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Chagas disease by Trypanosoma cruzi ( T . cruzi ) infection is a leading cause of myocarditis worldwide. Chagas cardiomyopathy is presented with a wide variety of conduction abnormalities including arrhythmias, first- and second-degree atrioventricular blockade, left ventricular systolic dysfunction and some cases heart failure leading to the death. Currently, there are no effective treatments available against advanced Chagas disease. With the advance in the development of novel therapies, it is important to utilize an animal model that can effectively replicate the diverse stages of Chagas disease, including chronic asymptomatic and symptomatic infection, that are akin to those observed in humans. Therefore, to characterize the cardiac alterations during the evolution of the infection, we evaluated the progression of cardiomyopathy caused by T . cruzi H1 infection in both BALB/c and ICR mouse models by performing electrocardiogram (ECG) studies in unanesthetized mice every month until 210 days post-infection (dpi). In the late chronic phase of infection, we also performed echocardiogram (ECHO) studies to further assess cardiac function. In conclusion, we demonstrated that ICR mice were more susceptible to cardiac alterations compared to BALB/c mice and both mouse strains are suitable experimental models to study chronic T . cruzi infection and novel treatments.

Rationale The endocannabinoid system has been implicated in the pathogenesis of major depression (MD) as well as in the mediation of antidepressant drug effects. Objectives To analyze CNR1 gene variants in MD and clinical response to citalopram (selective serotonin re-uptake inhibitors [SSRI]). Methods The role of CNR1 gene (rs806368, rs1049353, rs806371, rs806377 and rs1535255) was investigated in 319 outpatients with MD and 150 healthy individuals. A subsample of 155 depressive patients were treated with citalopram and evaluated for response (fourth week) and remission (12th week) by the 21-item Hamilton Depression Rating Scale (HDRS). Results We observed a higher frequency of rs806371 G carriers in MD patients with both presence of melancholia ( p  = 0.018) and psychotic symptoms ( p  = 0.007) than in controls. Haplotype frequency distributions between MD sample and controls showed a significant difference for Block 1 (rs806368–rs1049353–rs806371) ( p  = 0.008). This haplotype finding was consistent when we compared controls with MD subsample stratified by melancholia ( p  = 0.0009) and psychotic symptoms ( p  = 0.014). The TT homozygous of the rs806368 and rs806371 presented more risk of no Remission than the C carriers ( p  = 0.008 and 0.012, respectively). Haplotype frequency distributions according to Remission status showed a significant difference for Block 1 ( p  = 0.032). Also, we observed significant effect of time–sex–genotype interaction for the rs806368, showing that the C carrier men presented a better response to antidepressant treatment throughout the follow-up than TT homozygous men and women group ( p  = 0.026). Conclusions These results suggest an effect of CNR1 gene in the etiology of MD and clinical response to citalopram.

The aim of this study was to determine the genotypic diversity of 22 Cryptococcus gattii species complex clinical isolates from Argentina and to place these genotypes within the diversity of clinical, veterinary and environmental isolates from Latin America. Mating type and antifungal susceptibility of the isolates were also determined. By URA5 -RFLP, nine isolates were identified as molecular type VGI, 10 as VGII, one as VGIII and two as VGIV. Multilocus sequence typing (MSLT), following the International Society for Human and Animal Mycology (ISHAM) consensus MLST scheme, was used to determine the genotypic diversity. Our results suggest that, in Argentina, VGI isolates have low genetic diversity, while VGII isolates have high genetic diversity. Both isolates identified as VGIV by URA5 -RFLP were genotyped by MLST as belonging to the currently named VGVI clade. From all isolates, eight sequence types (STs) were unique for Argentina, while five STs have been reported already in other countries, being of high interest the genotypes ST20 and ST7 since they belong to the subtypes VGIIa and VGIIb, respectively, which are associated with hypervirulent strains responsible for outbreaks in North America. To note, geographical analysis showed that some genotypes may be associated with some regions in Argentina. Most isolates were MATα , but we are reporting one isolate MATa for the first time in the country. Antifungal susceptibility tests showed that itraconazole, voriconazole and posaconazole had high activity against all isolates, while amphotericin B, fluconazole and 5-fluorocytosine were the least active drugs against all studied isolates.

