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1.
Value Health Reg Issues ; 14: 28-32, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29254538

ABSTRACT

OBJECTIVES: To assess the impact on the 2015 national health budget of incorporating Daclatasvir/Asunaprevir (DCV / ASV) for the treatment of Hepatitis C genotype 1b (HC1b) in Chile. METHODS: A Chilean HC1b patients cohort was modelled using local prevalence and incidence data. Two scenarios were built and compared, one were all patients receive Peginterferon/Ribavirin (PR) and another were all patients are treated with DCV/ASV. The analysis was conducted from the perspective of public health system of Chile assuming 100% reimbursement and a time horizon of 5 years. Costs associated with drug treatment, adverse events, other relevant resources and costs associated with disease complications were used. RESULTS: At a total DCV/ASV treatment price of USD $55,039, an additional of USD $65,6MM are required during the first year (prevalent cases) equivalent to 0.71% of the 2015 national health budget. From year 2 (incident cases), an additional of USD $12,3MM are needed (0.13% of the 2015 health budget). A price reduction of 33% (USD $36,693), requires an additional of USD $38,2MM the first year and USD $7,16MM from the second year (0.11% and 0.6% of the health budget). If the treatment price is reduced further (USD $18,347), an additional USD $10,9MM are required for the first year and USD $2,03MM from the second year (0.3% and 0.057% of the 2015 heath budget). CONCLUSION: The impact on the health budget ranges between 0.3% and 0.71% the first year and decreases to less than 0.15% from the second year considering the price assessed price range.


Subject(s)
Antiviral Agents/therapeutic use , Cost-Benefit Analysis , Drug Therapy, Combination , Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/economics , Public Health , Antiviral Agents/economics , Carbamates , Chile/epidemiology , Cohort Studies , Genotype , Hepacivirus/genetics , Hepacivirus/physiology , Hepatitis C, Chronic/epidemiology , Humans , Imidazoles , Interferon-alpha/therapeutic use , Isoquinolines , Polyethylene Glycols/therapeutic use , Protease Inhibitors , Pyrrolidines , Recombinant Proteins/therapeutic use , Ribavirin/therapeutic use , Sulfonamides , Valine/analogs & derivatives
2.
Aliment Pharmacol Ther ; 45(9): 1225-1231, 2017 05.
Article in English | MEDLINE | ID: mdl-28261844

ABSTRACT

BACKGROUND: Per-oral tacrolimus administration is not always practicable. Sublingual administration is a potential alternative, but its feasibility and effectiveness compared with oral route has not been established. AIM: To compare tacrolimus drug exposure after sublingual and oral administration in liver transplant recipients. METHODS: Experimental, open-label, non-randomised, cross-over study. Tacrolimus exposure was evaluated in 32 liver transplant recipients receiving oral administration. 12 h tacrolimus area-under-the-curve (AUC0-12 h ) was calculated using tacrolimus blood concentrations at 0-0.5-1-2-4-6-8-12 hrs post-dose. Recipients were switched to sublingual administration, and dose was adjusted to reach similar trough levels, new AUC0-12 h was calculated. Correlation between AUC0-12 h and trough levels was determined for both oral and sublingual phases. RESULTS: Similar trough levels were accomplished with oral and sublingual administration (6.68 ± 2 ng/mL vs. 6.62 ± 1.9 ng/mL (P = 0.8)). Although concentration 2 h post dose was higher in oral phase (15.36 ± 7.14 vs. 13.18 ± 5.64, P = 0.015), AUC0-12 h was similar in both phases (116.6 ± 34.6 vs. 111.5 ± 36.93 ng/mL* h, P = 0.19). Daily dose of tacrolimus required in sublingual phase was 37% lower than that used in oral phase (P < 0.0001), suggesting significantly increased bioavailability of tacrolimus when employing sublingual route. Good correlation between AUC0-12 h and trough levels was observed in sublingual phase (r2 = 0.74). Twenty-two recipients were maintained on sublingual administration after the end of study (mean follow-up: 18.7 ± 5.8 months). No difference in liver function tests or rejection rates was found during follow-up period. CONCLUSIONS: Sublingual administration of tacrolimus is feasible and provides similar drug exposure compared with oral administration. In our study, at long-term follow-up, sublingual administration was not associated with liver transplant rejection.


