Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Factor VIII deficient plasma was made from pooled, HIV antibody and hepatitis B antigen screened, normal human plasma by cryoprecipitation and immuno-depletion, using three different monoclonal antibodies bound to Sepharose columns, in series. These monoclonal antibodies are specific respectively for von Willebrand factor, factor VIII heavy chain and factor VIII light chain. The immunodepleted plasma contained less than 0.002 u/ml factor VIII coagulation activity (VIII:C) less than 0.0001 u/ml von Willebrand factor antigen and 1-2 g/l fibrinogen, while the levels of other clotting factors were unchanged. This immunodepleted plasma was compared with commercial factor VIII deficient plasma obtained from a severe haemophilia A patient as substrate in the one-stage factor VIII assay. Plasmas obtained from 20 normal subjects and 28 patients with von Willebrand's disease or haemophilia A were assayed for VIII:C using the two substrates. The results were very highly correlated (r = 0.96). The columns have high capacity and can be regenerated at least 10 times. Large-scale production of a substrate for factor VIII assays free of virus contamination is now feasible.
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PMID:Production of factor VIII deficient plasma by immunodepletion using three monoclonal antibodies. 311 89

Titrated stocks of hepatitis B virus and Hutchinson strain non-A, non-B hepatitis virus were diluted in normal serum to contain, respectively, greater than or equal to 10(6) and greater than or equal to 10(4) chimpanzee infectious doses (CID50) per milliliter and exposed to 1% Tween 80 and 20% ether at 4 degrees C for 18 h. After evaporation of the ether, the treated sera were each inoculated into two chimpanzees. The animals remained free of serologic and biochemical evidence of hepatitis during a 6-month follow-up period, and were then shown to be susceptible to infection by challenge with the original untreated inocula. To assess the effect of exposure to Tween 80/ether on coagulation factors, four lots of antihemophilic factor (AHF) concentrate and 2 lots of commercial factor IX concentrate were treated as above. For the AHF concentrate there was an average of 70% recovery of factor VIII procoagulant activity, 93% recovery of factor VIII-related antigen, and 73% recovery of fibronectin opsonin activity and no detectable change in ristocetin cofactor activity or in fibronectin antigen. Crossed immunoelectrophoresis revealed no change in migration rate of fibrinogen, fibronectin, and von Willebrand factor (vWF), although the quantity of fibrinogen was reduced. Factor VIII procoagulant activity and vWF activity remained associated during chromatography on BioGel A15.
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PMID:Inactivation of hepatitis B and Hutchinson strain non-A, non-B hepatitis viruses by exposure to Tween 80 and ether. 642 34

In the last few years, plasma fractionation has been subjected to major technological changes which have contributed to improve the viral safety and overall purity of plasma derivatives. New viral inactivation treatments, primarily solvent-detergent and pasteurization, have been introduced in the manufacturing processes of plasma derivatives to ensure the inactivation of major plasma-borne viruses, including HIV and hepatitis B and C viruses. Concurrently, new highly purified products obtained by chromatographic methods (mainly ion exchange and/or immunopurification) have been developed in the last five years and have replaced former preparations, providing a significantly higher safety level in terms of purity and viral risks. For an example, the new generation of Factor VIII and Factor IX concentrates (to treat hemophilia A and hemophilia B, respectively), which have been introduced in the last five years, are purified over 10,000- to 20,000-fold from plasma, as compared to only 50- to 100-fold for the former products. Similarly, new, standardized, clotting factor or protease inhibitor concentrates have been made available, thus permitting to carry out selective hemotherapy of specific diseases. Examples include the development of von Willebrand factor, factor XI, protein C, or alpha 1-antitrypsin concentrates for the substitutive therapy of congenital or acquired deficiencies. In addition, the concept of good manufacturing practices has been implemented, whereas carefully controlled, validated processes are contributing to the consistency in the quality of those products. Current major problems in plasma fractionation relate to the potential occurrence of new pathogenic agents that could resist present viral inactivation treatments and to the potential effect of given purification technologies on the development of immunogenic properties of proteins. Current trends indicate that significant progress in viral safety of plasma derivatives (for example through the introduction of new concept such as viral filtration) are to be expected very soon. Further research in this very important field is mandatory as plasma should remain the starting material of important therapeutic products in the coming years.
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PMID:[Plasma fractionation. Progress, problems and perspectives]. 799 59

