Lobectomy Provides the Best Survival for Stage I Lung Cancer Patients Despite Advanced Age.

BACKGROUND: The Lung Cancer Study Group has shown that lobectomy provides the best survival in patients with non-small cell lung cancer. However, as patients become older, lobectomy may not provide a survival advantage compared with sublobar resection. METHODS: We analyzed the National Cancer Database for octogenarians with pathologic stage I lung cancer from 2004 to 2016. We then evaluated the patients who underwent lobectomy or sublobar (segmentectomy or wedge) resection for the treatment of cancer. We analyzed the 5-year survival rates of the groups as well as a cubic spline plot to determine age cutoffs where lobectomy does not provide improved survival. RESULTS: Among the octogenarians (227 134), there were 25 362 (26%) who had pathologic stage I lung cancer. There were 6370 (30%) patients who had sublobar resections (segmentectomy [n = 1192] and wedge resection [n = 5178]), whereas 14 594 (70%) patients had a lobectomy. There was significantly improved survival at 5 years with lobectomy compared with sublobar resection (48.5% vs 41.1%; P < .001). The cubic spline plot provided evidence that there was no age at which sublobar resection provided survival better than or equal to lobectomy (P < .001). CONCLUSIONS: In octogenarians with pathologic stage I lung cancer, lobectomy provided better 5-year survival compared with sublobar resection regardless of the age at surgical procedure. Hence, all patients with stage I cancer should be considered for a lobectomy if they are medically able to tolerate such a procedure.

Intraoperative diagnosis and treatment of Achalasia using EndoFLIP during Heller Myotomy and Dor fundoplication.

BACKGROUND: Manometry is the gold standard diagnostic test for achalasia. However, there are incidences where manometry cannot be obtained preoperatively, or the results of manometry is inconsistent with the patient's symptomatology. We aim to determine if intraoperative use of EndoFLIP can provide a diagnosis of achalasia and provide objective information during Heller myotomy and Dor fundoplication. METHODS: To determine the intraoperative diagnostic EndoFLIP values for patients with achalasia, we determined the optimal cut-off points of the distensibility index (DI) between patients with a diagnosis of achalasia and patients with a diagnosis of hiatal hernia. To evaluate the usefulness of EndoFLIP values during Heller myotomy and Dor fundoplication, we obtained a cohort of patients with EndoFLIP values obtained after Heller myotomy and after Dor fundoplication as well as Eckardt score before and after surgery. RESULTS: Our analysis of 169 patients (133 hiatal hernia and 36 achalasia) showed that patients with DI < 0.8 have a >99% probability of having achalasia, while DI > 2.3 have a >99% probability of having hiatal hernia. Patients with a DI 0.8-1.3 have a 95% probability of having achalasia, and patients with a DI of 1.4-2.2 have a 94% probability of having a hiatal hernia. There were 40 patients in the cohort to determine objective data during Heller myotomy and Dor fundoplication. The DI increased from a median of 0.7 to 3.2 after myotomy and decreased to 2.2 after Dor fundoplication (p < 0.001). The median Eckardt score went down from a median of 4.5 to 0 (p < 0.001). CONCLUSIONS: Our study shows that intraoperative use of EndoFLIP can facilitate the diagnosis of achalasia and is used as an adjunct to diagnose achalasia when symptoms are inconsistent. The routine use of EndoFLIP during Heller myotomy and Dor fundoplication provides objective data during the operation in a group of patients with excellent short-term outcomes.

Surgical Cardiac Sympathetic Denervation for Ventricular Arrhythmias: A Systematic Review.

Ventricular arrhythmias are potentially life-threatening disorders that are commonly treated with medications, catheter ablation and implantable cardioverter defibrillator (ICD). Adult patients who continue to be symptomatic, with frequent ventricular arrhythmia cardiac events or defibrillation from ICD despite medical treatment, are a challenging subgroup to manage. Surgical cardiac sympathetic denervation has emerged as a possible treatment option for people refractory to less invasive medical options. Recent treatment guidelines have recommendedcardiac sympathectomy for ventricular tachycardia (VT) or VT/fibrillation storm refractory to antiarrhythmic medications, long QT syndrome, and catecholaminergic polymorphic VT, with much of the data pertaining to pediatric literature. However, for the adult population, the disease indications, complications, and risks of cardiac sympathectomy are less understood, as are the most effective surgical cardiac denervation techniques for this patient demographic. This systematic review navigates available literature evaluating surgical denervation disease state indications, techniques, and sympathectomy risks for medically refractory ventricular arrhythmia in the adult patient population.

