ABSTRACT
Measuring the thermodynamic quantities and coordination structure of oxide ions in CaCl2-based melts is essential for comprehensively understanding the relationship between the thermodynamic and microscopic behaviors of high-temperature molten salts. In this study, the standard formal chemical potentials of oxide ion, µO2- o', and activity coefficient, γO2- , in NaCl-CaCl2, NaCl-KCl-CaCl2, and LiCl-KCl-CaCl2 melts at 873 K, were evaluated by measuring the dependence of potential of O2/O2- on the oxygen partial pressure by using non-consumable ceramic electrodes; the µO2- o' was -527 ± 0.3, - 535 ± 0.1, and -538 ± 0.2 kJ mol-1 and the γO2- was 0.10, 0.30, and 0.45 for each melt. In addition, the coordination structure of oxide ions in each melt was investigated by combining high-temperature Raman spectroscopy and density functional theory calculations. The coordination structures of oxide ions were identified as [NaO2]3- and [CaOCl3]3- in the NaCl-CaCl2 melt, [CaOCl2]2- in the NaCl-KCl-CaCl2 melt, and [LiCaO]+ and [Li3KO]2+ in the LiCl-KCl-CaCl2 melt, revealing that the stable structure was significantly different depending on the melt composition. The activity coefficients showed a tendency to depend on the nearest-neighbor cation coordinated with the oxide ion. The reported data will provide insights into the physicochemical properties of high-temperature melts and contribute to controlling the compatibility of materials and melts in pyrochemical engineering processes.
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The formation of Si(II) by the comproportionation reaction between electrodeposited silicon and Si(IV) ions [Si(IV) + Si0 â 2Si(II)] in fluoride melts has been discussed in many previous reports on the electrochemical processing of silicon. In this study, the coordination structure of Si(II) ions in LiF-KF, LiF-NaF, NaF-KF, and LiF-NaF-KF melts was investigated by high-temperature Raman spectroscopy and quantum chemical calculation based on density functional theory. The formation of Si(II) ions was induced by mixing metallic silicon powder as the source of Si0, with the melts containing hexafluoro silicate or silicon dioxide as the source of Si(IV) ions. The simulated vibrational modes of the Si(II) species and the experimental Raman bands showed good agreement. It was found that both Si(II) and Si(IV) species were detected in either fluoride melt, demonstrating that the proposed comproportionation reaction between Si0 and Si(IV) occurred. In addition, the interaction between Si(II) and F-, O2-, Li+, Na+, and K+ ions significantly changed depending on the composition of fluoride melts. The coordination structure of the Si(II) ions reported in this study will provide clues for controlling the electrodeposition process of silicon in fluoride melts.
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OBJECTIVES: The goal of this study was to identify the practical applications of intravenous cell therapy for single-ventricle physiology (SVP) by establishing experimental SVP models. METHODS: An SVP with a three-stage palliation was constructed in an acute swine model without cardiopulmonary bypass. A modified Blalock-Taussig (MBT) shunt was created using an aortopulmonary shunt with the superior and inferior venae cavae (SVC and IVC, respectively) connected to the left atrium (n = 10). A bidirectional cavopulmonary shunt (BCPS) was constructed using a graft between the IVC and the left atrium with an SVC cavopulmonary connection (n = 10). The SVC and the IVC were connected to the pulmonary artery to establish a total cavopulmonary connection (TCPC, n = 10). The survival times of half of the animal models were studied. The other half and the biventricular sham control (n = 5) were injected intravenously with cardiosphere-derived cells (CDCs), and the cardiac retention of CDCs was assessed after 2 h. RESULTS: All SVP models died within 20 h. Perioperative mortality was higher in the BCPS group because of lower oxygen saturation (P < 0.001). Cardiac retention of intravenously delivered CDCs, as detected by magnetic resonance imaging and histologic analysis, was significantly higher in the modified Blalock-Taussig and BCPS groups than in the TCPC group (P < 0.01). CONCLUSIONS: Without the total right heart exclusion, stage-specific SVP models can be functionally constructed in pigs with stable outcomes. Intravenous CDC injections may be applicable in patients with SVP before TCPC completion, given that the initial lung trafficking is efficiently bypassed and sufficient systemic blood flow is supplied from the single ventricle.
