8 research outputs found

    Biomechanical properties of bone in a mouse model of Rett syndrome

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    Rett syndrome (RTT) is an X-linked genetic disorder and a major cause of intellectual disability in girls. Mutations in the methyl-CpG binding protein 2 (<i>MECP2</i>) gene are the primary cause of the disorder. Despite the dominant neurological phenotypes, <i>MECP2</i> is expressed ubiquitously throughout the body and a number of peripheral phenotypes such as scoliosis, reduced bone mineral density and skeletal fractures are also common and important clinical features of the disorder. In order to explore whether MeCP2 protein deficiency results in altered structural and functional properties of bone and to test the potential reversibility of any defects, we have conducted a series of histological, imaging and biomechanical tests of bone in a functional knockout mouse model of RTT. Both hemizygous <i>Mecp2</i><sup>stop/y</sup> male mice in which <i>Mecp2</i> is silenced in all cells and female <i>Mecp2</i><sup>stop/+</sup> mice in which <i>Mecp2</i> is silenced in ~ 50% of cells as a consequence of random X-chromosome inactivation, revealed significant reductions in cortical bone stiffness, microhardness and tensile modulus. Microstructural analysis also revealed alterations in both cortical and cancellous femoral bone between wild-type and MeCP2-deficient mice. Furthermore, unsilencing of <i>Mecp2</i> in adult mice cre-mediated stop cassette deletion resulted in a restoration of biomechanical properties (stiffness, microhardness) towards wild-type levels. These results show that MeCP2-deficiency results in overt, but potentially reversible, alterations in the biomechanical integrity of bone and highlights the importance of targeting skeletal phenotypes in considering the development of pharmacological and gene-based therapies

    Survey of saproxylophagous Melolonthidae (Coleoptera) and some biological aspects in Aquidauana, MS

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    Coleoptera of the family Melolonthidae plays an important role in decomposition and nutrient recycling in the environment, however the information of this group is scarce in Brazil; therefore studies were developed with the objective of understanding the biological aspects of saproxylophagous. The studies were developed in the experimental farm of the State University of Mato Grosso do Sul, in Aquidauana, from March 2011 to April 2012. In a forest fragment of the cerrado, when encountering fallen tree trunks, they were cut into small pieces for extraction and acquisition of immature and adult Melolonthidae. Larvae were taken to the laboratory where they were reared until emergence of adults, obtaining biological and biometric data. A total of 145 larvae and 11 adults were collected. Third instar larvae of Strategus surinamensis Burmeister, 1847, collected in this phase lasted 230 days and 31.3 days in the pupal stage. Third instar larvae of Phileurus valgus (Linnaeus, 1758), in this phase lasted 49 days and 13 days in the pupal stage. Third instar larvae Pelidnota fulva Blanchard, 1850, after being collected remained for 61 days in this phase and 25.3 days in the pupal stage. Adults Pelidnota aff. vazdemeloi were collected inside tree trunks. To Macraspis festiva Burmeister, 1844, the third instar larvae collected lasted for 39 days at this stage, and pupae lasted 17 days. Third instar larvae of Rutela lineola (Linnaeus, 1767), in this phase lasted 23 days, and pupae lasted 16.3 days. To Hoplopyga liturata (Olivier, 1789), third instar larvae collected lasted 21 days and pupae lasted 18 days. To Hoplopyga boliviensis (Moser, 1918), third instar larvae lasted 33 days and pupae 16 days. Second and third larval instar Marmarina maculosa (Olivier, 1789) collected lasted respectively, 105 and 171.3 days and pupae lasted 26 days. The species collected in greatest quantity were M. festiva with 75 larvae,R. lineola with 20 larvae and H. boliviensis with 18 larvae. Larvae were collected during several months, where in July 32 larvae were sampled and in August 39 larvae, the largest quantities encountered

    The mediator role of body image-related cognitive fusion in the relationship between disease severity perception, acceptance and psoriasis disability

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    Psoriasis is a long-term skin disorder without a cure, whose patients are particularly susceptible to mental health diseases. Using a sample of patients diagnosed with psoriasis, this study aimed to: (1) identify the clinical and positive psychological variables that contribute the most to psoriasis disability and (2) assess the mediator role of body image-related cognitive fusion in the relation between disease severity perception and acceptance and self-compassion, on one hand, and psoriasis disability on the other. This is an initial cross-sectional exploratory study, with 75 patients diagnosed with psoriasis (males 52%; mean age 54.99 ± 13.72) answering a sociodemographic and a clinical questionnaire, the Psoriasis Disability Index (PDI), the Cognitive Fusion Questionnaire—Body Image (CFQ-BI), the Acceptance and Action Questionnaire—II (AAQ-II), and the Self-Compassion Scale (SCS). Descriptive and inferential statistics were used to characterize and assess the measures and the final model used. Through path analysis and a hierarchical multiple linear regression, it was found that the variables that significantly contributed to psoriasis disability were years of education, impact on social life and body image, explaining 70% of the variance. Body image-related cognitive fusion was a significant mediator in the relationship between disease severity and acceptance, and psoriasis disability. The implications of this study are considered to be extremely relevant, since it will allow additional information to be provided to psoriasis patients, appropriated to their educational level, aiming to reduce distorted perceptions of disease severity and intervene in the ability to accept this specific and important chronic health condition.info:eu-repo/semantics/publishedVersio

    A new colorimetric peptide nucleic acid-based assay for the specific detection of bacteria

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    Aim: Developments on synthetic molecules, such as peptide nucleic acid (PNA), make FISH procedures more robust for microbial identification. Fluorochromes use might hinder a broader implementation of PNA-FISH, but colorimetric applications are inexistent so far. Methods: A biotin-labeled eubacteria probe was used to develop a colorimetric PNA-in situ hybridization (ISH) assay. An enzymatic-conjugate, targeting biotin, was introduced. The procedure was optimized and evaluated regarding sensitivity, specificity and detection limit. Results: Results have shown strong ISH signals. The method was specific, but permeabilization problems were observed for Gram-positive bacteria. Detection limit was 5 × 107 CFU/ml, limiting current applications to pre-enriched samples. Conclusion: The PNA-ISH procedure described here is a simple alternative to other detection methods, and is also the base for the development of other PNA colorimetric systems
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