The long term and complex nature of Chagas disease in humans has restricted studies on vaccine feasibility. Animal models also have limitations due to technical difficulties in monitoring the ...extremely low parasite burden that is characteristic of chronic stage infections. Advances in imaging technology offer alternative approaches that circumvent these problems. Here, we describe the use of highly sensitive whole body in vivo imaging to assess the efficacy of recombinant viral vector vaccines and benznidazole-cured infections to protect mice from challenge with Trypanosoma cruzi.
Mice were infected with T. cruzi strains modified to express a red-shifted luciferase reporter. Using bioluminescence imaging, we assessed the degree of immunity to re-infection conferred after benznidazole-cure. Those infected for 14 days or more, prior to the onset of benznidazole treatment, were highly protected from challenge with both homologous and heterologous strains. There was a >99% reduction in parasite burden, with parasites frequently undetectable after homologous challenge. This level of protection was considerably greater than that achieved with recombinant vaccines. It was also independent of the route of infection or size of the challenge inoculum, and was long-lasting, with no significant diminution in immunity after almost a year. When the primary infection was benznidazole-treated after 4 days (before completion of the first cycle of intracellular infection), the degree of protection was much reduced, an outcome associated with a minimal T. cruzi-specific IFN-γ+ T cell response.
Our findings suggest that a protective Chagas disease vaccine must have the ability to eliminate parasites before they reach organs/tissues, such as the GI tract, where once established, they become largely refractory to the induced immune response.
Purpose
To evaluate the influence of post type and mechanical aging on compression force resistance, fracture pattern, and stress distribution in weakened roots.
Materials and methods
Bovine roots ...were endodontically treated and widened—and randomly divided into 8 groups (n = 10) according to post type (prefabricated glass fiber post and customized anatomic glass fiber post, milled glass fiber post‐and‐core, and milled polyetheretherketone post‐and‐core) and mechanical aging (without and with mechanical aging). Three hundred thousand cycles of mechanical fatigue were performed and compression force resistance (N) was analyzed by two‐way ANOVA and Tukey test (α = 0.05). Fracture patterns were reported and stress distribution was analyzed by finite elements analysis.
Results
There was a significant effect of post type (p = 0.032) and mechanical aging (p = 0.009), but no double interaction (p = 0.879). Higher values were recorded in the milled glass fiber and polyetheretherketone post‐and‐core groups compared to the prefabricated glass fiber post groups, and no significant difference was found among anatomic glass fiber post groups and other groups. Reparable fractures were predominant in the milled glass fiber and polyetheretherketone post‐and‐core groups. Prefabricated glass fiber posts and milled polyetheretherketone post‐and‐cores showed similar stress distribution.
Conclusions
Post type and mechanical aging influence the compression force resistance and fracture pattern of weakened roots. Milled glass fiber and polyetheretherketone post‐and‐cores exhibited higher compression force resistance and more reparable fractures compared to prefabricated glass fiber posts. Prefabricated glass fiber posts and milled polyetheretherketone post‐and‐cores showed similar stress distribution.
Retrospective cohort study.
To investigate paid work status and return to work (RTW) pathways after spinal cord injury (SCI).
SARAH Network of Rehabilitation Hospitals.
Participants were adults with ...traumatic SCI, aged between 18 and 60 years at the time of the injury, admitted between 2000 and 2017. In the first stage, socio-demographic, injury-related, and functional status data were collected from medical records. In the second stage, data on paid work, means of mobility, driving ability, return to study, ability to work, and satisfaction with the work status were collected through an online survey conducted between January and March 2020.
A total of 154 participants were included in the sample. Of these, 90% were working at the time of SCI and 23% were engaged in paid work at the time of the study. Three RTW pathways were identified among those who were working at the time of the injury and: did not return to work (78%); returned to a different occupation (12%) and returned to the same occupation (9%). Number of post-injury complications, returning to study, good work ability, and satisfaction with the work status were predictors of paid work. The model's adjusted coefficient was 56.5% (p = 0.001).
Working-age people with SCI who underwent rehabilitation in Brazil had a low rate of paid work. Fewer complications at the time of the injury, returning to study, good ability to work and greater satisfaction with the work status increased the likelihood of being engaged in paid work.
