Green synthesis of silver nanoparticles based on using Croton urucurana and their toxicity against freshwater snail species Biomphalaria glabrata.

Green plant-based silver nanoparticles (GP-Ag NPs) have contributed to the development of ecological technologies with low environmental impact and safer for human health, as well as demonstrating potential for the control of vectors and intermediate hosts. However, knowledge about its toxicity in the early stages of gastropod development remains scarce. Therefore, the current study aimed to investigate the toxicity of GP-Ag NPs synthesized from Croton urucurana leaf extracts in snail species Biomphalaria glabrata, which is an intermediate host for Schistosoma mansoni parasite. GP-Ag NPs were synthesized using two types of plant extracts (aqueous and hydroethanolic) and characterized using multiple techniques. Bioassays focused on investigating GP-Ag NPs and plant extracts were carried out with embryos and newly hatched snails, for 144 h and 96 h, respectively; toxicity was analyzed based on mortality, hatching, development inhibition, and morphological changes. Results have shown that both GP-Ag NPs were more toxic to embryos and newly hatched snails than the investigated plant extracts. GP-Ag NPs deriving from aqueous extract have higher molluscicidal activity than those deriving from hydroethanolic extract. Both GP-Ag NPs induced mortality, hatching delay, development inhibition, and morphological changes (i.e., hydropic embryos), indicating their molluscicidal activities. Moreover, embryos were more sensitive to GP-Ag NPs than newly hatched snails. Thus, the toxicity of GP-Ag NPs to freshwater snails depends on the type of extracts and the snail's developmental stages. These findings can contribute to the development of green nanobiotechnologies applicable to control snails of medical importance.

Atypical parathyroid adenoma with severe bone manifestations in early adolescence.

This is a case of primary hyperparathyroidism in a female teenager with multiple fractures and severe bone manifestations. The histopathology revealed atypical parathyroid adenoma, an exceedingly rare form of hyperparathyroidism; its main differential diagnosis is parathyroid carcinoma, as it shares both clinical and histological characteristics with it, in addition to its still uncertain malignant potential.

Effects of andiroba oil (Carapa guianensis aublet) on the immune system in inflammation and wound healing: A scoping review.

ETHNOPHARMACOLOGICAL RELEVANCE: Andiroba seed oil (Carapa guianensis Aubl.) is widely used by traditional populations in tropical countries, especially in the Brazilian Amazon, because of its anti-inflammatory, antirheumatic, antiseptic, healing and antipyretic properties, among others, which makes it useful for the treatment, mainly, of skin afflictions and wounds. AIM OF THE STUDY: To describe the modulation of the immune system by andiroba oil (Carapa guianensis Aubl.) in inflammation and wound healing. MATERIALS AND METHODS: A scoping review was performed, following the recommendations of the Joanna Briggs Institute (JBI) and PRISMA for Scoping Reviews (PRISMA-ScR). As inclusion criteria, in vitro, in vivo, ex vivo, and clinical studies were selected, in Portuguese, English, or Spanish, in thirteen databases of published studies, gray literature, and references of the included studies, which deal with immune modulation by andiroba oil in the context of the various therapeutic applications that make use of its anti-inflammatory and wound healing properties. The selection of information sources was carried out by two independent reviewers between November 2022 and January 2023. The process of data extraction and evidence analysis was conducted by four pairs of independent reviewers between January and February 2023. RESULTS: 22 sources of evidence were included in this scoping review, mostly scientific articles published between 2005 and 2021 with in vivo sampling. The evidence suggests that andiroba oil reduces inflammation and promotes the healing of wounds of multiple etiologies by reducing leukocyte infiltration, increasing phagocytic activity, enhancing interleukin and inflammatory cytokine activity, promoting fibroblast recovery, increasing growth factors, reducing apoptotic cells, promoting reepithelialization, as well as promoting angiogenesis, reducing edema, and stimulating the production of glucocorticoids that alleviate pain. Additionally, different formulations of the oil (such as nanoemulsions, films and gels) are more effective in modulating inflammation and wound healing compared to in natura oil. CONCLUSIONS: Evidence in the literature suggests that andiroba oil (Carapa guianensis Aubl.) has positive effects on immune modulation in inflammation and wound healing, which makes it a biocompound with high therapeutic potential.

