bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liver support technology – an update
Authors: Rozga Jacek 
Published: August 2006

Abstract:  Background:  Currently, there is no direct treatment for hepatic failure, and patients must receive a transplant or endure prolonged hospitalization, with significant morbidity and mortality. Because of the scarcity of donor organs, liver support strategies are being developed with the aim of either supporting patients with borderline functional liver cell mass until an appropriate organ becomes available for transplantation or until their livers recover from injury.Methods:  A literature review was performed using MEDLINE and library searches. Only major blood detoxification/purification devices and cell‐based techniques are included in this review.Results:  Currently, a number of blood purification systems and devices utilizing viable liver cells are in various stages of clinical development. Non‐biological systems include plasma exchange, albumin dialysis, hemo(dia)filtration, and sorbent‐based devices (charcoal, resin). These systems are able to remove toxins of hepatic failure, and their utility is limited by their inability to provide missing liver‐specific functions. In contrast, hepatocyte‐based devices are able to provide whole liver functions, including detoxification, biosynthesis, and biotransformation. Molecular adsorbent recycling system (MARS) blood detoxification system has been tested in thousands of patients, but additional well‐conducted controlled studies are warranted to better define the role of MARS® in the treatment of patients with acute hepatic failure and acute exacerbation of chronic liver disease. HepatAssist™ was tested in a phase II/III controlled clinical trial that demonstrated safety and proof of concept for use of biological liver support systems to improve patient survival in acute hepatic failure.Conclusions:  Developing an effective liver assist technology has proven difficult, because of the complexity of liver functions that must be replaced, as well as heterogeneity of the patient population. Non‐biological systems may have a role in the treatment of specific forms of liver failure where the primary goal is to provide blood detoxification/purification. Biological systems appear to be useful in treating liver failure where the primary objective is to provide whole liver functions which are impaired or lost. It is suggested that there will be a role for hybrid liver support systems that offer liver cell therapy and various forms of blood purification (sorption, hemofiltration and diafiltration) to treat patients with specific forms of liver failure at various stages of their illness.
ABO‐incompatible allotransplantation as a basis for clinical xenotransplantation
Authors: Stussi Georg , West Lori , Cooper David K. C. , Seebach Jörg D. 
Published: August 2006

Abstract:  The 8th Congress of the International Xenotransplantation Association (IXA), held in Goteborg in September, 2005, immediately followed the 2nd International Symposium on ABO‐Incompatibility in Transplantation, both congresses organized by Michael Breimer and Lennart Rydberg. The Proceedings of the Symposium on ABO‐Incompatibility in Transplantation have been published (Xenotransplantation 2006; 13 (2)). The present paper provides an overview of a workshop held at the 8th Congress of the IXA, and highlights the immunological concepts emerging from ABO‐incompatible allotransplants and discusses them in relation to xenotransplantation.Using specified immunomodulatory protocols, ABO‐incompatible solid organ allotransplantation has become a clinical reality for a small number of patients over the last two decades. ABO‐incompatible adult kidney and infant heart transplants have similar patient and graft survivals as their ABO‐compatible counterparts. In contrast, ABO‐incompatibility is present in up to 30% of all patients receiving hematopoietic stem cell transplants in the absence of specific immunomodulation, without affecting overall survival. Consequently, ABO‐incompatible solid organ transplants and hematopoietic stem cell transplants may serve as in vivo models to elucidate the immunological mechanisms of accommodation and/or tolerance in the clinical setting. Because of similarities in the immunological hurdles that need to be overcome, knowledge obtained from ABO‐incompatible allotransplantation might further promote advances in the field of xenotransplantation. The similarities and differences between ABO‐incompatible allotransplantation and xenotransplantation are discussed.
NK‐cell‐dependent acute xenograft rejection in the mouse heart‐to‐rat model
Authors: Chen Daxin , Weber Michele , Lechler Robert , Dorling Anthony 
Published: August 2006