Impact of da Vinci Xi robot in pulmonary resection.

BACKGROUND: This study sought to evaluate the impact of a da Vinci Xi surgical robot on perioperative outcomes after pulmonary resections. METHODS: A retrospective analysis of prospectively collected STS data was performed at a single institution for patients who underwent elective lung resections from 2012 to 2019. Patient outcomes were compared at three different time periods: before the adoption of the robot technology (predominately VATS), during the initial robot experience (the first 18 months), and after the mature robot experience (the second 18 months). Univariate and multivariate logistic regression modeling was performed to determine the factors associated with perioperative complications. RESULTS: Five hundred and four patients underwent pulmonary resection between the three time periods: 220 patients (43.7%) had surgery prior to the first use of the robot (predominately VATS), 126 patients (25%) had surgery during the initial experience with robot, and 158 patients (31.1%) had surgery during the mature robot experience. There were significantly less post-operative complications (15.2% vs. 34.9% vs. 39.1%, P<0.001), shorter median length of stay (2 vs. 3 vs. 4 days, P<0.001), and lower hospital readmission rates (1.9% vs. 4% vs. 11.8%, P<0.001) in the mature robot period compared to the initial robot period and the predominately VATS period, respectively. Multivariate analysis showed that the robot was associated with a decrease in post-operative complications (OR 0.36; 95% CI, 0.23-0.57, P<0.001). CONCLUSIONS: The adoption of a da Vinci Xi robot in our institution was associated with improved outcomes in patients having pulmonary resections.

Robot-assisted hiatal hernia repair demonstrates favorable short-term outcomes compared to laparoscopic hiatal hernia repair.

BACKGROUND: We postulated that the use of robotics may improve outcomes in hiatal hernia repair. METHODS: We performed a retrospective analysis of a prospectively collected Society of Thoracic Surgery database at a single institution of patients who underwent elective hiatal hernia repair from 2012 to 2017 using either laparoscopy or the da Vinci Xi robot. We compared patient characteristics and outcomes and then performed univariate and multivariate logistic regression modeling to determine the factors associated with postoperative morbidity. RESULTS: There were 293 consecutive patients who underwent elective hiatal hernia repair using either a laparoscopic (n = 151) or a robotic (n = 142) technique. There were no significant differences in age, gender, BMI, smoking history, presence of comorbidity, or hiatal hernia type. Seventy percent of the cases were a repair of either type III or type IV hiatal hernia. There were significantly higher ASA III and IV (7.9% vs. 4.2%, P = 0.03), higher Toupet fundoplication (83.4% vs. 44.4%, P < 0.001), and lower redo-repair (7.3% vs. 20.4%, P = 0.001) in the laparoscopic group compared to the robotic group. The hospital length of stay was significantly shorter (1.3 ± 1.8 vs. 1.8 ± 1.5 days, P = 0.003) and there were significantly lower rates of complications (6.3 vs. 19.2%, P = 0.001) after robotic compared to laparoscopic hiatal hernia repair. There was no difference in readmission rate and mortality. Multiple logistic regression analysis showed that older age and laparoscopic technique were associated with higher complications after surgery. CONCLUSION: The use of the Da Vinci Xi robot in our institution was associated with improved outcomes compared to laparoscopic hiatal hernia repair despite a higher incidence of re-operative cases in the robotic group. Thus, short-term outcomes of Da Vinci Xi robot-assisted hiatal hernia repair are not inferior to laparoscopic hiatal hernia repair. Further studies are needed to determine if Da Vinci Xi robot provides superior short-term and long-term outcome in treatment of symptomatic hiatal hernia.

Adjuvant Therapy for Node-Positive Esophageal Cancer After Induction and Surgery: A Multisite Study.