Subject(s)
Fontan Procedure , Heart Defects, Congenital , Univentricular Heart , Humans , Animals , Swine , Infusions, Intravenous , Fontan Procedure/methods , Pulmonary Artery/surgery , Models, Animal , Heart Atria/surgery , Stem Cells , Treatment Outcome , Heart Defects, Congenital/surgeryABSTRACT
BACKGROUND: CD44 and CD133 are stem cell markers in colorectal cancer (CRC). CD44 has distinctive isoforms with different oncological properties like total CD44 (CD44T) and variant CD44 (CD44V). Clinical significance of such markers remains elusive. METHODS: Sixty colon cancer were examined for CD44T/CD44V and CD133 at mRNA level in a quantitative PCR, and clarified for their association with clinicopathological factors. RESULTS: (1) Both CD44T and CD44V showed higher expression in primary colon tumors than in non-cancerous mucosas (p<0.0001), while CD133 was expressed even in non-cancerous mucosa and rather decreased in the tumors (p = 0.048). (2) CD44V expression was significantly associated with CD44T expression (R = 0.62, p<0.0001), while they were not correlated to CD133 at all in the primary tumors. (3) CD44V/CD44T expressions were significantly higher in right colon cancer than in left colon cancer (p = 0.035/p = 0.012, respectively), while CD133 expression were not (p = 0.20). (4) In primary tumors, unexpectedly, CD44V/CD44T/CD133 mRNA expressions were not correlated with aggressive phenotypes, but CD44V/CD44T rather significantly with less aggressive lymph node metastasis/distant metastasis (p = 0.040/p = 0.039, respectively). Moreover, both CD44V and CD133 expressions were significantly decreased in liver metastasis as compared to primary tumors (p = 0.0005 and p = 0.0006, respectively). CONCLUSION: Our transcript expression analysis of cancer stem cell markers did not conclude that their expression could represent aggressive phenotypes of primary and metastatic tumors, and rather represented less demand on stem cell marker-positive cancer cells.
Subject(s)
Colonic Neoplasms , Liver Neoplasms , Humans , Hyaluronan Receptors/genetics , Hyaluronan Receptors/metabolism , Colonic Neoplasms/pathology , Protein Isoforms/genetics , Neoplastic Stem Cells/metabolism , Liver Neoplasms/pathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , AC133 Antigen/genetics , AC133 Antigen/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolismABSTRACT
BACKGROUND/AIM: Invariant natural killer T (iNKT) cells are involved in the initiation and resolution of inflammatory responses. We previously reported that activated iNKT cells facilitate liver repair after hepatic ischemia reperfusion (I/R) injury by accelerating macrophage polarization during the early phase of hepatic I/R injury. Upon activation with α-galactosylceramide (α-GalCer), iNKT cell numbers transiently decrease before increasing within 72 h of stimulation. In the present study, we examined the role of expanded hepatic iNKT cells in the late phase of hepatic I/R injury. MATERIALS AND METHODS: iNKT cells were activated by intraperitoneal injection of α-GalCer in male C57/BL6 mice at the induction of hepatic ischemia followed by reperfusion. RESULTS: Numbers of activated hepatic iNKT cells immediately diminished after hepatic I/R and reached minimal levels at 24 h and 48 h post-reperfusion. Numbers of hepatic iNKT cells then increased at 72 h and 96 h post-reperfusion to levels approximately 2-fold higher than in mice that underwent a sham operation. Liver repair as demonstrated by decreased necrotic area and increased expression of proliferating cell nuclear antigen (PCNA) was enhanced in α-GalCer-treated mice at 96 h post-reperfusion. Interleukin (IL)-13 production by proliferating iNKT cells was observed at 96 h post-reperfusion, which was associated with enhanced liver repair and increased numbers of reparative macrophages. CONCLUSION: Repopulation of hepatic iNKT cells promotes liver repair by stimulating macrophage phenotype switching in the late phase of hepatic I/R injury.