Subject(s)
Immunosuppressive Agents/administration & dosage , Liver Transplantation , Tacrolimus/administration & dosage , Administration, Oral , Administration, Sublingual , Aged , Biological Availability , Cross-Over Studies , Female , Humans , Immunosuppressive Agents/blood , Immunosuppressive Agents/pharmacokinetics , Immunosuppressive Agents/therapeutic use , Male , Middle Aged , Pilot Projects , Tacrolimus/blood , Tacrolimus/pharmacokinetics , Tacrolimus/therapeutic use
3.
J Viral Hepat ; 20(4): 263-72, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23490371

ABSTRACT

Hepatitis C virus (HCV) is mainly hepatotropic; however, several reports document the presence of genomic viral RNA in extrahepatic sites including peripheral blood mononuclear cells (PBMCs). In this study, the presence of HCV RNA was initially evaluated in the plasma and peripheral blood mononuclear cells (PBMCs) of 53 HCV-infected patients who were treated per protocol. PBMC-associated HCV RNA was detectable in 79% of patients. Early virological response to combined pegylated interferon-α (PegIFN) and ribavirin (RBV) therapy in patients with undetectable levels of PBMCs-associated HCV RNA was 100%, while it was 60% (P = 0.003) in those who had detectable levels of PBMC-associated HCV RNA. A sustained virological response was observed in 35% of patients with detectable PBMC-associated HCV RNA, but was 70% in patients with undetectable levels of PBMC-associated HCV RNA (P = 0.07). In a multivariate analysis incorporating parameters such as HCV genotype, viral load, presence of cirrhosis and absence of PBMC-associated HCV RNA, a significant relationship was observed between the detection of PBMC-associated HCV RNA and the sustained virological response (OR 19.4, 95% CI: 2.1-486.2, P = 0.0061). The association between single nucleotide polymorphism (SNP) in IL28B, known predictor of antiviral therapy outcome, and the occurrence of HCV RNA in PBMC in 84 chronically infected patients was then evaluated. Results suggest that the presence of a G allele in rs8099917, known to associate to a poor response to PegIFN/RBV therapy, also predicts an increased association of HCV RNA with PBMC (OR: 3.564; 95% CI: 1.114-11.40, P = 0.0437).


Subject(s)
Hepacivirus/isolation & purification , Hepatitis C, Chronic/genetics , Hepatitis C, Chronic/immunology , Interleukins/genetics , Leukocytes, Mononuclear/virology , Polymorphism, Single Nucleotide , RNA, Viral/isolation & purification , Adult , Aged , Antiviral Agents/therapeutic use , Female , Hepatitis C, Chronic/drug therapy , Humans , Interferons/therapeutic use , Male , Middle Aged , Ribavirin/therapeutic use , Treatment Outcome
4.
Aliment Pharmacol Ther ; 31(9): 1018-27, 2010 May.
Article in English | MEDLINE | ID: mdl-20163377

ABSTRACT

BACKGROUND: Chronic infection with hepatitis C, genotype 2/3, responds better than other genotypes to peginterferon and ribavirin treatment. We hypothesized that a lower dose of peginterferon would be as effective, but less toxic than standard doses. AIM: To test the hypothesis that a lower dose of peginterferon would be as effective as, but less toxic than, standard doses. METHODS: A total of 30 patients were treated with low-dose peginterferon alfa-2a (90 microg/week) and 27 patients with standard doses (180 microg/week) for 24 weeks in combination with 800 mg/day of ribavirin. Patients who failed treatment were offered 48 weeks of standard-dose treatment. Viral and serum inducible protein 10 (IP-10) levels were measured and early viral kinetic parameters were calculated. RESULTS: Sustained virological response was achieved in 68% of the low-dose and 87% of the standard-dose patients (per protocol, P = 0.79 for non-inferiority). Re-treatment was successful in all patients who tolerated full dose and duration. The standard-dose group had greater first-phase declines of viral levels and faster time to negativity. The second-phase slope was not dose-dependent. IP-10 induction was significantly greater with the standard dose. Although fatigue and general feeling during treatment were worse for standard dose, haematological toxicity and depression did not differ between groups. CONCLUSION: A lower dose of peginterferon is associated with some symptomatic benefit, but the response is not equivalent to standard dosing.


