Descelularización y regeneración de tráquea porcina: un acercamiento a la ingeniería tisular / Decellularization and Regeneration of Porcine Trachea: an Approach to Tissue Engineering

Resumen Antecedentes: la ingeniería tisular permite obtener órganos como injertos a partir de tejidos descelularizados, regenerados con células autólogas. Objetivo: descelularizar y regenerar tráqueas porcinas. Material y métodos: se descelularizaron tráqueas porcinas colocándolas cada una en el epiplón de cuatro cerdos Yorkshire para su regeneración in vivo. Una tráquea desce-lularizada con tritón (DT), descelularizada con desoxicolato (DD), descelularizada con desoxicolato y reforzada con un polímero y células epiteliales (DDR), y una nativa crio-preservada (NC). Después de 8 días se obtuvieron la DD, NC y DDR; y al día 15, la DT. Se las evaluó mecánica e histológicamente, se realizó el análisis casuístico. Resultados: las tráqueas descelularizadas conservaron la integridad del cartílago, sin diferencias mecánicas, excepto la DDR con mayor rigidez. Las tráqueas regeneradas presentaron menor rigidez, excepto la DDR que además perdió el epitelio y la vascula-ridad. Las DT, DD mostraron epitelio no respiratorio, fibrosis y vasculogénesis con in-flamación. Conclusiones: las matrices conservaron sus características mecánicas. La regenera-ción in vivo ofrece ventajas como la esterilidad, interacción celular, nutrientes; es senci-llo, factible y económico, pero no hay control del crecimiento celular y vascularización, y los tejidos presentaron alteraciones mecánicas e histológicas. El polímero impidió la re-epitelialización y revascularización. Este estudio abre la posibilidad de mejorar las me-todologías de ingeniería tisular aplicadas al tejido traqueal.

Abstract Introduction: tissue engineering makes it possible to obtain organs as grafts from de-cellularized tissues, regenerated with autologous cells.Objective: decellularize and regenerate porcine tracheas.ARTÍCULO ORIGINAL | Respirar, 2023; 15(3): 188-199 | ISSN 2953-3414 | https://doi.org/10.55720/respirar.15.3.5RECIBIDO: 9 agosto 2023ACEP TADO: 31 agosto 2023 Elisa Barrera-Ramírezhttps://orcid.org/0000-0002-2778-0882Rubén Efraín Garrido-Cardonahttps://orcid.org/0000-0001-6083-5403Alejandro Martínez-Martínezhttps://orcid.org/0000-0003-3448-910XLuis Fernando Plenge-Tellecheahttps://orcid.org/0000-0002-1619-5004Edna Rico-Escobarhttps://orcid.org/0000-0002-0933-0220Esta revista está bajo una licencia de Creative Commons Reconocimiento 4.0 Internacional. Respirar 2023; 15 (3): 189ARTÍCULO ORIGINAL / E. Barrera-Ramírez, R.E. Garrido-Cardona, A. Martínez-Martínez, L.F. Plenge-Tellechea, E. Rico-EscobarDescelularización y regeneración de tráqueaISSN 2953-3414Materials and Methods: Porcine tracheas were decellularized by placing each one in the omentum of four Yorkshire pigs for regeneration in vivo. A trachea decellularized with triton (DT), decellularized with deoxycholate (DD), decellularized with deoxycho-late and reinforced with a polymer, and epithelial cells (DDR), and a cryopreserved na-tive (NC). After 8 days, the DD, NC and DDR were obtained; and on day 15, the DT. The evaluation was mechanically and histologically, performing the case analysis.Results: the decellularized tracheas preserved the integrity of the cartilage, with no me-chanical differences, except for the DDR with greater rigidity. The regenerated trache-as presented less rigidity, except the DDR, which also lost the epithelium and vascular-ity. The DT, DD showed non-respiratory epithelium, fibrosis and vasculogenesis with inflammation.Conclusions: the matrices retained their mechanical characteristics, in vivo regenera-tion offers advantages such as sterility, cell interaction, nutrients; it is simple, feasible and economical, but there is no control of cell growth and vascularization, and the tis-sues presented mechanical and histological alterations. The polymer prevented re-epi-thelialization and revascularization. This study opens the possibility of improving tissue engineering methodologies applied to tracheal tissue.

