Synthesis of 1,1'-Bicarbazoles by Sequential Iron(III)- and Palladium(II)-Catalyzed Oxidative Coupling Reactions.

The iron(III)-catalyzed oxidative coupling of diarylamines to 2,2'-bis(arylamino)-1,1'-biaryls and subsequent twofold palladium(II)-catalyzed oxidative cyclization provide a convergent synthetic route to 1,1'-bicarbazoles. Screening a range of different palladium(II) salts led to palladium(II) acetate, pivalate, and hexafluoroacetylacetonate as the most efficient catalysts. Remarkably, the twofold palladium(II)-catalyzed oxidative cyclization can also be performed under argon. The mechanism for the oxidative cyclization under an inert gas presumably involves regeneration of the catalytically active palladium(II) species by oxidative addition of pivalic acid.

Insertion of the CXXC domain of KMT2A into YAP1: An unusual mechanism behind the formation of a chimeric oncogenic protein.

Most neoplasia-associated gene fusions are formed through the fusion of the 5'-part of one gene with the 3'-part of another. We here describe a unique mechanism, by which a part of the KMT2A gene through an insertion replaces part of the YAP1 gene. The resulting YAP1::KMT2A::YAP1 (YKY) fusion was verified by RT-PCR in three cases of sarcoma morphologically resembling sclerosing epithelioid fibrosarcoma (SEF-like sarcoma). In all cases, a portion (exons 4/5-6) encoding the CXXC domain of KMT2A was inserted between exon 4/5 and exon 8/9 of YAP1. The inserted sequence from KMT2A thus replaced exons 5/6-8 of YAP1, which encode an important regulatory sequence of YAP1. To evaluate the cellular impact of the YKY fusion, global gene expression profiles from fresh frozen and formalin-fixed YKY-expressing sarcomas were compared with control tumors. The effects of the YKY fusion, as well as YAP1::KMT2A and KMT2A::YAP1 fusion constructs, were further studied in immortalized fibroblasts. Analysis of differentially upregulated genes revealed significant overlap between tumors and cell lines expressing YKY, as well as with previously reported YAP1 fusions. Pathway analysis of upregulated genes in cells and tumors expressing YKY revealed an enrichment of genes included in key oncogenic signaling pathways, such as Wnt and Hedgehog. As these pathways are known to interact with YAP1, it seems likely that the pathogenesis of sarcomas with the YKY fusion is linked to distorted YAP1 signaling.

Long-term outcome after surgical resection of non-high-risk gastrointestinal stromal tumours without adjuvant therapy.

BACKGROUND: Gastrointestinal stromal tumour (GIST) is the most common intra-abdominal sarcoma. Risk classification systems, commonly the modified National Institutes of Health consensus criteria, identify tumour properties relating to patient outcomes. However, owing to limited long-term evidence, most guidelines recommend up to 10-year follow-up for all risk groups except very low-risk GIST. METHODS: This retrospective multicentre study included patients who had complete resection of primary, non-metastatic GIST from three Scandinavian sarcoma centres: Gothenburg (2004-2020), Stockholm (2000-2019), and Oslo (2000-2017). Medical records were reviewed for clinical details regarding diagnosis, treatment, and follow-up, and recurrence-free and disease-specific survival evaluated. RESULTS: The total cohort consisted of 1213 patients with GIST. High-risk patients and those treated with tyrosine kinase inhibitors were excluded. The remaining 649 patients were included in the present analysis: 118 with very low-, 381 with low-, and 150 with intermediate-risk GISTs. Five-year recurrence-free survival rates were 100, 98.5, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.246). Disease-specific survival rates 10 years after surgery were 100, 98.4, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.262). CONCLUSION: Patients with completely resected non-high-risk GISTs have an excellent long-term outcome, irrespective of risk group. Follow-up programmes to detect disease recurrences in these patients are probably not indicated.

Gastrointestinal stromal tumours (GISTs) originate from the muscle layer of the gastrointestinal tract. They are divided into risk groups according to size, location, and how quickly they grow. Patients with GIST, regardless of risk group, have been followed with imaging for several years after their tumour has been successfully removed with an operation. The aim of this study was to evaluate whether follow-up is necessary for patients in the lower-risk groups. Six hundred and forty-nine patients with GISTs from the lower-risk groups were followed for 5 years (median). Only 1.2 per cent of the patients experienced a recurrence of their cancer. It was concluded that patients with GIST in the lower-risk groups do not need follow-up with imaging after a successful operation.

