Chagas disease, caused by the protozoan Trypanosoma cruzi, remains a serious health concern due to the lack of effective vaccines or satisfactory treatment. In the search for new compounds against ...this neglected disease, we have previously demonstrated that the compound 3-Hydroxy-2-methylene-3-(4-nitrophenylpropanenitrile) (MBHA3), derived from the Morita-Baylis-Hillman reaction, effectively caused a loss of viability in both the epimastigote and trypomastigote forms. However, the mechanisms of parasite death elicited by MBHA3 remain unknown. The aim of this study was to better understand the morphophysiological changes and the mechanism of cell death induced by MBHA3 treatment on T. cruzi. To perform this analysis, we used confocal microscopy and flow cytometry to monitor the fluorescent probes such as annexin-V/propidium iodide (AV/PI), calcein-AM/ethidium homodimer (CA/EH), acridine orange (AO) and rhodamine 123 (Rho 123). Lower concentrations of MBHA3 led to alterations in the mitochondrial membrane potential and AO labeling, but did not decrease the viability of the epimastiogote forms, as determined by the CA/EH and AV/PI assays. Conversely, treatment with higher concentrations of MBHA3 led to extensive plasma membrane damage, loss of mitochondrion membrane potential, DNA fragmentation and acidification of the cytoplasm. Our findings suggest that at higher concentrations, MBHA3 induces T. cruzi epimastigote death by necrosis in a mitochondrion-dependent manner.
Nanotechnology has played a prominent role in biomedical engineering, offering innovative approaches to numerous treatments. Notable advances have been observed in the development of medical devices, ...contributing to the advancement of modern medicine. This article briefly discusses key applications of nanotechnology in tissue engineering, controlled drug release systems, biosensors and monitoring, and imaging and diagnosis. The particular emphasis on this theme will result in a better understanding, selection, and technical approach to nanomaterials for biomedical purposes, including biological risks, security, and biocompatibility criteria.
The objective of this study was to evaluate the effect of chemical treatment with glutamic acid to avoid calcification of biological cardiac valves. The bovine pericardium (BP) tissues were fixed ...with 0.5% glutaraldehyde (BP/GA), followed by treatment with glutamic acid (BP/GA + Glu) for neutralization of the free aldehyde groups. Microscopic analysis showed that the wavy structure of collagen fibrils was preserved, but changes in elastin's integrity occurred. However, the treatment did not promote undesirable changes in the thermal and mechanical properties of the modified BPs. These samples were systematically studied in rat subcutaneous tissue: control (BP/GA) and anticalcificant (BP/GA + Glu). After 60 days, both groups induced similar inflammatory reactions. In terms of calcification, BP/GA + Glu remained more stable with a lower index (3.1 ± 0.2 μg Ca2+/mg dry tissue), whereas for BP/GA it was 5.7 ± 1.3 μg Ca2+/mg dry tissue. Bioprostheses made from BP/GA + Glu were implanted in the pulmonary position in sheep, and in vivo echocardiographic analyses revealed maintenance of valvar function after 180 days, with low gradients and minimal valve insufficiency. The explanted tissues of the BP/GA + Glu group had a lower average calcium content 3.8 ± 3.0 μg Ca2+/mg dry tissue. The results indicated high anticalcification efficiency of BP/GA + Glu in both subcutaneous implant in rats and in the experimental sheep model, which is an advantage that should encourage the industrial application of these materials for the manufacture of bioprostheses.
Nanomaterials based on graphene oxide nanoribbons (GNR) and nanohydroxyapatite (nHAp) serve as attractive materials for bone tissue engineering. Herein, we evaluated the potential of nHAp/GNR toward ...in vitro analysis of specific genes related to osteogenesis and in vivo bone regeneration using animal model. Three different concentrations of nHAp/GNR composites were analyzed in vitro using a cytotoxicity assay, and osteogenic potential was determined by ALP, OPN, OCN, COL1, and RUNX2 genes and alkaline phosphatase assays. In vivo bone neoformation using a well-established in vivo rat tibia defect model was used to confirm the efficiency of the optimized composite. The scaffolds were nontoxic, and the osteogenesis process was dose-dependent (at 200 μg mL–1 of nHAp/GNR) compared to controls. The in vivo results showed higher bone neoformation after 15 days of nHAp/GNR implantation compared to all groups. After 21 days, both nHAp/GNR composites showed better lamellar bone formation compared to control. We attributed this enhanced bone neoformation to the high bioactivity and surface area presented by nHAp/GNR composites, which was systematically evaluated in previous studies. These new in vivo results suggest that nHAp/GNR composites can be exploited for a range of strategies for the improved development of novel dental and orthopedic bone grafts to accelerate bone regeneration.