Subject(s)
Antiviral Agents/therapeutic use , Hepatitis C, Chronic/drug therapy , Interferon-alpha/administration & dosage , Polyethylene Glycols/administration & dosage , Ribavirin/administration & dosage , Adult , Aged , Cytokines/metabolism , Dose-Response Relationship, Drug , Drug Therapy, Combination , Female , Genotype , Humans , Interferon alpha-2 , Male , Middle Aged , RNA, Messenger/metabolism , Recombinant Proteins , Treatment Outcome
5.
Transplant Proc ; 42(1): 299-301, 2010.
Article in English | MEDLINE | ID: mdl-20172336

ABSTRACT

UNLABELLED: Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver. Liver transplantation is the best treatment for HCC; it improves survival, cures cirrhosis, and abolishes local recurrence. We describe the outcomes of patients with HCC who underwent liver transplantation in two liver transplantation centers in Chile. METHODS: This study is a clinical series elaborated from the liver transplantation database of Pontificia Universidad Católica and Clínica Alemana between 1993 and 2009. The survival of patients was calculated using the Kaplan-Meier survival analysis. The significant alpha level was defined as <.05. RESULTS: From 250 liver transplantations performed in this period, 29 were due to HCC. At the end of the study, 25 patients (86%) were alive. The mean recurrence-free survival was 30 months (range 5 months to 8 years). The 5-year survival for patients transplanted for HCC was >80%; however, the 5-year overall survival of patients who exceeded the Milan criteria in the explants was 66%. There was no difference in overall survival between patients transplanted for HCC versus other diagnosis (P = .548). CONCLUSION: This series confirmed that liver transplantation is a good treatment for patients with HCC within the Milan criteria.


Subject(s)
Carcinoma, Hepatocellular/surgery , Liver Neoplasms/surgery , Liver Transplantation/physiology , Alcoholism/complications , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/virology , Chile , Female , Hepatitis B/complications , Hepatitis C/complications , Humans , Liver Neoplasms/etiology , Liver Neoplasms/virology , Liver Transplantation/mortality , Male , Middle Aged , Retrospective Studies , Survival Analysis
6.
Transplant Proc ; 42(1): 296-8, 2010.
Article in English | MEDLINE | ID: mdl-20172335

ABSTRACT

BACKGROUND: Orthotopic liver transplantation (OLT) is currently an established therapy for small, early-stage hepatocellular carcinoma (HCC) within the Milan criteria. Long waiting times due to the shortage of donor organs can result in tumor progression and drop-out from OLT candidacy. Therefore a wide variety of procedures are necessary before OLT. The aim of this retrospective study was to review our experience in relation to bridge therapy prior to OLT for HCC. METHODS: This was a retrospective database review of all of the patient who underwent transplantation in our institutions between January 1993 and June 2009. We analyzed patients with a diagnosis of HCC in the explant. RESULTS: Among 29 patients, including 12 who were diagnosed by the explant and 17 prior to transplantation, 88% underwent bridge therapy during a mean waiting time to OLT of 12 months. Among the 23 procedures, namely 1.5 procedures per patient, included most frequently chemoembolization (48%), alcohol ablation (30%), radiofrequency ablation (13%), and surgery (9%). Thirty-three percent of the explants contained lesions within the Milan criteria. In our series the 5-year survival rate for patients transplanted for HCC was 86%; in the bridge therapy group, it was 73%. CONCLUSIONS: The incidence of patients who underwent bridge therapy (52%) was similar to other reported experiences, but the fulfillment of Milan criteria in the explants was lower. Among the bridge therapy group, the survival was slightly lower, probably because this group displayed more advanced disease.


Subject(s)
Carcinoma, Hepatocellular/surgery , Liver Neoplasms/surgery , Liver Transplantation/methods , Alcoholism/complications , Carcinoma, Hepatocellular/etiology , Catheter Ablation , Chemoembolization, Therapeutic , Chile , Female , Hepatitis B/complications , Hepatitis C/complications , Humans , Liver Neoplasms/etiology , Liver Neoplasms/therapy , Liver Transplantation/mortality , Male , Retrospective Studies , Survival Analysis , Waiting Lists
7.
Lupus ; 18(6): 539-46, 2009 May.
Article in English | MEDLINE | ID: mdl-19395456