Subject(s)
Natural Killer T-Cells , Reperfusion Injury , Male , Mice , Animals , Natural Killer T-Cells/metabolism , Mice, Inbred C57BL , Liver/metabolism , Reperfusion Injury/metabolism , IschemiaABSTRACT
INTRODUCTION: Whether rectal cancer surgery by robotic-assisted laparoscopic surgery provides beneficial advantages remains controversial. Although favorable outcomes in terms of the safety and technical feasibility of robotic-assisted laparoscopic surgery have been demonstrated for rectal cancer, long-term oncological outcomes for robotic-assisted laparoscopic surgery have only been examined in a few studies. This retrospective study of subjects who underwent robotic-assisted laparoscopic surgery evaluated short- and long-term outcomes of consecutive rectal cancer patients. METHODS: Between November 2016 and January 2020, we analyzed the records of 62 consecutive patients who underwent robotic-assisted laparoscopic surgery for rectal adenocarcinoma without distant metastasis to evaluate short- and long-term outcomes. RESULTS: Tumors were located in the lower or mid-rectum (88.7%) in most patients. The median operative time was 357 min. No patient received transfusions, and the median blood loss was 10.5 ml. Open laparotomy was not required in any patient. A Clavien-Dindo classification of all grades was observed in 12 patients (19.4%). Positive radial margin was not observed in any patient. Duration of median follow-up was 40.5 mo, while 3-y overall survival and 3-y relapse-free survival rates were 96.8% and 85.0%, respectively. The local recurrence rate was 3.4%. CONCLUSION: Favorable short- and long-term outcomes demonstrated robotic-assisted laparoscopic surgery was safe and technically feasible for rectal cancer.
Subject(s)
Laparoscopy , Rectal Neoplasms , Robotic Surgical Procedures , Humans , Laparoscopy/adverse effects , Neoplasm Recurrence, Local/epidemiology , Neoplasm Recurrence, Local/surgery , Rectal Neoplasms/pathology , Rectal Neoplasms/surgery , Retrospective Studies , Robotic Surgical Procedures/adverse effects , Treatment OutcomeABSTRACT
INTRODUCTION: The advantages of robotic-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short-term outcomes of RALS for rectal cancer with those of conventional laparoscopic surgery (CLS). METHODS: The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score-matched analysis. After matching, 188 patients were enrolled in our study to compare short-term outcomes, such as operative results, postoperative complications, and pathological findings, in each group. RESULTS: After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p < 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p < 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested. CONCLUSION: Robotic-assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short-term outcomes. Further studies are required to validate long-term oncological outcomes.
Subject(s)
Laparoscopy , Rectal Neoplasms , Robotic Surgical Procedures , Humans , Laparoscopy/methods , Postoperative Complications/etiology , Propensity Score , Rectal Neoplasms/pathology , Retrospective Studies , Robotic Surgical Procedures/methods , Treatment OutcomeABSTRACT
Chylothorax is a critical complication after surgery for congenital heart disease, which markedly compromises the postoperative course with increased mortality. As the cardiovascular load additively causes stagnation of the thoracic duct, chylothorax after palliative cardiac surgery can be highly refractory to the therapies. Here we report a case of two patients with refractory chylothorax attributed to hemodynamic load which was successfully treated with minocycline pleurodesis. In combination with congenital heart disease, extremely low birth weight coupled with prematurity in case 1 and venous obstruction with excessive volume load due to additional aortopulmonary shunt in case 2 additively increased resistance to the therapies, including fasting with total parenteral nutrition (TPN), XIII factor supplementation, octreotide infusion, as well as the use of steroids. As pleural effusion was sustained at more than 50 ml/kg/day, the condition of both patients deteriorated severely; pleurodesis using minocycline was urgently introduced. Pleural effusion declined at every session and both cases were in remission in a few sessions without unfavorable acute reaction. No symptoms suspecting chronic adverse effects were observed during follow-up, including respiratory dysfunction, pulmonary hypertension, tooth staining, or abnormal bone mineralization. Although the application of minocycline for children should be minimized, minocycline pleurodesis can be an option for patients with refractory and life-threatening chylothorax.
