Automated Assessment of Cell Infiltration and Removal in Decellularized Scaffolds - Experimental Study in Rabbits.

Objective Semiquantitative and automated measurement of nuclear material removal and cell infiltration in decellularized tendon scaffolds (DTSs). Method 16 pure New Zealand rabbits were used, and the gastrocnemius muscle tendon was collected bilaterally from half of these animals (16 tendons collected); 4 were kept as control and 12 were submitted to the decellularization protocol (DTS). Eight of the DTSs were used as an in vivo implant in the experimental rotator cuff tear (RCT) model, and the rest, as well as the controls, were used in the semiquantitative and automated evaluation of nuclear material removal. The eight additional rabbits were used to make the experimental model of RCT and subsequent evaluation of cellular infiltration after 2 or 8 weeks, within the DTS. Results The semiquantitative and automated analysis used demonstrated a removal of 79% of nuclear material ( p < 0.001 and power > 99%) and a decrease of 88% (p < 0.001 and power >99%) in the area occupied by nuclear material after the decellularization protocol. On cell infiltration in DTS, an increase of 256% (p < 0.001 and power >99%) in the number of cells within the DTS was observed in the comparison between 2 and 8 weeks postoperatively. Conclusion The proposed semiquantitative and automated measurement method was able to objectively measure the removal of nuclear material and cell infiltration in DTS.

Automated Assessment of Cell Infiltration and Removal in Decellularized Scaffolds - Experimental Study in Rabbits / Avaliação automatizada da infiltração e remoção celular em scaffolds descelularizados - Estudo experimental em coelhos

Abstract Objective Semiquantitative and automated measurement of nuclear material removal and cell infiltration in decellularized tendon scaffolds (DTSs). Method 16 pure New Zealand rabbits were used, and the gastrocnemius muscle tendon was collected bilaterally from half of these animals (16 tendons collected); 4 were kept as control and 12 were submitted to the decellularization protocol (DTS). Eight of the DTSs were used as an in vivo implant in the experimental rotator cuff tear (RCT) model, and the rest, as well as the controls, were used in the semiquantitative and automated evaluation of nuclear material removal. The eight additional rabbits were used to make the experimental model of RCT and subsequent evaluation of cellular infiltration after 2 or 8 weeks, within the DTS. Results The semiquantitative and automated analysis used demonstrated a removal of 79% of nuclear material (p< 0.001 and power > 99%) and a decrease of 88% (p < 0.001 and power >99%) in the area occupied by nuclear material after the decellularization protocol. On cell infiltration in DTS, an increase of 256% (p < 0.001 and power >99%) in the number of cells within the DTS was observed in the comparison between 2 and 8 weeks postoperatively. Conclusion The proposed semiquantitative and automated measurement method was able to objectively measure the removal of nuclear material and cell infiltration in DTS.

Resumo Objetivo Mensuração semiquantitativa e automatizada da remoção de material nuclear e da infiltração celular em scaffolds tendinosos descelularizados (STDs). Método Foram utilizados 16 coelhos Nova Zelândia puros, sendo o tendão do músculo gastrocnêmio coletado bilateralmente de metade destes animais (16 tendões coletados); 4 foram mantidos como controle e 12 foram submetidos ao protocolo de descelularização (STD). Dos STDs, 8 foram utilizados como implante in vivo no modelo experimental de lesão do manguito rotador (LMR) e os restantes, assim como os controles, foram utilizados na avaliação semiquantitativa e automatizada da remoção de material nuclear. Os oito coelhos adicionais foram utilizados na confecção do modelo experimental de LMR e posterior avaliação da infiltração celular após 2 ou 8 semanas, dentro do STD. Resultados A análise semiquantitativa e automatizada utilizada demonstrou uma remoção de 79% do material nuclear (p< 0,001 e poder > 99%) e uma diminuição de 88% (p< 0,001 e poder > 99%) na área ocupada por material nuclear após o protocolo de descelularização. Sobre a infiltração celular no STD, foi observado um aumento de 256% (p< 0,001 e poder > 99%) no número de células dentro do STD na comparação entre 2 e 8 semanas de pós-operatório. Conclusão O método de mensuração semiquantitativo e automatizado proposto foi capaz de mensurar objetivamente a remoção de material nuclear e a infiltração celular no STD.

Treatment of Muscle Injury with Stem Cells - Experimental Study in Rabbits.

Objective Histological and macroscopic evaluation of the healing process of acute lesions of the femoral rectus muscle using stem cells derived from adipose tissue-derived stem cells (ADSCs). Method An experimental study was conducted with 18 hind legs of New Zealand rabbits, which were divided into three study groups according to the intervention to be performed. In group I, no surgical procedure was performed; in group II-SHAN, the experimental lesion was performed without any additional intervention protocol; in group III-Intervention, the addition of ADSCs was performed in the same topography of the experimental lesion. After the proposed period, 2 weeks, the material was collected and submitted to macroscopic and histological evaluation. Results The quantitative analysis showed that the addition of ADSCs is related to the reduction of inflammatory cells in the 2-week evaluation (164.2 cells in group II - SHAN to 89.62 cells in group III - ADSC). The qualitative analysis of the slides with Picrosirius red, noticed an increase in orange/yellow fibers in group III - ADSC, which evidences a final healing process. The macroscopic evaluation found no difference between the groups. Conclusion The use of ADSCs in the treatment of acute muscle injury presented histological advantages when compared to their non-use.