Antipsychotic drugs fail to achieve adequate response in 30–50% of treated patients and about 50% of them develop severe and lasting side effects. Treatment failure results in poorer prognosis with devastating repercussions for the patients, carers and broader society. Our study evaluated the clinical benefits of a pharmacogenetic intervention for the personalisation of antipsychotic treatment. Pharmacogenetic information in key CYP polymorphisms was used to adjust clinical doses in a group of patients who started or switched treatment with antipsychotic drugs (PharmG+, N = 123), and their results were compared with those of a group of patients treated following existing clinical guides (PharmG−, N = 167). There was no evidence of significant differences in side effects between the two arms. Although patients who had their antipsychotic dose adjusted according to CYPs polymorphisms (PharmG+) had a bigger reduction in side effects than those treated as usual (PharmG−), the difference was not statistically significant (p > 0.05 for all comparisons). However, PharmG+ patients treated with CYP2D6 substrates that were carriers of CYP2D6 UMs or PMs variants showed a significantly higher improvement in global, psychic and other UKU side effects than PharmG− patients (p = 0.02, p = 0.05 and p = 0.01, respectively). PharmG+ clozapine treated patients with CYP1A2 or CYP2C19 UM and PMs variants also showed higher reductions in UKU scores than PharmG− clozapine patients in general. However, those differences were not statistically significant. Pharmacogenetic interventions may improve the safety of antipsychotic treatments by reducing associated side effects. This intervention may be particularly useful when considering treatment with antipsychotics with one major metabolic pathway, and therefore more susceptible to be affected by functional variants of CYP enzymes.

The well-established relationship between childhood adversity and psychosis is likely to involve other factors such as genetic variants that can help us to understand why not everyone exposed to adverse events develops psychotic symptoms later in life. We investigated the influence of childhood abuse and neglect on positive and negative psychotic-like experiences in adulthood and the potential moderating effect of the BDNF-Val66Met polymorphism. Psychotic-like experiences and childhood adversity were assessed in 533 individuals from the general population. Childhood abuse showed a strong independent effect on the positive dimension of psychotic-like experiences (β = 0.16, s.e. = 0.05, P = 0.002). Furthermore, this association was moderated by the BDNF-Val66Met polymorphism (β = 0.27, s.e. = 0.10, P = 0.004). Individuals exposed to childhood abuse are more likely to report positive psychotic-like experiences. Met carriers reported more positive psychotic-like experiences when exposed to childhood abuse than did individuals carrying the Val/Val genotype. Therefore, the observed gene-environment interaction effect may be partially responsible for individual variation in response to childhood abuse.

The expression of Neuritin-1 ( NRN1 ), a neurotrophic factor crucial for neurodevelopment and synaptic plasticity, is enhanced by the Brain Derived Neurotrophic Factor ( BDNF ). Although the receptor of NRN1 remains unclear, it is suggested that NRN1’s activation of the insulin receptor (IR) pathway promotes the transcription of the calcium voltage-gated channel subunit alpha1 C ( CACNA1C ). These three genes have been independently associated with schizophrenia (SZ) risk, symptomatology, and brain differences. However, research on how they synergistically modulate these phenotypes is scarce. We aimed to study whether the genetic epistasis between these genes affects the risk and clinical presentation of the disorder via its effect on brain structure. First, we tested the epistatic effect of NRN1 and BDNF or CACNA1C on (i) the risk for SZ, (ii) clinical symptoms severity and functionality (onset, PANSS, CGI and GAF), and (iii) brain cortical structure (thickness, surface area and volume measures estimated using FreeSurfer) in a sample of 86 SZ patients and 89 healthy subjects. Second, we explored whether those brain clusters influenced by epistatic effects mediate the clinical profiles. Although we did not find a direct epistatic impact on the risk, our data unveiled significant effects on the disorder’s clinical presentation. Specifically, the NRN1 -rs10484320 x BDNF -rs6265 interplay influenced PANSS general psychopathology, and the NRN1 -rs4960155 x CACNA1C -rs1006737 interaction affected GAF scores. Moreover, several interactions between NRN1 SNPs and BDNF -rs6265 significantly influenced the surface area and cortical volume of the frontal, parietal, and temporal brain regions within patients. The NRN1 -rs10484320 x BDNF -rs6265 epistasis in the left lateral orbitofrontal cortex fully mediated the effect on PANSS general psychopathology. Our study not only adds clinical significance to the well-described molecular relationship between NRN1 and BDNF but also underscores the utility of deconstructing SZ into biologically validated brain-imaging markers to explore their mediation role in the path from genetics to complex clinical manifestation.