Detection and Genotyping of Trypanosoma cruzi Samples in Species of Genus Rhodnius from Different Environments in the Brazilian Amazon.

Background: In the Amazon region, several species of triatomines occur in the natural environments. Among them, species of the genus Rhodnius are a risk to human populations due to their high rates of infection with Trypanosoma cruzi. The aim of this study was to identify the T. cruzi genotypes in Rhodnius specimens and their relationship with sylvatic hosts from different environments in the Brazilian Amazon. Methods: A total of 492 triatomines were collected from the municipalities of Monte Negro, Rondônia state, and Humaitá, Amazonas state, 382 of them being nymphs and 110 adults. Genotyping of T. cruzi in six discrete typing units (DTUs) was performed using conventional multilocus PCR. The triatomines that were positive for T. cruzi and engorged with blood were also targeted for amplification of the cytochrome B (cytB) gene to identify bloodmeal sources. Results: Of the 162 positive samples, the identified DTUs were TcI (87.65%) and TcIV (12.35%). It was observed that 102 specimens were engorged with a variety of bloodmeals. Triatomines infected with TcI were associated with DNA of all identified vertebrates, except Plecturocebus brunneus. TcIV was detected in triatomines that fed on Coendou prehensilis, Didelphis marsupialis, Mabuya nigropunctata, P. brunneus, Pithecia irrorata, Sapajus apella, and Tamandua tetradactyla. Conclusion: Results highlight the need to understand the patterns of T. cruzi genotypes in Rhodnius spp. and their association with sylvatic hosts to better elucidate their role in the transmission of Chagas disease in the Amazon region.

Epidemiological profile, temporal analysis, and future projections of suicide cases in rural cities in the extreme south of Brazil.

The present study aimed to verify the time series (2000-2017) of death rates by suicide and its associated factors in 4 municipalities in the extreme south of Brazil. Data were obtained through the analysis of medical reports and police report bulletins at the Instituto Médico Legal, in the city of Rio Grande. The suicide rate in the Rio Grande region varied from 4 to 11 suicides per 100,000 inhabitants and it is estimated that by 2030 this rate could reach 16.5 suicides per 100,000 inhabitants. The rural cities of Santa Vitória do Palmar and Chuí present even higher suicide averages when compared to Rio Grande, the most populous city of the four. The death rate from suicide increased gradually in the period analyzed, with the prevalence rising among the youngest and the elderly population. A more comprehensive understanding of the influences of environmental issues on suicidal decisions constitutes an important action that needs to be taken, both because of regional vulnerabilities and the target population identified. Evidence indicates that knowledge of factors affecting individuals residing in this Brazilian region where increased suicide rates are recorded needs to be recognized as a priority.

Prediction of heavy metals in polluted mangrove soils in Brazil with the highest reported levels of mercury using near-infrared spectroscopy.