Treatment of Muscle Injury with Stem Cells - Experimental Study in Rabbits / Tratamento da lesão muscular com células-tronco - Estudo experimental em coelhos

Abstract Objective Histological and macroscopic evaluation of the healing process of acute lesions of the femoral rectus muscle using stem cells derived from adipose tissue-derived stem cells (ADSCs). Method An experimental study was conducted with 18 hind legs of New Zealand rabbits, which were divided into three study groups according to the intervention to be performed. In group I, no surgical procedure was performed; in group II—SHAN, the experimental lesion was performed without any additional intervention protocol; in group III—Intervention, the addition of ADSCs was performed in the same topography of the experimental lesion. After the proposed period, 2 weeks, the material was collected and submitted to macroscopic and histological evaluation. Results The quantitative analysis showed that the addition of ADSCs is related to the reduction of inflammatory cells in the 2-week evaluation (164.2 cells in group II - SHAN to 89.62 cells in group III - ADSC). The qualitative analysis of the slides with Picrosirius red, noticed an increase in orange/yellow fibers in group III - ADSC, which evidences a final healing process. The macroscopic evaluation found no difference between the groups. Conclusion The use of ADSCs in the treatment of acute muscle injury presented histological advantages when compared to their non-use.

Resumo Objetivo Avaliação histológica e macroscópica do processo de cicatrização das lesões agudas do músculo reto femoral, com utilização de células-tronco derivadas de tecido adiposo (ADSCs, na sigla em inglês). Método Foi realizado um estudo experimental com 18 patas traseiras de coelhos Nova Zelândia, que foram divididos em três nos grupos de estudo de acordo com a intervenção a ser realizada. No grupo I não foi realizado procedimento cirúrgico; no grupo II - SHAN foi realizado a lesão experimental sem nenhum protocolo de intervenção adicional; e no grupo III - Intervenção foi realizado a adição de ADSCs na mesma topografia onde foi realizada a lesão experimental. Após o período proposto, 2 semanas, o material foi coletado, submetido a avaliação macroscópica e histológica. Resultados A análise quantitativa demonstrou que a adição de ADSCs está relacionada com a diminuição de células inflamatórias na avaliação com 2 semanas (164,2 células no grupo II - SHAN para 89,62 células no grupo III - ADSC). A análise qualitativa das lâminas coradas com Picrosírius red demonstrou um aumento das fibras de cor laranja/amarela no grupo III - ADSC, o que evidencia um processo final de cicatrização. A avaliação macroscópica não encontrou diferença entre os grupos. Conclusão A utilização de ADSCs no tratamento de lesão muscular aguda apresentou vantagens histológicas quando comparada a sua não utilização.

Lipidomics of mesenchymal stem cell differentiation.

Mesenchymal stem cells (MSCs), such as adipose-derived stem cells (ADSCs) and skeletal muscle-derived stem cells (MDSCs), are potential sources for cell-based therapeutic strategies. However, there is little knowledge about the lipid composition of these stem cells and the mechanisms of their differentiation. Lipids have important biological and physiological functions that are critical for understanding the regulation and control of stem cell fate. This study sought to analyze the lipidome of rabbit ADSCs and MDSCs and their adipogenic and osteogenic differentiation. The MSCs were isolated and were characterized by flow cytometry. Lipids were extracted from both MSCs and differentiated cells, and the lipids were subsequently analyzed with a hybrid triple quadrupole time-of-flight mass spectrometer. The results showed a total of 1687 lipid species. MSCs exhibited different lipid profiles as well as changes in lipid composition after differentiation. Furthermore, the expression levels of N-acyl-phosphatidylethanolamine (NAPE) 54:7+NH4 (-FA 17:0(NH4)) and phosphatidylcholine (PC) 42:6+Na were higher in the adipogenic lineages in of both MSC types, and NAPE 58:2+NH4 (-FA 17:0 (NH4)) and NAPE 56:2+NH4 (-FA 17:0 (NH4)) had higher levels in the osteogenic lineages, suggesting lipid similarities in cells differentiated from different stem cell sources.

EVALUATION AND COMPARISON OF OPEN AND CLOSED TIBIA SHAFT FRACTURES IN A QUATERNARY REFERENCE CENTER.