OBJECTIVE To determine the prevalence of metabolic syndrome and its components in Brazilian adolescents. METHODS We evaluated 37,504 adolescents who were participants in the Study of Cardiovascular ...Risks in Adolescents (ERICA), a cross-sectional, school-based, national study. The adolescents, aged from 12 to 17 years, lived in cities with populations greater than 100,000 inhabitants. The sample was stratified and clustered into schools and classes. The criteria set out by the International Diabetes Federation were used to define metabolic syndrome. Prevalences of metabolic syndrome were estimated according to sex, age group, school type and nutritional status. RESULTS Of the 37,504 adolescents who were evaluated: 50.2% were female; 54.3% were aged from 15 to 17 years, and 73.3% were from public schools. The prevalence of metabolic syndrome was 2.6% (95%CI 2.3-2.9), slightly higher in males and in those aged from 15 to 17 years in most macro-regions. The prevalence was the highest in residents from the South macro-region, in the younger female adolescents and in the older male adolescents. The prevalence was higher in public schools (2.8% 95%CI 2.4-3.2), when compared with private schools (1.9% 95%CI 1.4-2.4) and higher in obese adolescents when compared with nonobese ones. The most common combinations of components, referring to 3/4 of combinations, were: enlarged waist circumference (WC), low HDL-cholesterol (HDL-c) and high blood pressure; followed by enlarged WC, low HDL-c and high triglycerides; and enlarged WC, low HDL-c, high triglycerides and blood pressure. Low HDL was the second most frequent component, but the highest prevalence of metabolic syndrome (26.8%) was observed in the presence of high triglycerides. CONCLUSIONS ERICA is the first Brazilian nation-wide study to present the prevalence of metabolic syndrome and describe the role of its components. Despite the prevalence of Metabolic Syndrome being low, the high prevalences of some components and participation of others in the syndrome composition shows the importance of early diagnosis of this changes, even if not grouped within the metabolic syndrome.
A series of eighteen quinones and structurally-related oxiranes were synthesized and evaluated for in vitro inhibitory activity against the chloroquine-sensitive 3D7 clone of the human malaria ...parasite Plasmodium falciparum. 2-amino and 2-allyloxynaphthoquinones exhibited important antiplasmodial activity (median inhibitory concentrations (IC50) < 10 μM). Oxiranes 6 and 25, prepared respectively by reaction of α-lapachone and tetrachloro-p-quinone with diazomethane in a mixture of ether and ethanol, exhibited the highest antiplasmodial activity and low cytotoxicity against human fibroblasts (MCR-5 cell line). The active compounds could represent a good prototype for an antimalarial lead molecule.
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•Quinone derivatives containing an epoxide ring were synthesized.•Oxiranes and quinones were assayed against Plasmodium falciparum.•Two compounds exhibited antiplasmodial activity and low cytotoxicity.
Due to the high cost and insufficient offer, the request for Intensive Care (ICU) beds for postoperative recovery needs adequate criteria. Therefore, we studied the characteristics of patients ...referred to postoperative care at an ICU from the perspective of anesthesiologists, surgeons, and intensive care physicians.
A questionnaire on referrals to postoperative intensive care was applied to physicians at congresses in Brazil. Anesthesiologists, surgeons, and intensive care physicians who agreed to fill out the questionnaire were included. The questionnaire consisted of hypothetical clinical scenarios and cases for participants to choose which would be the priority for referral to the ICU.