BACKGROUND: The benefit of adjuvant treatment for esophageal cancer patients with positive lymph nodes after induction therapy and esophagectomy is uncertain. This in-depth multicenter study assessed the benefit of adjuvant therapy in this population. METHODS: A retrospective cohort study from 9 institutions included patients who received neoadjuvant treatment, underwent esophagectomy from 2000 to 2014, and had positive lymph nodes on pathology. Factors associated with administration of adjuvant therapy were assessed using multilevel random-intercept modeling to account for institutional variation in practice. Kaplan-Meier analyses were performed based on adjuvant treatment status. Variables associated with survival were identified using Cox proportional hazards modeling. RESULTS: The study analyzed 1082 patients with node-positive cancer after induction therapy and esophagectomy: 209 (19.3%) received adjuvant therapy and 873 (80.7%) did not. Administration of adjuvant treatment varied significantly from 3.2% to 50.0% between sites (P < .001). Accounting for institution effect, factors associated with administration of adjuvant therapy included clinically positive and negative prognostic characteristics: younger age, higher pathologic stage, pathologic grade, no neoadjuvant radiotherapy nonsmoking status, and absence of postoperative infection. Kaplan-Meier analysis showed patients receiving adjuvant therapy had a longer median survival of 2.6 years vs 2.3 years (P = .02). Cox modeling identified adjuvant treatment as independently associated with improved survival, with a 24% reduction in mortality (hazard ratio, 0.76; P = .005). CONCLUSIONS: Adjuvant therapy was associated with improved overall survival. Therefore, consideration should be given to administration of adjuvant therapy to esophageal cancer patients who have persistent node-positive disease after induction therapy and esophagectomy and are able to tolerate additional treatment.

Hospitalization Costs After Surgery in High-Risk Patients With Early Stage Lung Cancer.

BACKGROUND: We previously reported that early stage lung cancer patients who are considered high risk for surgery can undergo resection with favorable perioperative results and long-term mortality. To further elucidate the role of surgical resection in this patient cohort, this study evaluated the length of stay and total hospitalization cost among patients classified as standard or high risk with early stage lung cancer who underwent pulmonary resection. METHODS: A total of 490 patients from our institutional Society of Thoracic Surgeons data from 2009 to 2013 underwent resection for clinical stage I lung cancer. High-risk patients were identified by American College of Surgeons Oncology Group z4032-z4099 criteria. Demographics, length of stay, and hospitalization cost between high-risk and standard-risk patients undergoing lobectomy and sublobar resection were compared. Univariate analysis was performed using the chi-square test or Fisher's exact test. Multivariate analysis was performed using a linear regressions model. RESULTS: A total of 180 (37%) of patients were classified as high risk. These patients were older (70 years of age vs. 65 years of age; p < 0.0001), had worse forced expiratory volume in 1 second (57% vs. 85%; p < 0.0001), and had worse diffusion capacity of carbon dioxide (47% vs. 77%; p < 0.0001). The baseline cost and length of stay was represented by a thoracoscopic wedge resection in a standard-risk patient. A larger extent of resection, thoracotomy, or high-risk classification increased the cost and length of stay. CONCLUSIONS: Our previous study showed that good clinical outcomes after surgery for early stage lung cancer can be achieved in patients classified as high risk. In this study, although surgery in high-risk patients led to slightly increased costs, these costs seemed negligible when viewed along with the patients' excellent short-term and long-term results. This study suggests that surgical resection on high-risk patients with early stage lung cancer is associated with acceptable hospital lengths of stay and overall cost when compared with standard-risk patients.

Laparoscopic Approach for Treatment of Symptomatic Intra-Pericardial Cyst.

Symptomatic pericardial cysts requiring operative management are rare entities. We present a patient with a symptomatic intra-pericardial cystic lesion with intermittent syncope who underwent treatment using a laparoscopic approach, thus minimizing pain and allowing quick recovery.

Fibronectin from alpha 1,3-galactosyltransferase knockout pigs is a xenoantigen.

