Oxidized alginate hydrogels with the GHK peptide enhance cord blood mesenchymal stem cell osteogenesis: A paradigm for metabolomics-based evaluation of biomaterial design

Oxidized alginate hydrogels are appealing alternatives to natural alginate due to their favourable biodegradability profiles and capacity to self-crosslink with amine containing molecules facilitating functionalization with extracellular matrix cues, which enable modulation of stem cell fate, achieve highly viable 3-D cultures, and promote cell growth. Stem cell metabolism is at the core of cellular fate (proliferation, differentiation, death) and metabolomics provides global metabolic signatures representative of cellular status, being able to accurately identify the quality of stem cell differentiation. Herein, umbilical cord blood mesenchymal stem cells (UCB MSCs) were encapsulated in novel oxidized alginate hydrogels functionalized with the glycine-histidine-lysine (GHK) peptide and differentiated towards the osteoblastic lineage. The ADA-GHK hydrogels significantly improved osteogenic differentiation compared to gelatin-containing control hydrogels, as demonstrated by gene expression, alkaline phosphatase activity and bone extracellular matrix deposition. Metabolomics revealed the high degree of metabolic heterogeneity in the gelatin-containing control hydrogels, captured the enhanced osteogenic differentiation in the ADA-GHK hydrogels, confirmed the similar metabolism between differentiated cells and primary osteoblasts, and elucidated the metabolic mechanism responsible for the function of GHK. Our results suggest a novel paradigm for metabolomics-guided biomaterial design and robust stem cell bioprocessing. STATEMENT OF SIGNIFICANCE: Producing high quality engineered bone grafts is important for the treatment of critical sized bone defects. Robust and sensitive techniques are required for quality assessment of tissue-engineered constructs, which result to the selection of optimal biomaterials for bone graft development. Herein, we present a new use of metabolomics signatures in guiding the development of novel oxidised alginate-based hydrogels with umbilical cord blood mesenchymal stem cells and the glycine-histidine-lysine peptide, demonstrating that GHK induces stem cell osteogenic differentiation. Metabolomics signatures captured the enhanced osteogenesis in GHK hydrogels, confirmed the metabolic similarity between differentiated cells and primary osteoblasts, and elucidated the metabolic mechanism responsible for the function of GHK. In conclusion, our results suggest a new paradigm of metabolomics-driven design of biomaterials

Prevalência do consumo de álcool e drogas entre adolescentes: análise dos dados da Pesquisa Nacional de Saúde Escolar Prevalence of alcohol and drug consumption among adolescents: data analysis of the National Survey of School Health

OBJETIVO: Descrever a prevalência do consumo de álcool e outras drogas entre estudantes adolescentes. MÉTODO: Estudo transversal com amostra de conglomerados de 60.973 estudantes do nono ano do Ensino Fundamental de escolas públicas e privadas das capitais dos estados brasileiros e do Distrito Federal, em 2009. Foram analisadas as prevalências e os intervalos de confiança de 95% (IC95%) do consumo de álcool e drogas. RESULTADOS: Para o conjunto dos alunos entrevistados, identificou-se o seguinte: experimentação de bebida alcoólica (71,4%; IC95% 70,8-72,0); consumo regular de álcool (27,3%; IC95% 26,7-28,0); embriaguez na vida (22,1%; IC95% 21,6-22,7); preocupação da família se chegasse bêbado em casa (93,8%; IC95% 93,3-94,2); problemas com uso de álcool (9,0%; IC95% 8,6-9,4) e experimentação de outras drogas (8,7%; IC95% 8,3-9,1). CONCLUSÃO: O estudo demonstra a extensão do problema do uso de álcool e drogas entre adolescentes brasileiros, destacando a facilidade com que os jovens entrevistados tiveram acesso ao álcool em festas, bares, lojas e até em suas próprias casas.<br>OBJECTIVE: To describe the prevalence of alcohol and other drugs consumption, among adolescent students. METHODS: A cross-sectional study with conglomerate samples of 60,973 students at freshman year high school in public and private schools in capitals and the Federal District in Brazil, in 2009. The 95% confidence interval and the prevalence of alcohol and drug consumption were analyzed. RESULTS: For the set of surveyed students, the following were identified: experimenting alcoholic beverages (71.4%; 95%CI 70.8-72.0); regular alcoholic beverage consumption (27.3%; 95%CI 26.7-28.0); drunkenness in lifetime (22.1%; 95%CI 21.6-22.7); family is worried when the student gets home drunk (93.8%; 95%CI 93.3-94.2); problems with alcohol use (9.0%; 95%CI 8.6-9.4); consumption of other drugs (8.7%; 95%CI 8.3-9.1). CONCLUSION: This study shows the extension of the alcohol and drugs problem among Brazilian adolescents, with special emphasis on the easy access of students to alcoholic beverages at parties, bars, stores, and at home