Abstract:  Background:  Acute humoral xenograft rejection is characterized by widespread intravascular thrombosis with a significant NK‐cell and macrophage infiltrate. Although in vitro and ex vivo data have shown that NK cells are capable of killing xenogeneic tissue, the precise role they play in vivo is still not certain. Consequently, there are few tested strategies for dealing with NK‐cell‐mediated rejection, should this prove to be a problem. One reason for this has been the lack of a relevant rodent model in which rejection by these cells can be easily studied.Methods:  Prior to transplantation of mouse hearts, we depleted rat recipients of fibrinogen using a snake venom, ANCROD, from the Malayan pit viper. Graft survival was examined by manual palpation and the rejected hearts were examined by histology. Levels of circulating interferon gamma (IFN‐γ), used as a surrogate marker for NK‐cell activation, were determined by an enzyme‐linked immunosorbent assay.Results:  Depletion of fibrinogen to approximately 5% of normal allowed surgery without a significant increase in the technical failure rates and prolonged graft survival compared with that seen in unmanipulated rats. Rejected hearts showed no evidence of intravascular thrombosis but did show significant antibody and complement deposition. There was little T‐cell infiltration and cyclosporin had no influence on survival. Instead, hearts were infiltrated with NK cells and macrophages and rejection was associated with significant IFN‐γ production. Depletion of NK cells with anti‐asialo‐GM‐1 from ANCROD‐treated recipients led to a further significant prolongation of graft survival. Conclusions:  Inhibition of intravascular thrombosis by fibrinogen depletion, in the absence of any other manipulation, unmasks NK‐cell‐dependent acute xenograft rejection in the mouse‐to‐rat heart transplantation model. This relatively simple model is expected to be useful to investigate the mechanisms of NK‐cell‐mediated rejection and to provide insight into the types of graft manipulation that could modify this process.
Xenotransplantation of purified pre‐natal porcine beta cells in mice normalizes diabetes when a short anti‐CD4–CD8 antibody treatment is combined with transient insulin injections
Authors: Veld Peter In't , Pavlovic Dejan , Bogdani Marika , Pipeleers‐Marichal Miriam , Pipeleers Daniel 
Published: August 2006

Abstract:Background:  Pre‐natal porcine endocrine islet cell grafts were recently shown to contain immature beta cells with a marked potential for growth and differentiation following transplantation, and hence for a progressive and long‐term correction of diabetes in immune‐incompetent mice. The present study investigates whether these grafts are also capable of correcting hyperglycemia in immune‐competent mice receiving a short treatment with anti‐CD4–CD8 antibodies.Methods:  Pure endocrine islet cell grafts with 0.5 to 1.0 million beta cells were prepared from pre‐natal pigs and transplanted under the kidney capsule of alloxan‐diabetic CBA/Ca mice. Survival, growth and function of implanted beta cells were followed by measuring plasma porcine C‐peptide and glucose, and graft insulin content at start and at post‐transplant (PT) week 35. The effect was studied of a 5‐day treatment with non‐depleting anti‐CD4 YTS177 and depleting anti‐CD8 YTS169 antibody, either without or with transient insulin injections.Results:  Without antibody treatment, all graft recipients remained porcine C‐peptide negative and died. Antibody treatment decreased CD4‐expression and percentage CD8 cells for 10 and 18 weeks respectively. It resulted in a 30 week‐survival of nine out of 14 graft recipients; all nine had progressively become C‐peptide positive but only one proceeded to normoglycemia. When antibody treatment was combined with transient insulin injections, 11 out of 14 graft recipients survived long‐term, eight became C‐peptide positive and six were normoglycemic at PT week 30. In both groups, surviving recipients exhibited a graft insulin content that was 6‐ to 9‐fold higher than at implantation.Conclusions:  Pre‐natal porcine beta cells grow and differentiate when transplanted in diabetic immune‐competent mice that have been transiently immune suppressed with anti‐CD4 and anti‐CD8 monoclonal antibodies. They develop metabolic control when recipients are also transiently treated with insulin injections.
Compatibility of porcine and human interleukin 2: implications for xenotransplantation
Authors: Zhang Baojun , Ge Basheng , Xia Xuepei , Liu Jun , Sun Liguang , Rao Enyu , Zhao Yong 
Published: August 2006