ABSTRACT

The role of autoantibodies in the pathogenesis of systemic lupus erythematosus (SLE) has not been completely defined. From more than a hundred autoantibodies described in SLE, relatively few have been associated with clinical manifestations. The glycan-binding proteins of the galectin family can modulate the immune system. Anti-galectin autoantibodies thus could have functional and/or pathogenic implications in inflammatory processes and autoimmunity. We previously reported function-blocking autoantibodies against galectin-8 (Gal-8) in SLE. Here we tested these autoantibodies against a series of other human galectins and demonstrated their specificity for Gal-8, being detectable in 23% of 78 SLE patients. Remarkably, they associated with lymphopenia (50% of 18 anti-Gal-8-positive versus 18% of 60 anti-Gal-8-negative cases, Fisher's Exact test two-tailed: P < 0.012). Lymphopenia is a common clinical manifestation in SLE, yet of unknown mechanism. In addition, six of eight patients with both lymphopenia and malar rash had anti-Gal-8 in their sera. Occurrence of these autoantibodies was not confined to SLE as we also found them in sera of patients with rheumatoid arthritis (16%) and septicemia (20%). This study thus establishes occurrence of specific anti-Gal-8 autoantibodies in autoimmune rheumatic diseases and in acute inflammation, with an apparent association to a clinical subset in SLE.


Subject(s)
Arthritis, Rheumatoid/immunology , Autoantibodies/immunology , Galectins/immunology , Lupus Erythematosus, Systemic/complications , Lymphopenia/immunology , Adolescent , Adult , Aged , Antigens, Neoplasm , Arthritis, Rheumatoid/complications , Arthritis, Rheumatoid/genetics , Autoantibodies/blood , Blotting, Western , Child , DNA/genetics , Electrophoresis, Polyacrylamide Gel , Female , Follow-Up Studies , Galectins/blood , Galectins/genetics , Gene Expression , Humans , Lupus Erythematosus, Systemic/genetics , Lupus Erythematosus, Systemic/immunology , Lymphopenia/complications , Lymphopenia/genetics , Male , Middle Aged , Polymerase Chain Reaction , Prospective Studies , Young Adult
8.
J Viral Hepat ; 16(9): 633-43, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19254350

ABSTRACT

Peripheral blood mononuclear cells (PBMCs) from 45 treatment naïve, HIV-negative, chronically hepatitis C virus (HCV)-infected patients were analyzed for the presence of HCV RNA. Viral RNA was detected in 73% of the studied patients. Single-strand conformation polymorphism assays and sequence analysis of the HCV 5'untranslated regions amplified from RNA recovered from both Plasma and PBMCs suggested virus compartmentalization in 57.6% of patients studied. In summary, our study presents evidence that HCV RNA can be found in PBMCs of treatment naïve chronically infected patients that are not immunocompromised or co-infected with the human immunodeficiency virus.


Subject(s)
Hepacivirus/classification , Hepacivirus/genetics , Hepatitis C, Chronic/virology , Leukocytes, Mononuclear/virology , Plasma/virology , 5' Untranslated Regions , Base Sequence , Female , Hepacivirus/isolation & purification , Humans , Male , Middle Aged , Molecular Sequence Data , Phylogeny , Polymorphism, Single-Stranded Conformational , RNA, Viral/genetics , RNA, Viral/isolation & purification , Sequence Alignment , Sequence Analysis, DNA
9.
Rheumatology (Oxford) ; 47(5): 622-6, 2008 May.
Article in English | MEDLINE | ID: mdl-18375405

ABSTRACT

OBJECTIVES: Autoantibodies against the 20S-proteasome display a broad diversity with a remarkably low frequency of individual cross-reactivity against the different subunits of the proteasome. Although their pathogenic and diagnostic significance remains obscure, an involvement in the clearance of circulating proteasomes as well as an interaction with the activity of the proteolytic complex was assumed in previous studies. METHODS: To investigate the anti-proteasome response in more detail and to disclose reactivities against former neglected subunits, two-dimensional electrophoresis followed by immunoblotting was used. As a novel antigen source, the immunosubunits LMP2 (beta1i) and LMP7 (beta5i) were expressed as recombinant proteins and employed in ELISA. RESULTS: The subunits Iota (alpha1) and Zeta (alpha5) of the outer rings as well as the catalytic subunit Delta (beta1) and all three immunosubunits [MECL-1 (beta2i), LMP2 (beta1i) and LMP7 (beta5i)] of the inner rings of the proteasome were identified as autoantigens for the first time. Using a panel of anti-proteasome antibody-positive sera of patients with SLE, autoimmune myositis (PM/DM) and primary Sjögren's syndrome (pSS), an autoimmune response was documented against LMP2 (beta1i) and LMP7 (beta5i) in all three patient groups in ELISA. CONCLUSIONS: The frequent autoimmune response against LMP2 (beta1i) and LMP7 (beta5i) might indicate a role of inflammatory processes in the primary induction of the anti-proteasomal immune reaction, while the diversity of the humoral response against the proteasome system supports the assumption of a specific antigen-driven process leading to these extended autoimmune reactivities.


