206 results on '"Juan Antonio Quiroga"'
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2. Seidel Aberrations and Zernike Polynomials
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Juan Antonio Quiroga, José A. Gómez-Pedrero, and José Alonso
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symbols.namesake ,Zernike polynomials ,symbols ,Applied mathematics ,Mathematics - Published
- 2019
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3. Reversible photoalignment of liquid crystals: a path toward the creation of rewritable lenses
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Jose I. Alonso, Juan Antonio Quiroga, Daniel Crespo, and Ignacio Canga
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Materials science ,Phase (waves) ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,lcsh:Medicine ,Optical power ,02 engineering and technology ,01 natural sciences ,Article ,law.invention ,Compensation (engineering) ,010309 optics ,Small lens ,law ,Liquid crystal ,0103 physical sciences ,medicine ,Optica ,lcsh:Science ,Óptica ,Multidisciplinary ,business.industry ,Liquid crystals ,lcsh:R ,Presbyopia ,021001 nanoscience & nanotechnology ,medicine.disease ,Lens (optics) ,Anti-reflective coating ,Optoelectronics ,lcsh:Q ,0210 nano-technology ,business ,Materials for optics - Abstract
In this work, we describe a new reversible photoalignment effect for the director in nematic liquid crystals that provides an approach for the creation of lenses whose optical power can be recorded and erased. The possibility of creating a rewritable lens has very important practical implications, for example, in the ophthalmic lens industry. A rewritable ophthalmic lens could be a convenient solution for patients whose compensation needs change over time due to age-related physiological changes, such as the onset and progression of presbyopia. Using rewritable lenses, small lens power corrections could be implemented through a rewriting procedure on the mounted lens without resurfacing or manufacturing and mounting a new lens. More generally, this new effect multiple potential applications in the creation of rewritable optical systems, such as reconfigurable optical networks, index-tunable antireflective coatings and optically rewritable phase gratings.
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- 2020
4. Filters and Coatings
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Juan Antonio Quiroga, José Alonso, and José A. Gómez-Pedrero
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Computer science - Published
- 2019
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5. Low Vision Aids and High Power Lenses
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José A. Gómez-Pedrero, José Alonso, and Juan Antonio Quiroga
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Computer science ,Optometry ,Low vision aids ,Power (physics) - Published
- 2019
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6. Aberrations and Lens Design
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José A. Gómez-Pedrero, Juan Antonio Quiroga, and José Alonso
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Optics ,business.industry ,Computer science ,Lens (geology) ,business - Published
- 2019
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7. Detection of hepatitis C virus (HCV) core–specific antibody suggests occult HCV infection among blood donors
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José M. Echevarría, Rocío González, Juan Antonio Quiroga, Ricardo Palacios, Vicente Carreño, Luis A. Richart, María Andréu, Sonia Pérez, Inmaculada Castillo, Ana Avellón, Elena Flores, Javier Alcover, Javier Bartolomé, María Isabel Jiménez González, and Diater (Spain)
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Male ,0301 basic medicine ,Blood transfusion ,Blood Safety ,medicine.medical_treatment ,Hepatitis C virus ,Immunology ,Blood Donors ,030204 cardiovascular system & hematology ,medicine.disease_cause ,Peripheral blood mononuclear cell ,Virus ,Donor Selection ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Immunology and Allergy ,biology ,Donor selection ,business.industry ,Transfusion Reaction ,Hematology ,Hepatitis C ,Hepatitis C Antibodies ,medicine.disease ,Virology ,030104 developmental biology ,biology.protein ,RNA, Viral ,Female ,Sample collection ,Antibody ,business - Abstract
Background: Blood transfusion safety is based on reliable donor screening for transmissible infections such as the hepatitis C virus (HCV) infection. Study design and methods: A novel HCV core-specific antibody was assayed on random single donations from 2007 first-time blood donors who tested negative for anti-HCV and HCV RNA on routine screening. Sample collection broke the code between donations and donors for ethical reasons. Results: Forty-two donations (2.1%) displayed reactivity in the novel test. The specificity of the reactivity was evaluated by a peptide inhibition assay, and testing against additional nonoverlapping HCV core peptide epitopes and other HCV antigens was performed on these samples. Six donations (14.3%; 0.30% from the total) were considered to contain anti-HCV after such supplemental testing. HCV RNA detection was also performed in peripheral blood mononuclear cells (PBMNCs) and serum or plasma samples from reactive donors after virus concentration by ultracentrifugation. HCV RNA tested negative in all PBMNCs samples, and a very low amount of viral genome was detected in serum or plasma concentrates from three anti-HCV core-reactive donors (7.1%) but not among concentrates from 100 randomly selected nonreactive donors. Sequencing of these polymerase chain reaction products revealed differences between the isolates that excluded partially sample contamination from a common source. Conclusion: These findings argue in favor of an ongoing occult HCV infection among these blood donors and account for some rather low, but perhaps not negligible, infection risk for such donations. Future studies involving larger samples of donations from traceable donors would enlighten the significance of these findings for the viral safety of the blood supply. This work was supported by research grants from DIATERS.A., Madrid, Spain. Sí