Infrared reflectance spectroscopy has demonstrated potential as a tool for monitoring and preventing contamination in different environments. The objective of this study was to evaluate the usage of near-infrared spectroscopy for predicting heavy-metal contamination in mangrove soils from the Botafogo River estuary located in Pernambuco State, Northeastern Brazil. These soils exhibit the highest mercury (Hg) levels ever reported for Brazilian mangrove soils. Sixty-one samples (obtained at depths ranging from 0 to 5 cm) were collected and measured using near-infrared (1000-2500 nm) reflectance spectroscopy. Preprocessing methods were applied, and partial least squares regression was used to build prediction models for attributes such as clay content, soil organic matter (SOM), pH, Eh, and concentrations of Cr, Cu, Hg, Ni, Pb, and Zn. The models were evaluated using root mean squared error (RMSE), the adjusted coefficient of determination (R2adj), bias, the ratio of performance to interquartile distance (RPIQ), and Lin's concordance correlation coefficient (CCC). The best outcomes were noted for concentrations of Cr, Cu, Hg, Ni, and Pb (RPIQ > 2.5 and R2adj > 0.80); second-best outcomes were found for Zn and SOM (RPIQ > 1.5 and R2adj > 0.70). Clay content, pH and Eh exhibited the poorest outcomes (RPIQ < 1.5). The importance of spectral preprocessing is highlighted, notably with Savitzky-Golay derivatives and Multiplicative Scatter Corrections, which boosted performance for most of the variables. Near-infrared spectroscopy can be efficiently used to predict Cr, Cu, Hg, Ni, Pb and SOM and represents a technique complementary to traditional analyses.

Two new species of Hyalella Smith, 1874 (Malacostraca: Amphipoda: Hyalellidae) from the state of Santa Catarina, Brazil.

The genus Hyalella Smith, 1874 occurs exclusively in the Americas. In Brazil, the states of Santa Catarina and Rio Grande do Sul have the largest number of records with 20 species. This paper presents two new species for the state of Santa Catarina, Brazil. The serrate setae with accessory seta, a new type of seta, is registered for the genus and observed on gnathopods 1 and 2. Additionally, microtrichs are reported on articles, a detail that has not been mentioned in previous studies. Hyalella carsone sp. nov. is characterized by gnathopod 1 with comb-scales from the basis to the carpus, gnathopod 2 dactylus with proximal margin strongly serrated and the presence of serrate setae on the articles of gnathopods 1 and 2. Hyalella wangarie sp. nov. is characterized by gnathopod 2 palm not sinuous with margin inconspicuously serrated, peduncle and inner ramus of the pleopod with simple setae, presence of curved seta on uropod 1 of male and gnathopod 1 palm on female slightly serrated. In this work we expand the number of species from Brazil and increase the morphological knowledge of the genus Hyalella.

The Low Variability of Tc24 in Trypanosoma cruzi TcI as an Advantage for Chagas Disease Prophylaxis and Diagnosis in Mexico.

(1) Background: Chagas disease is the main neglected tropical disease in America. It is estimated that around 6 million people are currently infected with the parasite in Latin America, and 25 million live in endemic areas with active transmission. The disease causes an estimated economic loss of USD 24 billion dollars annually, with a loss of 75,200 working years per year of life; it is responsible for around ~12,000 deaths annually. Although Mexico is an endemic country that recorded 10,186 new cases of Chagas disease during the period of 1990-2017, few studies have evaluated the genetic diversity of genes that could be involved in the prophylaxis and/or diagnosis of the parasite. One of the possible candidates proposed as a vaccine target is the 24 kDa trypomastigote excretory-secretory protein, Tc24, whose protection is linked to the stimulation of T. cruzi-specific CD8+ immune responses. (2) Methods: The aim of the present study was to evaluate the fine-scale genetic diversity and structure of Tc24 in T. cruzi isolates from Mexico, and to compare them with other populations reported in the Americas with the aim to reconsider the potential role of Tc24 as a key candidate for the prophylaxis and improvement of the diagnosis of Chagas disease in Mexico. (3) Results: Of the 25 Mexican isolates analysed, 48% (12) were recovered from humans and 24% (6) recovered from Triatoma barberi and Triatoma dimidiata. Phylogenetic inferences revealed a polytomy in the T. cruzi clade with two defined subgroups, one formed by all sequences of the DTU I and the other formed by DTU II-VI; both subgroups had high branch support. Genetic population analysis detected a single (monomorphic) haplotype of TcI throughout the entire distribution across both Mexico and South America. This information was supported by Nei's pairwise distances, where the sequences of TcI showed no genetic differences. (4) Conclusions: Given that both previous studies and the findings of the present work confirmed that TcI is the only genotype detected from human isolates obtained from various states of Mexico, and that there is no significant genetic variability in any of them, it is possible to propose the development of in silico strategies for the production of antigens that optimise the diagnosis of Chagas disease, such as quantitative ELISA methods that use this region of Tc24.

