Home About us Contact
|
Home About us Contact | ||
|
|
||
Pig Liver (pig + liver)
Selected AbstractsComparison of genomic and cDNA sequences of guinea pig CYP2B18 and rat CYP2B2: Absence of a phenobarbital-responsive enhancer module in the upstream region of the CYP2B18 geneJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2004Midori Yamamoto Abstract Potential mechanisms were investigated whereby CYP2B18, a cytochrome P450 gene exhibiting high constitutive expression but only low levels of phenobarbital-inducibility in the guinea pig liver, may be differentially regulated versus the highly inducible rat CYP2B2 gene. To comparatively assess potential regulatory sequences associated with CYP2B18, a guinea pig genomic library was screened enabling isolation of the CYP2B18 gene. The genomic screening process resulted in the identification of at least four closely-related CYP2B18 genes, designated here as CYP2B18A-D. Of these isolates, CYP2B18A exhibited sequence identical to that of the CYP2B18 cDNA. Further, the deduced amino acid sequence of the CYP2B18 cDNA was identical to that of N-terminal and internally-derived peptide sequences obtained in this investigation from CYP2B18 protein isolated from guinea pig liver. Genomic structural sequences were derived for CYP2B18A, together with the respective 5,-upstream and intronic regions of the gene. Comparison of the CYP2B18A and CYP2B2 gene sequences revealed the lack of repetitive LINE gene sequences in CYP2B18A, putative silencing elements that effect neighboring genes, although these sequences were present in both 5,-upstream and 3,-downstream regions of CYP2B2. We determined that the phenobarbital-responsive enhancer module was absent from the 5,-upstream region as well as the intronic regions of CYP2B18A gene. We hypothesize that the compromised phenobarbital inducibility of CYP2B18A stems from its lack of a functional phenobarbital responsive enhancer module. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:124,130, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20016 [source] Low specificity of anti-tissue transglutaminase antibodies in patients with primary biliary cirrhosisJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 5 2006N. Bizzaro Abstract The association between celiac disease (CD) and primary biliary cirrhosis (PBC) is well documented in medical literature; however, a high frequency of false positive results of the anti-transglutaminase (anti-tTG) test has been reported in patients with PBC. To verify if the positive results for anti-tTG autoantibody are false positives due to cross reactivity with mitochondrial antigens, we studied 105 adult patients affected with PBC, positive for anti-mitochondrial M2 antibodies. Anti-tTG IgA antibodies were studied by using six different immunoenzymatic assays that employ the tTG antigen obtained from different sources (human recombinant, placenta, red blood cells, and guinea pig liver). On the whole, 28 out of 105 PBC subjects tested positive for anti-tTG IgA antibodies, but only two were eventually found to be affected by CD; the other 26 were shown to be false positive. The specificity of the various antigenic substrates ranged from 88.5% of the human erythrocytes tTG to 97.1% of the human recombinant tTG. The results of this study showed that a true association between PBC and CD was present in only 2% of the patients and that, in most cases, the false positive results were attributable to the type of substrate utilized in the assay. J. Clin. Lab. Anal. 20:184,189, 2006. © 2006 Wiley-Liss, Inc. [source] Biosynthesis of ascorbic acid by extant actinopterygiansJOURNAL OF FISH BIOLOGY, Issue 3 2000R. Moreau Polypterus senegalus, the longnose gar Lepisosteus osseus and the bowfin Amia calva had gulonolactone oxidase activity in the kidney and thus can synthesize ascorbic acid de novo. The enzyme activity was associated with the microsomal fraction. The common carp Cyprinus carpio and the goldfish Carassius auratus had no gulonolactone oxidase activity. Antibodies directed against white sturgeon gulonolactone oxidase showed cross-reactivity with lake sturgeon, bowfin and longnose gar kidney enzymes, but not with enzymes from Polypterus, sea lamprey, and tadpole kidney or pig liver. Given cross-reactivity, gulonolactone oxidase relatedness matched actinopterygian phylogeny, and suggested homology of the character throughout fishes. Modern teleosts may have lost the ability to synthesize ascorbic acid since the late Triassic as a result