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We report the case of a 16-year-old boy in whom we successfully repaired a distal aortic arch aneurysm associated with pseudocoarctation using double aortic cannulation and antegrade selective cerebral perfusion through the L-incision approach. This approach provided excellent exposure from the ascending aorta to the descending aorta, which enabled total body perfusion. We avoided cardiac arrest and hypothermic circulatory arrest during the surgery. The L-incision approach could be a better alternative for aortic arch surgery in adolescents.
Subject(s)
Aortic Aneurysm, Thoracic , Aortic Aneurysm , Heart Defects, Congenital , Adolescent , Aorta, Thoracic/diagnostic imaging , Aorta, Thoracic/surgery , Aortic Aneurysm/surgery , Aortic Aneurysm, Thoracic/complications , Aortic Aneurysm, Thoracic/diagnostic imaging , Aortic Aneurysm, Thoracic/surgery , Cerebrovascular Circulation , Circulatory Arrest, Deep Hypothermia Induced , Humans , Male , PerfusionABSTRACT
We describe a seven-month-old boy with tetralogy of Fallot and an absent left pulmonary artery. Due to the diminutive size of the left pulmonary artery, we performed a native tissue left pulmonary artery reconstruction and intrapulmonary artery septation procedure with a left modified Blalock-Taussig shunt. After confirming left pulmonary artery growth, the patient underwent tetralogy of Fallot repair, removal of septation patch, and division of the Blalock-Taussig shunt. Nine months post-surgery, we confirmed his balanced lung perfusion (R/L ratio 6:4). The intrapulmonary artery septation procedure would be suitable for both the resuscitation and reconstruction of the hypoplastic absent pulmonary artery.
Subject(s)
Blalock-Taussig Procedure , Tetralogy of Fallot , Humans , Infant , Male , Pulmonary Artery/diagnostic imaging , Pulmonary Artery/surgery , Tetralogy of Fallot/diagnostic imaging , Tetralogy of Fallot/surgery , Treatment OutcomeABSTRACT
Macrophage polarization is critical for liver tissue repair following acute liver injury. However, the underlying mechanisms of macrophage phenotype switching are not well defined. Invariant natural killer T (iNKT) cells orchestrate tissue inflammation and tissue repair by regulating cytokine production. Herein, we examined whether iNKT cells played an important role in liver repair after hepatic ischemia-reperfusion (I/R) injury by affecting macrophage polarization. To this end, we subjected male C57BL/6 mice to hepatic I/R injury, and mice received an intraperitoneal (ip) injection of α-galactosylceramide (α-GalCer) or vehicle. Compared with that of the vehicle, α-GalCer administration resulted in the promotion of liver repair accompanied by acceleration of macrophage differentiation and by increases in the numbers of Ly6Chigh pro-inflammatory macrophages and Ly6Clow reparative macrophages. iNKT cells activated with α-GalCer produced interleukin (IL)-4 and interferon (IFN)-γ. Treatment with anti-IL-4 antibodies delayed liver repair, which was associated with an increased number of Ly6Chigh macrophages and a decreased number of Ly6Clow macrophages. Treatment with anti-IFN-γ antibodies promoted liver repair, associated with reduced the number of Ly6Chigh macrophages, but did not change the number of Ly6Clow macrophages. Bone marrow-derived macrophages up-regulated the expression of genes related to both a pro-inflammatory and a reparative phenotype when co-cultured with activated iNKT cells. Anti-IL-4 antibodies increased the levels of pro-inflammatory macrophage-related genes and decreased those of reparative macrophage-related genes in cultured macrophages, while anti-IFN-γ antibodies reversed the polarization of macrophages. Cd1d-deficient mice showed delayed liver repair and suppressed macrophage switching, compared with that in wild-type mice. These results suggest that the activation of iNKT cells by α-GalCer facilitated liver repair after hepatic I/R injury by both IL-4-and IFN-γ-mediated acceleration of macrophage polarization. Therefore, the activation of iNKT cells may represent a therapeutic tool for liver repair after hepatic I/R injury.