Baseline concentrations, source apportionment, and probabilistic risk assessment of heavy metals in urban street dust in Northeast Brazil.

Heavy metal pollution by accelerating urbanization is an emerging socio-environmental issue that poses a potential risk to human health and the environment. In this scenario, street dust is a primary source of contaminants. Here, the metal concentrations in street dust of one of the biggest Brazilian cities were assessed aiming to identify and quantify the sources of contamination. The metal bioaccessibility and estimated probabilistic (non)-carcinogenic risks to humans were also evaluated. Thirty-six dust samples were collected in the metropolitan region of Recife. Results showed that the traffic governed the distribution and accumulation of metals in street dust. Emissions from vehicles were the primary source (> 70 %) of heavy metals, except for Cd, which had a mixed origin (natural, traffic, and industrial). Moderate to heavy dust contamination by Ba, Cu, Mn, Pb, and Zn were found, with a very high potential ecological risk. The main exposure route depended on the metal. Barium, Cu, and Pb had ingestion rather than dermal contact as the main route of exposure, while inhalation and dermal contact posed the main risks to Mn and Cr, respectively. The risk for children was higher than for adults. The probabilities of unacceptable carcinogenic risk scenarios (TCRI >10-6) for children and adults were 27 and 4 %, respectively, with Cr being the most concerning metal for the health of the urban population.

Protective Effects of Kefir Against Unpredictable Chronic Stress Alterations in Mice Central Nervous System, Heart, and Kidney.

Kefir is a probiotic mixture with anxiolytic and antioxidant properties. Chronic stress can lead to anxiety disorders and increase oxidative damage in organs such as the heart and kidney. In this study, we examined whether kefir ameliorates the anxiety-like behavior of mice submitted to chronic unpredictable stress (CUS) by modulating brain-derived neurotrophic factor (BDNF) and corticosterone levels and whether kefir modifies the oxidative parameters in the heart and kidney of mice. Male Swiss mice received kefir (0.3 mL/100 g/day) or milk for 30 days (gavage). On the 10th day, the mice were submitted to CUS. Behavioral analysis was performed using the elevated plus maze and forced swimming tests. BDNF levels were analyzed in brain tissues. Heart and kidney superoxide dismutase (SOD), catalase, glutathione (GSH), thiobarbituric acid reactive substances (TBARS), 3-nitrotyrosine, metalloproteinase-2 (MMP-2), and plasma corticosterone were evaluated. Kefir reverted the CUS-induced decrease in the time spent in the open arms, the increase in grooming frequency, and decrease in the head dipping frequency, but not the reduced immobility time. CUS decreased the cerebellum BDNF levels and increased corticosterone levels, which were restored by Kefir. Neither catalase and SOD activities nor GSH, TBARS, 3-nitrotyrosine, and MMP-2 were modified by CUS in the heart. In the kidney, CUS increased 3-nitrotyrosine and MMP-2. Kefir increased the antioxidant defense in the heart and kidney of control and CUS mice. These results suggest that kefir ameliorated CUS-induced anxiety-like behavior by modulating brain BDNF and corticosterone levels. Kefir also increased the antioxidant defense of mice heart and kidney.

High Parasitic Loads Quantified in Sylvatic Triatoma melanica, a Chagas Disease Vector.