BACKGROUND: Antibody-mediated rejection continues to be an obstacle for xenotransplantation despite development of α1,3-galactosyltransferase knockout (GTKO) pigs. Fibronectin (Fn) from GTKO pigs was identified as a xenoantigen in baboons. N-glycolylneuraminic acid (Neu5Gc), similar to galactose α1,3-galactose, is an antigenic carbohydrate found in pigs. We evaluated human antibody reactivity and performed initial antigenic epitope characterization of Fn from GTKO pigs. MATERIALS AND METHODS: GTKO pig aortic endothelial cells (AEC) were isolated and assessed for antibody-mediated complement-dependent cytotoxicity (CDC). Human and GTKO pig Fn were purified and analyzed using immunoblots. GTKO pig and human AEC absorbed human sera were assessed for CDC and anti-GTKO pig Fn antibodies. GTKO pig proteins were assessed for Neu5Gc. Immunoaffinity-purified human IgG anti-GTKO pig (hIgG-GTKOp) Fn using a GTKO pig Fn column were evaluated for cross-reactivity with other proteins. RESULTS: GTKO pig AEC had greater human antibody binding, complement deposition and CDC compared with allogeneic human AEC. Human sera absorbed with GTKO pig AEC resulted in diminished anti-GTKO pig Fn antibody. Neu5Gc was identified on GTKO pig Fn and other proteins. The hIgG-GTKOp Fn cross-reacted with multiple GTKO pig proteins and was enriched with anti-Neu5Gc antibody. CONCLUSIONS: Removal of antigenic epitopes from GTKO pig AEC would improve xenograft compatibility. GTKO pig Fn has antigenic epitopes, one identified as Neu5Gc, which may be responsible for pathology and cross-reactivity of hIgG-GTKOp Fn. Genetic knockout of Neu5Gc appears necessary to address significance and identification of non-Neu5Gc GTKO pig Fn antigenic epitopes.

Double knockout pigs deficient in N-glycolylneuraminic acid and galactose α-1,3-galactose reduce the humoral barrier to xenotransplantation.

BACKGROUND: Clinical xenotransplantation is not possible because humans possess antibodies that recognize antigens on the surface of pig cells. Galα-1,3-Gal (Gal) and N-glycolylneuraminic acid (Neu5Gc) are two known xenoantigens. METHODS: We report the homozygous disruption of the α1, 3-galactosyltransferase (GGTA1) and the cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) genes in liver-derived female pig cells using zinc-finger nucleases (ZFNs). Somatic cell nuclear transfer (SCNT) was used to produce healthy cloned piglets from the genetically modified liver cells. Antibody-binding and antibody-mediated complement-dependent cytotoxicity assays were used to examine the immunoreactivity of pig cells deficient in Neu5Gc and Gal. RESULTS: This approach enabled rapid production of a pig strain deficient in multiple genes without extensive breeding protocols. Immune recognition studies showed that pigs lacking both CMAH and GGTA1 gene activities reduce the humoral barrier to xenotransplantation, further than pigs lacking only GGTA1. CONCLUSIONS: This technology will accelerate the development of pigs for xenotransplantation research.

Immortalized porcine liver sinusoidal endothelial cells: an in vitro model of xenotransplantation-induced thrombocytopenia.

BACKGROUND: Xenotransplantation has the potential to solve the critical shortage of human organs available for allotransplantation. The major barrier to porcine liver xenotransplantation is sequestration of human platelets causing thrombocytopenia. Porcine liver sinusoidal endothelial cells (LSEC) bind and phagocytose human platelets at least in part through binding of the asialoglycoprotein receptor 1 (ASGR1). Our purpose was to generate an immortalized porcine LSEC (iLSEC) line that mimics primary LSEC in ASGR1 expression and phagocytosis of human platelets. Porcine iLSEC would enable continued study of xenotransplantation-induced thrombocytopenia in vitro with fewer animals sacrificed. METHODS: Primary domestic porcine LSEC were transduced with lentiviral vector expressing the large and small T antigen of SV40 (SV40 TAg). The phenotype and genotype of the immortalized LSEC were compared with primary LSEC. RESULTS: A total of eight clones expressing SV40 TAg were isolated, and one clone was subcultured and analyzed for growth, phenotype, and function during passages 15-40. Expression of the SV40 TAg was confirmed by confocal microscopy and western blot. MTS cell proliferation assay demonstrated that the clone rapidly grew in culture medium with 2-10% fetal bovine serum. iLSEC expressed the endothelial cell marker, CD31, as determined by confocal microscopy and flow cytometry. Activation of iLSEC by treatment with lipopolysaccharide (LPS) resulted in upregulation of the inflammatory cytokine interleukin 6 (IL 6) by qPCR and ELISA. iLSEC phagocytosed human serum albumin and latex beads as measured by flow cytometry. Human platelets were phagocytosed by immortalized porcine LSEC. CONCLUSIONS: Immortalized porcine LSEC retain a phagocytic phenotype, making them a good model for the study of xenotransplantation-induced thrombocytopenia and may provide further insight into the phagocytic role of LSEC.