of a single reversal in the founding population. Wild bowfin and longnose gar exhibited high ascorbate concentrations in liver and spleen when compared with the teleosts rainbow trout Oncorhynchus mykiss and common carp fed vitamin C-supplemented diets. [source] Comparison of Deamidation Activity of TransglutaminasesJOURNAL OF FOOD SCIENCE, Issue 1 2001T. Ohtsuka ABSTRACT: A comparison was made of the deamidation activity of transglutaminases fro m guinea pig liver (GTGase), fish red sea bream liver (FTGase) and microorganisms (MTGase). Against the Z-Gln-Gly, kinetic constants of the deamidation and incorporation of primary amine were measured. GTGase and FTGase showed similar deamidation activity, however, that of MTGase was less than 1/7 of the other two TGases. Against the proteins, N, N-dimethylated casein and native gliadin, FTGase was the most active and deamidated respectively 45.5% and 38.2% of Gln residues. The deamidation rate of these proteins by GTGase was less than 1/2 and these results were expected to be caused by the difference of substrate specificity of the TGases. [source] Electrolytic ablation is as effective as radiofrequency ablation in the treatment of artificial liver metastases in a pig modelJOURNAL OF SURGICAL ONCOLOGY, Issue 2 2008Sebastian Hinz MD Abstract Background The best treatment option for liver metastases is complete surgical resection. Unfortunately, at the time of diagnosis, not all patients are candidates for complete resection. Electrolytic therapy (ECT) is a novel non-thermal method of tissue destruction. We evaluated its safety and effectiveness in comparison with radiofrequency ablation (RFA). Methods Tumor mimics were created by injecting a gel into the pig liver. The volume of the lesions was measured by ultrasound before treatment. The tumor mimics were treated with either RFA or electrolytic ablation. 48 h after treatment the liver was fixed in formalin and subjected to histological examination. Results Histological investigation confirmed that all lesions were completely surrounded by necrosis after treatment with either ECT or RFA. Two different types of necrosis were identified. After RFA the cell membranes disappeared but the nuclei were still intact, whereas after ECT these structures were completely disrupted. After ECT the necrosis was often surrounded by infiltrating lymphocytes. This inflammatory reaction was not apparent after RFA. Conclusion ECT produced predictable and reproducible necrosis in pig livers and was as effective as RFA at destroying a defined target lesion. A local inflammatory reaction after ECT may favour the development of a systemic immune response. Our results indicate that ECT is an alternative treatment option for irresectable liver metastases. J. Surg. Oncol. 2008;98:135,138. © 2008 Wiley-Liss, Inc. [source] Interspecies differences in hepatic Ca2+ -ATPase activity and the effect of cold preservation on porcine liver Ca2+ -ATPase functionLIVER TRANSPLANTATION, Issue 2 2001Piotr K. Janicki MD The accumulation of intracellular calcium ([Ca2+]i) caused by ischemia-reperfusion during liver transplantation has been implicated as a factor leading to primary graft nonfunction. Plasma membrane (PM) and endoplasmic reticulum (ER) Ca2+ -adenosinetriphosphatases (ATPases) are the primary transporters that maintain [Ca2+]i homeostasis in the liver. We hypothesized that the porcine liver is better than the rat liver as a model for the study of human liver Ca2+ -ATPase activity. We also hypothesized that cold preservation would depress Ca2+ -ATPase activity in the porcine liver. Pig and rat livers were harvested, and human liver samples were obtained from surgical resection specimens. All were preserved with University of Wisconsin solution, and porcine livers were also preserved on ice for 2 to 18 hours. Ca2+ -ATPase activity was measured after incubation with 45Ca2+ and adenosine triphosphate in the presence of specific Ca2+ -ATPase inhibitors. Porcine PM and ER Ca2+ -ATPase activities were 0.47 ± 0.03 and 1.57 ± 0.10 nmol of Ca2+/mg of protein/min, respectively. This was not significantly different from human liver, whereas rat liver was significantly greater at 2.60 ± 0.03 and 9.2 ± 0.9 nmol of Ca2+/mg of protein/min, respectively. We conclude that the Ca2+ -ATPase activity in the pig liver is equivalent to that of human liver, and thus, the pig liver is a better model than the rat liver. Cold preservation studies showed a significant decrease in porcine hepatic PM Ca2+ -ATPase activity