Abstract
Although severe COVID-19 in children is rare, they may develop multisystem inflammatory syndrome, long-COVID and downstream effects of COVID-19, including social isolation and disruption of ...education. Data on the effectiveness of the CoronaVac vaccine is scarce during the Omicron period. In Brazil, children between 6 to 11 years are eligible to receive the CoronaVac vaccine. We conducted a test-negative design to estimate vaccine effectiveness using 197,958 tests from January 21, 2022, to April 15, 2022, during the Omicron dominant period in Brazil among children aged 6 to 11 years. The estimated vaccine effectiveness for symptomatic infection was 39.8% (95% CI 33.7–45.4) at ≥14 days post-second dose. For hospital admission vaccine effectiveness was 59.2% (95% CI 11.3–84.5) at ≥14 days. Two doses of CoronaVac in children during the Omicron period showed low levels of protection against symptomatic infection, and modest levels against severe illness.
Trypanosoma cruzi is the etiologic agent of Chagas' disease. Infected cells with T. cruzi activate several responses that promote unbalance of reactive oxygen species (ROS) that may cause DNA damage ...that activate cellular responses including DNA repair processes. In this work, HeLa cells and AC16 human cardiomyocyte cell line were infected with T. cruzi to investigate host cell responses at genome level during parasites intracellular life cycle. In fact, alkaline sensitive sites and oxidized DNA bases were detected in the host cell genetic material particularly in early stages of infection. These DNA lesions were accompanied by phosphorylation of the histone H2Ax, inducing γH2Ax, a marker of genotoxic stress. Moreover, Poly ADP-ribose polymerase-1 (PARP1) and 8-oxoguanine glycosylase (OGG1) are recruited to host cell nuclei, indicating activation of the DNA repair process. In infected cells, chromatin-associated proteins are carbonylated, as a possible consequence of oxidative stress and the nuclear factor erythroid 2-related factor 2 (NRF2) is induced early after infection, suggesting that the host cell antioxidant defenses are activated. However, at late stages of infection, NRF2 is downregulated. Interestingly, host cells treated with glutathione precursor, N-acetyl cysteine, NRF2 activator (Sulforaphane), and also Benznidonazol (BNZ) reduce parasite burst significantly, and DNA damage. These data indicate that the balance of oxidative stress and DNA damage induction in host cells may play a role during the process of infection itself, and interference in these processes may hamper T. cruzi infection, revealing potential target pathways for the therapy support.
Little is known about vaccine effectiveness over time among adolescents, especially against the SARS-CoV-2 omicron (B.1.1.529) variant. This study assessed the associations between time since ...two-dose vaccination with BNT162b2 and the occurrence of symptomatic SARS-CoV-2 infection and severe COVID-19 among adolescents in Brazil and Scotland.
We did test-negative, case-control studies in adolescents aged 12–17 years with COVID-19-related symptoms in Brazil and Scotland. We linked records of SARS-CoV-2 RT-PCR and antigen tests to national vaccination and clinical records. We excluded tests from individuals who did not have symptoms, were vaccinated before the start of the national vaccination programme, received vaccines other than BNT162b2 or a SARS-CoV-2 booster dose of any kind, or had an interval between their first and second dose of fewer than 21 days. Additionally, we excluded negative SARS-CoV-2 tests recorded within 14 days of a previous negative test, negative tests recorded within 7 days after a positive test, any test done within 90 days after a positive test, and tests with missing sex and location information. Cases (SARS-CoV-2 test-positive adolescents) and controls (test-negative adolescents) were drawn from a sample of individuals in whom tests were collected within 10 days of symptom onset. We estimated the adjusted odds ratio and vaccine effectiveness against symptomatic COVID-19 for both countries and against severe COVID-19 (hospitalisation or death) for Brazil across fortnightly periods.
We analysed 503 776 tests from 2 948 538 adolescents in Brazil between Sept 2, 2021, and April 19, 2022, and 127 168 tests from 404 673 adolescents in Scotland between Aug 6, 2021, and April 19, 2022. Vaccine effectiveness peaked at 14–27 days after the second dose in both countries during both waves, and was significantly lower against symptomatic infection during the omicron-dominant period in Brazil (64·7% 95% CI 63·0–66·3) and in Scotland (82·6% 80·6–84·5), than it was in the delta-dominant period (80·7% 95% CI 77·8–83·3 in Brazil and 92·8% 85·7–96·4 in Scotland). Vaccine efficacy started to decline from 27 days after the second dose for both countries, reducing to 5·9% (95% CI 2·2–9·4) in Brazil and 50·6% (42·7–57·4) in Scotland at 98 days or more during the omicron-dominant period. In Brazil, protection against severe disease remained above 80% from 28 days after the second dose and was 82·7% (95% CI 68·8–90·4) at 98 days or more after receiving the second dose.
We found waning vaccine protection of BNT162b2 against symptomatic COVID-19 infection among adolescents in Brazil and Scotland from 27 days after the second dose. However, protection against severe COVID-19 outcomes remained high at 98 days or more after the second dose in the omicron-dominant period. Booster doses for adolescents need to be considered.
UK Research and Innovation (Medical Research Council), Scottish Government, Health Data Research UK BREATHE Hub, Fiocruz, Fazer o Bem Faz Bem programme, Brazilian National Research Council, and Wellcome Trust.
For the Portuguese translation of the abstract see Supplementary Materials section.