An outbreak of cattle abortion associated with the consumption of Hesperocyparis (Cupressus) macrocarpa and Cupressus arizonica needles has been reported in Uruguay. Twenty-five of 125 pregnant ...heifers in late-term pregnancy aborted after being introduced into a paddock containing numerous H. macrocarpa, C. arizonica and Casuarina cunninghamiana trees. There were no significant macroscopic or histological findings in the two fetuses analyzed. Abortifacient labdane acids were detected in the needles of H. macrocarpa (1.68%, D.W.) and C. arizonica (0.36%, D.W.) but none were found in C. cunninghamiana.
•Hesperocyparis macrocarpa caused an abortion outbreak in cattle in Uruguay.•Abortifacient labdane acids were detected in needles of H. macrocarpa.•Cupressus arizonica also contains labdane acids but in small amounts.•Both trees may be an important cause of abortion in South America.
Monitoring the vital signs of mice is an essential practice during imaging procedures to avoid populational losses and improve image quality. For this purpose, a system based on a set of devices ...(piezoelectric sensor, optical module and thermistor) able to detect the heart rate, respiratory rate, body temperature and arterial blood oxygen saturation (SpO2) in mice anesthetized with sevoflurane was implemented. Results were validated by comparison with the reported literature on similar anesthetics. A new non-invasive electrocardiogram (ECG) module was developed, and its first results reflect the viability of its integration in the system. The sensors were strategically positioned on mice, and the signals were acquired through a custom-made printed circuit board during imaging procedures with a micro-PET (Positron Emission Tomography). For sevoflurane concentration of 1.5%, the average values obtained were: 388 bpm (beats/minute), 124 rpm (respirations/minute) and 88.9% for the heart rate, respiratory rate and SpO2, respectively. From the ECG information, the value obtained for the heart rate was around 352 bpm for injectable anesthesia. The results compare favorably to the ones established in the literature, proving the reliability of the proposed system. The ECG measurements show its potential for mice heart monitoring during imaging acquisitions and thus for integration into the developed system.
Accumulating evidence shows depression as a risk factor for frailty, but studies are mainly population-based and widely differ in their assessment of either depression or frailty. We investigated the ...association between depression and frailty among geriatric outpatients using different assessment instruments for both conditions.
Among 315 geriatric outpatients (mean age 72.1 years, 68.3% female sex) participating the MiMiCS-FRAIL cohort study, major and subthreshold depression were measured with psychiatric diagnostic interview according to DSM-5 criteria (SCID-5) as well as with instruments to screen and measure severity of depressive symptoms (GDS-15 and PHQ-9). Frailty was assessed according to a screening instrument (FRAIL-BR) and a multidimensional Frailty Index (FI-36 items). Multiple logistic and linear regression were performed to assess the association between depression (independent variable) and frailty (dependent variable) adjusted for confounders.
Frailty prevalence in patients with no, subthreshold or major depressive disorder increases from either 14.5%, 46.5% to 65.1% when using the FRAIL-BR questionnaire, and from 10.2%, 20.9%, to 30.2% when using the FI-36 index. These association remain nearly the same when adjusted for covariates. Both the FRAIL-BR and the FI-36 were strongly associated with major depressive disorder, subthreshold depression, and depressive symptoms by PHQ-9 and GDS-15.
Late life depression and frailty are associated in a dose-dependent manner, irrespective of the used definitions. Nonetheless, to avoid residual confounding, future research on underlying biological mechanisms should preferably be based on formal psychiatric diagnoses and objectively assessment frailty status.
Capybaras are the largest rodents cohabiting with humans within urban and peri-urban green areas and are known by their prolificity. Surgical contraception has been recommended by official ...organizations as a way to control capybara populations in areas of zoonotic disease transmission, but little data are available concerning surgical anatomy. To obtain objective anatomical descriptions related to reproductive organs, eight female capybaras cadavers were dissected. The stratigraphy of the lateral (flank) and ventral, post-umbilical (on the linea alba) abdominal wall is described as well as the vascular anatomy of reproductive organs and their syntopy with the abdominal viscera. We commented on the access to the uterine tubes and uterine horns for each approach, and for better description of abdominal wall stratigraphy, abdominal ultrasonography was performed in one live female. All of the animals were provenient from "in situ" population management projects that were properly authorized. Similar abdominal wall stratigraphy was found in comparison to domestic mammals, with emphasis on a thick cutaneous muscle, a thin linea alba, and a large, loose cecum. The uterine tubes were easily accessed by bilateral laparotomy, allowing tubal removal/ligation procedures, while uterine horn exposure was more readily reached by a midline post umbilical celiotomy, favoring horn ligature and hysterotomy techniques. This study can help achieve more efficient contraceptive surgeries in capybaras, reducing the total surgical time and enhancing animal welfare.