Overlapping morphological, immunohistochemical and genetic features of superficial CD34-positive fibroblastic tumor and PRDM10-rearranged soft tissue tumor.

Superficial CD34-positive fibroblastic tumor (SCD34FT) is a recently recognized soft tissue tumor that is considered to be of borderline malignancy. The pathogenesis of this tumor remains incompletely understood, but it has been suggested that SCD34FT overlaps with tumors showing fusions involving the PRDM10 gene. Previous analyses of PRDM10-rearranged tumors have demonstrated that they have a distinct gene expression profile, resulting in high expression of CADM3 (also known as SynCam3), which can be detected immunohistochemically. Here, we investigated a series (n = 43) of SCD34FT or PRDM10-rearranged tumors and potential mimics (n = 226) with regard to morphological, genetic, and immunohistochemical features. The results show that SCD34FT and PRDM10-rearranged tumor are morphologically indistinguishable; 41 of 43 tumors of both entities are CADM3-positive. Hence, we suggest that they constitute a single entity, preferably referred to as SCD34FT. Expression of CADM3 was only rarely seen in other soft tissue tumors, except in tumors with Schwann cell differentiation. Thus, IHC for CADM3, in combination with the characteristic morphological features, is a valuable adjunct in the diagnosis of SCD34FT.

Mechanistic Studies on the Hexadecafluorophthalocyanine-Iron-Catalyzed Wacker-Type Oxidation of Olefins to Ketones*.

The hexadecafluorophthalocyanine-iron complex FePcF16 was recently shown to convert olefins into ketones in the presence of stoichiometric amounts of triethylsilane in ethanol at room temperature under an oxygen atmosphere. Herein, we describe an extensive mechanistic investigation for the conversion of 2-vinylnaphthalene into 2-acetylnaphthalene as model reaction. A variety of studies including deuterium- and 18 O2 -labeling experiments, ESI-MS, and 57 Fe Mössbauer spectroscopy were performed to identify the intermediates involved in the catalytic cycle of the oxidation process. Finally, a detailed and well-supported reaction mechanism for the FePcF16 -catalyzed Wacker-type oxidation is proposed.

Poorly differentiated chordoma showing loss of SMARCB1/INI1: Clinicopathological and radiological spectrum of nine cases, including uncommon features of a relatively under-recognized entity.

Poorly differentiated chordoma is a newly recognized entity in the recent World Health Organization (WHO) classification of tumors of soft tissue and bone. Slightly over 60 such cases have been documented. Herein, we present a clinicopathological profile, including radiological features, of nine cases, which occurred in five males and four females, with age varying from 1 to 29 years (median = 43), in the cervical spine (n = 2), skull base (n = 2), clivus (n = 2), thoracic spine (n = 1) lumbar spine (n = 1) and coccyx (n = 1) Average tumor size was 4.8 cm. None of the 6-referral cases was diagnosed as a poorly differentiated chordoma at the referring laboratory. Histopathologically, all cases displayed a cellular tumor comprising polygonal cells (n = 9) displaying moderate to marked nuclear pleomorphism with prominent nucleoli (n = 7), eosinophilic (n = 9) to vacuolated cytoplasm (n = 7), rhabdoid morphology (n = 4), interspersed mitotic figures (n = 5), focal necrosis (n = 6) and inflammatory cells (n = 9). A single tumor displayed areas resembling classic chordoma, transitioning into poorly differentiated areas. There were multinucleate giant cells and physaliphorous cells in two tumors, each, respectively. Immunohistochemically, tumor cells were positive for AE1/AE3 (7/7), EMA (7/7), cytokeratin (CK) MNF116 (1/1), OSCAR (1/1), brachyury (9/9, diffusely), S100P (4/7, mostly focally), and glypican 3(2/4). SMARCB1/INI1 was completely lost in all nine tumors. A single case tested by FISH showed homozygous deletion of the SMARCB1 gene. Therapeutically (n = 7), all patients were treated with surgical resection (invariably incomplete) (n = 5), followed by adjuvant radiation therapy (n = 4) and chemotherapy (n = 4). While a single patient partially responded to treatment and another patient is alive with no evidence of disease after 23 years, three patients died of disease, six, eight, and 11 months post-diagnosis, despite adjuvant treatments. A single patient presented with a metastatic lung nodule, while another developed widespread metastasis. Poorly differentiated chordomas display a spectrum of features, are associated with a lower index of suspicion for a diagnosis, and display aggressive outcomes. Critical analysis of radiological and histopathological features, including necessary immunostains (brachyury and SMARCB1/INI1), is necessary for their timely diagnosis. These tumors show loss of SMARCB1/INI1 immunostaining and homozygous deletion of INI1/SMARCB1 gene.