Acanthocytosis and brain damage in area postrema and choroid plexus: Description of novel signs of Loxosceles apachea envenomation in rats.

Loxocelism is a neglected medical problem that depends on its severity, can cause a cutaneous or viscero-cutaneous syndrome. This syndrome is characterized by hemostatic effects and necrosis, and the severity of the loxoscelism depends on the amount of venom injected, the zone of inoculation, and the species. In the Chihuahuan desert, the most abundant species is L. apachea. Its venom and biological effects are understudied, including neurological effects. Thus, our aim is to explore the effect of this regional species of medical interest in the United States-Mexico border community, using rat blood and central nervous system (CNS), particularly, two brain structures involved in brain homeostasis, Area postrema (AP) and Choroid plexus (PC). L. apachea specimens were collected and venom was obtained. Different venom concentrations (0, 0.178 and 0.87 µg/g) were inoculated into Sprague-Dawley rats (intraperitoneal injection). Subsequently, blood was extracted and stained with Wright staining; coronal sections of AP were obtained and stained with Hematoxylin-Eosin (HE) staining and laminin γ immunolabelling, the same was done with CP sections. Blood, AP and CP were observed under the microscope and abnormalities in erythrocytes and fluctuation in leukocyte types were described and quantified in blood. Capillaries were also quantified in AP and damage was described in CP. L. apachea venom produced a segmented neutrophil increment (neutrophilia), lymphocyte diminishment (leukopenia) and erythrocytes presented membrane abnormalities (acanthocytosis). Extravasated erythrocytes were observed in HE stained sections from both, AP and CP, which suggest that near to this section a hemorrhage is present; through immunohistofluorescence, a diminishment of laminin γ was observed in AP endothelial cells and in CP ependymal cells when these structures were exposed to L. apachea venom. In conclusion, L. apachea venom produced leukopenia, netrophilia and acanthocytosis in rat peripheral blood, and also generated hemorrhages on AP and CP through degradation of laminin γ.

[Tissue engineering applied to the trachea as a graft]. / Ingeniería tisular aplicada a la tráquea como injerto.

Tissue engineering offers, through new technologies, an ex vivo generation of organs and functional tissues as grafts for transplants, for the improvement and substitution of biological functions, with an absence of immunological response. The treatment of extended tracheal lesions is a substitution of the affected segment; nevertheless, the allogeneic transplant has failed and the use of synthetic materials has not had good results. New tissue engineering technology is being developed to offer a tracheal graft for a posterior implantation. The purpose of this article is to review all the methods and components used by the engineering of tissue for tracheal grafts.

Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (< LOD) to 215 ng/g lipid, with a mean total PBDEs level of 29.5 ± 53.0 ng/g lipid (geometric mean ± standard deviation). The mean total PCBs level in the study participants was 29.0 ± 10.5 ng/g lipid (range 4.50-50.0 ng/g lipid). The mean concentration of total DDT (DDT + DDE) was 11.9 ± 6.70 ng/g lipid (range 3.00-26.0 ng/g lipid). The mean 1-OHP levels was 1.2 ± 1.1 µmol/mol creatinine (range

[History and progress of trachea transplantation in Mexico]. / Historia y avances en trasplante de tráquea en México.

Central airway obstruction and particularly tracheal stenosis is a clinical problem where definite resolution is a tracheal resection, evaluating the magnitude, length, and ventilatory compromise of patient. The resectable fragment is limited to 30% of the total length in children, or 6 cm in adults with terminal end anastomosis. The replacement of longer sections through allogeneic transplantation has been disappointing due to the unfeasibility of the organ, rejection of the graft, and the highly complicated surgical procedure. Tissue bioengineering has designed the replacement of functional organs generated in vitro in the short term, with the absence of immunological responses to the graft. This is based on a non-biological matrix where epithelial and mesenchymal cells are planted in such a matrix. In this document, we review the history and development of trachea transplantation in Mexico as well as the application of these new technologies in the context of its world development, which is a reality in other countries as a new alternative in obstructive illness of the airway.