Abstract:  Background:  Xenotransplantation provides a possible solution to the severe shortage of allogeneic organ donors. The pig, which shares many physiological similarities with humans, makes it an optimal species for preclinical experimentation and clinical applications. Interleukin 2 (IL2) is a potent growth factor secreted primarily by T helper lymphocytes and it is vital to the cellular expansion required for a productive immune response and the development and peripheral expansion of CD4+CD25+ regulatory T cells. Therefore, it is essential to understand of the compatibility of IL2 between pigs and humans.Methods:  We first compared the cDNA and protein sequences and the crystal structures of human and porcine IL2 and IL2 receptors, respectively. The effect of IL2 to induce T cell proliferation was determined by 3H‐thymidine incorporation and cell cycle detection.Results:  Porcine IL2 induced very limited proliferation of human lymphocytes while it functioned well on porcine lymphocytes. Human IL2 had remarkably reduced effects on porcine lymphocytes whereas it worked well on human lymphocytes.Conclusion:  Our present study showed that the interaction of IL2 and IL2R across species might have defects. Together with the wide physiological functions of IL2, our data indicated that physiological disorders could be caused by the poor function of xenogeneic donor IL2 on host cells in full hematopoietic chimera. Our data suggested an additional potential advantage for the mixed xenogeneic chimeras.
Effect of tandem forms of DAF(CD55) on complement‐mediated xenogeneic cell lysis
Authors: Miyagawa Shuji , Fukuta Daisuke , Kitano Etsuko , Kobayashi Chizuko , Fumimoto Yuichi , Shirasu Akio , Hattori Hiroyuki , Shirakura Ryota , Fukuzawa Masahiro 
Published: August 2006

Abstract:  Background:  It is difficult to produce a transgenic animal with high expression of decay‐accelerating factor (CD55: DAF) or other molecules. The purpose of this study was to assess the effect of tandem forms of DAF on a xenogeneic cell membrane against human complement.Methods:  cDNAs of the delta‐Short Consensus Repeat (SCR) 1‐DAF, the double‐DAF, the triple‐DAF, and the tetra‐DAF with a FLAG‐tag were established. Chinese hamster ovary (CHO) cell lines and a pig endothelial cell (PEC) line expressing these molecules were established. The amelioration of complement‐mediated lysis by the transfectant molecules on these cells was examined. The CHO cell transfectants were also incubated with normal human serum, and the amount of C3 deposited was determined by FACS analysis.Results:  Stable CHO cells and PEC transfectants, in which each molecule was clearly expressed, and Western blots showed that each band corresponded to the expected molecular weight. The extent of amelioration of complement‐mediated lysis by these four molecules was then examined. A clear tendency was found, as follows: The higher the tandem number of DAF, the greater was the effect on cytotoxicity. Additional experiments focusing on triple‐DAF and tetra‐DAF did not indicate any significant difference in complement‐mediated lysis. Consistent with the complement‐regulatory ability, the inhibitory effect of the deposition of C3 fragments by these molecules was closely related to the degree of amelioration.Conclusion:  These data indicate that tandem DAF, especially a triple‐DAF, is a very effective form for protecting against complement activation.
Recognition of a carbohydrate xenoepitope by human NKRP1A (CD161)
Authors: Christiansen Dale , Mouhtouris Effie , Milland Julie , Zingoni Alessandra , Santoni Angela , Sandrin Mauro S. 
Published: August 2006

Abstract:  Background:  Many immunologically important interactions are mediated by leukocyte recognition of carbohydrates via cell surface receptors. Uncharacterized receptors on human natural killer (NK) cells interact with ligands containing the terminal Galα(1,3)Gal xenoepitope. The aim of this work was to isolate and characterize carbohydrate binding proteins from NK cells that bind αGal or other potential xenoepitopes, such as N‐acetyllactosamine (NAcLac), created by the deletion of α1,3galactosyltransferase (GT) in animals.Methods and results:  Initial analysis suggested the human C‐type lectin NKRP1A bound to a pool of glycoconjugates, the majority of which contained the terminal Galα(1,3)Gal epitope. This was confirmed by high level binding of cells expressing NKRP1A to mouse laminin, which contains a large number of N‐linked oligosaccharides with the Galα(1,3)Gal structure. The consequence of removing the terminal αGal was then investigated. Elevated NAcLac levels were observed on thymocytes from GT−/− mice. Exposing NAcLac on laminin, by α‐galactosidase treatment, resulted in a significant increase in NKRP1A binding.Conclusions:  NKRPIA binds to the αGal epitope. Moreover, exposing NAcLac by removal of αGal resulted in an increase in binding. This may be relevant in the later phases of xenotransplant rejection if GT−/− pigs, like GT−/− mice, display increased NAcLac expression.
A study of the xenoantigenicity of neonatal porcine islet‐like cell clusters (NPCC) and the efficiency of adenovirus‐mediated DAF (CD55) expression
Authors: Omori Takeshi , Nishida Toshirou , Komoda Hiroshi , Fumimoto Yuichi , Ito Toshinori , Sawa Yoshiki , Gao Congxiao , Nakatsu Shino , Shirakura Ryota , Miyagawa Shuji 
Published: August 2006