Subject(s)
Galactosylceramides/pharmacology , Liver Regeneration/physiology , Liver/immunology , Macrophage Activation , Natural Killer T-Cells/immunology , Animals , Antigens, CD1d/genetics , Antigens, CD1d/immunology , Cells, Cultured , Coculture Techniques , Interferon-gamma/antagonists & inhibitors , Interferon-gamma/biosynthesis , Interleukin-4/antagonists & inhibitors , Interleukin-4/biosynthesis , Liver/blood supply , Liver Regeneration/immunology , Lymphocyte Activation/drug effects , Macrophages/classification , Macrophages/immunology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Natural Killer T-Cells/drug effects , Natural Killer T-Cells/metabolism , Reperfusion InjuryABSTRACT
BACKGROUND/AIM: Although the pathology of sinusoidal obstruction syndrome (SOS) is characterized by damage to liver sinusoidal endothelial cells (LSECs), the processes underlying LSEC repair are incompletely understood. The angiopoietin (Ang)/Tie system contributes to angiogenesis. The present study aimed to examine the processes of LSEC repair and the involvement of the Ang/Tie pathway in LSEC recovery. MATERIALS AND METHODS: Experimentally, SOS was induced by intraperitoneal injection of monocrotaline (MCT) to C57/BL6 mice. RESULTS: Levels of LSEC markers were up-regulated during the repair phase of MCT-induced hepatotoxicity. The damaged LSECs recovered from the injury by expanding LSECs expressing lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) in the peri-central area of MCT-injured livers, while LSECs in the same area of uninjured livers lacked LYVE-1 expression. Bone marrow (BM)-derived cells did not incorporate into the restored LSECs. Tie2 expression was related to LSEC recovery in MCT-injured liver tissue. CONCLUSION: The resident LSECs neighboring uninjured tissue replace damaged LSECs in MCT-injured livers. Tie2 is involved in LSEC recovery from MCT-induced hepatotoxicity.
Subject(s)
Chemical and Drug Induced Liver Injury, Chronic , Monocrotaline , Animals , Endothelial Cells , Hepatocytes , Liver , Mice , Monocrotaline/toxicityABSTRACT
Proximal aortic clamping under normothermia is generally adequate for operative repair of abdominal aortic rupture; however, the hypothermic circulatory arrest (HCA) technique is not as common. Proximal exposure and clamping are sometimes difficult due to the risk of bleeding, rerupture, and ischemia. We present a successful case of a ruptured abdominal aortic aneurysm (AAA) that was repaired using cardiopulmonary bypass with HCA. A 75-year-old man presented with sudden back pain and was diagnosed with a ruptured AAA using computed tomography. The aneurysm had a maximal diameter of 100 mm and protruded anteriorly just below the renal arteries. The rupture site was close to the renal arteries, and thus, there was a high risk of bleeding and shock during proximal exposure. Cardiopulmonary bypass was established by cannulation of the right axillary artery and right femoral vein, following which open laparotomy was performed. Proximal exposure and anastomosis could be safely performed using HCA. This cardiopulmonary bypass with HCA technique may be useful as a surgical strategy for ruptured juxta-renal AAAs.
Subject(s)
Aortic Aneurysm, Abdominal/surgery , Aortic Rupture/surgery , Blood Vessel Prosthesis Implantation , Circulatory Arrest, Deep Hypothermia Induced , Aged , Anastomosis, Surgical , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Rupture/diagnostic imaging , Cardiopulmonary Bypass , Humans , Ligation , Male , Treatment OutcomeABSTRACT
The right internal thoracic artery to the right coronary artery bypass with ligation of the proximal native vessel is a simple and reliable option for the treatment of an anomalous aortic origin of the right coronary artery arising from the left sinus of Valsalva without an intramural course. Coronary artery bypass grafting is an uncomplicated option for elderly patients, those with connective tissue diseases, and those for whom combined aortic valve procedures are planned. Herein, we present four cases of this anomaly that underwent right internal thoracic artery anastomosis to the distal right coronary artery along with proximal right coronary artery ligation using a surgical clip. There was no occurrence of complications such as hypoperfusion syndrome, graft occlusion, recurrent symptoms, or late cardiac events.