Selection of an optimal promoter is necessary for efficient expression of foreign genes with vaccinia virus. Since a variety of powerful (homologous) vaccinia virus promoters and foreign (heterologous) promoter systems have been described for use in vaccinia, we have addressed the question of whether a general rule exists that allows the prediction of the optimal promoter/gene combination. We have compared the expression properties of four secreted proteins, the human blood clotting factor IX (FIX), the human blood glycoprotein Protein S (ProtS), the human von Willebrand factor (vWF), and the Hepatitis B virus (HBV) middle surface glycoprotein preS2, with proteins that were reported not to be secreted, the HBV large surface glycoprotein preS1 and the murine leukemia virus (MuLV) BM-5 Eco gag protein. In addition, we have included in our study an internal control protein, the vaccinia virus p11 protein, to monitor possible side effects of the promoter system used. Genes encoding the foreign proteins were placed either under control of a synthetic vaccinia virus early/late promoter (selP) or under control of the bacteriophage T7 promoter (T7/emc system). The secreted proteins were more efficiently expressed when fused to the homologous promoter. Direct comparison of the two promoters indicated that the expression level ranged between 1.4 (ProtS) and 3.9 (FIX)-fold higher with the selP than with the T7 promoter. In contrast, the cell-associated HBV preS1 was more efficiently expressed under the T7 promoter and the MuLV BM-5 Eco gag polypeptide was expressed equally well from both promoters. These data indicate that a careful prediction of optimal promoter/foreign gene combinations for the vaccinia virus expression system is possible. The choice of the optimal promoter/expression system is based on a simple classification scheme, discriminating secreted and nonsecreted proteins.
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PMID:Requirements for optimal expression of secreted and nonsecreted recombinant proteins in vaccinia virus systems. 853 47

The study documents the immunohistochemical features of a case of infantile hemangioendothelioma (IHE) of the liver, which was found incidentally at autopsy in a 44-day-old girl. A precardial apical systolic murmur and hepatomegaly were found on day 4 of life. The tumor was multifocal and histologically composed of vascular channels lined by endothelial cells that were positive for von Willebrand factor, CD31, vimentin, and Ulex europaeus agglutinin 1, and that were invested in a continuous basement membrane (BM) on the antiluminal border. The endothelial cells, especially in the region of intravascular buds, showed intracytoplasmic synthesis of BM components (laminin and collagen IV). Underlying the endothelial cells were cells with cytoplasm that was positive for alpha-smooth muscle actin and antimuscle actin and negative for desmin, and that were enveloped with BM. The immunophenotype, appearance, and location of these cells are characteristic of pericytes. We found neither signs of endocrine secretion nor hepatitis B virus in the tumor tissue. The appearance of this tumor in the neonatal period supports a fetal origin of IHE.
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PMID:Infantile hemangioendothelioma of the liver in a neonate. Immunohistochemical observations. 866 36

Von Willebrand disease (VWD) is the most commonly inherited bleeding disorder, caused by inheritance of a quantitative or qualitative abnormality of von Willebrand factor (VWF). While the majority of patients with VWD are successfully treated with adjunctive therapies or with the synthetic vasopressin analog desmopressin acetate (DDAVP), a subset of patients requires replacement therapy. In the past, cryoprecipitate was the mainstay of therapy; however, it was associated with seroconversion to hepatitis B (HBV), hepatitis C (HCV), and the human immunodeficiency virus (HIV) in treated individuals. With the advent of virucidal methodology and, more recently, nucleic acid testing (NAT) of plasma fractions, the plasma-derived concentrates containing VWF are now considered the therapeutic standard of care.
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PMID:Advances in the treatment of von Willebrand disease. 1168 20

Effects of a 4-week course of recombinant human erythropoietin (rHuEpo) therapy on four circulating endothelium-derived cardiovascular risk markers were studied in 20 patients receiving maintenance hemodialysis in relation to surrogates of chronic inflammation, liver function, and arterial blood pressure. Soluble intercellular adhesion molecule-1 (sICAM-1), antigens of plasminogen activator inhibitor-1 (PAI-1:Ag) and von Willebrand factor (vWF:Ag), and soluble thrombomodulin (sTM) were determined by immunoenzymatic assays. C-reactive protein; alpha1 acid-glycoprotein; alpha1-antitrypsin; immunoglobulin M, A, and G; interleukin-6; lipoprotein(a); fibrinogen; total protein; albumin; total cholesterol; hepatitis B and C markers; liver enzymes; prothrombin time; and phosphorus were measured by routine methods. The rHuEpo treatment resulted in a 25% increase in sICAM-1 (Wilcoxon's p = 0.001), a 50% increase in PAI-1:Ag (p = 0.004), a 15% increase in sTM (p = 0.002), and did not change vWF:Ag levels. The increase in sICAM-1 concentration directly correlated with that of PAI-1:Ag (Spearman's rho = 0.483, p = 0.031). The rHuEpo-induced increases in hemoglobin, platelets, and pre-dialysis diastolic blood pressure levels did not correlate with the increments in the endothelial markers studied. In conclusion, short-term rHuEpo therapy activates vascular endothelium in patients receiving maintenance hemodialysis. This specific effect may influence cardiovascular risk.
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PMID:Effects of recombinant erythropoietin therapy on circulating endothelial markers in hemodialysis patients. 1465 47