Abstract:  Background:  The pig pancreas is considered to be the most suitable source of islets for xenotransplantation in patients with type I diabetes. The objective of this study was to assess the antigenicity of neonatal porcine islet‐like cell clusters (NPCC), including the Galα1–3Galβ1–4GlcNAc‐R (α‐Gal) and Hanganutziu–Deicher (H–D) antigens, and the pathway involved in human complement activation. The efficiency of expression of human decay‐accelerating factor (DAF: CD55) on NPCC by adenoviral transduction was also examined, and the functional capacity of DAF was also estimated.Methods:  The deposition of human natural antibodies, immunoglobulin (Ig)G and IgM, and the expression of α‐Gal and H–D antigens on NPCC were investigated by FACS analysis. The downregulation in the antigenicity to human natural antibodies, including the α‐Gal and H–D antigens on NPCC by treatment with tunicamycin, PDMP and neuraminidase were also examined. In addition, complement‐mediated islet lysis was examined using factor D‐deficient and C1‐deficient sera. An adenovirus encoding DAF under the control of the cytomegalovirus promoter, Ad.pCMV‐DAF, was then constructed, and used for transducing NPCC. The amelioration of complement‐dependent cytotoxicity of the NPCC by the transduced DAF was assessed as an in vitro hyperacute rejection model of a pig to human xenograft.Results:  The NPCC clearly expressed the α‐Gal epitope, and the human natural antibodies, IgG and IgM, and the anti‐H–D antibody also reacted with the NPCC. Treatment of NPCC with tunicamycin led to a drastic reduction in the extent of deposition of IgG, indicating the importance of N‐linked sugars on the islets, presumably related to α‐Gal expression on N‐linked sugars. Neuraminidase treatment indicated the presence of, not only the H–D antigen, but also other sialic acid antigens which reacted with the human natural antibody, especially IgG. The complement deposition of factor B on NPCC was clear, and the alternative pathway‐mediated NPCC killing accounted for approximately 30% of that by the total complement pathway. On the other hand, approximately 90% of the NPCC could be transduced to express DAF by the adenovector, Ad.pCMV‐DAF. The expressed DAF showed an approximately 50–62% suppression in complement‐dependent NPCC lysis.Conclusion:  The origin of the antigenicity of NPCC is mainly N‐linked sugars including α‐Gal and sialic acid antigens, and NPCC expressed the transduced molecule in high efficiency by the adenovector.
The Effect of Nitric Oxide Inhibition and Temporal Expression Patterns of the mRNA and Protein Products of Nitric Oxide Synthase Genes During In Vitro Development of Bovine Pre‐implantation Embryos
Authors: Tesfaye D , Kadanga A , Rings F , Bauch K , Jennen D , Nganvongpanit K , Hölker M , Tholen E , Ponsuksili S , Wimmers K , Montag M , Gilles M , Kirfel G , Herzog V , Schellander K 
Published: August 2006