Triatoma melanica is a sylvatic vector species in Brazil. In We aimed to characterize the Trypanosoma cruzi discrete typing units (DTUs), the parasitic loads, and the blood meal sources of insects collected in rocky outcrops in rural areas in the state of Minas Gerais. An optical microscope (OM) and kDNA-PCR were used to examine natural infection by T. cruzi, and positive samples were genotyped by conventional multilocus PCR. Quantification of the T. cruzi load was performed using qPCR, and the blood meal sources were identified by Sanger sequencing the 12S rRNA gene. A total of 141 T. melanica were captured. Of these, ~55% (61/111) and ~91% (63/69) were positive by OM and KDNA-PCR, respectively. We genotyped ~89% (56/63) of the T. cruzi-positive triatomines, with TcI (~55%, 31/56) being the most prevalent DTU, followed by TcIII (~20%, 11/56) and TcII (~7%, 4/56). Only TcI+TcIII mixed infections were detected in 10 (~18%) specimens. A wide range of variation in the parasitic loads of T. melanica was observed, with an overall median value of 104 parasites/intestine, with females having higher T. cruzi loads than N2, N4, and N5. TcII showed lower parasitic loads compared to TcI and TcIII. The OM positive diagnosis odds ratio between T. cruzi infection when the parasite load is 107 compared to 103 was approximately 29.1. The most frequent blood meal source was Kerodon rupestris (~58%), followed by Thrichomys apereoides (~18%), Wiedomys cerradensis (~8%), Galactis cuja (~8%) and Gallus gallus (~8%). Our findings characterize biological and epidemiological aspects of the sylvatic population of T. melanica in the study area, highlighting the need to extend surveillance and control to this vector.

Interest Groups as an Alternative for Medical Education in Sleep Medicine: Experience Report at a Brazilian Medical School.

Sleep medicine classes and teachings are usually deficient and insufficient during undergraduate medical education. In order to circumvent the educational deficits in sleep medicine, students at a Brazilian Medical School created a sleep medicine interest group-an academic organization for teaching purposes whose administration is carried out by the undergraduate students themselves. This study aims to describe the establishment of a sleep medicine interest group, as well as to evaluate the results of its first edition on the knowledge about sleep medicine among undergraduate medical students. Classes were taken biweekly and consisted of lectures by invited professors, presentation of clinical cases, and discussion with the students. By the end of the course, both attendees and non-attendees were invited to fill out a questionnaire including an objective assessment of knowledge (15 multiple choice questions). The questionnaire was filled out by 32 participants, of which 18 were attendees and 14 were non-attendees. The average result on the final exam was significantly higher among the attendees (6.1 ± 1.2) in comparison with non-attendees (4.9 ± 1.3-p = 0.015). The results demonstrate that an interest group proved to be feasible as a source of complementary information to undergraduate medical students and a valid alternative to circumvent the educational deficits.

Phenotypic Evaluation of Nucleoside Analogues against Trypanosoma cruzi Infection: In Vitro and In Vivo Approaches.

Chagas disease, caused by Trypanosoma cruzi (T. cruzi), is a serious public health problem. Current treatment is restricted to two drugs, benznidazole and nifurtimox, displaying serious efficacy and safety drawbacks. Nucleoside analogues represent a promising alternative as protozoans do not biosynthesize purines and rely on purine salvage from the hosts. Protozoan transporters often present different substrate specificities from mammalian transporters, justifying the exploration of nucleoside analogues as therapeutic agents. Previous reports identified nucleosides with potent trypanocidal activity; therefore, two 7-derivatized tubercidins (FH11706, FH10714) and a 3'-deoxytubercidin (FH8513) were assayed against T. cruzi. They were highly potent and selective, and the uptake of the tubercidin analogues appeared to be mediated by the nucleoside transporter TcrNT2. At 10 µM, the analogues reduced parasitemia >90% in 2D and 3D cardiac cultures. The washout assays showed that FH10714 sterilized the infected cultures. Given orally, the compounds did not induce noticeable mouse toxicity (50 mg/kg), suppressed the parasitemia of T. cruzi-infected Swiss mice (25 mg/kg, 5 days) and presented DNA amplification below the limit of detection. These findings justify further studies with longer treatment regimens, as well as evaluations in combination with nitro drugs, aiming to identify more effective and safer therapies for Chagas disease.