For environmental reasons, the production of plastic from renewable sources is gaining importance worldwide. In the case of polyethylene made from sugarcane-based ethanol, Brazil, being the world ...leader in sugarcane production, plays a fundamental role. Nevertheless, the absence of national regulations for monitoring the manufacturing process or verifying the biogenic fraction of what is already on the market raises concerns in Brazil. The main reason for the lack of such regulations is that the only approach fully capable of distinguishing identical chemical compounds of biogenic or fossil origin is the measurement of radiocarbon concentrations using an expensive and time-consuming method. Nevertheless, the measurement of stable carbon isotopes ratios has proven to be an acceptable approach to distinguish between C4 plant-derived plastics and petroleum-derived plastics. The present study compares the potential of the conventional mass spectrometry and radiocarbon accelerator mass spectrometry techniques as tools to determine the biogenic fraction of green polyethylene in Brazil. For plastics derived from either corn or sugarcane sources, δ13C values less negative than −20‰ indicate biofractions of 51% or higher. Other values would indicate the need to follow up to the radiocarbon accelerator mass spectrometry measurement, since it would not be possible to distinguish between lower biofractions and the presence of wheat or soy. The conventional mass spectrometry method can be employed for the preliminary screening of bio-based materials in manufacturing industries, representing a relatively cheap and accessible way of inspecting these products in developing countries.
•Plastic marketed as bio-based may have petroleum as a significant source.•Biofractions of plastics derived from C4 plants can be resolved via IRMS analyses.•Sugarcane based plastics were measured by both IRMS and 14C-AMS techniques.•IRMS represents a cheaper alternative to 14C-AMS analyses in biofraction studies.
Epidemiological studies have demonstrated rates of incontinence and enuresis as high as 20% in school-age children. This cross-sectional study aimed to investigate the prevalence of lower urinary ...tract (LUT) symptoms in 739 children aged 6–12 years enrolled in three government schools with different socioeconomic levels in Minas Gerais, Brazil. Symptoms of LUT were evaluated using a modified version of the Dysfunction Voiding Scoring System in which the cutoff point considered as an indicator of LUT dysfunction is >6 for girls and >9 for boys. Children with a score indicative of symptoms received an educational booklet on the functioning of the LUT and were sent for clinical evaluation. LUT dysfunction symptoms were detected in 161 (21.8%) children. Symptoms were most frequent in girls (
p
< 0.001), children aged 6–8 (
p
< 0.028), and attended the school with the lowest social level (
p
< 0.001). Intestinal constipation was the most prevalent finding (30.7%), independent of LUT score. The most common urinary symptoms in children with an elevated score were diurnal urinary incontinence (30.7%), holding maneuvers (19.1%), and urinary urgency (13.7%). Stress factors were associated in 28.4% of children. Our findings suggest that LUT symptoms must be investigated carefully at routine pediatric visits.
In Brazilian archaeological shellmounds, many species of land snails are found abundantly distributed throughout the occupational layers, forming a contextualized set of samples within the sites and ...offering a potential alternative to the use of charcoal for radiocarbon dating analyses. In order to confirm the effectiveness of this alternative, one needs to prove that the mollusk shells reflect the atmospheric carbon isotopic concentration in the same way charcoal does. In this study, 18 terrestrial mollusk shells with known collection dates from 1948 to 2004 AD, around the nuclear bombs period, were radiocarbon dated. The obtained dates fit the SH1-2 bomb curve within less than 15 years range, showing that certain species from the Thaumastus and Megalobulimus genera are reliable representatives of the atmospheric carbon isotopic ratio and can, therefore, be used to date archaeological sites in South America.
PDF