Subject(s)
Autoantibodies/blood , Autoimmune Diseases/immunology , Proteasome Endopeptidase Complex/immunology , Adult , Aged , Cysteine Endopeptidases/immunology , Electrophoresis, Gel, Two-Dimensional , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Lupus Erythematosus, Systemic/immunology , Middle Aged , Multienzyme Complexes/immunology , Myositis/immunology , Prospective Studies , Sjogren's Syndrome/immunology , Statistics, Nonparametric
10.
J Immunol ; 165(2): 768-78, 2000 Jul 15.
Article in English | MEDLINE | ID: mdl-10878350

ABSTRACT

The proteasome is a large protease complex that generates most of the peptide ligands of MHC class I molecules either in their final form or in the form of N-terminally extended precursors. Upon the stimulation of cells with IFN-gamma, three constitutively expressed subunits of the 20S proteasome are replaced by the inducible subunits LMP2 (low-molecular mass polypeptide 2), LMP7, and MECL-1 (multicatalytic endopeptidase complex-like-1) to form so-called immunoproteasomes. We show in this study that overexpression of these three subunits in triple transfectants led to a marked enhancement in the H-2Ld-restricted presentation of the immunodominant nonameric epitope NP118, which is derived from the nucleoprotein (NP) of lymphocytic choriomeningitis virus. Overexpression of the alpha and beta subunits of the IFN-gamma-inducible proteasome regulator PA28, in contrast, did not have a comparable effect. In vitro, immunoproteasomes as compared with constitutive proteasomes generated higher amounts of 11- and 12-mer fragments containing the NP118 epitope. These are likely to be cytosolic precursors of NP118, as a proline anchor residue in the second position of NP118 may interfere with TAP-mediated transport of the nonameric epitope itself. In conclusion, we provide evidence that up-regulation of the three inducible subunits, LMP2, LMP7, and MECL-1, can result in a marked improvement of Ag presentation and that, depending on the epitope, PA28 and immunoproteasomes may differentially affect Ag processing.


Subject(s)
Adjuvants, Immunologic/biosynthesis , Antigen Presentation/immunology , Cysteine Endopeptidases/biosynthesis , Epitopes, T-Lymphocyte/metabolism , Immunodominant Epitopes/metabolism , Lymphocytic choriomeningitis virus/immunology , Multienzyme Complexes/biosynthesis , Protein Biosynthesis , Adjuvants, Immunologic/genetics , Adjuvants, Immunologic/physiology , Amino Acid Sequence , Animals , Antigen Presentation/genetics , Autoantigens , Cell Line , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/immunology , Cytosol/immunology , Cytosol/metabolism , Epitopes, T-Lymphocyte/genetics , H-2 Antigens/biosynthesis , H-2 Antigens/genetics , Histocompatibility Antigen H-2D , Hybridomas , Immunodominant Epitopes/genetics , Lymphocytic choriomeningitis virus/genetics , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Multienzyme Complexes/genetics , Multienzyme Complexes/immunology , Nucleoproteins/biosynthesis , Nucleoproteins/genetics , Nucleoproteins/immunology , Nucleoproteins/metabolism , Peptide Fragments/biosynthesis , Peptide Fragments/genetics , Peptide Fragments/immunology , Peptide Fragments/metabolism , Proteasome Endopeptidase Complex , Protein Precursors/biosynthesis , Protein Precursors/genetics , Proteins/genetics , Proteins/immunology , Transfection , Viral Proteins/biosynthesis , Viral Proteins/genetics , Viral Proteins/immunology , Viral Proteins/metabolism
11.
Mol Immunol ; 37(1-2): 13-9, 2000.
Article in English | MEDLINE | ID: mdl-10781831

ABSTRACT

PA28 is an interferon-gamma inducible modulator of proteasome function composed of two subunits, i.e. PA28alpha and PA28beta. Previously we showed that stabile overexpression of the PA28alpha subunit alone supported MHC class I antigen presentation of two viral epitopes. However, no information was obtained on the consequences when PA28alpha and PA28beta function in concert or when PA28beta is overexpressed on its own. Here we demonstrate that overexpression of PA28alpha and beta together is similarly efficient in supporting MHC class I antigen presentation of the MCMV pp89 9mer epitope as PA28alpha alone, excluding a potentially potentiating role of PA28beta. Surprisingly, and despite the fact that PA28beta alone was thought to be inactive and to only stabilize PA28 activity, overexpression of PA28beta also resulted in improved antigen presentation. However, by northernblot and immunoprecipitation experiments we show that while PA28alpha is able to act alone the observed effect in the PA28beta and PA28alphabeta transfectant cell lines is due to increased levels of PA28alphabeta complexes.