Case Report: Composite pheochromocytoma with ganglioneuroma component: A report of three cases.

Composite pheochromocytoma (CP) is a very rare tumor originating from neural crest cells, predominantly composed of pheochromocytoma (PCC), a chromaffin cell tumor arising in adrenal medulla, and ganglioneuroma, a tumor derived from autonomic ganglion cells of the nervous system. Moreover, CP may be present in the hereditary syndromes of which pheochromocytoma is part. Literature offers scarce data on this subject, and particularly about its biological behavior, clinical evolution, and molecular profile. We report the phenotype and outcome of three cases of CP (PCC and ganglioneuroma components), followed up at the Endocrine Service of the Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil. Two nonsyndromic patients (cases 1 and 2) were negative to germline mutations in genes VHL, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and MAX, while the third case (case 3) had clinical diagnosis of neurofibromatosis syndrome. Cases 1, 2, and 3 were diagnosed at 29, 39, and 47 years old, respectively, and were followed up for 3, 17, and 9 years without no CP recurrence. All cases had apparent symptoms of catecholaminergic excess secreted by PCC. Ganglioneuroma, the neurogenic component present in all three cases, had a percentage representation ranging from 5% to 15%. Tumors were unilateral and large, measuring 7.0 cm × 6.0 cm × 6.0 cm, 6.0 cm × 4.0 cm × 3.2 cm, and 7.5 cm × 6.0 cm × 4.5 cm, respectively. All cases underwent adrenalectomy with no recurrence, metastasis, or development of contralateral tumor during follow-up. Genetic testing has been scarcely offered to CP cases. However, a similar frequency of genetic background is found when compared with classic PCC, mainly by the overrepresentation of NF1 cases in the CP subset. By literature review, we identified a notorious increase in cases reported with CP in the last decade, especially in the last 3 years, indicating a recent improvement in the diagnosis of this rare disorder in clinical practice.

The hole is deeper: description of two new species within the Parastacus brasiliensis (von Martens, 1869) species complex with an integrative taxonomy approach.

In this contribution, we describe two new species of burrowing crayfish species complex Parastacus brasiliensis from forestry areas in the central region of the state of Rio Grande do Sul, southern Brazil. We used an integrative taxonomy approach with morphology and the mitochondrial DNA 16S rRNA gene and also evaluated their conservation status according to the IUCN Red List Criteria. Parastacus guapo sp. nov. was collected near the municipality of Pantano Grande and it differs from all other congeneric species in having an epistome anterolateral section with a large conical projection ending in a big sharp spine on both sides. It also differs from P. brasiliensis sensu stricto in the shape of the rostral surface, sub-orbital angle, postorbital carina straight, sub-orbital angle > 90, postorbital carinae prominent in anterior and middle portions, carpal spine present, the internal surface of chelipeds palm with sparse tubercules, areola narrow and pleon short. Parastacus gomesae sp. nov. was collected in the municipality of So Jernimo, it differs from all analysed species for rostral spine absent, epistome anteromedian lobe heptagonal and mandible incisive process with seven teeth (the second tooth from the anterior margin is the largest). It is also distinguished of P. brasiliensis sensu stricto in the sub-orbital angle > 90, postorbital carinae prominent in anterior and middle portions, 34 rows of verrucose tubercles irregularly distributed on the palm dorsal surface of chelipeds, areola narrow and pleon short. Phylogenetic relationships confirmed the distinct position of these new species to the already described species. The extent of occurrence (EOO) / area of occurrence (AOO) of P. guapo sp. nov and P. gomesae sp. nov. were estimated at 937 km / 1,87 km, and 2.107 km / 23,9 km respectively. The main threats identified were continued decline in the quality of habitats, resulting from deforestation and forestry areas. However, as we know only one point of occurrence for each new species, we suggest that both be categorized as Data Deficient.

