Surgical Model of Auxiliary Partial Liver Transplantation in the Rat

Abstract

Auxiliary liver transplantation is an effective solution currently available for acute liver failure and liver-based metabolic diseases. It ensures sufficient functioning liver mass to allow for native liver recovery, preserves native liver function in case of liver graft loss and the remaining donor liver can be transplanted into a second. Therefore, an animal model of this surgery offers unique and exciting opportunities to delineate and evaluate the underlying mechanisms and therapeutic interventions that can contribute to graft regeneration. Here we describe a standardized procedure for rat model of donor liver graft surgery (40-50 min operative time) and auxiliary partial liver transplantation (100-120 min operative time), which, to a high degree, resembles operations in humans. We also provide detailed protocols for both pre-and postoperative techniques that ensure a high success rate in the operations. This protocol provides the opportunity to mechanistically investigate liver regeneration in auxiliary transplantation. APOLT for metabolic disease has a possible advantage in that the remnant native liver may work as a reservoir, if the donor liver fails. Moreover, patients undergoing hepatic resection for the treatment of hepatic malignancies can also benefit from APOLT, as many of them undergo liver function impairment due to the reduced absolute amount of hepatic parenchyma 6. Also, very important, different donor liver segments can be transplanted in several recipients, thereby maximizing benefit to our waitlisted population with every single deceased donor liver 7. However, the likelihood of regeneration and the timing for withdrawal of immunosuppression has not been fully established 8,9. Given the severity of the growing demand for liver transplantation, there is an urgent need for a detailed understanding of the mechanisms underlying pathophysiology of liver regeneration in order to enable the development of effective therapies in the setting of auxiliary liver transplantation. Although partial hepatectomy has been used as an experimental model for decades, contributing to the understanding of physiologic principles of initiation and termination of liver regeneration, partial hepatectomy does not necessarily reflect the regenerative process during human disease 10. Liver regeneration in patients is influenced by numerous factors, including tissue necrosis, innate immunity, and varying degrees of acute or chronic inflammation. Robust animal models for the regeneration that occurs in the context of human liver diseases do not currently exist. Despite the profound effects of auxiliary liver transplantation on acute or metabolic liver diseases, this operation represents an invaluable experimental model for scientific investigations of liver regeneration, liver mass regulation and bioengineered implantable liver grafts. Studies in humans have been difficult to document due to the practical and ethical challenges associated to the procedure. Besides, for most patients, biopsy examination often would be an ...

Actividad económica, créditos comerciales y nómina en México

“…Lo que significa, que un aumento en la cantidad de dinero en el mercado, ocasionado por un incremento en el crédito comercial, no ocasiona un aumento en la demanda que afecte al ITAEE; o, que el incremento en la cantidad de dinero en el mercado y en la demanda, producido por un aumento en el crédito comercial, no impacta al ITAEE. Así que, en México, a nivel estatal, no hay una relación entre el crédito comercial y el crecimiento económico (vía demanda), como lo señala la teoría económica (Gutiérrez, 2015;Domínguez y Marroquín, 2016;Tercero et al, 2020).…”

“…Ya que a través del crédito comercial, el cual, se destina al consumo, se puede aumentar la cantidad de dinero en el mercado e influir en la demanda, lo que impacta en el crecimiento económico. Se debe agregar que este impacto es en el crecimiento de la actividad económica agregada a corto plazo, y no sobre el crecimiento económico a largo plazo (Gutiérrez, 2015;Domínguez y Marroquín, 2016;Tercero et al, 2020;López et al, 2018;Garrido y Martínez, 2004;Martínez, 2021).…”

“…De esta manera, como lo indican algunos autores, López et al, (2018), Gutiérrez (2015) y Tercero et al, (2020)los créditos comerciales dados por las instituciones bancarias comerciales a los individuos a nivel estatal (BANXICO, 2022 a), deberían afectar al ITAEE (INEGI, 2022 a). Ya que los créditos comerciales estimulan a la demanda y a la actividad económica.…”

“…Algunos de estos, son la alta concentración de mercado, es decir, que pocos bancos concentran una gran parte del mercado financiero, por ejemplo, en 2014, Banamex y BBVA, tenían más del 50 % de la cartera de crédito vigente al consumo total de México; que se encuentra principalmente en manos extranjeras; que hay una reducida profundidad financiera; y, que hay una exclusión financiera persistente. Ante estas problemáticas, se han hecho reformas al sistema financiero, como la de 2014, que han permitido que entraran nuevas instituciones financieras al mercado de los créditos y así, haya más oferta (Levy, 2013;Gutiérrez, 2015;Domínguez y Marroquín, 2016;Zurita et al, 2009;Morales et al, 2013;Clavellina, 2013).…”