Subject(s)
Antigen Presentation , Epitopes , Histocompatibility Antigens Class I/biosynthesis , Interferon-gamma/pharmacology , Muromegalovirus/immunology , Proteins/physiology , Animals , Autoantigens , Cell Line , Mice , Proteasome Endopeptidase Complex , Rabbits , Transfection
12.
Eur J Immunol ; 30(12): 3672-9, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11169410

ABSTRACT

PA28alpha/beta is a regulatory complex of the 20S proteasome which consists of two IFN-gamma inducible subunits. Both subunits, alpha and beta, contribute equally to the formation of hexa- or heptameric rings which can associate with the 20S proteasome. Previously, we have shown that overexpression of the PA28alpha subunit enhanced the MHC class I-restricted presentation of two viral epitopes and that purified PA28alpha/beta accelerated T cell epitope generation by the 20S proteasome in vitro, indicating a role for PA28alpha/beta in antigen presentation. This conclusion was recently confirmed in PA28beta gene targeted mice which were severely deficient in MHC class I-restricted antigen presentation. These mice displayed a defect in the assembly of immunoproteasomes, suggesting that a lack of the proteasome subunits LMP2, LMP7, and MECL-1 may account for the deficiency in antigen presentation. In this study we investigated whether the effect of PA28alpha/beta on antigen presentation is dependent on a change of proteasome subunit composition. We have analyzed the assembly and subunit composition of proteasomes in fibroblast transfectants overexpressing both, alpha and beta subunits of PA28. In these transfectants we found a marked enhancement in the presentation of the immunodominant H-2Ld-restricted pp89 epitope of murine cytomegalovirus, although the 20S proteasome composition was the same as in recipient cells. We, therefore, conclude that PA28alpha/beta can enhance antigen processing independently of changes in 20S proteasome subunit composition or assembly.


Subject(s)
Antigen Presentation , Cysteine Endopeptidases/physiology , Multienzyme Complexes/physiology , Proteins/physiology , Animals , Autoantigens , Cysteine Endopeptidases/chemistry , Interferon-gamma/pharmacology , Mice , Mice, Inbred BALB C , Multienzyme Complexes/chemistry , Proteasome Endopeptidase Complex , Protein Subunits , Transfection
13.
Biol Chem ; 380(3): 293-7, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10223331

ABSTRACT

The generation of antigenic peptides bound and presented to the immune system by MHC class I molecules predominantly depends on the function of the proteasome system. Stimulation of cells with interferon gamma induces the incorporation of three active site bearing beta-subunits into the 20S proteasome and the formation of the PA28 proteasome modulator complex. PA28 alters the cleavage properties of the proteasome and enhances MHC class I antigen presentation. Thus, by cytokine induced change of the proteasome system cells may alter the proteolytic properties of the 20S proteasome and may render an organism more flexible in its peptide generation capacity.


Subject(s)
Cysteine Endopeptidases/immunology , Multienzyme Complexes/immunology , Muscle Proteins , Proteins/immunology , Enzyme Activation , Histocompatibility Antigens Class I/immunology , Humans , Immunity, Cellular , Interferon-gamma/immunology , Proteasome Endopeptidase Complex , Vaccination
14.
Rev Med Chil ; 127(12): 1487-91, 1999 Dec.
Article in Spanish | MEDLINE | ID: mdl-10835757

ABSTRACT

We report a 72 years old diabetic male that, after the use of combined amoxicillin-clavulanic acid, developed pruritus and jaundice. Liver function tests showed serum total bilirubin of 4.3 mg/dL aspartate aminotransferase 140 U/l (normal < 35 U/L), alanine aminotransferase 470 U/L (normal < 40) and alkaline phosphatases of 400 U/L (normal < 100). Serology for hepatitis A, B and C viruses was negative, ERCP showed a normal biliary tree and liver biopsy disclosed a cholestatic hepatitis. Ursodeoxycholic was started to relieve pruritus. Liver function tests improved shortly thereafter, suggesting that this drug may be useful in the treatment of drug induced cholestasis.