Modulating the thermodynamics, kinetics and photochemistry of 7-diethylamino-4'-dimethylaminoflavylium in water/ethanol, SDS and CTAB micelles.

The thermodynamics and kinetics of compound 7-diethylamino-4'-dimethylaminoflavylium were studied in water : ethanol (1 : 1) and water in the presence of SDS and CTAB micelles. The blue flavylium cation is in equilibrium with the pink protonated flavylium cation defined by pKAH2+/AH+ and the yellow trans-chalcone, defined by pKAH+/Ct. The difference between these two pKs gives the pH domain of the flavylium cation, ΔpK = 1.95 in CTAB, ΔpK = 5.6 in water/ethanol (1 : 1) and ΔpK = 8.5 in SDS micelles. On the other hand, the pH domain of the trans-chalcone is limited by pKAH+/Ct and pKCt/Ct-. It is lower in SDS micelles ΔpK = 2.7, increases in ethanol/water (1 : 1) ΔpK = 5.1 and is maximum in CTAB micelles, ΔpK = 6.8. All these effects can be explained by the electric charge present at the micellar surface. Relative energy level diagrams that allow for the explanation of the driving forces for any pH stimuli or light absorption were constructed from the calculated equilibrium constants. Irradiation of the trans-chalcone at 466 nm leads to the formation of the flavylium cation. In water : ethanol (1 : 1), the photochemistry is residual with Φ < 0.00002, while in SDS micelles at pH = 7 light increases the rate of the spontaneous conversion of trans-chalcone to the flavylium cation, with quantum yield Φ = 0.002; photochromism from trans-chalcone to give the flavylium cation with the same quantum yield is also observed in CTAB micelles.

RNA as a feasible marker of Trypanosoma cruzi viability during the parasite interaction with the triatomine vector Rhodnius prolixus (Hemiptera, Triatominae).

A recurring question concerning Trypanosoma cruzi DNA detection/quantification is related to the fact that DNA amplification, by itself, does not differentiate between viable or dead parasites. On the other hand, RNA can be considered a potential molecular marker of pathogens viability. Herein, we developed a quantitative real-time PCR with reverse Transcription (RT-qPCR) to quantify viable T. cruzi in artificially infected Rhodnius prolixus whilst evaluating differences between DNA and mRNA quantification along the insect midgut during 5, 9, 15 and 29 days after feeding. The RT-qPCR presented an improved performance with linearities ranging from 107 to 102 parasites equivalents and 3 to 0.0032 intestine unit equivalents, and efficiencies of 100.3% and 102.8% for both T. cruzi and triatomine targets, respectively. Comparing both RT-qPCR and qPCR, we confirmed that RNA is faster degraded, no longer being detected at day 1 after parasite lysis, while DNA detection was stable, with no decrease in parasite load over the days, even after parasite lysis. We also observed statistical differences between the quantification of the parasite load by DNA and by RNA on day 15 after feeding of experimentally infected R. prolixus. When assessing different portions of the digestive tract, by RT-qPCR, we could detect a statistically significant reduction in the parasite amount in the anterior midgut. Oppositely, there was a statistically significant increase of the parasite load in the hindgut. In conclusion, for this study parasite's viability in R. prolixus digestive tract were assessed targeting T. cruzi mRNA. In addition, differences between DNA and RNA detection observed herein, raise the possibility that RNA is a potential molecular viability marker, which could contribute to understanding the dynamics of the parasite infection in invertebrate hosts.

Bidirectional associations between chronic low back pain and sleep quality: A cohort study with schoolteachers.