Subject(s)
Coronary Vessel Anomalies , Mammary Arteries , Aged , Aorta , Coronary Angiography , Coronary Artery Bypass , Coronary Vessel Anomalies/diagnostic imaging , Coronary Vessel Anomalies/surgery , HumansABSTRACT
PURPOSE: To demonstrate how artificial intelligence (AI) can expand radiologists' capacity, we visualized the features of invasive ductal carcinomas (IDCs) that our algorithm, developed and validated for basic pathological classification on mammograms, had focused on. MATERIALS AND METHODS: IDC datasets were built using mammograms from patients diagnosed with IDCs from January 2006 to December 2017. The developing dataset was used to train and validate a VGG-16 deep learning (DL) network. The true positives (TPs) and accuracy of the algorithm were externally evaluated using the test dataset. A visualization technique was applied to the algorithm to determine which malignant findings on mammograms were revealed. RESULTS: The datasets were split into a developing dataset (988 images) and a test dataset (131 images). The proposed algorithm diagnosed 62 TPs with an accuracy of 0.61-0.70. The visualization of features on the mammograms revealed that the tubule forming, solid, and scirrhous types of IDCs exhibited visible features on the surroundings, corners of the masses, and architectural distortions, respectively. CONCLUSION: We successfully showed that features isolated by a DL-based algorithm trained to classify IDCs were indeed those known to be associated with each pathology. Thus, using AI can expand the capacity of radiologists through the discovery of previously unknown findings.
Subject(s)
Algorithms , Breast Neoplasms/diagnostic imaging , Carcinoma, Ductal, Breast/diagnostic imaging , Deep Learning , Mammography/methods , Adult , Aged , Aged, 80 and over , Breast Neoplasms/classification , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/classification , Carcinoma, Ductal, Breast/pathology , Female , Humans , Middle AgedABSTRACT
Bovine jugular vein (BJV) and expanded polytetrafluoroethylene (ePTFE) conduits have been described as alternatives to the homograft for right ventricular outflow tract (RVOT) reconstruction. This study compared RVOT reconstructions using BJV and ePTFE conduits performed in a single institution. The valve functions and outcomes of patients aged < 18 years who underwent primary RVOT reconstruction with a BJV or ePTFE conduit between 2013 and 2017 were retrospectively investigated. 44 patients (20 and 24 with BJV and ePTFE conduits, respectively) met the inclusion criteria. The mean follow-up time was 4.5 ± 1.5 years. No significant differences in peak RVOT velocity (1.8 ± 0.9 m/s vs 2.1 ± 0.9 m/s, P = 0.27), branch pulmonary stenosis (P = 0.50), or pulmonary regurgitation (P = 0.44) were found between the BJV and ePTFE conduit groups, respectively. Aneurysmal dilatation of the conduit was observed in 25.0% of the patients in the BJV conduit group but not in the ePTFE conduit group (P = 0.011). All the cases with aneurysmal dilatation of the BJV conduit were complicated with branch pulmonary stenosis up to 3.0 m/s (P = 0.004). No conduit infections occurred during the follow-up period, and no significant difference in conduit replacement (20.0% vs 8.3%, P = 0.43) was found between the BJV and ePTFE conduit groups, respectively. The outcomes of the RVOT reconstructions with BJV and ePTFE conduits were clinically satisfactory. Aneurysmal dilatation was found in the BJV conduit cases, with branch pulmonary stenosis as the risk factor.