Subject(s)
Amoxicillin-Potassium Clavulanate Combination/adverse effects , Chemical and Drug Induced Liver Injury/etiology , Drug Therapy, Combination/adverse effects , Aged , Chemical and Drug Induced Liver Injury/blood , Chemical and Drug Induced Liver Injury/drug therapy , Cholagogues and Choleretics/therapeutic use , Follow-Up Studies , Humans , Liver/pathology , Male , Ursodeoxycholic Acid/therapeutic use
15.
FEBS Lett ; 413(1): 27-34, 1997 Aug 11.
Article in English | MEDLINE | ID: mdl-9287111

ABSTRACT

We have cloned the mouse PA28 proteasome activator cDNAs. Northern blot demonstrates high PA28 mRNA levels in liver, kidney and lung. mRNA levels are low in thymus, spleen and brain. In contrast, PA28 protein levels vary little between these tissues. Immunocytological analysis and cell fractionation experiments demonstrate that both subunits are almost equally distributed between the cytoplasm and the nucleus. Interestingly, PA28alpha spares nucleoli, while PA28beta is strongly enhanced in the nucleolus. This indicates for the first time that the PA28alpha and PA28beta subunits may serve nuclear functions which may be different from and independent of each other.


Subject(s)
Cell Nucleus/metabolism , Cytoplasm/metabolism , Proteins/genetics , Amino Acid Sequence , Animals , Autoantigens , Blotting, Northern , Brain/metabolism , Cells, Cultured , Cloning, Molecular , Fluorescent Antibody Technique, Indirect , Immunohistochemistry , Kidney/metabolism , Liver/metabolism , Lung/metabolism , Mice , Molecular Sequence Data , Proteasome Endopeptidase Complex , Proteins/metabolism , RNA, Messenger/metabolism , Sequence Homology, Amino Acid , Spleen/metabolism , Thymus Gland/metabolism , Tissue Distribution
17.
Nature ; 381(6578): 166-8, 1996 May 09.
Article in English | MEDLINE | ID: mdl-8610016

ABSTRACT

Cytotoxic T cells recognize viral proteins as peptide fragments which are produced in the cytosol and transported on major histocompatibility complex (MHC) class I proteins to the cell surface. Viral peptides that meet the stringent binding characteristics of class I proteins are generated by the 20S proteasome. The interferon (IFN)-gamma-inducible activator of the 20S proteasome, PA28, strongly influences the proteasomal cleavage pattern in vitro. This led us to investigate whether changes in cellular levels of PA28 affect the efficiency of viral antigen processing. A mouse fibroblast line expressing the murine cytomegalovirus pp89 protein was transfected with either the human or murine gene encoding the PA28alpha subunit, which is sufficient to activate the peptide-hydrolysing activity of the 20S proteasome in vitro. Here we report that enhanced expression of PA28alpha at a level similar to that obtained after IFN-gamma induction resulted in a marked enhancement of recognition by pp89-specific cytotoxic T cells; the presentation of influenza nucleoprotein was also significantly improved. These results demonstrate a fundamental in vivo function for PA28alpha in antigen processing.


Subject(s)
Antigen Presentation/physiology , Cysteine Endopeptidases/physiology , Multienzyme Complexes/physiology , Muscle Proteins , Proteins/physiology , Amino Acid Sequence , Animals , Antigen Presentation/immunology , Autoantigens , Base Sequence , Blotting, Western , Cell Line , Cloning, Molecular , Cytomegalovirus/immunology , DNA Primers , Enzyme Activation , Flow Cytometry , H-2 Antigens/immunology , Histocompatibility Antigen H-2D , Humans , Immediate-Early Proteins/genetics , Immediate-Early Proteins/immunology , Influenza A virus/immunology , Interferon-gamma/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Molecular Sequence Data , Proteasome Endopeptidase Complex , Proteins/genetics , Proteins/immunology , Recombinant Proteins/genetics , Recombinant Proteins/immunology , T-Lymphocytes, Cytotoxic/immunology , Transfection
18.
J Exp Med ; 183(2): 499-514, 1996 Feb 01.
Article in English | MEDLINE | ID: mdl-8627162