A nano-molecularly imprinted polymer (N-MIP) assembled on a screen-printed electrode for the cardiac troponin T (cTnT) was developed. The biomimetic surface was obtained by a co-polymer matrix ...assembled on the reduced graphene oxide (RGO) electrode surface. The cTnT active sites were engineered using pyrrole and carboxylated pyrrole that was one-step electropolymerized jointly with cTnT by cyclic voltammetry. The stepwise preparation of the biomimetic surface was characterized by cyclic and differential pulse voltammetries using the ferrocyanide/ferricyanide as redox probe. Structural and morphological characterization was also performed. The optimal relation of pyrrole and pyrrole-3-acid carboxylic to perform the cTnT biomimetic nanosurface was obtained at 1:5 ratio. The analytical performance of cTnT N-MIP performed by differential pulse voltammetry showed a linear range from 0.01 to 0.1ngmL−1 (r=0.995, p«0.01), with a very low limit of detection (0.006ngmL−1). The synergic effect of conductive polymer and graphene forming 3D structures of reactive sites resulted in a N-MIP with excellent affinity to cTnT binding (KD=7.3 10−13molL−1). The N-MIP proposed is based on a simple method of antibody obtaining with a large potential for point-of-care testing applications.
•A biomimetic sensor as imprinted thin-film was developed to cardiac troponin T.•A sensor was assembled based on graphene and conductive polymer synergism.•The biomimetic sensor was assembled onto a disposable screen-printed electrode.•The functionalized pyrrole was explored to mimetizes the cTnT antibodies.•The biomimetic cTnT sensor achieved a good limit of detection (0.006ngmL−1).
Ctenopharyngodon idella (Grass carp) is one of the most widely produced species in aquaculture. This species is capable of feeding on forage crops and algae. However, few studies have investigated ...forage feeding in the production of this species. The aim of this work was to evaluate the impact of fresh Lolium multiflorum feeding on the fatty acid and antioxidant fat-soluble vitamin composition, antioxidant status, and lipid stability of C. idella meat. For this purpose, a 120-day feeding trial was conducted. Approximately 300 juvenile C. idella (7.97 ± 0.6 g and 8.82 ± 0.73 cm) were used. Two experimental diets were used: L. multiflorum Lam (annual ryegrass) forage, or pasture diet (PD), and artificial grain diet (GD). Juveniles of C. idella fed PD accumulated a greater concentration of EPA, DPA, and DHA fatty acids after 60 and 120 days (P < 0.05). Conversely, fish fed a grain-based diet accumulated higher omega 6 fatty acid content in their meat. The PD group meat had a higher content of α-tocopherol, lutein, β-carotene, and retinol than the GD group (P < 0.05). The action of these fat-soluble vitamins and micronutrients increased the FRAP and decreased TBARS in the meat of the PD group. These results suggest that L. multiflorum (ryegrass) feeding improves the quality of C. idella meat by increasing the fatty acids beneficial to human health, such as EPA, DPA, and DHA contents. In addition, this diet increases the antioxidant fat-soluble vitamin contents, thus not only improving the nutritional value of the meat but also contributing to lipid stability.
•HUFAs n-3 from the meat of C. idella were enhanced with ryegrass diet.•A better accumulation of fat-soluble vitamins and antioxidants were obtained in the meat of C. idella fed ryegrass.•The antioxidant status was increased in the meat of C. idella fed ryegrass.•The ryegrass fed strategy improved the lipid stability of the meat of C. idella.
To complete its life cycle within the mammalian host,
, the agent of Chagas' disease, must enter cells. Trypomastigotes originating from the insect vector (metacyclic) or from infected cells ...(bloodstream/tissue culture-derived) are the classical infective forms of the parasite and enter mammalian cells in an actin-independent manner. By contrast, amastigotes originating from the premature rupture of infected cells or transformed from swimming trypomastigotes (designated extracellular amastigotes, EAs) require functional intact microfilaments to invade non-phagocytic host cells. Earlier work disclosed the key features of EA-HeLa cell interplay: actin-rich protrusions called 'cups' are formed at EA invasion sites on the host cell membrane that are also enriched in actin-binding proteins, integrins and extracellular matrix elements. In the past decades we described the participation of membrane components and secreted factors from EAs as well as the actin-regulating proteins of host cells involved in what we propose to be a phagocytic-like mechanism of parasite uptake. Thus, regarding this new perspective herein we present previously described EA-induced 'cups' as parasitic synapse since they can play a role beyond its architecture function. In this review, we focus on recent findings that shed light on the intricate interaction between extracellular amastigotes and non-phagocytic HeLa cells.
•An evanescent wave fiber optic sensor, based on a MIP as recognition element.•The MIP is coated ex situ by dip-coating.•Sensing is based on evanescent wave absorbance.•The dye basic red 9 is ...detected in the μM concentrations in water.•We believe that this method can be used for on-site routine monitoring and screening.
A cheap and robust method for the detection and quantification of textile dyes is the use of biomimetic sensors with optical transduction, employing a molecularly imprinted polymer (MIP) as the recognition element. This paper presents the optimization of a MIP for the dye, basic red 9 (BR9) and the immobilization of these polymers on a disposable 4-cm long polystyrene optical waveguide for the development of an evanescent wave fiber optic sensor aimed at the determination and quantification of this dye in different matrices and industrial effluents. MIPs were synthesized using 2-acrylamido-2-methyl-1-propanesulfonic acid and ethylene glycol dimethacrylate, as functional monomer and cross-linker, respectively. The polymer was then immobilized on the waveguide by dip-coating the fiber in the polymer suspension. The sensing element was interrogated with a fiber-coupled spectrophotometer. BR9 could be detected in the low μM range, thus making it a promising device for determining this compound in textile effluents.