Identification of human preformed antibody targets in GTKO pigs.

BACKGROUND: Human preformed antibodies continue to recognize porcine xenografts, despite the advent of α-galactosyltransferase knockout (GTKO) pigs. This study examined the potential reactivity of human preformed IgG and IgM antibodies toward antigens in the GTKO pig liver. METHODS: Human serum was analyzed for the concentration of IgG, IgM, anti-αgal antibody, anti-non-αgal antibody and cytotoxicity toward domestic and GTKO fibroblasts and liver sinusoidal endothelial cells (LSEC). We detected preformed antibodies in human serum directed toward GTKO pig liver cells and tissue samples using advanced proteomic techniques. The targets of preformed antibodies were identified by MALDI TOF TOF mass spectrometry and validated by confocal microscopy, immunoblot, and immunoprecipitation. RESULTS: Human serum used in this study contained 2.06 µg/ml IgG and 0.013 µg/ml IgM directed toward GTKO fibroblasts. Human IgG and IgM bound to GTKO LSEC in a dose-dependent manner and were cytotoxic. We detected 357 protein spots recognized by human IgG and 233 by human IgM. Two hundred and nineteen proteins were common to both human IgG and IgM. Mass spectrometry identified numerous immunoreactive proteins, of which 19 were membrane proteins on liver cells. The most significant to this study were α-enolase, CFTR, and E-cadherin, which were abundant in GTKO pig tissues and expressed on the surface of GTKO LSEC. Human IgG captured α-enolase, CFTR, and E-cadherin by immunoprecipitation validating the proteomic identification. CONCLUSION: These experiments indicate that several membrane antigens in GTKO pigs could be recognized directly by human IgG or IgM. Further studies on the contribution of these antigens to antibody-mediated xenograft rejection are necessary.

Differences in human and porcine platelet oligosaccharides may influence phagocytosis by liver sinusoidal cells in vitro.

BACKGROUND: Acute thrombocytopenia was revealed as a limiting factor to porcine liver xenotransplantation from in vitro and in vivo studies using porcine liver in human and baboon transplant models. The asialoglycoprotein receptor 1 (ASGR1) on liver sinusoidal endothelial cells (LSEC) and macrophage antigen complex-1 (Mac-1) on Kupffer cells (KC) mediate platelet phagocytosis and have carbohydrate-binding sites that recognize galactose and N-acetyl glucosamine in the beta conformation. Analysis of these receptor carbohydrate-binding domains and surface carbohydrates on human and porcine platelets may shed light on the mechanism of xenotransplantation-induced thrombocytopenia. METHODS: An amino acid sequence comparison of human and porcine ASGR1 lectin-binding domains was performed. Using fluorescent labeled-lectins, human platelets, domestic and α1,3 galactosyltransferase knockout/human decay accelerating factor, porcine platelets were characterized by flow cytometry and lectin blot analyses. After desialylation, human and porcine platelets were examined by flow cytometry to determine whether sialic acid capping of galactose and N-acetyl glucosamine oligosaccharides in the beta conformation was a factor. Further, desialylated human platelets were studied on primary porcine liver sinusoidal cells with regard to binding and phagocytosis. RESULTS: Human platelets have four times more exposed galactose ß1-4 N-acetyl glucosamine (Galß) and N-acetyl glucosamine ß1-4 N-acetyl glucosamine (ßGlcNAc) than fresh porcine platelets. Galß and ßGlcNAc moieties on porcine platelets were not masked by sialic acid. Removal of sialic acid from human platelets increased binding and phagocytosis by LSEC and KC. CONCLUSIONS: Differences between human and porcine ASGR1 and Mac-1, in combination with a significantly higher number of galactose and N-acetyl glucosamine-containing oligosaccharides on human platelets contribute, in part, to platelet loss seen in porcine liver xenotransplantation.