ABSTRACT

Expression of class I major histocompatibility complex antigens on the surface of cells transformed by adenovirus 12 (Ad12) is generally very low, and correlates with the in vivo oncogenicity of this virus. In primary embryonal fibroblasts (H-2b) that express transgenic swine class I antigen (PD1), Ad12-mediated transformation results in inhibition in transport of newly synthesized class I molecules, as well as significant reduction in transporter associated with antigen presentation (TAP) gene expression. In this report we show that reexpression of TAP molecules either by stable transfection of mouse TAP genes or by infection with recombinant vaccinia viruses expressing human TAP genes, only partially reconstitutes the expression and transport of the class I molecules. Further analysis of Ad12-transformed cells revealed that the expression of both LMP2 and LMP7, but not of other proteasome complex components, was downregulated, resulting in altered proteolytic activities of the 20S proteasomes. Reconstitution of both TAP and LMP expression resulted in complete restoration of PD1 cell surface expression and enhanced expression of the endogenous H-2D(b) molecules encoded by recombinant vaccinia viruses, in reconstituted Ad12-transformed cells, efficient transport of H-2 class I molecules could only be achieved by treatment of the cells with gamma-interferon. These data suggest that an additional factor(s) that is interferon-regulated plays a role in the biosynthetic pathway of the class I complex, and that its function is deficient in this cell system. Thus, Ad12 viral transformation appears to suppress the expression of multiple genes that are important for antigen processing and presentation, which allows such transformed cells to escape immune surveillance. This coordinate downregulation of immune response genes must likely occur through their use of common regulatory elements.


Subject(s)
ATP-Binding Cassette Transporters/biosynthesis , Antigen Presentation , Cysteine Endopeptidases/biosynthesis , Gene Expression Regulation , Histocompatibility Antigens Class I/metabolism , Mastadenovirus , Multienzyme Complexes/biosynthesis , Oncogenic Viruses , Peptides/metabolism , Animals , Biological Transport , Cell Line , Cell Transformation, Viral , Cysteine Endopeptidases/genetics , Endopeptidases/biosynthesis , Endopeptidases/genetics , Histocompatibility Antigens Class I/genetics , Mice , Mice, Transgenic , Multienzyme Complexes/genetics , Proteasome Endopeptidase Complex , Swine
19.
Rev Chil Obstet Ginecol ; 59(5): 390-2, 1994.
Article in Spanish | MEDLINE | ID: mdl-7569157

ABSTRACT

We report a case of a 32 week pregnant patient who was admitted to our ward in preterm labor. After delivery, the examination of the placental tissue showed a large pedunculated tumor, complicated with torsion. Histology of the tumor revealed a placental chorioangioma. We propose that the complication of the tumor is the etiologic factor that brought about preterm labor in this patient.


Subject(s)
Hemangioma/complications , Obstetric Labor, Premature/etiology , Placenta Diseases/complications , Pregnancy Complications, Neoplastic , Adult , Female , Hemangioma/pathology , Humans , Placenta Diseases/pathology , Pregnancy
20.
Rev. chil. pediatr ; 63(3): 134-8, mayo-jun. 1992. tab, ilus
Article in Spanish | LILACS | ID: lil-112450

ABSTRACT

Durante 4 meses de 1988, en la Unidad de Neonatología del Hospital San Juan de Dios, se realizó un proyecto de control de Staphylococus aureus meticilina-resistente, y se compararon tasas de incidencia y tipo de infecciones en relación a un período anterior de 4 meses. Las medidas de control del brote epidémico incluyeron: información y motivación del personal especialmente en relación a técnica de lavado de manos y aislamiento, ordenamiento del ingreso y flujo de circulación de los niños en la unidad, aplicación de técnicas de aislamiento estricto en colonizados e infectados, control microbiológico de los recién nacidos, personal y ambiente; y erradicación del agente etiológico con antibióticos tópicos y orales. En este período de cuatro meses, en comparación a los 4 meses anteriores, disminuyó significativamente la tasa de colonización e infección debida a Staphylococcus aureus resistente a meticilina de 30,7 a 16% y de 12,6 a 6,8%, respectivamente. Con esta medida de control de infección intrahospitalaria realizada simultáneamente, fue posible disminuir en forma significativa la colonización e infección por Staphylococcus aureus resistente a meticilina


Subject(s)
Infant, Newborn , Humans , Drug Resistance, Microbial , Staphylococcal Infections/prevention & control , Methicillin/therapeutic use , Staphylococcus aureus/pathogenicity , Cross Infection , Intensive Care Units, Neonatal
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