Iron-Catalyzed Wacker-type Oxidation of Olefins at Room Temperature with 1,3-Diketones or Neocuproine as Ligands*.

Herein, we describe a convenient and general method for the oxidation of olefins to ketones using either tris(dibenzoylmethanato)iron(III) [Fe(dbm)3 ] or a combination of iron(II) chloride and neocuproine (2,9-dimethyl-1,10-phenanthroline) as catalysts and phenylsilane (PhSiH3 ) as additive. All reactions proceed efficiently at room temperature using air as sole oxidant. This transformation has been applied to a variety of substrates, is operationally simple, proceeds under mild reaction conditions, and shows a high functional-group tolerance. The ketones are formed smoothly in up to 97 % yield and with 100 % regioselectivity, while the corresponding alcohols were observed as by-products. Labeling experiments showed that an incorporated hydrogen atom originates from the phenylsilane. The oxygen atom of the ketone as well as of the alcohol derives from the ambient atmosphere.

PHF1 fusions cause distinct gene expression and chromatin accessibility profiles in ossifying fibromyxoid tumors and mesenchymal cells.

Ossifying fibromyxoid tumor (OFMT) is a soft tissue tumor frequently displaying gene fusions, most of which affect the PHF1 gene. PHF1 encodes plant homeodomain finger protein 1, which is involved in various processes regulating gene transcription, including those orchestrated by the polycomb repressor complex 2. Here, a series of 37 OFMTs, including 18 typical, 9 atypical, and 10 malignant variants, was analyzed with regard to transcriptomic features, gene fusion and copy number status, and/or single-nucleotide variants. The effects on gene expression and chromatin accessibility of three detected fusions (EP400-PHF1, MEAF6-PHF1, and PHF1-TFE3) were further evaluated in fibroblasts. Genomic imbalances showed a progression-related pattern, with more extensive copy number changes among atypical/malignant lesions than among typical OFMTs; loss of the RB1 gene was restricted to atypical/malignant OFMTs, occurring in one-third of the cases. RNA sequencing identified fusion transcripts in >80% of the cases analyzed, including a novel CSMD1-MEAF6. The gene-expression profile of OFMT was distinct from that of other soft tissue tumors, with extensive transcriptional upregulation of genes in OFMT. These findings were largely recapitulated in gene fusion-expressing fibroblast lines, suggesting that genes involved in, e.g., Wnt signaling and/or being regulated through trimethylation of lysine 27 in histone 3 (H3K27me3) are pivotal for OFMT development. The genes showing differentially higher expression in fusion-expressing cells paralleled increased chromatin accessibility, as revealed by ATAC sequencing. Thus, the present study suggests that OFMT develops through gene fusions that have extensive epigenetic consequences.

Undifferentiated pleomorphic sarcomas with PRDM10 fusions have a distinct gene expression profile.

Undifferentiated pleomorphic sarcoma (UPS) is a highly aggressive soft tissue tumor. A subset of UPS is characterized by a CITED2-PRDM10 or a MED12-PRDM10 gene fusion. Preliminary data suggest that these so-called PRDM10-rearranged tumors (PRT) are clinically more indolent than classical high-grade UPS, and hence important to recognize. Here, we assessed the spectrum of accompanying mutations and the gene expression profile in PRT using genomic arrays and sequencing of the genome (WGS) and transcriptome (RNA-seq). The fusion protein's function was further investigated by conditional expression of the CITED2-PRDM10 fusion in a fibroblast cell line, followed by RNA-seq and an assay for transposase-accessible chromatin (ATAC-seq). The CADM3 gene was found to be differentially up-regulated in PRT and cell lines and was also evaluated for expression at the protein level using immunohistochemistry (IHC). The genomic analyses identified few and nonrecurrent mutations in addition to the structural variants giving rise to the gene fusions, strongly indicating that the PRDM10-fusions represent the critical driver mutations. RNA-seq of tumors showed a distinct gene expression profile, separating PRT from high-grade UPS and other soft tissue tumors. CADM3 was among the genes that was consistently and highly expressed in both PRT and fibroblasts expressing CITED2-PRDM10, suggesting that it is a direct target of the PRDM10 transcription factor. This conclusion is in line with sequencing data from ATAC-seq, showing enrichment of PRDM10 binding sites, suggesting that the amino-terminal fusion partner contributes by making the DNA more accessible to PRDM10 binding. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Gene fusion involving the insulin-like growth factor 1 receptor in an ALK-negative inflammatory myofibroblastic tumour.