Subject(s)
Heart Valve Prosthesis Implantation/instrumentation , Jugular Veins/transplantation , Plastic Surgery Procedures/methods , Polytetrafluoroethylene/therapeutic use , Ventricular Outflow Obstruction/surgery , Adolescent , Animals , Bioprosthesis/adverse effects , Cattle , Child , Child, Preschool , Female , Heart Valve Prosthesis/adverse effects , Heart Valve Prosthesis Implantation/adverse effects , Heart Valve Prosthesis Implantation/methods , Heart Ventricles/surgery , Humans , Infant , Male , Prosthesis Design , Pulmonary Valve Insufficiency/epidemiology , Pulmonary Valve Stenosis/epidemiology , Retrospective Studies , Time Factors , Treatment OutcomeABSTRACT
In donation after circulatory death heart transplantation, the donor heart is exposed to circulatory load. The right ventricle, due to its structure, has high compliance for volume load but is particularly vulnerable to increased pressure load. This study used a porcine model to conduct a functional assessment of the hemodynamics of the heart, with a focus on the right ventricle. Six pigs weighing 24.6 ± 1.4 kg were used. Circulatory death was induced by asphyxiation after median sternotomy. After 30 minutes in the state of global warm ischemia, the ascending aorta was clamped, followed by a 20-minute reperfusion of the heart with a 20°C blood cardioplegia solution. Systemic circulation was established by cardiopulmonary bypass after aortic cross-clamping. After initial reperfusion, the blood cardioplegia solution was replaced with blood. The blood was then rewarmed while the heart was still in a non-working state. Cardiac function was assessed twice in situ, first by the thermodilution method, and then, by the pressure-volume measurement both at preischemia and at three hours after initiation of reperfusion. The recovery rate of cardiac output was 75%. End-systolic elastance (P = .02) and pulmonary arterial elastance significantly increased (P = .03), but the ratio of arterial elastance to end-systolic elastance was preserved (P = .91) in the right ventricle. Despite a decrease in cardiac output after reperfusion from warm ischemia, the right ventricle had a potential to respond the elevated afterload. It is important that donations after circulatory death heart transplantation should be performed with attention to avoiding right ventricular distension.
Subject(s)
Heart Transplantation/methods , Heart Ventricles/physiopathology , Tissue and Organ Harvesting/methods , Warm Ischemia/adverse effects , Animals , Cardiac Output/physiology , Cardiopulmonary Bypass/methods , Female , Hemodynamics/physiology , Models, Animal , Organ Preservation/methods , Reperfusion/methods , Sus scrofa , Tissue DonorsABSTRACT
Destruction of liver sinusoidal endothelial cells (LSECs) is an initial event in sinusoidal obstruction syndrome (SOS) that leads to accumulation of platelets in the liver. Herein, we explored the role of platelets during progression of experimental SOS induced by monocrotaline (MCT) in mice. Depletion of platelets using an anti-CD41 antibody or anti-thrombocyte serum exacerbated MCT-induced liver injury in C57BL/6 mice, as indicated by an increase in the alanine transaminase (ALT) level, which was associated with hemorrhagic necrosis. Thrombocytosis induced by thrombopoietin (TPO) or the TPO receptor agonist romiplostim (ROM) attenuated MCT-induced liver injury, as evidenced by lower levels of ALT and mRNA encoding matrix metalloproteinase (MMP) 9, and higher levels of mRNA encoding vascular endothelial growth factor receptor (VEGFR) 2 and VEGFR3. The level of activated hepatic platelets was higher in TPO- and ROM-treated mice than in saline-treated mice. Co-culture with a high number of platelets increased the viability of LSECs and their mRNA levels of CD31, VEGFR2, and VEGFR3, and decreased their mRNA level of MMP9. The level of VEGF-A was increased in the culture medium of LSECs co-cultured with platelets. These results indicate that platelets attenuate MCT-induced liver injury by minimizing damage to LSECs.
