Dynamics of the Trypanosoma cruzi infection in adipose tissue: Assessing gene expression of PNPLA2, FASN, and ACAT1 under Benzonidazole treatment and indirect mononuclear immune cells interaction.

Trypanosoma cruzi is a parasite with a high capacity to adapt to the host. Animal models have already demonstrated that the tropism of this parasite occurs not only in cardiac/digestive tissues but also in adipose tissue (AT). That said, the consequences ofT. cruziinfection for AT and the implications of treatment with Benzonidazole in this tissue are under discussion. Here, we tested the hypothesis that T. cruzi infection in adipose tissue upon treatment with Benzonidazole (Bz) and the interaction of mononuclear immune cells (PBMC) influences the relative expression of ACAT1, FASN, and PNPLA2 genes. Thus, stem cells derived from adipose tissue (ADSC) after adipogenic differentiation were indirectly cultivated with PBMC after infection with the T. cruzi Y strain and treatment with Bz. We use the TcSAT-IAM system and RT-qPCR to evaluate the parasite load and the relative quantification (ΔCt) of the ACAT1, FASN, and PNPLA2 genes. Our results demonstrate that treatment with Bz did not reduce adipocyte infection in the presence (p-value: 0.5796) or absence (p-value: 0.1854) of cultivation with PBMC. In addition, even though there is no statistical difference when compared to the control group (AT), T. cruzi induces the FASN expression (Rq: 14.00). However, treatment with Bz in AT suggests the increases of PNPLA2 expression levels (Rq: 12.58), even in the absence of T. cruzi infection. During indirect cultivation with PBMC, T. cruzi smooths the expression of PNPLA2 (Rq: 0.824) and instigates the expression of ACAT1 (Rq: 1.632) and FASN (Rq: 1.394). Furthermore, the treatment with Bz during infection induces PNPLA2 expression (Rq: 1.871), maintaining FASN expression levels (Rq: 1.334). Given this, our results indicate that treatment with Benzonidazole did not decrease T. cruzi infection in adipose tissue. However, treating the adipocyte cells with Bz during the interaction with PBMC cells influences the lipid pathways scenario, inducing lipolytic metabolism through the expression of PNPLA2.

Green microalgae as a potential source of trypanocide compounds.

Due to the limitations of Chagas disease therapy, microalgae can be promising in the search of new trypanocidal compounds, since these organisms produce bioactive compounds with large pharmaceutical applications, including antiparasitic effects. In this work, trypanocidal activity of aqueous extract of Tetradesmus obliquus and, for the first time, aqueous extract of Chlorella vulgaris, were evaluated against trypomastigote forms of Trypanosoma cruzi. In addition, cytotoxic activity in Vero cells was evaluated. Our results showed that C. vulgaris and T. obliquus present trypanocidal activity (IC50 = 32.9 µg ml-1 and 36.4 µg ml-1, respectively), however, C. vulgaris did not present cytotoxic effects in Vero cells (CC50 > 600 µg ml-1) and displayed a higher selectivity against trypomastigotes forms of T. cruzi (SI > 18). Thus, microalgae extracts, such as aqueous extract of C. vulgaris, are promising potential candidates for the development of natural antichagasic drugs.

Distinguishing SARS-CoV-2 bonafide re-infection from pre-existing minor variant reactivation.

Different groups have recently reported events of SARS-CoV-2 reinfection, where patients had a sequence of positive-negative-positive RT-PCR tests. However, such events could be explained by different scenarios such as intermittent viral shedding, bonafide re-infection or multiple infection with alternating predominance of different viruses. Analysis of minor variants is an important tool to distinguish between these scenarios. Using ARTIC network PCR amplification and next-generation sequencing, we obtained SARS-CoV-2 sequences from two timepoints (with a time span of 102 days) of a patient followed at the Brazilian National Cancer Institute. Within-host variant analysis evidenced three single nucleotide variants (SNVs) at the consensus viral sequence in the second timepoint that were already present in the first timepoint as minor variants. Another five SNVs found in the second timepoint were not detected in the first sample sequenced, suggesting an additional infection by a yet another new virus. Our observation shed light into the existence of different viral populations that are present in dynamic frequencies and fluctuate during the course of SARS-CoV-2 infection. The detection of these variants in distinct disease events of an individual highlights a complex interplay between viral reactivation from a pre-existing minority variant and reinfection by a different virus.

Physical activity but not sedentary time is associated with vitamin D status in adolescents: study of cardiovascular risk in adolescents (ERICA).