Suspected acute toxoplasmosis in pregnant women Suspeita de toxoplasmose aguda em gestantes

OBJECTIVE: To determine the prevalence of reagent serology for suspected acute toxoplasmosis in pregnant women and to describe clinical, laboratory and therapeutic profiles of mothers and their children. METHODS: A retrospective study was conducted with IgM-anti-Toxoplasma gondii-reagent pregnant women and their children who attended the public health system in the state of Paraná, Southern Brazil, from January 2001 to December 2003. Information were obtained from clinical, laboratory (ELISA IgM/IgG) and ultrasonographic data and from interviews with the mothers. To test the homogeneity of the IgM indices in relation to the treatment used, the Pearson's Chi-square test was applied. Comparisons were considered significant at a 5% level. RESULTS: Two hundred and ninety (1.0%) cases of suspected IgM-reagent infection were documented, with a prevalence of 10.7 IgM-reagent women per 1,000 births. Prenatal care started within the first 12 weeks for 214/290; 146/204 were asymptomatic. Frequent complaints included headaches, visual disturbance and myalgia. Ultrasonography revealed abnormalities in 13 of 204 pregnancies. Chemoprophylaxis was administered to 112/227; a single ELISA test supported most decisions to begin treatment. Pregnant women with IgM indices =2.000 tended to be treated more often. Among exposed children, 44/208 were serologically followed up and all were IgG-reagent, and three IgM-reagent cases showed clinical symptoms. CONCLUSIONS: The existence of pregnant women with laboratorially suspected acute toxoplasmosis who were not properly followed up, and of fetuses that were not adequately monitored, shows that basic aspects of the prenatal care are not being systematically observed. There is need of implementing a surveillance system of pregnant women and their children exposed to T. gondii.<br>OBJETIVO: Determinar a prevalência de gestantes com sorologia reagente suspeita de toxoplasmose aguda e descrever as variáveis maternas e do concepto relacionadas ao perfil clínico, laboratorial e terapêutico. MÉTODOS: Estudo retrospectivo com gestantes IgM anti-Toxoplasma gondii reagentes e conceptos atendidos em serviço público de saúde do Paraná, de janeiro/2001-dezembro/2003. Foram obtidas informações a partir de dados dos registros clínicos, laboratoriais (ELISA IgM/IgG), ultrassonográficos e de entrevista materna. Para testar a homogeneidade dos indices de IgM em relação ao tratamento usado, aplicou-se o qui-quadrado de Pearson. O nível de significância adotado foi de 5%. RESULTADOS: Ocorreram 290 casos (1,0%) IgM reagentes, evidenciando prevalência de 10,7 gestantes com sorologia reagente a cada 1.000 nascimentos. Duzentos e quatorze de 290 gestantes iniciaram o pré-natal até a 12ª semana de gestação; 146/204 foram assintomáticas; cefaléia, distúrbios visuais e mialgia foram queixas freqüentes; 13/204 gestantes apresentaram anormalidades ao ultrassom; 112/227 gestantes receberam quimioprofilaxia; um único teste ELISA apoiou a maioria das tomadas de decisão para a quimioprofilaxia. Houve tendência em tratar gestantes com índices de IgM=2.000. Dentre as crianças expostas, 44/208 tiveram algum acompanhamento sorológico, das quais todas foram IgG reagentes e três casos IgM reagentes apresentaram manifestações clínicas. CONCLUSÕES: A existência de gestantes com suspeita laboratorial de toxoplasmose aguda não devidamente investigada e de conceptos sem monitoração adequada evidenciam que aspectos fundamentais da assistência pré-natal não estão sendo sistematicamente observados. Aponta-se a necessidade de implementar o sistema de vigilância para gestantes e crianças expostas ao T. gondii