Schizophrenia (SCZ) is a complex disorder that typically arises in late adolescence or early adulthood. Age at onset (AAO) of SCZ is associated with long-term outcomes of the disease. We explored the genetic architecture of AAO with a genome-wide association study (GWAS), heritability, polygenic risk score (PRS), and copy number variant (CNV) analyses in 4 740 subjects of European ancestry. Although no genome-wide significant locus was identified, SNP-based heritability of AAO was estimated to be between 17 and 21%, indicating a moderate contribution of common variants. We also performed cross-trait PRS analyses with a set of mental disorders and identified a negative association between AAO and common variants for SCZ, childhood maltreatment and attention-deficit/hyperactivity disorder. We also investigated the role of copy number variants (CNVs) in AAO and found an association with the length and number of deletions (P-value = 0.03), whereas the presence of CNVs previously reported in SCZ was not associated with earlier onset. To our knowledge, this is the largest GWAS of AAO of SCZ to date in individuals from European ancestry, and the first study to determine the involvement of common variants in the heritability of AAO. Finally, we evidenced the role played by higher SCZ load in determining AAO but discarded the role of pathogenic CNVs. Altogether, these results shed light on the genetic architecture of AAO, which needs to be confirmed with larger studies.

Background: Childhood maltreatment increases the risk of suicide attempts in the general population, possibly having similar effects among patients with major depressive disorder (MDD). The few studies that have addressed this association have been restricted to specific populations (e.g. treatment-resistant depression, personality disorders) and have rarely taken sex into account. Objective: To examine the impact of childhood maltreatment on suicide attempts among MDD patients above and beyond other risk factors and potential confounders, while considering potential sex-specific effects. Methods: The study assessed 165 patients with a principal diagnosis of MDD. Neurological alterations, psychiatric comorbidities, and drug abuse were reasons for exclusion. Logistic regressions using the whole sample, and divided by sex, were run to test the association between childhood maltreatment and history of suicide attempts, controlling for symptom severity, comorbidities, and treatment-resistant depression. Results: There was a significant and clinically relevant association between childhood maltreatment and history of suicide attempts in the total sample. Patients with childhood maltreatment were 3.01 times more likely to present a history of suicide attempts than patients without childhood maltreatment. A family history of psychiatric disorders also contributed to the variance of attempted suicide, but its interaction with childhood maltreatment was not statistically significant. When testing the model separately, the effect of childhood maltreatment on suicide attempts remained for females, whereas for males, age of MDD onset and Childhood Trauma Questionnaire minimization-denial scale were predictive variables. Conclusions: Childhood maltreatment is a clear predictor of suicidal behaviour among MDD patients, and this effect remains significant after controlling for potential confounders. Also, the sex of patients emerges as a relevant factor that may model the mechanisms underlying the prediction of suicide attempts. Since suicide is the main cause of premature death among MDD patients, interventions targeting childhood maltreatment should be included in preventive and clinical strategies. * Childhood maltreatment significantly increases the risk of suicide attempts in MDD patients, above and beyond previously proposed factors.* This association is particularly evident among female MDD patients.* The underlying mechanisms in male patients may be dependent on further biopsychological factors.* MDD patients should be screened for childhood maltreatment as a strategy to prevent suicide attempts in adulthood.

Menopause is a process characterized by a decline in estrogen levels and is therefore a period of biological vulnerability for psychotic relapse in women with schizophrenia. Our goal was to correlate not only gonadal hormone levels but also follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels with improvement in specific clinical symptoms. Thirty-seven acutely ill postmenopausal schizophrenia women with a newly initiated, clinically determined change in antipsychotic medication participated in a 12-week prospective observational outcome study. Scales used were the PANSS scale for psychotic symptoms, the PSP for functioning, and CGI for global clinical impression. Circulating FSH, LH, estradiol, progesterone, and testosterone serum levels were determined by chemiluminescent immunoassay. Partial correlational analyses were performed along with a Bonferroni significance correction ( p  < 0.0007). After adjustment for confounding factors, the FSH/LH ratio correlated positively with mean changes in PANSS positive scores, and there was a correlation with worsening of CGI total and cognitive scores. Testosterone was also positively associated with improvement in PANSS positive scores. However, after correction for multiple testing, the initial correlations were no longer statistically significant. In summary, while the hormone assays we did in this small sample did not prove to be significantly linked to clinical improvement in any of the schizophrenia symptom domains, we recommend further investigation of pituitary, adrenal, and gonadal hormone ratios as potential markers of clinical improvement in this population.