Primary porcine Kupffer cell phagocytosis of human platelets involves the CD18 receptor.

BACKGROUND: Hepatic failure has been treated successfully with clinical extracorporeal perfusions of porcine livers. However, dog-to-pig and pig-to-baboon liver xenotransplant models have resulted in severe bleeding secondary to liver xenograft-induced thrombocytopenia. Kupffer cells (KC) are abundant phagocytic cells in the liver. KC express the CD11b/CD18 receptor, which has been implicated in chilled platelet binding and phagocytosis through interaction with platelet surface proteins and carbohydrates. We sought to identify the role of KC CD18 in liver xenograft-induced thrombocytopenia. METHODS: Primary pig KC were characterized by flow cytometry, immunoblots, and quantitative polymerase chain reaction. Pig KC were used in inhibition assays with fluorescently labeled human platelets. The CD18 receptor was targeted for siRNA knockdown. RESULTS: Domestic and α1,3-galactosyltransferase double knockout porcine KC cultures were approximately 92% positive for CD18 as detected by quantitative polymerase chain reaction and flow cytometry. Use of CD18 blocking antibodies resulted in reduction of human platelet binding and phagocytosis. Additionally, asialofetuin, not fetuin, inhibited platelet phagocytosis suggesting the involvement of an oligosaccharide-binding site. Furthermore, reduced CD18 expression by siRNA resulted in decreased human platelet binding. CONCLUSIONS: Our data suggest that primary pig KC bind and phagocytose human platelets with involvement of CD18. Further understanding and modification of CD18 expression in pigs may result in a liver xenograft with reduced thrombocytopenic effects, which could be used as a bridge to allogeneic liver transplantation.

ASGR1 expressed by porcine enriched liver sinusoidal endothelial cells mediates human platelet phagocytosis in vitro.

BACKGROUND: Porcine liver xenografts represent a potential solution to the organ shortage, but thrombocytopenia occurs within minutes to hours after xenotransplantation, preventing clinical application. Recently, it was discovered that porcine liver sinusoidal endothelial cells (LSEC) bind and phagocytose human platelets. We examined the role of ASGR1 in binding and removing human platelets by the pig liver endothelium. METHODS: Primary porcine enriched LSEC (eLSEC) were characterized by flow cytometry, immunoblot, quantitative PCR, and immunohistochemistry using confocal microscopy. Phagocytosis inhibition assays using anti-ASGR1 and an ASGR1 substrate were performed. ASGR1 was targeted for siRNA knockdown, and ASGR1-reduced cells were tested for human platelet binding and phagocytosis. RESULTS: ASGR1 is expressed by eLSEC. Human platelet binding and phagocytosis by porcine eLSEC was inhibited by asialofetuin, but not fetuin, suggesting an interaction with galactose ß1-4 N-acetyl glucosamine. Anti-ASGR1 antibodies inhibited human platelet binding in a dose-dependent manner. Knockdown experiments using siRNA reduced ASGR1 expression in asynchronous primary eLSEC by 40%-80%. There was a 20% reduction in translated protein significantly correlated with a 21% decrease in human platelet binding. CONCLUSIONS: ASGR1 on porcine eLSEC mediates phagocytosis of xenogeneic platelets.

The fate of human platelets perfused through the pig liver: implications for xenotransplantation.

