Experimental necrotizing enterocolitis using oral lipopolysaccharide and protective role of breastmilk. / Enterocolitis necrotizante experimental con lipopolisacárido oral y función protectora de la leche materna.

INTRODUCTION: Necrotizing enterocolitis (NEC) is a life-threatening condition that afflicts neonates. Breastfeeding has demonstrated to play a protective role against it. By administering lipopolysaccharides (LPS) orally in newborn rats (NBR), we have developed an experimental model to induce NEC-like gut damage. Our aim was to assess the macroscopic and microscopic appearance of the gut, to evaluate the presence of NEC and study the role of breast milk (BM). MATERIALS AND METHODS: NBR were divided into 3 groups: Group A (control, n= 10) remained with the mother, group B (LPS, n= 25) was isolated after birth, gavage-fed with special rat formula and oral LPS, then submitted to stress (hypoxia after gavage) and group c (BM, n= 12) was breastfed once after birth, then isolated, and submitted to stress like group B. On day 4, NBR were sacrificed, and intestine was harvested and assessed. RESULTS: In the control group NEC was not present either macroscopically or histologically. Both groups submitted to stress (B and C) presented a global incidence of NEC of 73%. Most of group B developed histologic signs of NEC (85%) and group C showed a statistically lower incidence of NEC (50%, p= 0.04), playing the BM a protective role against NEC (OR= 0.19; 95% CI: 0.40-0.904). CONCLUSION: Our model showed a significant incidence of NEC in NBR (73%) with the same protective role of BM as in newborn humans, achieving a reliable and reproducible experimental NEC model. This will allow us to investigate new potential therapeutic targets for a devastating disease that currently lacks treatment.

INTRODUCCION: La enterocolitis necrotizante (ECN) es una enfermedad potencialmente mortal que afecta a los neonatos, y frente a la que la leche materna ha demostrado tener un papel protector. Administrando lipopolisacáridos (LPS) por vía oral en ratas recién nacidas (RRN), hemos desarrollado un modelo experimental para inducir un daño intestinal similar al que provoca la ECN con objeto de evaluar el aspecto macroscópico y microscópico del intestino, y de ese modo, analizar la presencia de ECN y estudiar el papel que desempeña la leche materna (LM). MATERIAL Y METODOS: Las RRN se dividieron en tres grupos: el grupo A (control, n= 10) permaneció con su madre; el grupo B (LPS, n= 25) fue aislado tras el nacimiento, alimentado por sonda con una fórmula especial para ratas y LPS oral, y sometido a estrés (hipoxia tras sonda); y el grupo C (LM, n= 12) fue alimentado con leche materna tras el nacimiento y posteriormente aislado y sometido a estrés al igual que el grupo B. El día 4 se sacrificó a las RRN y se recuperaron sus intestinos para su posterior evaluación. RESULTADOS: En el grupo de control, no se observó ECN ni macroscópica ni histológicamente, mientras que los dos grupos sometidos a estrés (B y C) presentaron una incidencia global de la ECN del 73%. La mayoría de los sujetos del grupo B desarrollaron signos histológicos de ECN (85%), y los del grupo C registraron una incidencia de la ECN estadísticamente menor (50%, p= 0,04), lo que significa que la LM desempeña una función protectora frente a la ECN (OR= 0,19; IC 95%: 0,40-0,904). CONCLUSION: Nuestro modelo reveló una incidencia significativa de la ECN en RRN (73%), desempeñando la LM la misma función protectora que en el caso de los humanos recién nacidos, lo que significa que este modelo experimental de ECN es fiable y reproducible. Gracias a dicho logro, podremos investigar nuevos y potenciales objetivos terapéuticos para una peligrosa enfermedad que, a día de hoy, carece de tratamiento.

Efficacy of transplantation of lipoaspired mesenchymal stem cells in the treatment of chronic rotator cuff tears. Experimental model in rats. / Eficacia del trasplante de células madre mesenquimales de lipoaspirado en el tratamiento de lesiones crónicas del manguito rotador. Modelo experimental en ratas.

BACKGROUND AND AIM: Rotator cuff tears emerge in approximately 30% of the population over 60 years of age. Arthroscopic surgical treatment of these lesions is the treatment of choice, however, despite the improved repair techniques, the rate of re-tears ranges between 11 and 94%. Therefore, researchers seek to improve the biological healing process through the use of different alternatives such as mesenchymal stem cells (MSCs). Our objective is to evaluate the efficacy of a Cellular Therapy Drug made from allogeneic stem cells derived from adipose tissue in a rat model of chronic rotator cuff injury. MATERIAL AND METHODS: The supraspinatus lesion was created in 48 rats for subsequent suturing at 4 weeks. MSCs in suspension were added to 24 animals after suturing, and HypoThermosol-FRS® (HTS) to 24 animals as a control group. Histology (Åström and Rausing scale) and the maximum load, displacement and elastic constant of the supraspinatus tendon were analyzed in both groups 4 months after the repair. RESULTS: No statistically significant differences were found in the histological score comparing the tendons treated with MSCs with respect to the tendons treated with HTS (P=.811) nor in the results of maximum load (P=.770), displacement (P=.852) or elastic constant (P=.669) of the tendon in both groups. CONCLUSIONS: The addition of adipose-derived cells in suspension to the repair of a chronic cuff injury does not improve the histology or biomechanics of the sutured tendon.

[Translated article] Efficacy of transplantation of lipoaspired mesenchymal stem cells in the treatment of chronic rotator cuff tears. Experimental model in rats.

BACKGROUND AND AIM: Rotator cuff tears emerge in approximately 30% of the population over 60 years of age. Arthroscopic surgical treatment of these lesions is the treatment of choice, however, despite the improved repair techniques, the rate of re-tears ranges between 11 and 94%. Therefore, researchers seek to improve the biological healing process through the use of different alternatives such as mesenchymal stem cells (MSCs). Our objective is to evaluate the efficacy of a cellular therapy drug made from allogeneic stem cells derived from adipose tissue in a rat model of chronic rotator cuff injury. MATERIAL AND METHODS: The supraspinatus lesion was created in 48 rats for subsequent suturing at 4 weeks. MSCs in suspension were added to 24 animals after suturing, and HypoThermosol-FRS® (HTS) to 24 animals as a control group. Histology (Åström and Rausing scale) and the maximum load, displacement and elastic constant of the supraspinatus tendon were analysed in both groups 4 months after the repair. RESULTS: No statistically significant differences were found in the histological score comparing the tendons treated with MSCs with respect to the tendons treated with HTS (P=0.811) nor in the results of maximum load (P=0.770), displacement (P=0.852) or elastic constant (P=0.669) of the tendon in both groups. CONCLUSIONS: The addition of adipose-derived cells in suspension to the repair of a chronic cuff injury does not improve the histology or biomechanics of the sutured tendon.