INTRODUCTION: Tibia shaft fractures are among the most common in orthopedic practice, but Brazilian literature remains limited on the subject. OBJECTIVE: To evaluate the characteristics of tibia shaft fractures and conduct a comparison between exposed and closed fractures of the tibia. METHODS: This comparative prospective study examined all tibia shaft fractures admitted to our services over a twelve-month period. The cases were evaluated according to age, trauma mechanism, sex, associated fractures, treatment, hospital stay, and readmission rate during the six months after discharge. RESULTS: Fifty-three cases met the inclusion criteria. The average age was 36 years (SD 14.3) and 83% were males (p<0.001). Traffic accidents were responsible for 73.6% of fractures (p<0.001). Exposed fractures were found in 52.8% of the cases (p=0.56). When initial treatment consisted of stabilization with external fixation, these cases were more likely to be rehospitalized (p=0.009). Cases of open fracture also had longer hospital stays (p<0.001) and a higher readmission rate (p=0.028). CONCLUSION: Open fractures are associated with more severe trauma, expressed in longer hospital stays and high rates of readmission. Cases of fracture which were initially treated with external fixation had a higher readmission rate. Level of Evidence II; Prospective comparative study.

INTRODUÇÃO: Fratura diafisária de tíbia é uma das fraturas mais comuns na prática ortopédica, porém a literatura brasileira ainda é limitada na sua avaliação. OBJETIVO: Avaliar as características das fraturas diafisárias de tíbia e realizar uma comparação entre as expostas e fechadas. MATERIAL E MÉTODOS: Foi realizado um estudo, prospectivo comparativo por 12 meses, com todas as fraturas diafisárias de tíbia admitidas. Os pacientes foram avaliados nos seguintes critérios: idade, mecanismo de trauma, sexo, fraturas associadas, tratamento, tempo de internação e índice de reinternação nos seis meses subsequentes à alta. RESULTADOS: Foram avaliados 53 casos que se encaixavam nos critérios de inclusão. A idade média dos pacientes avaliados no nosso estudo era de 36 anos (DP14,3), 83% eram homens (p<0,001). Acidente de tráfego foi responsável por 73,6% (p<0,001). Lesões expostas foram encontradas em 52,8% (p=0,56). O fixador externo, quando utilizado como método de estabilização inicial, apresentou maior índice de reinternação (p=0,009). As lesões expostas apresentaram tempo de internação (p<0,001) e índice de reinternação superior as fechadas (p=0,028). CONCLUSÕES: As fraturas expostas estão envolvidas com traumas de maior gravidade, tanto pelo tempo aumentado de internação hospitalar quanto pelo alto índice de reinternação. Fraturas tratadas inicialmente com fixador externo apresentam maior taxa de reinternação. Nível de Evidência II; Estudo prospectivo comparativo.

Evaluation and comparison of open and closed tibia shaft fractures in a quaternary reference center / Comparação das fraturas diafisárias de tibia expostas e fechadas em um serviço quaternário

ABSTRACT Introduction Tibia shaft fractures are among the most common in orthopedic practice, but Brazilian literature remains limited on the subject. Objective To evaluate the characteristics of tibia shaft fractures and conduct a comparison between exposed and closed fractures of the tibia. Methods This comparative prospective study examined all tibia shaft fractures admitted to our services over a twelve-month period. The cases were evaluated according to age, trauma mechanism, sex, associated fractures, treatment, hospital stay, and readmission rate during the six months after discharge. Results Fifty-three cases met the inclusion criteria. The average age was 36 years (SD 14.3) and 83% were males (p<0.001). Traffic accidents were responsible for 73.6% of fractures (p<0.001). Exposed fractures were found in 52.8% of the cases (p=0.56). When initial treatment consisted of stabilization with external fixation, these cases were more likely to be rehospitalized (p=0.009). Cases of open fracture also had longer hospital stays (p<0.001) and a higher readmission rate (p=0.028). Conclusion Open fractures are associated with more severe trauma, expressed in longer hospital stays and high rates of readmission. Cases of fracture which were initially treated with external fixation had a higher readmission rate. Level of Evidence II; Prospective comparative study.

RESUMO Introdução Fratura diafisária de tíbia é uma das fraturas mais comuns na prática ortopédica, porém a literatura brasileira ainda é limitada na sua avaliação. Objetivo Avaliar as características das fraturas diafisárias de tíbia e realizar uma comparação entre as expostas e fechadas. Material e Métodos Foi realizado um estudo, prospectivo comparativo por 12 meses, com todas as fraturas diafisárias de tíbia admitidas. Os pacientes foram avaliados nos seguintes critérios: idade, mecanismo de trauma, sexo, fraturas associadas, tratamento, tempo de internação e índice de reinternação nos seis meses subsequentes à alta. Resultados Foram avaliados 53 casos que se encaixavam nos critérios de inclusão. A idade média dos pacientes avaliados no nosso estudo era de 36 anos (DP14,3), 83% eram homens (p<0,001). Acidente de tráfego foi responsável por 73,6% (p<0,001). Lesões expostas foram encontradas em 52,8% (p=0,56). O fixador externo, quando utilizado como método de estabilização inicial, apresentou maior índice de reinternação (p=0,009). As lesões expostas apresentaram tempo de internação (p<0,001) e índice de reinternação superior as fechadas (p=0,028). Conclusões As fraturas expostas estão envolvidas com traumas de maior gravidade, tanto pelo tempo aumentado de internação hospitalar quanto pelo alto índice de reinternação. Fraturas tratadas inicialmente com fixador externo apresentam maior taxa de reinternação. Nível de Evidência II; Estudo prospectivo comparativo.