Concerns over the replicability and reproducibility of published research have grown in many research fields, but empirical data to inform policies are still scarce. Biomedical research in Brazil expanded rapidly over the last three decades, with no systematic assessment of the replicability of its findings. With this in mind, we set up the Brazilian Reproducibility Initiative, a multicenter replication of published experiments from Brazilian science using three common experimental methods: the MTT assay, the reverse transcription polymerase chain reaction (RT-PCR) and the elevated plus maze (EPM). A total of 56 laboratories performed 143 replications of 56 experiments; of these, 90 replications of 45 experiments were considered valid by an independent committee. Replication rates for these experiments varied between 20 and 44% according to five predefined criteria. In median terms, ratios between group means were 58% lower in replications than in original experiments, while coefficients of variation were 82% higher. Effect size decrease was smaller for MTT experiments, original results with less variability and those considered more challenging to replicate, while t values for replications were positively correlated with researcher predictions about replicability, and negatively correlated with the rate of publications by the original article’s last author. Deviations from preregistered protocols were very common in replications, most frequently due to reasons inherent to the experimental model or related to infrastructure and logistics. Our results highlight factors that limit the replicability of results published by researchers in Brazil and suggest ways by which this scenario can be improved.
The uterine tube extracellular matrix is a key component that regulates tubal tissue physiology, and it has a region-specific structural distribution, which is directly associated to its functions. Considering this, the application of biological matrices in culture systems is an interesting strategy to develop biomimetic tubal microenvironments and enhance their complexity. However, there are no established protocols to produce tubal biological matrices that consider the organ morphophysiology for such applications. Therefore, this study aimed to establish region-specific protocols to obtain decellularized scaffolds derived from porcine infundibulum, ampulla, and isthmus to provide suitable sources of biomaterials for tissue-engineering approaches. Porcine uterine tubes were decellularized in solutions of 0.1% SDS and 0.5% Triton X-100. The decellularization efficiency was evaluated by DAPI staining and DNA quantification. We analyzed the ECM composition and structure by optical and scanning electronic microscopy, FTIR, and Raman spectroscopy. DNA and DAPI assays validated the decellularization, presenting a significative reduction in cellular content. Structural and spectroscopy analyses revealed that the produced scaffolds remained well structured and with the ECM composition preserved. YS and HEK293 cells were used to attest cytocompatibility, allowing high cell viability rates and successful interaction with the scaffolds. These results suggest that such matrices are applicable for future biotechnological approaches in the reproductive field.
Objective: To describe the ultrastructure of the interface between periodontal tissues and titanium mini-implants in rat mandibles. Materials and Methods: A titanium mini-implant was placed between the buccal roots of the mandibular first molar of 24 adult rats. After 21, 30, 45, 60, 90, and 120 days of implantation, the mandibular portion was removed and fixed in cacodylate-buffered 2% glutaraldehyde + 2.5% formaldehyde. The material was decalcified and processed for scanning and transmission electron microscopy. Results: Ultrastructural analysis revealed a thin cementum-like layer at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant. Conclusions: The alveolar bone and the periodontal ligament reorganized their constituents around the implant, and a thin cementum-like layer was formed at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant.
1 December 2017 in Biochemical and Biophysical Research Communications
Well-controlled intrauterine development is an essential condition for many aspects of normal adult physiology and health. This process is disrupted by poor maternal nutrition status during pregnancy. Indeed, physiological adaptations occur in the fetus to ensure nutrient supply to the most vital organs at the expense of the others, leading to irreversible consequences in tissue formation and differentiation. Evidence indicates that maternal undernutrition in early life promotes changes in key hormones, such as glucocorticoids, growth hormones, insulin-like growth factors, estrogens and androgens, during fetal development. These alterations can directly or indirectly affect hormone release, hormone receptor expression/distribution, cellular function or tissue organization, and impair tissue growth, differentiation and maturation to exert profound long-term effects on the offspring. Within the male reproductive system, maternal protein malnutrition alters development, structure, and function of the gonads, testes and prostate gland. Consequently, these changes impair the reproductive capacity of the male offspring. Further, permanent alterations in the prostate gland occur at the molecular and cellular level and thereby affect the onset of late life diseases such as prostatitis, hyperplasia and even prostate cancer. This review assembles current thoughts on the concepts and mechanisms behind the developmental origins of health and disease as they relate to protein malnutrition, and highlights the effects of maternal protein malnutrition on rat prostate development and homeostasis. Such insights on developmental trajectories of adult-onset prostate disease may help provide a foundation for future studies in this field.