Indocyanine green fluorescence quantification during normothermic ex situ perfusion for the assessment of porcine liver grafts after circulatory death.

Current graft evaluation during normothermic ex situ liver perfusion lacks real-time parameters for predicting posttransplant hepatocyte and biliary function. Indocyanine green (ICG) imaging has been widely used in liver surgery, enabling the visualization of hepatic uptake and excretion through bile using near-infrared light. In this research, porcine livers under various ischemic conditions were examined during a 5-hour normothermic ex situ liver perfusion procedure, introducing ICG at 1 hour through the hepatic artery. These conditions included livers from heart-beating donors, donation after circulatory death (DCD) with warm ischemic durations of 60 minutes (DCD60) and 120 minutes (DCD120), as well as interventions utilizing tissue plasminogen activator in DCD120 cases (each n = 5). Distinct hepatic fluorescence patterns correlated with different degrees of ischemic injury ( p = 0.01). Low ICG uptake in the parenchyma (less than 40% of maximum intensity) was more prevalent in DCD120 (21.4%) compared to heart-beating donors (6.2%, p = 0.06) and DCD60 (3.0%, p = 0.02). Moreover, ICG clearance from 60 minutes to 240 minutes was significantly higher in heart-beating donors (69.3%) than in DCD60 (17.5%, p < 0.001) and DCD120 (32.1%, p = 0.01). Furthermore, thrombolytic intervention using tissue plasminogen activator in DCD120 resulted in noteworthy outcomes, including significantly reduced ALP levels ( p = 0.04) and improved ICG clearance ( p = 0.02) with a trend toward mitigating fibrin deposition similar to DCD60, as well as enhancements in bile production ( p = 0.09). In conclusion, ICG fluorescence imaging during normothermic ex situ liver perfusion provides real-time classification of hepatic vascular and biliary injuries, offering valuable insights for the more accurate selection and postintervention evaluation of marginal livers in transplantation.

Perfil epidemiológico de los donadores de dientes humanos extraídos en establecimientos de Salud Pública, ubicados en Santa Ana, San Salvador y San Vicente durante el año 2019 / Epidemiological profile of donors of human teeth extracted in Public Health facilities, located in Santa Ana, San Salvador and San Vicente during the year 2019

Objetivo: Determinar el perfil epidemiológico de los donadores de dientes humanos extraídos en establecimientos de salud pública, durante el año 2019. Metodología: Se realizó un estudio de tipo observacional, descriptivo y transversal de 224 donadores de dientes humanos entre 7 a 71 o más años que acudieron a las UCSF de Chalchuapa, Planes de Renderos, Cuscatancingo, Vía Mariona y San Lorenzo. Fueron caracterizados según indicadores sociales, clínicos bucales e historia médica del donador, causas de extracción y características físicas de los dientes extraídos. La recolección de datos se realizó con cédulas de entrevista y guías de observación. Se realizaron 250 extracciones. Resultados: El sexo prevalente es el femenino con 68.75%, siendo la zona urbana más afectada con el 66.97% y el grupo etario de 21 a 30 años con 23.21%, el 14.73% presentó hipertensión arterial. Según los indicadores clínicos bucales, el 10.27% mostró bruxismo, siendo la caries dental la enfermedad más prevalente con un 91.96%, observando un nivel ISHO óptimo de 58.48%. La principal causa de extracción fue la caries dental con 67.20%, el diente extraído con mayor frecuencia fue el 4-6(FDI). Entre las características de la corona, el 64.4% presentaron caries cavitadas > 2 mm. Respecto a la raíz el 94.40% poseen raíz completa y el 44.40% 1 raíz. Conclusión: La caries dental es la principal causa de extracción afectando más a las mujeres de 21 a 30 años que residen en el área urbana, siendo el diente 4- 6 el más afectado.

Objective: To determine the epidemiological profile of donors of human teeth extracted in public health facilities during the year of 2019. Methods: An observational, descriptive, and transversal study of 224 donors of human teeth 7 to 71 years old or more who attended the UCSF of Chalchuapa, Planes de Renderos, Cuscatancingo, Via Mariona, and San Lorenzo. The participants were characterized according to social and oral clinical indicators, medical history of the donor, causes of extraction, and physical characteristics of the extracted teeth. Data collection was done with interview cards and observation guides. A total of 250 extractions were performed. Results: The prevalent sex is female with 68.75%, being the urban area the most affected with 66.97% and the age group from 21 to 30 years old with 23.21%, 14.73% of participants presented arterial hypertension. According to oral clinical indicators, 10.27% of participants showed bruxism, being dental cavities the most prevalent disease with 91.96%, observing an optimal ISHO level of 58.48%. The main cause of extraction was dental cavities with 67.20%, the 4-6 (FDI) was the most frequently extracted tooth. Among the characteristics of the crown, 64.4% presented cavitated cavities > 2 mm. In regard to the root, 94.40% had complete root and 44.40% had one root. Conclusions: Dental cavities are the main cause of extraction, affecting mainly women from 21 to 30 years old living in urban areas, being tooth 4-6 the most affected.

Single cell RNA sequencing of human liver reveals distinct intrahepatic macrophage populations.

