 peptide or propranolol, suggesting the involvement of the C-terminal end of ribosomal P proteins and the ß-adrenergic pathway. Moreover, we observed high rates of cardiomyocyte apoptosis in two tissue samples from cChHD patients by using a TUNEL assay and staining of active caspase-3. Our data demonstrate that Abs developed during T. cruzi infection have a strong cardiomyocyte apoptosis inducing ability, which could contribute to the heart disease developed in patients with cChHD.

Las estadísticas de salud en México: ideas, actores e instituciones, 1810-2010 / Health statistics in México: ideas, actors and institutions, 1810-2010

El desarrollo de la sociedad es resultado de la interacción de factores diversos, muchos de los cuales surgen y tiene manifestaciones en el presente, pero que generalmente tiene una gran historia que contar como resultado del hacer histórico del hombe, de sus instituciones y de sus costumbres: del pasado. el conocimiento do de ésto nos permite comprender mejor el presente, intentar y elegir mejores soluciones hacia el futuro deseado fundamentado en los principios democráticos, de justicia y solidaridad. la historia la hemos podido reconstruir a través d elos sistemas de comunicación e información que el hombre ha inventado, información que cada vez se organiza y sistematiza de modo que es más útil, accesible, objetiva y oportuna para la toma de decisiones. Esta obra está conformada por una antología de las principales investigaciones en salud basadas en el uso de estadísticas de 1810 a 2010, rescata dos aspectos fundamentales : por un lado el aspecto humano quien hace la hisotira; por otro, el institucional, de donde se hace la historia de las estadísticas de México. este es un trabajo valioso de interés general para profesionales e historiadores no sólo de aquellos dedicados a la salud, que condensa y redescubre la abundante información existente para el siglo XIX y XX, frente a la escasez y dispersión documental propia del pasado.(AU)

Inappropriate sinus tachycardia may be related to an immunologic disorder involving cardiac beta andrenergic receptors.

BACKGROUND: The mechanisms underlying inappropriate sinus tachycardia are not fully known. An autonomic imbalance seems to play a role, but no attempts have been made to investigate a relationship between this arrhythmia and the antiautonomic membrane receptor antibodies found in other heart disorders and arrhythmias. OBJECTIVE: The purpose of this study was to investigate the prevalence and the functional and biochemical effects of circulating antiautonomic receptor antibodies in patients with inappropriate sinus tachycardia. METHODS: We studied 21 patients with inappropriate sinus tachycardia and 15 healthy volunteers. The chronotropic effects of the IgG fractions (also of affinity-purified anti-beta1 adrenergic receptor antibodies in selected cases) were assessed on cultured cardiomyocytes before and after exposure to atropine and propranolol. The effects of the IgG fractions from five patients and five healthy volunteers on cAMP production were evaluated in COS-7 cells transfected with genes encoding for beta1 or beta2 adrenergic receptor. RESULTS: The IgG fractions from patients with inappropriate sinus tachycardia exerted a positive chronotropic action with a high prevalence of anti-beta receptor antibodies (52%) and induced a clear-cut and long lasting increment of cAMP. No anti-M2 cholinergic receptor antibodies were found. The IgG fractions from healthy volunteers did not contain antiautonomic receptor antibodies. CONCLUSIONS: Our results suggest, for the first time, a link between inappropriate sinus tachycardia and circulating anti-beta adrenergic receptor antibodies that induce a persistent increment in cAMP production. This finding offers new insight into the physiopathology of inappropriate sinus tachycardia with potential therapeutic consequences.

Thrombocytosis induced in mice after subacute and subchronic V2O5 inhalation.

Reports about vanadium (V) inhalation toxicity on the hematopoietic system, specifically about coagulation are limited. Therefore, we decided to evaluate the effects of V with a complete blood count and morphologic analysis of platelets on blood smears. CD-1 male mice inhaled V2O5 0.02 M 1 h twice weekly over 12 weeks. Blood samples were obtained by direct heart puncture; Wright stained smears were used for platelet quantification. An increase in platelet count from the third week of exposure was observed, as well as the presence of megaplatelets. Our results demonstrate, for the first time, that V induces thrombocytosis and it might correlate with some thromboembolic diseases. Further analysis is needed to evaluate the functionality of these platelets as well as the cause of its increase.