after 4 hours of storage and near-total inhibition after 12 hours. Porcine hepatic ER Ca2+ -ATPase activity showed a 45% decrease in activity by 12 hours and a 69% decrease by 18 hours. We conclude that cold ischemia at clinically relevant times depresses PM Ca2+ -ATPase more than ER Ca2+ -ATPase activity in pig liver homogenates. [source] Determination of nucleic acid by [tetra-(3-methoxy-4-hydroxyphenyl)],Tb3+ porphyrin as the fluorescence spectral probe in bis(2-ethylhexyl)sulfosuccinate sodium salt micelle systemLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4 2009Xin Chen Abstract A new system for the determination of nucleic acid by rare earth metallic porphyrin of [tetra-(3-methoxy-4-hydroxyphenyl)],Tb3+ [T(3-MO-4HP),Tb3+] porphyrin as fluorescence spectral probe has been developed in this paper. Nucleic acid can enhance the fluorescence intensity of the T(3-MO-4HP),Tb3+ porphyrin in the presence of bis(2-ethylhexyl)sulfosuccinate sodium salt(AOT) micelle. In pH 8.00 Tris,HCl buffer solution, under optimum conditions, the enhanced fluorescence intensity is in proportion to the concentration of nucleic acids in the range of 0.05,3.00 µg mL,1 for calf thymus DNA (ct DNA) and 0.03,4.80 µg mL,1 for fish sperm DNA(fs DNA). Their detection limits are 0.03 and 0.01 µg mL,1, respectively. In addition, the binding interaction mechanism between T(3-MO-4HP),Tb3+ porphyrin and ct DNA is also investigated by resonance scattering and fluorescence spectra. The maximum binding number is calculated by molar ratio method. The new system can be used for the determination of nucleic acid in pig liver, yielding satisfactory results. Copyright © 2009 John Wiley & Sons, Ltd. [source] MR temperature measurement in liver tissue at 0.23 T with a steady-state free precession sequenceMAGNETIC RESONANCE IN MEDICINE, Issue 5 2002D. Germain Abstract MRI can be used for monitoring temperature during a thermocoagulation treatment of tumors. The aim of this study was to demonstrate the suitability of a 3D steady-state free precession sequence (3D Fast Imaging with Steady-State Precession, 3D TrueFISP) for MR temperature measurement at 0.23 T, and to compare it to the spin-echo (SE) and spoiled 3D gradient-echo (3D GRE) sequences. The optimal flip angle for the TrueFISP sequence was calculated for the best temperature sensitivity in the image signal from liver tissue, and verified from the images acquired during the thermocoagulation of excised pig liver. Factors influencing the accuracy of the measured temperatures are discussed. The TrueFISP results are compared to the calculated values of optimized SE and 3D GRE sequences. The accuracy of TrueFISP in the liver at 0.23 T, in imaging conditions used during thermocoagulation procedures, is estimated to be ±3.3°C for a voxel of 2.5 × 2.5 × 6 mm3 and acquisition time of 18 s. For the SE and GRE sequences, with similar resolution and somewhat longer imaging time, the uncertainty in the temperature is estimated to be larger by a factor of 2 and 1.2, respectively. Magn Reson Med 47:940,947, 2002. © 2002 Wiley-Liss, Inc. [source] Impact of Thrombocytopenia on Survival of Baboons with Genetically Modified Pig Liver Transplants: Clinical RelevanceAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2010B. Ekser A lack of deceased human donor livers leads to a significant mortality in patients with acute-on-chronic or acute (fulminant) liver failure or with primary nonfunction of an allograft. Genetically engineered pigs could provide livers that might bridge the patient to allotransplantation. Orthotopic liver transplantation in baboons using livers from ,1,3-galactosyltransferase gene-knockout (GTKO) pigs (n = 2) or from GTKO pigs transgenic for CD46 (n = 8) were carried out with a clinically acceptable immunosuppressive regimen. Six of 10 baboons survived for 4,7 days. In all cases, liver function was adequate, as evidenced by tests of detoxification, protein synthesis, complement activity and coagulation parameters. The major problem that prevented more prolonged survival beyond 7 days was a profound thrombocytopenia that developed within 1 h after reperfusion, ultimately resulting in spontaneous hemorrhage at various sites. We postulate that this is associated with the expression of tissue factor on platelets after contact with pig endothelium, resulting in platelet and platelet-peripheral blood mononuclear cell(s) aggregation and deposition of aggregates in the liver graft, though we were unable to confirm this conclusively. If