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- 2016
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8. Interleukin-28B polymorphisms and interferon gamma inducible protein-10 serum levels in seronegative occult hepatitis C virus infection
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Javier Bartolomé, Vicente Carreño, Inmaculada Castillo, and Juan Antonio Quiroga
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0301 basic medicine ,business.industry ,Hepatitis C virus ,Interleukin ,medicine.disease_cause ,Virology ,Peripheral blood mononuclear cell ,Occult ,digestive system diseases ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Infectious Diseases ,Interleukin 28B ,Immune system ,Immunology ,Genotype ,Medicine ,030211 gastroenterology & hepatology ,Interferon gamma ,business ,medicine.drug - Abstract
Polymorphisms upstream interleukin (IL)-28B gene and serum levels of interferon gamma inducible protein-10 (IP-10) are associated with spontaneous and treatment-induced hepatitis C virus (HCV) clearance. Patients with seronegative occult HCV infection are anti-HCV and serum HCV-RNA negative but have viral RNA in liver and abnormal values of liver enzymes. We examined if the rs12979860 polymorphism of IL-28B and serum IP-10 levels differ between chronic and seronegative occult CV infection. IL-28B polymorphism was determined with allele specific TaqMan probes in total DNA isolated from peripheral blood mononuclear cells and IP-10 by an enzyme-linked immunosorbent assay in serum from 99 patients with seronegative occult HCV infection and 130 untreated patients with chronic hepatitis C. IL-28B genotypes were also determined in 54 healthy volunteers. Prevalence of the IL-28B CC genotype was significantly higher in seronegative occult HCV infection (52/99; 52.5%) than in chronic hepatitis C (32/130; 24.6%, P
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- 2015
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9. Numerical model of the inhomogeneous scattering by the human lens
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Juan Antonio Quiroga, Luis Miguel Sanchez-Brea, José A. Gómez-Pedrero, Alexander Cuadrado, and Francisco Jose Torcal-Milla
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Forward scatter ,Mie scattering ,Monte Carlo method ,01 natural sciences ,Article ,Light scattering ,law.invention ,010309 optics ,03 medical and health sciences ,symbols.namesake ,law ,0103 physical sciences ,Electromagnetismo ,Optica ,Rayleigh scattering ,Óptica ,030304 developmental biology ,Physics ,0303 health sciences ,Scattering ,Atomic and Molecular Physics, and Optics ,Computational physics ,Lens (optics) ,Óptica fisiológica ,symbols ,Ray tracing (graphics) ,Biotechnology - Abstract
We present in this work a numerical model for characterizing the scattering properties of the human lens. After analyzing the scattering properties of two main scattering particles actually described in the literature through FEM (finite element method) simulations, we have modified a Monte Carlo’s bulk scattering algorithm for computing ray scattering in non-sequential ray tracing. We have implemented this ray scattering algorithm in a layered model of the human lens in order to calculate the scattering properties of the whole lens. We have tested our algorithm by simulating the classic experiment carried out by Van der Berg et al for measuring “in vitro” the angular distribution of forward scattered light by the human lens. The results show the ability of our model to simulate accurately the scattering properties of the human lens.
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- 2019
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10. High prevalence of occult hepatitis C virus infection in patients with chronic hepatitis B virus infection
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Inmaculada Castillo, Juan Antonio Quiroga, Vicente Carreño, and Javier Bartolomé
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Adult ,Liver Cirrhosis ,Male ,Microbiology (medical) ,Hepatitis B virus ,Hepatitis C virus ,Hepacivirus ,Real-Time Polymerase Chain Reaction ,medicine.disease_cause ,Microbiology ,Virus ,Hepatitis B, Chronic ,Chronic hepatitis ,Prevalence ,Humans ,Medicine ,In patient ,Clinical significance ,In Situ Hybridization ,Hepatitis B Surface Antigens ,High prevalence ,biology ,business.industry ,virus diseases ,General Medicine ,Hepatitis C ,Virology ,Occult ,digestive system diseases ,Liver ,DNA, Viral ,biology.protein ,RNA, Viral ,Female ,Antibody ,business - Abstract
Hepatitis C virus (HCV) infection in the absence of detectable antibodies against HCV and of viral RNA in serum is called occult HCV infection. Its prevalence and clinical significance in chronic hepatitis B virus (HBV) infection is unknown. HCV RNA was tested for in the liver samples of 52 patients with chronic HBV infection and 21 (40 %) of them were positive for viral RNA (occult HCV infection). Liver fibrosis was found more frequently and the fibrosis score was significantly higher in patients with occult HCV than in negative ones, suggesting that occult HCV infection may have an impact on the clinical course of HBV infection.