AIMS: Inflammatory myofibroblastic tumour (IMT) is a soft tissue tumour primarily affecting children and young adults. Approximately 50% of IMTs have gene fusions involving the receptor tyrosine kinase (RTK)-encoding ALK gene, providing a molecular rationale for treating IMT patients with unresectable tumours with tyrosine kinase inhibitors (TKI). However, a subset of IMT instead displays fusions affecting other RTKencoding genes, so far including NTRK3, PDGFRB and ROS1. Also, IMTs with variant RTK fusions may respond well to TKI treatment, but can be dif?cult to identify as they are negative for ALK staining at immunohistochemistry, the standard method for detection of ALK rearrangements. MATERIALS AND METHODS: We used RNA-sequencing to search for alternate fusion events in an ALK-negative IMT. RESULTS AND CONCLUSIONS: We found a novel fusion gene - FN1-IGF1R. The FN1 gene, encoding ?bronectin, is thought to provide a strong promoter activity for the kinase domain of the RTK insulin-like growth factor 1 receptor, a mechanism similar to previously described RTK fusions in IMT.

Conversion of Olefins into Ketones by an Iron-Catalyzed Wacker-type Oxidation Using Oxygen as the Sole Oxidant.

We describe a mild and operationally simple procedure for the oxidation of olefins into ketones. The reaction is catalyzed by the hexadecafluorinated iron-phthalocyanine complex FePcF16 with stoichiometric amounts of triethylsilane as an additive under oxygen atmosphere to give ketones in good to high yields with excellent chemoselectivity and functional group tolerance. Ketone formation proceeds in up to 95 % yield and with 100 % regioselectivity while the corresponding alcohols were observed as side products.

Synthesis of Tetranuclear Palladium(II) Complexes and Their Catalytic Activity for Cross-Coupling Reactions.

We have developed a short and simple synthesis of tetranuclear palladium(II) complexes that have been structurally confirmed by X-ray analysis. These complexes were formed in about 30 % overall yield by spontaneous metalation of dimethylaminoarene derivatives and exhibit a high stability. We have studied the utility of the tetranuclear palladium(II) complexes as precatalysts for Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions. Our novel complexes show excellent catalytic activities with high turnover numbers (TON) and high turnover frequencies (TOF) (e.g., for the Suzuki-Miyaura reaction: TON up to 538000 and TOF up to 23400 h-1 at room temperature).

FN1-EGF gene fusions are recurrent in calcifying aponeurotic fibroma.

Calcifying aponeurotic fibroma (CAF) is a soft tissue neoplasm with a predilection for the hands and feet in children and adolescents. Its molecular basis is unknown. We used chromosome banding analysis, fluorescence in situ hybridization (FISH), mRNA sequencing (RNA-seq), RT-PCR, and immunohistochemistry to characterize a series of CAFs. An insertion ins(2;4)(q35;q25q?) was identified in the index case. Fusion of the FN1 and EGF genes, mapping to the breakpoint regions on chromosomes 2 and 4, respectively, was detected by RNA-seq and confirmed by RT-PCR in the index case and two additional cases. FISH on five additional tumours identified FN1-EGF fusions in all cases. CAFs analysed by RT-PCR showed that FN1 exon 23, 27 or 42 was fused to EGF exon 17 or 19. High-level expression of the entire FN1 gene in CAF suggests that strong FN1 promoter activity drives inappropriate expression of the biologically active portion of EGF, which was detected immunohistochemically in 8/9 cases. The FN1-EGF fusion, which has not been observed in any other neoplasm, appears to be the main driver mutation in CAF. Although further functional studies are required to understand the exact pathogenesis of CAF, the composition of the chimera suggests an autocrine/paracrine mechanism of transformation. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Molecular pathology of bone tumours: diagnostic implications.