this problem can be resolved, we would anticipate that a pig liver could provide a period during which a patient in liver failure could be successfully bridged to allotransplantation. [source] Crystallization and preliminary X-ray diffraction analysis of thermophilic imidase from pig liverACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2003Cheng-Yang Huang Imidase is an enzyme, also known as dihydropyrimidinase (EC 3.5.2.2), hydantoinase, dihydropyrimidine hydrase or dihydropyrimidine amidohydrolase, that catalyzes the reversible hydrolysis of 5,6-dihydrouracil to 3-ureidopropionate and many other imides. Substrate specificity, metal content and amino-acid sequence all differ significantly between bacterial and mammalian imide-hydrolyzing enzymes. In this study, a thermophilic imidase was isolated from pig liver and crystallized. Two kinds of imidase crystals were grown by the hanging-drop vapour-diffusion method using polyethylene glycol MME 5000 and 2-propanol as precipitants. One belongs to the triclinic P1 space group, with unit-cell parameters a = 96.35, b = 96.87, c = 154.87,Å, , = 82.10, , = 72.54, , = 77.19°, and the other belongs to the orthorhombic C2221 space group, with unit-cell parameters a = 113.92, b = 157.22, c = 156.21,Å. [source] Electrolytic ablation is as effective as radiofrequency ablation in the treatment of artificial liver metastases in a pig modelJOURNAL OF SURGICAL ONCOLOGY, Issue 2 2008Sebastian Hinz MD Abstract Background The best treatment option for liver metastases is complete surgical resection. Unfortunately, at the time of diagnosis, not all patients are candidates for complete resection. Electrolytic therapy (ECT) is a novel non-thermal method of tissue destruction. We evaluated its safety and effectiveness in comparison with radiofrequency ablation (RFA). Methods Tumor mimics were created by injecting a gel into the pig liver. The volume of the lesions was measured by ultrasound before treatment. The tumor mimics were treated with either RFA or electrolytic ablation. 48 h after treatment the liver was fixed in formalin and subjected to histological examination. Results Histological investigation confirmed that all lesions were completely surrounded by necrosis after treatment with either ECT or RFA. Two different types of necrosis were identified. After RFA the cell membranes disappeared but the nuclei were still intact, whereas after ECT these structures were completely disrupted. After ECT the necrosis was often surrounded by infiltrating lymphocytes. This inflammatory reaction was not apparent after RFA. Conclusion ECT produced predictable and reproducible necrosis in pig livers and was as effective as RFA at destroying a defined target lesion. A local inflammatory reaction after ECT may favour the development of a systemic immune response. Our results indicate that ECT is an alternative treatment option for irresectable liver metastases. J. Surg. Oncol. 2008;98:135,138. © 2008 Wiley-Liss, Inc. [source] Segmental nature of the porcine liver and its potential as a model for experimental partial hepatectomy,BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2003F. G. Court Background: In-depth knowledge of pig liver anatomy allows potential research into segmental liver resections and hepatic regeneration, as well as liver transplantation techniques. The segmental anatomy, however, remains largely unknown. This study aimed to delineate the segmental anatomy of the porcine liver in comparison with that of the human. Methods: The segmental anatomy of the porcine liver was determined using acrylic injection casting of ex vivo pig livers, allowing the arterial, venous and biliary supply to be visualized directly. This was correlated using multi-slice computed tomography (CT) and three-dimensional reconstructions. Results: Although the external morphology of the porcine liver differs from that of the human, the segmental anatomy is remarkably similar in term of its vascularity and biliary tree. Conclusion: Acrylic casting of the porcine liver accurately delineates the vascular and biliary anatomy, and is a useful tool for performing experimental liver surgery. The similarities between porcine and human segmental anatomy allow domestic swine to be used as a comparable model. Three-dimensional CT reconstructions can also accurately visualize the anatomy and may be used to perform virtual surgery, or to assess segmental volumes. Copyright © 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] | |||||||||||||