BACKGROUND/OBJECTIVES: The association between active lifestyle components and vitamin D status in adolescents remains relatively unexplored. We aimed to investigate independent and joint associations of moderate-to-vigorous physical activity (MVPA) and screen time with serum 25-hydroxyvitamin D [25(OH)D] concentrations in adolescents. METHODS: This multicenter cross-sectional study involved 1152 Brazilian adolescents (age 12-17 years). Serum 25(OH)D was measured in a single laboratory and categorized as ≤20, 21-29, or ≥30 ng/mL. Demographic and lifestyle characteristics were assessed by self-reports. Ordered logistic regression was used to investigate potential associations of being physically active (MVPA ≥ 300 min/week) and excessive screen time (>2 h/day) with serum 25(OH)D concentrations. RESULTS: The prevalence of higher serum 25(OH)D concentrations (≥30 ng/mL) was 36.4%. In adjusted models, being physically active was associated with higher serum 25(OH)D concentrations only in boys [proportional odds ratio (POR) = 2.04, 95% CI 1.42-2.93], while excessive screen time was not associated with serum 25(OH)D. Adolescents who were physically active and limited their screen time had higher odds of a higher serum 25(OH)D concentration, but the association was significant only for boys (POR = 2.11, 95% CI 1.19-3.74). CONCLUSIONS: MVPA may play an important role in increasing serum 25(OH)D concentrations in adolescence, especially for boys, regardless of screen time.

Clinical performance and "ex vivo" dehydration of silicone hydrogel contact lenses with two new multipurpose solutions.

PURPOSE: To compare the performance of two novel multipurpose disinfecting solutions (MPDS) in preventing silicone hydrogel contact lens dehydration, provide higher scores of subjective comfort and stable optical quality during a month of lens wear in neophyte volunteers. METHOD: This is a prospective, double-blind, contralateral and randomised study involving the contra lateral use of Complete RevitaLens and Biotrue MPDS. Twenty-five neophytes wore Air Optix Aqua for 1 month. Volunteers were evaluated on day 1 and day 30 at 2 and 10h after lens insertion. Tear film stability using Tearscope Plus (Keeler, UK), whole eye aberrations for 4.5mm pupil size (IRx3, ImaginEyes, France) and subjective comfort (0-10 score) along with the dehydration values obtained with a gravimetric method were collected at each follow-up visit. RESULTS: NIBUT values decreased significantly with both care systems from baseline to 10h visit on day 1 (p=0.032 and 0.016, mean difference=-6.7s and -7.0 s, for Complete Revitalens and Biotrue, respectively). Dehydration rates and ocular aberrations did not change significantly over the month of follow-up (p>0.05, ANOVA with Bonferroni post hoc corrections), nor between visits within the same day (p>0.05, paired sample T-test). End-of-day dryness sensation worsened similarly with both MPDS after 1 month (p=0.021 and 0.005, mean difference=-1.4 and -1.3, for Complete Revitalens and Biotrue, respectively). CONCLUSIONS: Regardless of their different chemical compositions in terms of moisture additives both MPDS solutions evaluated performed similarly regarding objective measures of dehydration, tear stability and optical quality but presented significant differences in subjective symptoms.

Sex differences in brain cholinergic activity in MSG-obese rats submitted to exercise.

Obesity is an epidemic disease most commonly caused by a combination of increased energy intake and lack of physical activity. The cholinergic system has been shown to be involved in the regulation of food intake and energy expenditure. Moreover, physical exercise promotes a reduction of fat pads and body mass by increasing energy expenditure, but also influences the cholinergic system. The aim of this study is to evaluate the interaction between physical exercise (swimming) and central cholinergic activity in rats treated with monosodium glutamate (MSG, a model for obesity) during infancy. Our results show that MSG treatment is able to induce obesity in male and female rats. Specifically, MSG-treated rats presented a reduced body mass and nasoanal length, and increased perigonadal and retroperitoneal fat pads in relation to the body mass. Physical exercise was able to reduce body mass in both male and female rats, but did not change the fat pads in MSG-treated rats. Increased food intake was only seen in MSG-treated females submitted to exercise. Cholinergic activity was increased in the cortex of MSG-treated females and physical exercise was able to reduce this activity. Thalamic cholinergic activity was higher in sedentary MSG-treated females and exercised MSG-treated males. Hypothalamic cholinergic activity was higher in male and female MSG-treated rats, and was not reduced by exercise in the 2 sexes. Taken together, these results show that MSG treatment and physical exercise have different effects in the cholinergic activity of males and females.