Alongside histomorphology and immunohistochemistry, molecular pathology is now established as one of the cornerstones in the tissue diagnosis of bone tumours. We describe the principal molecular pathological techniques employed, and each of the bone tumour entities where their identified characteristic molecular pathological changes can be detected to support and confirm the suspected histological diagnosis. Tumours discussed include fibrous dysplasia, classical and subtype osteosarcomas, central and surface cartilaginous tumours, Ewing's sarcoma, vascular tumours, aneurysmal bone cyst, chordoma, myoepithelioma, and angiomatoid fibrous histiocytoma. This is a rapidly evolving field with discoveries occurring every few months, and some of the newer entities (the Ewing's-like sarcomas), which are principally identified by their molecular pathology characteristics, are discussed.

Myoepithelioma of bone with a novel FUS-POU5F1 fusion gene.

AIMS: Myoepithelial tumours of soft tissue are rare lesions with a broad morphological and clinical spectrum. Previous studies have found EWSR1 rearrangements in approximately half of all cases and PBX1, ZNF44 and POU5F1 have been identified as recurrent fusion partners. In bone, only a small number of myoepithelial tumours have been described. We investigated an intraosseous myoepithelioma of the sacrum in a 54-year-old man without EWSR1 rearrangement for the presence of other fusion genes. METHODS AND RESULTS: G-banding analysis, SNP-array and fluorescence in situ hybridisation suggested rearrangement of the FUS and POU5F1 genes. RT-PCR confirmed a chimeric in-frame transcript fusing FUS exon 5 to POU5F1 exon 2. The clinical course after en bloc resection was without recurrence or metastasis over a period of 87 months. CONCLUSION: We report a novel FUS-POU5F1 fusion gene in an intraosseous myoepithelioma of the sacrum. This case highlights that FUS can replace EWSR1 as the N-terminal transactivator in oncogenic fusion genes in myoepithelial tumours, similar to that which has previously been demonstrated in other tumour entities. Thus, in addition to EWSR1, also FUS needs to be considered as a potential fusion partner in the molecular work up of myoepithelial tumours.

Autophagy-enhancing drug carbamazepine diminishes hepatocellular death in fibrinogen storage disease.

Fibrinogen storage disease (FSD) is a rare autosomal-dominant hereditary disorder characterized by hypofibrinogenemia and accumulation of fibrinogen aggregates within the hepatocellular endoplasmatic reticulum (ER). Some FSD patients present with elevated amino-transferases and fibrosis/cirrhosis similar to alpha-1-antitrypsin deficiency (ATD), also an ER storage disease. Pharmacological stimulation of autophagy has been shown to mediate clearance of protein aggregates and halt progression of liver fibrosis in in vivo models of ATD. Our aim was to evaluate the presence of autophagy and a possible response to autophagy-enhancing therapy in patients with FSD. Hepatic fibrosis was assessed by transient elastography in 2 newly identified FSD families with fibrinogen Aguadilla and Brescia mutations, encompassing 8 affected members. Available liver biopsies were assessed for autophagy. Two patients, who had had elevated alanine amino-transaminase levels (2-5 above upper limit of normal), were treated with the autophagy enhancer carbamazepine (CBZ). Transient elastography did not show evidence of significant fibrosis in any affected family members. Quantitative electron microscopy of one patient showed a 5.15-fold increase of late stage autophagocytic vacuoles compared to control livers. CBZ at low anticonvulsive treatment levels led to rapid normalization of alanine-aminotransferase and decrease of caspase-cleaved and uncleaved cytokeratin-18 fragments (M30 and M65). These effects reversed after discontinuation of treatment. Response to CBZ may be mediated by pharmacologically enhanced autophagy resulting in reduction of aggregate-related toxicity in FSD. These results suggest clinical applicability of pharmacological stimulation of autophagy in FSD, but potentially also in other related disorders.

Diagnostic Yield From a Nationwide Implementation of Precision Medicine for all Children With Cancer.