AIMS: Although both chronic low back pain (cLBP) and sleep problems are prevalent among active workers, the relation between these variables is not well established. This study aimed to examine the bidirectional association between cLBP and sleep in schoolteachers. METHODS: The Pittsburgh Sleep Quality Index (PSQI) and cLBP were self-reported by 530 schoolteachers in Londrina, Brazil, at baseline and after 2 years of follow-up. Generalized estimating equations were adjusted for sociodemographic, lifestyle and mental health variables. RESULTS: Poor sleep quality at baseline was associated with cLBP at follow-up after adjusting for sociodemographic and lifestyle variables (OR=1.61; 95% confidence interval [95% CI]=1.06, 2.47). Changes in the PSQI score over time were also associated with a higher likelihood of cLBP at follow-up (OR=1.13; 95% CI=1.07, 1.20 for each 1-point increase in the PSQI score), regardless of mental health condition. cLBP at baseline was associated with worse sleep quality at follow-up after adjusting for sociodemographic and lifestyle variables (OR=1.56; 95% CI=1.02, 2.37). The presence of cLBP also changed the PSQI score over time (ß coefficient=1.153; 95% CI=0.493, 1.814). CONCLUSIONS: Worse sleep quality was prospectively and bidirectionally associated with cLBP. Concretely, changes in PSQI values after 2 years of follow-up increased the likelihood of reporting cLBP, and baseline cLBP was associated with sleep quality worsening (i.e., higher score in the PSQI). Mental health conditions such as self-rated health, depression and anxiety play a relevant confounding role in the bidirectional associations between sleep and chronic low back pain.

Sleepiness profiles in mice submitted to acute and chronic sleep deprivation.

Sleepiness is a behavioural consequence of sleep pressure, which shows interindividual variation, a characteristic possibly related to central sleep mechanisms. However, there is a lack of evidence linking progressive sleep need and sleepiness with factors of individual variability, which could be tested by total acute and chronic sleep deprivation. Thus, the objective of the study was to investigate the development of sleepiness in sleep deprived mice. Male C57BL/6J mice were distributed in sleep deprivation, sleep rebound and control groups. Animals underwent acute sleep deprivation for 3, 6, 9 or 12 h or chronic sleep deprivation for 6 h for 5 consecutive days. Sleep rebound groups had a sleep opportunity for 1, 2, 3, or 4 h after acute sleep deprivation or 24 h after chronic sleep deprivation. During the protocols, sleep attempts were counted to calculate a sleepiness index. After euthanasia, blood was collected for corticosterone assessment. Using the average of group sleep attempts, it was possible to differentiate between sleepy (mean>group average) and resistant animals (mean

Biomphalaria embryotoxicity test (BET): 60 years of research crossing boundaries for developing standard protocols.

Snail's embryotoxicity test is a suitable approach for toxicity assay of traditional and emerging pollutants, environmental risk assessment, as well as screening and development of new molluscicides. Among the snail species, Biomphalaria spp. has been indicated as a promising model system for developing standardized test protocols for assessing the chemical toxicity using early developmental stages. Thus, the current study aimed to review the data available in the scientific literature concerning the experimental approach, type of chemicals and the response of multiple biomarkers (survival, hatching rate, development delays, morphological and behavior changes) in snail embryos applied in toxicity tests. Revised data showed that the use of Biomphalaria embryos to assess chemical toxicity began in 1962. Snail's embryotoxicity test was applied mainly for analyzing the toxicity and development of new molluscicides, while its use in ecotoxicological studies is emerging. Biomphalaria glabrata was the main species analyzed. Embryos exposed to chemicals showed bioaccumulation, mortality, hatching inhibition, development delays, and morphological malformations, which were classified into four categories (hydropic, shell, cephalic and unspecified malformations). Besides, research gaps and recommendations for future research are indicated. Overall, the results showed that the Biomphalaria embryotoxicity test (BET) is a suitable tool for toxicity and health risk assessment.