The liver is the largest solid organ in the body and is critical for metabolic and immune functions. However, little is known about the cells that make up the human liver and its immune microenvironment. Here we report a map of the cellular landscape of the human liver using single-cell RNA sequencing. We provide the transcriptional profiles of 8444 parenchymal and non-parenchymal cells obtained from the fractionation of fresh hepatic tissue from five human livers. Using gene expression patterns, flow cytometry, and immunohistochemical examinations, we identify 20 discrete cell populations of hepatocytes, endothelial cells, cholangiocytes, hepatic stellate cells, B cells, conventional and non-conventional T cells, NK-like cells, and distinct intrahepatic monocyte/macrophage populations. Together, our study presents a comprehensive view of the human liver at single-cell resolution that outlines the characteristics of resident cells in the liver, and in particular provides a map of the human hepatic immune microenvironment.

PPAR-gamma activation is associated with reduced liver ischemia-reperfusion injury and altered tissue-resident macrophages polarization in a mouse model.

BACKGROUND: PPAR-gamma (γ) is highly expressed in macrophages and its activation affects their polarization. The effect of PPAR-γ activation on Kupffer cells (KCs) and liver ischemia-reperfusion injury (IRI) has not yet been evaluated. We investigated the effect of PPAR-γ activation on KC-polarization and IRI. MATERIALS AND METHODS: Seventy percent (70%) liver ischemia was induced for 60mins. PPAR-γ-agonist or vehicle was administrated before reperfusion. PPAR-γ-antagonist was used to block PPAR-γ activation. Liver injury, necrosis, and apoptosis were assessed post-reperfusion. Flow-cytometry determined KC-phenotypes (pro-inflammatory Nitric Oxide +, anti-inflammatory CD206+ and anti-inflammatory IL-10+). RESULTS: Liver injury assessed by serum AST was significantly decreased in PPAR-γ-agonist versus control group at all time points post reperfusion (1hr: 3092±105 vs 4469±551; p = 0.042; 6hr: 7041±1160 vs 12193±1143; p = 0.015; 12hr: 5746±328 vs 8608±1259; p = 0.049). Furthermore, liver apoptosis measured by TUNEL-staining was significantly reduced in PPAR-γ-agonist versus control group post reperfusion (1hr:2.46±0.49 vs 6.90±0.85%;p = 0.001; 6hr:26.40±2.93 vs 50.13±8.29%; p = 0.048). H&E staining demonstrated less necrosis in PPAR-γ-agonist versus control group (24hr:26.66±4.78 vs 45.62±4.57%; p = 0.032). The percentage of pro-inflammatory NO+ KCs was significantly lower at all post reperfusion time points in the PPAR-γ-agonist versus control group (1hr:28.49±4.99 vs 53.54±9.15%; p = 0.040; 6hr:5.51±0.54 vs 31.12±9.58%; p = 0.009; 24hr:4.15±1.50 vs 17.10±4.77%; p = 0.043). In contrast, percentage of anti-inflammatory CD206+ KCs was significantly higher in PPAR-γ-agonist versus control group prior to IRI (8.62±0.96 vs 4.88 ±0.50%; p = 0.04). Administration of PPAR-γ-antagonist reversed the beneficial effects on AST, apoptosis, and pro-inflammatory NO+ KCs. CONCLUSION: PPAR-γ activation reduces IRI and decreases the pro-inflammatory NO+ Kupffer cells. PPAR-γ activation can become an important tool to improve outcomes in liver surgery through decreasing the pro-inflammatory phenotype of KCs and IRI.

Continuous Normothermic Ex Vivo Kidney Perfusion Improves Graft Function in Donation After Circulatory Death Pig Kidney Transplantation.

BACKGROUND: Donation after circulatory death (DCD) is current clinical practice to increase the donor pool. Deleterious effects on renal graft function are described for hypothermic preservation. Therefore, current research focuses on investigating alternative preservation techniques, such as normothermic perfusion. METHODS: We compared continuous pressure-controlled normothermic ex vivo kidney perfusion (NEVKP) with static cold storage (SCS) in a porcine model of DCD autotransplantation. After 30 minutes of warm ischemia, right kidneys were removed from 30-kg Yorkshire pigs and preserved with 8-hour NEVKP or in 4°C histidine-tryptophan-ketoglutarate solution (SCS), followed by kidney autotransplantation. RESULTS: Throughout NEVKP, electrolytes and pH values were maintained. Intrarenal resistance decreased over the course of perfusion (0 hour, 1.6 ± 0.51 mm per minute vs 7 hours, 0.34 ± 0.05 mm Hg/mL per minute, P = 0.005). Perfusate lactate concentration also decreased (0 hour, 10.5 ± 0.8 vs 7 hours, 1.4 ± 0.3 mmol/L, P < 0.001). Cellular injury markers lactate dehydrogenase and aspartate aminotransferase were persistently low (lactate dehydrogenase < 100 U/L, below analyzer range; aspartate aminotransferase 0 hour, 15.6 ± 9.3 U/L vs 7 hours, 24.8 ± 14.6 U/L, P = 0.298). After autotransplantation, renal grafts preserved with NEVKP demonstrated lower serum creatinine on days 1 to 7 (P < 0.05) and lower peak values (NEVKP, 5.5 ± 1.7 mg/dL vs SCS, 11.1 ± 2.1 mg/dL, P = 0.002). The creatinine clearance on day 4 was increased in NEVKP-preserved kidneys (NEVKP, 39 ± 6.4 vs SCS, 18 ± 10.6 mL/min; P = 0.012). Serum neutrophil gelatinase-associated lipocalin at day 3 was lower in the NEVKP group (1267 ± 372 vs 2697 ± 1145 ng/mL, P = 0.029). CONCLUSIONS: Continuous pressure-controlled NEVKP improves renal function in DCD kidney transplantation. Normothermic ex vivo kidney perfusion might help to decrease posttransplant delayed graft function rates and to increase the donor pool.