PURPOSE: Several studies have indicated that broad genomic characterization of childhood cancer provides diagnostically and/or therapeutically relevant information in selected high-risk cases. However, the extent to which such characterization offers clinically actionable data in a prospective broadly inclusive setting remains largely unexplored. METHODS: We implemented prospective whole-genome sequencing (WGS) of tumor and germline, complemented by whole-transcriptome sequencing (RNA-Seq) for all children diagnosed with a primary or relapsed solid malignancy in Sweden. Multidisciplinary molecular tumor boards were set up to integrate genomic data in the clinical decision process along with a medicolegal framework enabling secondary use of sequencing data for research purposes. RESULTS: During the study's first 14 months, 118 solid tumors from 117 patients were subjected to WGS, with complementary RNA-Seq for fusion gene detection in 52 tumors. There was no significant geographic bias in patient enrollment, and the included tumor types reflected the annual national incidence of pediatric solid tumor types. Of the 112 tumors with somatic mutations, 106 (95%) exhibited alterations with a clear clinical correlation. In 46 of 118 tumors (39%), sequencing only corroborated histopathological diagnoses, while in 59 cases (50%), it contributed to additional subclassification or detection of prognostic markers. Potential treatment targets were found in 31 patients (26%), most commonly ALK mutations/fusions (n = 4), RAS/RAF/MEK/ERK pathway mutations (n = 14), FGFR1 mutations/fusions (n = 5), IDH1 mutations (n = 2), and NTRK2 gene fusions (n = 2). In one patient, the tumor diagnosis was revised based on sequencing. Clinically relevant germline variants were detected in 8 of 94 patients (8.5%). CONCLUSION: Up-front, large-scale genomic characterization of pediatric solid malignancies provides diagnostically valuable data in the majority of patients also in a largely unselected cohort.

Rapid early HDV RNA decline in the peripheral blood but prolonged intrahepatic hepatitis delta antigen persistence after liver transplantation.

BACKGROUND & AIMS: Chronic HDV infection is an inflammatory liver disease and liver transplantation (LTX) remains the only curative treatment option for most patients. The hepatitis D virus (HDV) uses HBsAg as its surface protein, however, it is controversial to what extend HDV may be detected independently of HBsAg in blood and liver after LTX. The aims of this study were to investigate kinetics of HDV RNA and HBsAg early after LTX, to apply the data to a mathematical model and to study long-term persistence of HDV after LTX. METHODS: We retrospectively analyzed 26 patients with chronic hepatitis delta who underwent LTX between 1994 and 2009. Blood samples were obtained every 1-3 days during the first 14 days after LTX. Data were applied to a mathematical model to study viral kinetics. Available liver biopsy samples were stained for HBV and HDV viral antigens and tested for HBV DNA/cccDNA. RESULTS: HBsAg and HDV RNA became negative after a median of 5 days (range 1-13) and 4 days (range 1-10), respectively. Early HDV RNA and HBsAg decline paralleled almost exactly in all patients; however the mathematical model showed a high variability of virion death. HDAg stained positive in transplanted livers in six patients in the absence of liver HBV DNA/cccDNA, serum-HBsAg, and HDV RNA for up to 19 months after LTX. CONCLUSIONS: HDV RNA and HBsAg decline follow almost identical kinetic patterns within the first days after LTX. Nevertheless, intrahepatic latency of HDAg has to be considered when exploring novel concepts to withdraw HBIG.

Extracorporeal liver perfusion system for artificial liver support across a membrane.

BACKGROUND: An extracorporeal porcine liver perfusion (ECPLP) system circumvents the limitations of hepatocyte based bio-artificial liver, but its clinical application has been limited so far due to the potential risk of transmission of porcine endogenous retroviruses. The aim of this study was to develop an ECPLP model that can provide artificial hepatic support across a semi-permeable membrane, which has the potential to block porcine viruses due to its pore size. MATERIALS AND METHODS: Livers from white landrace pigs were perfused with normothermic oxygenated blood using Medtronic BP560 centrifugal pump (Medtronic, Inc., Minneapolis. MN). This ECPLP system was used to support a "surrogate" patient across the filter Evaclio-EC4A. Function of liver was measured by indocyanine green retention at 15 min (ICGR15). Clearance of galactose, ammonia, and para-aminobenzoic acid infused into the "surrogate" patient circulation was calculated to assess liver support across the membrane. The study was designed as test (n = 15) versus control (n = 5), with control experiments having no liver in the circuit. RESULTS: For the test experiments, we perfused 15 livers with mean hepatic artery pressure of 87 mm Hg and flows of 1.2 L/min. ICGR15 in test experiments was 11%. Ammonia clearance was 945 mg/min/kg, galactose metabolic rate was 111.7 mg/min/Kg, and the hippurate ratio was 91% in the test. In contrast, the control experiments did not show any significant change in the concentration of any of these compounds. CONCLUSION: Our ECPLP model was able to provide hepatic support in an experimental setting across a hollow fiber filter. Further work on an anhepatic animal is needed prior to application in human trials.