Exposición infantil al plomo en sitios contaminados / Children exposure to lead in contaminated sites

OBJETIVO: Determinar el grado de la exposición infantil al plomo en diversos tipos de sitios contaminados. MATERIAL Y MÉTODOS: El estudio se realizó de junio 2008 a diciembre 2009 en cuatro sitios de México: metalúrgica de Ávalos, Chihuahua.; metalúrgica de Morales, San Luis Potosí (SLP); zona alfarera en La Trinidad, Tlaxcala, y sitio minero en Cedral, SLP. Se cuantificó plomo en polvo y se realizó un biomonitoreo humano en niños de la comunidad. RESULTADOS: Los valores obtenidos de plomo en polvo exterior superaron el límite establecido de 400 mg/kg para suelos residenciales en un intervalo de valores para los cuatro sitios de 62 a 5 187 mg/kg. En cuanto al monitoreo biológico, todas las poblaciones presentaron valores extremos, desde los 22 µg/dL en Cedral, 31 µg/dL en Morales, y 32 µg/dL en Ávalos, hasta los 52 µg/dL en La Trinidad. Es importante señalar que encontramos una correlación positiva y significativa entre los valores de plomo en polvo y plomo en sangre en todos los sitios de estudio (p<0.001). CONCLUSIÓN: Estos sitios son un ejemplo de los riesgos en salud relacionados con la exposición a plomo en México; por consiguiente, se requiere de un programa nacional de salud pública dirigido a reducir la exposición a este metal en poblaciones vulnerables.

OBJECTIVE: To assess the exposure to lead in children living in various types of contaminated sites. MATERIALS AND METHODS: The study was conducted from June 2008 to December 2009 at four sites in Mexico: Avalos metallurgical, Chihuahua; Morales metallurgical, San Luis Potosí (SLP); Trinidad pottery area, Tlaxcala and Cedral mine site, SLP. These sites contain different sources of lead. The metal levels were quantified in outdoor dust and in peripheral blood of children. RESULTS: Lead dust concentrations exceed the National Guidelines for residential soils (400 mg/kg) in a range of values for the four sites from 62 to 5 187 mg/kg. Regarding biological monitoring, the studied children showed maximum lead blood levels of 22 µg/dL in Cedral, 31 µg/dL in Morales, 32 µg/dL in Avalos, and 52 µg/dL in Trinidad. It is important to mention that in all the studied sites, a significative positive correlation was found between blood lead levels and the lead concentrations in dust. CONCLUSION: These sites are an example of the health risks related to lead exposure in Mexico; therefore, there is an urgent need for a national public health program aimed at reducing lead exposure in vulnerable populations.

[Children exposure to lead in contaminated sites]. / Exposición infantil al plomo en sitios contaminados.

OBJECTIVE: To assess the exposure to lead in children living in various types of contaminated sites. MATERIALS AND METHODS: The study was conducted from June 2008 to December 2009 at four sites in Mexico: Avalos metallurgical, Chihuahua; Morales metallurgical, San Luis Potosí (SLP); Trinidad pottery area, Tlaxcala and Cedral mine site, SLP. These sites contain different sources of lead. The metal levels were quantified in outdoor dust and in peripheral blood of children. RESULTS: Lead dust concentrations exceed the National Guidelines for residential soils (400 mg/kg) in a range of values for the four sites from 62 to 5 187 mg/kg. Regarding biological monitoring, the studied children showed maximum lead blood levels of 22 µg/dL in Cedral, 31 µg/dL in Morales, 32 µg/dL in Avalos, and 52 µg/dL in Trinidad. It is important to mention that in all the studied sites, a significative positive correlation was found between blood lead levels and the lead concentrations in dust. CONCLUSION: These sites are an example of the health risks related to lead exposure in Mexico; therefore, there is an urgent need for a national public health program aimed at reducing lead exposure in vulnerable populations.