Subject(s)
Blood Platelets/drug effects , Chemical and Drug Induced Liver Injury, Chronic/blood , Hepatic Veno-Occlusive Disease/blood , Hepatic Veno-Occlusive Disease/chemically induced , Monocrotaline/toxicity , Thrombocytosis/blood , Animals , Blood Platelets/cytology , Cell Survival/drug effects , Chemical and Drug Induced Liver Injury, Chronic/prevention & control , Coculture Techniques , Endothelial Cells/drug effects , Endothelial Cells/pathology , Hepatic Veno-Occlusive Disease/prevention & control , Liver Function Tests , Male , Mice, Inbred C57BL , Platelet Count , Receptors, Fc , Receptors, Thrombopoietin/agonists , Recombinant Fusion Proteins/pharmacology , Thrombocytosis/chemically induced , Thrombopoietin/pharmacologyABSTRACT
Hepatic tissue repair plays a critical role in determining the outcome of hepatic ischemia-reperfusion (I/R) injury. Hepatic lymphatics participate in the clearance of dead tissues and contribute to the reparative process after acute hepatic injury; however, it remains unknown whether lymphangiogenesis in response to hepatic inflammation is involved in liver repair. Herein, we determined if hepatic lymphangiogenesis improves liver repair after hepatic I/R injury. Using a mouse model of hepatic I/R injury, we investigated hepatic lymphatic structure, growth, and function in injured murine livers. Hepatic I/R injury enhanced lymphangiogenesis around the portal tract and this was associated with increased expression of pro-lymphangiogenic growth factors including vascular endothelial growth factor (VEGF)-C and VEGF-D. Recombinant VEGF-D treatment facilitated liver repair in association with the expansion of lymphatic vessels and increased expression of genes related to the reparative macrophage phenotype. Treatment with a VEGF receptor 3 (VEGFR3) inhibitor suppressed liver repair, lymphangiogenesis, drainage function, and accumulation of VEGFR3-expressing reparative macrophages. VEGF-C and VEGF-D upregulated expression of genes related to lymphangiogenic factors and the reparative macrophage phenotype in cultured macrophages. These results suggest that activation of VEGFR3 signaling increases lymphangiogenesis and the number of reparative macrophages, both of which play roles in liver repair. Expanded lymphatics and induction of reparative macrophage accumulation may be therapeutic targets to enhance liver repair after hepatic injury.
Subject(s)
Liver Diseases/metabolism , Liver Regeneration , Liver/metabolism , Lymphangiogenesis , Macrophages/metabolism , Reperfusion Injury/metabolism , Animals , Liver/pathology , Liver Diseases/pathology , Macrophages/pathology , Male , Mice , Reperfusion Injury/pathology , Vascular Endothelial Growth Factor C/metabolism , Vascular Endothelial Growth Factor D/metabolism , Vascular Endothelial Growth Factor Receptor-3/metabolismABSTRACT
Macrophage plasticity is essential for liver wound healing; however, the mechanisms underlying macrophage phenotype switching are largely unknown. Dendritic cells (DCs) are critical initiators of innate immune responses; as such, they orchestrate inflammation following hepatic injury. Here, we subjected EP3-deficient (Ptger3-/- ) and wild-type (WT) mice to hepatic ischemia-reperfusion (I/R) and demonstrate that signaling via the prostaglandin E (PGE) receptor EP3 in DCs regulates macrophage plasticity during liver repair. Compared with WT mice, Ptger3-/- mice showed delayed liver repair accompanied by reduced expression of hepatic growth factors and accumulation of Ly6Clow reparative macrophages and monocyte-derived DCs (moDCs). MoDCs were recruited to the boundary between damaged and undamaged liver tissue in an EP3-dependent manner. Adoptive transfer of moDCs from Ptger3-/- mice resulted in impaired repair, along with increased numbers of Ly6Chigh inflammatory macrophages. Bone marrow macrophages (BMMs) up-regulated expression of genes related to a reparative macrophage phenotype when co-cultured with moDCs; this phenomenon was dependent on EP3 signaling. In the presence of an EP3 agonist, interleukin (IL)-13 derived from moDCs drove BMMs to increase expression of genes characteristic of a reparative macrophage phenotype. The results suggest that EP3 signaling in moDCs facilitates liver repair by inducing IL-13-mediated switching of macrophage phenotype from pro-inflammatory to pro-reparative.