ContentsThis study was conducted to determine the effect of Nitric oxide (NO) inhibition in bovine in vitro development and expression analysis of the three Nitric oxide synthase (NOS) isoforms: endothelial (eNOS), neuronal (nNOS) and inducible (iNOS), mRNA and protein in bovine oocytes and embryos. Selective inhibitor of NOS, N‐ω‐nitro‐l‐arginine methyl ester (l‐NAME) was applied at different doses (0, 0.1, 1 and 10 mm) in maturation (experiment 1A), culture medium (experiment 1B) and in both maturation and culture media (experiment 1C). No significant differences were observed in cleavage and blastocyst rates when oocytes were matured in the presence of l‐NAME as long as the inhibitor was omitted during fertilization and culture. However, significantly lower blastocyst rates were observed when l‐NAME was present at higher level (10 mm) in culture medium alone and in both maturation and culture media. In experiment 2, mRNA isolated from triplicate pools of oocytes and embryos (n = 15–20) was subjected to quantitative real time reverse transcription polymerase chain reaction to investigate the expression of eNOS, iNOS and nNOS mRNA in normal IVP bovine oocytes and embryos. While eNOS and iNOS transcripts were detected at higher level in oocytes (immature and mature), two‐cell and four‐cell stage embryos, the nNOS was detected only in immature oocyte, two‐cell and morula stages. In experiment 3, eNOS and iNOS protein expression analysis was performed in IVP oocytes and embryos and both proteins were detected in the cytoplasm and the nuclei (weak) of oocytes and embryos. These data provide the first evidence for the role of NO production and the presence of mRNA and protein products of NOS isoforms during bovine embryogenesis.
The Role of Oestradiol in the Uterine Peristalsis in the Perfused Swine Uterus
Authors: Maltaris T , Dittrich R , Widjaja W , Sindhuwinata C , Hoffmann I , Beckmann MW , Mueller A 
Published: August 2006

ContentsThis study was designed to examine the effects of oestradiol (E2) on sperm transport in the swine uterus. The bicornuate swine uterus is optimal for the study of the uterine transport and peristalsis because the influence of various factors can be examined on each uterine horn independently. Forty swine uteri (with or without ovarectomy) were perfused for a period of up to 7 h. Two different E2 concentrations (3 or 30 pg/ml) in the perfusion medium were administered for 30 min unilaterally. Through an intracervical catheter 1 ml of a high concentrated dextran blue solution was administered directly in the upper part of the cervix. After bilateral perfusion of the swine uterus with a bolus of 0.3 IU oxytocin the distribution of coloured particles was assessed macroscopically before and after incision of the uterine horns. Coloration was evaluated by two observers blinded to the site‐specific administration of E2. In the 10 ovarectomized uteri with the 3 pg/ml E2 concentration a unilateral distribution towards the side of oestradiol administration was observed in six uteri, in four it was a bilateral distribution. In the 10 non‐ovarectomized uteri with the 3 pg/ml E2 concentration a uni‐ and ipsilateral coloration was observed in five uteri, in five it was a bilateral distribution. In the 20 uteri with 30 pg/ml E2, a unilateral coloration of the uterus horns was observed in all uteri. Oestradiol is one of the main factors, which influences the direction of the sperm transport in a dose‐dependent manner, in the perfused swine uterus.
Transcript Profiles of Some Developmentally Important Genes Detected in Bovine Oocytes and In Vitro‐produced Blastocysts Using RNA Amplification and cDNA Microarrays
Authors: Mamo S , Sargent CA , Affara NA , Tesfaye D , El‐Halawany N , Wimmers K , Gilles M , Schellander K , Ponsuksili S 
Published: August 2006

ContentsTo study the mRNA transcript profiles of some potential candidate developmental genes during bovine oocyte and blastocyst stages, RNA amplification procedures, cDNA microarray of 82 target genes spotted onto glass slide and real‐time polymerase chain reaction (PCR) were used. Messenger RNAs were isolated from in vitro‐produced bovine matured oocytes and blastocysts. Using equal amounts of input mRNAs but different cycles of amplifications, cDNAs were produced and served as template for RNA amplification by the in vitro transcriptions. After amplification, the RNA yields transcribed from cDNAs of different cycles were evaluated both by hybridization on the cDNA microarrays and by using real‐time PCR techniques. The analyses indicated best results from lower amplification cycle templates with consistent signals at hybridization. Generally, the RNA yield was directly proportional to the amplification cycle but inversely related with signal consistency at repeated hybridizations. Using the protocols established, equal amounts of amplified RNA from matured oocytes and blastocysts were hybridized to the array. Analyses of replicated hybridizations indicated that 35 transcripts were differentially expressed. Most of these were not described in previous bovine embryo studies. Independent analyses of 23 transcripts with real‐time PCR and unamplified RNA confirmed the results of 22 genes. Moreover, the functional analyses showed various roles related to development. Hence, it is possible to conclude that the genes identified here are potential candidates for characterizing developmental competence, and that the methods established can be used for large‐scale gene expression analysis with more comprehensive arrays.