Abstract Osteogenesis Imperfecta (OI) is a heterogeneous genetic disorder characterized by bone fragility and fracture. Mutations in 20 distinct genes can cause OI, and therefore, the genetic diagnosis of OI is frequently difficult to obtain because of the great number of genes that can be related with this disease. Studies that report the most frequently mutated genes in OI patients can help to improve molecular strategies for diagnosis of the disease. In order to characterize the mutation profile of OI in Brazilian patients, we analyzed 30 unrelated patients through SSCP screening, NGS gene panel, and/or Sanger sequencing for the 11 most frequently mutated genes in the database of mutations, including COL1A1, COL1A2, P3H1, CRTAP, PPIB, SERPINH1, SERPINF1, FKBP10, SP7, WNT1 and IFITM5. Disease-causing variants were identified in COL1A1, COL1A2, FKBP10, P3H1, and IFITM5. A total of 28 distinct mutations were identified, including seven novel changes. Our data show that the analysis of these five genes is able to detect at least 95% of causative mutations in OI disorder from Brazilian population. However, it has to be taken into considerations that distinct populations can have different frequencies of disease-causing variants. Hence, it is important to replicate this study in other groups.

INTRODUÇÃO: O enxerto de gordura nos últimos anos voltou a ter destaque como aliado dos cirurgiões plásticos no preenchimento de partes moles, no rejuvenescimento facial volumétrico, nos refinamentos de reconstruções mamárias e por ser rica fonte de células-tronco de comportamento mesenquimal (células-tronco adipoderivadas). Considerando que essas células têm importante papel na angiogênese e na diferenciação adipogênica, com impacto direto na sobrevivência dos enxertos de gordura, determinar parâmetros que otimizem a sua obtenção é imperativo. Nesse contexto, o objetivo deste trabalho é avaliar e comparar dois métodos de obtenção do tecido adiposo da região abdominal quanto ao número de células viáveis presentes na fração vásculo-estromal e analisar a expressão de marcadores de superfície. MÉTODO: Foram selecionadas 9 pacientes do sexo feminino submetidas a lipoaspiração. O tecido adiposo foi obtido da região abdominal infraumbilical. Da metade direita foram coletados 20 ml de gordura, empregando-se cânula acoplada a uma seringa, cujo êmbolo foi tracionado de 2 cc em 2 cc, gerando baixas pressões de aspiração (grupo manual). O mesmo processo foi repetido na metade esquerda, entretanto a cânula estava acoplada a um coletor intermediário estéril e esse a uma máquina de vácuo sob pressão negativa constante de 350 mmHg (grupo a vácuo). As amostras foram centrifugadas e a gordura da camada intermediária dos dois grupos foi submetida a contagem celular, estabelecimento de culturas e posterior imunofenotipagem. RESULTADOS: Este estudo demonstrou que, apesar de não haver diferença estatisticamente significativa, a obtenção da gordura da região abdominal empregando-se lipoaspirador com pressão negativa de 350 mmHg proporcionou maior número de células presentes na fração vásculo-estromal quando comparado à obtenção por meio de seringas de 10 ml, com baixas pressões de aspiração. CONCLUSÕES: O emprego de pressão negativa de 350 mmHg é seguro para a obtenção das células-tronco adipoderivadas e o rendimento celular entre os dois grupos não apresentou diferença estatisticamente significativa.

BACKGROUND: In recent years, fat grafts have become useful in plastic surgery. They are mainly used to fill soft tissues, refine breast reconstructions, and for volumetric facial rejuvenation. They are also a rich source of mesenchymal stem cells (i.e., adipose-derived stem cells [ADSCs]), which directly influence fat graft survival. Since ADSCs play an important role in angiogenesis and adipogenic differentiation, it is essential to optimize their isolation. Therefore, in this study, we evaluated and compared 2 procedures used to isolate viable cells from the stromal vascular fraction of abdominal adipose tissue and assess the expressions of surface markers. METHODS: We examined 9 female subjects who were scheduled to undergo liposuction. The adipose tissue was isolated from the abdominal infraumbilical region. Fat (20 mL) was collected from the right side by using a cannula attached to a syringe; the plunger was pulled back every 2 cm³ to create low-pressure suction (manual group). The same procedure was repeated on the left side, but the cannula was attached to a sterile and intermediate collector coupled to a vacuum pump that provided a constant negative pressure of 350 mmHg (pump group). The samples were centrifuged, and the adipocytes of the intermediate layer were counted, cultured, and immunophenotyped. RESULTS: The isolation of abdominal adipocytes with a pump providing a negative pressure of 350 mmHg yielded a higher concentration of cells in the stromal vascular fraction than that obtained using 10-mL syringes and low-pressure suction, although the difference was not significant. CONCLUSIONS: A negative pressure of 350 mmHg may be safely applied to isolate ADSCs. The cell yield did not indicate any statistically significant difference between the techniques.