360 physicians participated in the study, with median time of 10 (5–18) years after graduation. Of the interviewees, 36.4% were anesthesiologists, 30.0% surgeons, and 33.6% intensive care physicians. We found that anesthesiologists were more conservative, and surgeons less conservative in ICU referrals. As to patients with risk of bleeding, 75.0% of the surgeons would refer them to the ICU, in contrast with 52.1% of the intensive care physicians, and 43.5% of the anesthesiologists (p < 0.001). As to elderly persons with limited reserve, 62.0% of the surgeons would refer them to the ICU, in contrast with 47.1% of the intensive care physicians, and 22.1% of the anesthesiologists (p < 0.001). As to patients with risk of respiratory complications, 64.5% of the surgeons would recommend the ICU, versus 43.0% of the intensive care physicians, and 32.1% of the anesthesiologists (p < 0.001). Intensive care physicians classified priorities better in indicating ICU, and the main risk indicator was the ASA physical status in all specialties (p < 0.001). There was no agreement among the specialties and surgeries on prioritizing post-operative intensive care.
Anesthesiologists, surgeons, and intensive care physicians presented different perspectives on postoperative referral to the ICU.
To present the recruitment and communication strategies of the ELSA-Brasil (Estudo Longitudinal de Saúde do Adulto - Brazilian Longitudinal Study for Adult Health).
The strategies were directed at ...dissemination, institutionalization and recruitment. The communication actions intended to promote the strengthening of a positive institutional image for the study, knowledge management and an effective dialogue with its target audience. An official website was created in order to communicate with different audiences, to disseminate scientific knowledge, and to contribute to consolidate the image of the study within society.
We recruited 16,435 men and women, active employees and retirees of six public institutions of education and research, to constitute the cohort of 15,105 participants. The recruitment goals were fully achieved in the six centers, with a slight predominance of women and of younger adults, and slightly fewer employees with lower level of schooling.
The strategies used were adequate and essential to the successful inclusion and participation of the employees.
OBJECTIVE To estimate the prevalence of arterial hypertension and obesity and the population attributable fraction of hypertension that is due to obesity in Brazilian adolescents. METHODS Data from ...participants in the Brazilian Study of Cardiovascular Risks in Adolescents (ERICA), which was the first national school-based, cross-section study performed in Brazil were evaluated. The sample was divided into 32 geographical strata and clusters from 32 schools and classes, with regional and national representation. Obesity was classified using the body mass index according to age and sex. Arterial hypertension was defined when the average systolic or diastolic blood pressure was greater than or equal to the 95th percentile of the reference curve. Prevalences and 95% confidence intervals (95%CI) of arterial hypertension and obesity, both on a national basis and in the macro-regions of Brazil, were estimated by sex and age group, as were the fractions of hypertension attributable to obesity in the population. RESULTS We evaluated 73,399 students, 55.4% female, with an average age of 14.7 years (SD = 1.6). The prevalence of hypertension was 9.6% (95%CI 9.0-10.3); with the lowest being in the North, 8.4% (95%CI 7.7-9.2) and Northeast regions, 8.4% (95%CI 7.6-9.2), and the highest being in the South, 12.5% (95%CI 11.0-14.2). The prevalence of obesity was 8.4% (95%CI 7.9-8.9), which was lower in the North region and higher in the South region. The prevalences of arterial hypertension and obesity were higher in males. Obese adolescents presented a higher prevalence of hypertension, 28.4% (95%CI 25.5-31.2), than overweight adolescents, 15.4% (95%CI 17.0-13.8), or eutrophic adolescents, 6.3% (95%CI 5.6-7.0). The fraction of hypertension attributable to obesity was 17.8%. CONCLUSIONS ERICA was the first nationally representative Brazilian study providing prevalence estimates of hypertension in adolescents. Regional and sex differences were observed. The study indicates that the control of obesity would lower the prevalence of hypertension among Brazilian adolescents by 1/5.
In the 35 years since its inception, the Brazilian National Program for the Conservation of Marine Turtles (TAMAR) has had great success in protecting the five species of sea turtles that occur in ...Brazil. It has also contributed significantly to worldwide scientific data and knowledge about these species’ biology, such as life cycles and migration patterns. TAMAR’s conservation strategies have always relied on a variety of environmental education and social inclusion (EESI) activities highly adapted to the socio-environmental evolving contexts of its 25 locations distributed across nine states. Diversity and flexibility are critical to enable timely and effective local responses to existing or potential threats to sea turtles. The intuitive, locally adapted, decentralized, and independent way EESI activities have been carried out have generated positive results in the resolution of specific and evolving local problems through the course of the project. This article brings EESI under the same conceptual framework that underlies its conservation approach by adopting an adaptive threat management framework to organize and qualify its educational and social inclusion interventions according to the main categories of threat addressed by TAMAR.
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