It has been demonstrated that CD34-positive cells isolated from human peripheral blood differentiate into endothelial cells and contribute to neoangiogenesis in adults. We investigated the role of CD34-positive endothelial cells in liver samples from patients with hepatitis B virus (HBV)-associated chronic liver diseases. Tissue sections were obtained by liver biopsy from 25 patients with HBV-associated chronic liver diseases and were examined by immunohistochemistry using anti-CD34, anti-von Willebrand factor (vWF), and anti-vascular endothelial growth factor (VEGF) antibodies. CD34-positive, but vWF-negative endothelial cells were observed, particularly in the sinusoids and vascular endothelial cells. We counted these cells and expressed the results as a CD34-labeling index (LI). The CD34 LI did not correlate with VEGF expression and the CD34 LI of patients who progressed to hepatocellular carcinoma (HCC) tended to increase compared to those that did not progress to HCC. CD34 LI was an independent risk factor for development of HCC (relative risk, 35.689; P = 0.033). We conclude that CD34-positive endothelial cells in patients with HBV-associated chronic liver diseases might play a role in hepatocarcinogenesis.
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PMID:Expression of CD34-positive sinusoidal endothelial cells in patients with HBV-associated chronic liver diseases. 1525 62

Protein products fractionated from human plasma are an essential class of therapeutics used, often as the only available option, in the prevention, management, and treatment of life-threatening conditions resulting from trauma, congenital deficiencies, immunologic disorders, or infections. Modern plasma product production technology remains largely based on the ethanol fractionation process, but much has evolved in the last few years to improve product purity, to enhance the recovery of immunoglobulin G, and to isolate new plasma proteins, such as alpha1-protease inhibitor, von Willebrand factor, and protein C. Because of the human origin of the starting material and the pooling of 10,000 to 50,000 donations required for industrial processing, the major risk associated to plasma products is the transmission of blood-borne infectious agents. A complete set of measures--and, most particularly, the use of dedicated viral inactivation and removal treatments--has been implemented throughout the production chain of fractionated plasma products over the last 20 years to ensure optimal safety, in particular, and not exclusively, against HIV, hepatitis B virus, and hepatitis C virus. In this review, we summarize the practices of the modern plasma fractionation industry from the collection of the raw plasma material to the industrial manufacture of fractionated products. We describe the quality requirements of plasma for fractionation and the various treatments applied for the inactivation and removal of blood-borne infectious agents and provide examples of methods used for the purification of the various classes of plasma protein therapies. We also highlight aspects of the good manufacturing practices and the regulatory environment that govern the whole chain of production. In a regulated and professional environment, fractionated plasma products manufactured by modern processes are certainly among the lowest-risk therapeutic biological products in use today.
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PMID:Modern plasma fractionation. 1739 61

Efficient hemodialysis requires establishing a permanent stable vascular access. Our study was designed to evaluate formaldehyde-fixed arterial allografts as hemodialysis access for end-stage renal disease. Various parameters were determined for 68 formaldehyde-fixed, cadaver-derived allografts transplanted into 43 hemodialysis patients. The sources of the allografts were determined to be free of cytomegalovirus, hepatitis B and hepatitis C, and HIV infections. These allografts were monitored for rejection, blood flow, patency rates, and complications. Overall, antigenicity of the allografts was reduced after formaldehyde fixation with no acute rejection. The mean access blood flow was 696+/-282 ml with reasonable primary and secondary patency rates even after 3 years. Allograft intimal hyperplasia, determined by immunohistochemistry, was evident as the proliferation of smooth muscle-like cells expressing actin but cells not expressing the endothelial markers von Willebrand factor or CD34. The incidence of thrombus formation was about 37% after allograft transplant with other limited complications of pseudoaneurysms and local infection. Our results support the clinical use of formaldehyde-fixed arterial allografts for hemodialysis access.
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PMID:Clinical studies of hemodialysis access through formaldehyde-fixed arterial allografts. 1797 6


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