BACKGROUND: Pig liver xenotransplantation could offset the shortage of livers available for orthotopic liver transplantation. Studies in pig and baboon liver xenografts revealed the main obstacle to be a lethal thrombocytopenia that occurred within minutes to hours of transplantation. METHODS: We have created a model of xenotransplantation-induced thrombocytopenia using ex vivo pig liver perfusion with human platelets. Thrombocytopenia was examined using fluorescently labeled platelets during the ex vivo perfusion and coculture with primary liver sinusoidal endothelial cells (LSEC). RESULTS: Ex vivo liver perfusion revealed that 93% of human platelets were removed from circulation after 15 min. Endothelial cells and platelets were not activated based on tissue factor release into the perfusate. Biopsies from the ex vivo perfusion at 15 and 30 min and in vitro analysis indicated that human platelets are phagocytosed by pig LSEC and degraded in phagosomes. Sixty to 120 min after the addition of platelets to the ex vivo perfusion system, we observed platelet fragments and degraded platelets in hepatocytes. Platelet phagocytosis was not mediated by opsonization as Fc blocking had no effect on platelet phagocytosis. In vitro uptake of human platelets by primary LSEC cultures peaked at 15 min followed by a greater than 55% decrease in platelet fluorescence after 3 h. Primary pig LSEC phagosomes containing human platelets were colocalized with lysosomes positive for lysosome-associated membrane protein-1 (LAMP1), indicating the formation of mature phagosomes within pig LSEC. CONCLUSIONS: Our observation of pig LSEC phagocytosis of human platelets describes a novel mechanism of large-particle uptake in the liver. The creation of a model system to study xenotransplantation-induced thrombocytopenia makes possible the investigation into mechanisms that mediate platelet loss.

BIN2 functions redundantly with other Arabidopsis GSK3-like kinases to regulate brassinosteroid signaling.

GLYCOGEN SYNTHASE KINASE3 (GSK3) is a highly conserved serine/threonine kinase involved in a variety of developmental signaling processes. The Arabidopsis (Arabidopsis thaliana) genome encodes 10 GSK3-like kinases that are clustered into four groups. Forward genetic screens have so far uncovered eight mutants, all of which carry gain-of-function mutations in BRASSINOSTEROID-INSENSITIVE2 (BIN2), one of the three members in group II. Genetic and biochemical studies have implicated a negative regulatory role for BIN2 in brassinosteroid (BR) signaling. Here, we report the identification of eight ethyl methanesulfonate-mutagenized loss-of-function bin2 alleles and one T-DNA insertional mutation each for BIN2 and its two closest homologs, BIN2-Like1 and BIN2-Like2. Our genetic, biochemical, and physiological assays revealed that despite functional redundancy, BIN2 plays a dominant role among the three group II members in regulating BR signaling. Surprisingly, the bin2bil1bil2 triple T-DNA insertional mutant still responds to BR and accumulates a more phosphorylated form of a BIN2 substrate than the wild-type plant. Using the specific GSK3 inhibitor lithium chloride, we have provided strong circumstantial evidence for the involvement of other Arabidopsis GSK3-like kinases in BR signaling. Interestingly, lithium chloride treatment was able to suppress the gain-of-function bin2-1 mutation but had a much weaker effect on a strong BR receptor mutant, suggesting the presence of a BIN2-independent regulatory step downstream of BR receptor activation.

Comparison of histidine-tryptophan-ketoglutarate solution and University of Wisconsin solution in extended criteria liver donors.

Liver, pancreas, and kidney allografts preserved in histidine-tryptophan-ketoglutarate (HTK) and University of Wisconsin (UW) solutions have similar clinical outcomes. This study compares HTK and UW in a large number of standard criteria donor (SCD) and extended criteria donor (ECD) livers at a single center over 5 years. All adult, cadaveric liver and liver-kidney transplants performed between July 1, 2001 and June 30, 2006 were reviewed (n = 698). There were 435 livers (62%) categorized as ECD for severe physiologic stress and 70 (10%) because of old age. Recipient outcomes included perioperative death or graft loss and overall survival. Liver enzymes were analyzed for the first month post-transplant. Biliary complications were assessed through chart review. Overall, 371 donor livers were preserved in HTK (53%), and 327 were preserved in UW (47%). There were no statistically significant differences in any of the primary outcome measures comparing HTK and UW. The HTK group overall had a higher day 1 median aspartate aminotransferase and alanine aminotransferase, but the two groups were similar in function thereafter. HTK was superior to UW in protection against biliary complications. Kaplan-Meier graft survival curves failed to demonstrate a significant difference in SCD or ECD livers. In conclusion, HTK and UW are not clinically distinguishable in this large sample of liver transplants, although HTK may be protective against biliary complications when compared to UW. These findings persisted for both SCD and ECD livers. Given the lower cost per donor for HTK, this preservation solution may be preferable for general use.