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- 2013
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11. Occult Hepatitis C Virus Infection in Patients with Diabetic Nephropathy: Epidemiological and Clinical Implications
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Teresa Olea, Inmaculada Castillo, Javier Bartolomé, Rosario Madero, Vicente Carreño, Juan Antonio Quiroga, Lucía Rodríguez-Gayo, Elena González, Rafael Selgas, and Marco Antonio Vaca
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Diabetic nephropathy ,medicine.medical_specialty ,business.industry ,Internal medicine ,Hepatitis C virus ,Epidemiology ,medicine ,In patient ,medicine.disease_cause ,medicine.disease ,business ,Occult ,Gastroenterology - Published
- 2017
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12. HCV-indeterminate blood donors or occult HCV infection?
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Vicente Carreño and Juan Antonio Quiroga
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Text mining ,business.industry ,Immunology ,Medicine ,General Medicine ,business ,Indeterminate ,Occult - Published
- 2016
13. Diagnosis of occult hepatitis C without the need for a liver biopsy
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Javier Bartolomé, Guillermina Barril, Vicente Carreño, Inmaculada Castillo, and Juan Antonio Quiroga
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Adult ,Male ,Hepacivirus ,Hepatitis C virus ,Enzyme-Linked Immunosorbent Assay ,medicine.disease_cause ,Polymerase Chain Reaction ,Sensitivity and Specificity ,Flaviviridae ,Virology ,Biopsy ,Humans ,Medicine ,medicine.diagnostic_test ,biology ,business.industry ,Viral Core Proteins ,virus diseases ,Hepatitis C ,Hepatitis C Antibodies ,Middle Aged ,medicine.disease ,biology.organism_classification ,Occult ,digestive system diseases ,Infectious Diseases ,Liver biopsy ,Immunology ,Leukocytes, Mononuclear ,RNA, Viral ,Female ,Viral disease ,business ,Ultracentrifugation - Abstract
The diagnosis of occult hepatitis C virus (HCV) infection is based on the presence of HCV-RNA in the liver. This study aimed to evaluate the use of combining non-invasive assays to diagnose occult HCV. A total of 122 patients with occult HCV (HCV-RNA in the liver without detectable anti-HCV and serum HCV-RNA) and 45 patients with cryptogenic chronic hepatitis (without HCV-RNA in the liver and negative for anti-HCV and serum HCV-RNA) were included. HCV-RNA was tested in peripheral blood mononuclear cells (PBMCs) and in 2 ml of ultracentrifuged serum. Anti-core HCV was examined by a non-commercial enzyme-linked immunosorbent assay. All controls were negative for the three HCV markers studied. Among patients with occult HCV, 36% were anti-core HCV positive, 57% had serum HCV-RNA after ultracentrifugation, and 61% had HCV-RNA in PBMCs. Combining the results of the assays, 91% of the patients were positive for at least one marker. Intrahepatic HCV-RNA load was significantly higher in patients who were positive simultaneously for the three HCV markers than in patients who were negative for all markers (P = 0.006) and than in those with one or two HCV markers (P = 0.039). Replication of HCV in liver was detected more frequently in patients with three (93%, P = 0.002), two (82%, P = 0.001), and one HCV marker (73%, P = 0.011) than in those without markers (27%). In conclusion, testing for all these markers allows diagnosis of occult HCV without the need for a liver biopsy and these assays may help to elucidate the clinical significance of occult HCV infection.
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- 2010
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14. Effect of hemodialysis schedules and membranes on hepatocyte growth factor and hepatitis C virus RNA levels
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Javier Bartolomé, J. A. Traver, P. Sanz, Emmanuela Buoncristiani, Umberto Buoncristiani, Guillermina Barril, Rafael Selgas, Juan Antonio Quiroga, Inmaculada Castillo, and Vicente Carreño
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Male ,Time Factors ,Hepacivirus ,Hepatitis C virus ,medicine.medical_treatment ,Viremia ,medicine.disease_cause ,Virus ,Renal Dialysis ,Virology ,medicine ,Humans ,Aged ,Membranes ,biology ,Hepatocyte Growth Factor ,business.industry ,RNA ,Hepatitis C ,Middle Aged ,Viral Load ,biology.organism_classification ,medicine.disease ,Infectious Diseases ,RNA, Viral ,Female ,Hepatocyte growth factor ,Hemodialysis ,business ,medicine.drug - Abstract
Hemodialysis induces production of the hepatocyte growth factor (HGF) and decrease of serum hepatitis C virus (HCV) RNA in patients with HCV infection, but it is not known if the hemodialysis schedule or type of membrane affect both the HGF production and HCV viremia. The effects on both parameters of alternate-day intermittent hemodialysis and short-daily hemodialysis and high and low flux membranes were investigated in 41 patients treated by hemodialysis. Sixteen (39%) patients were anti-HCV positive and 11 (69%) had HCV RNA. Twenty-six patients were on alternate-day intermittent and 15 on short-daily hemodialysis. High flux membranes were used for 29 patients and low flux membranes for 12 patients. A decrease in HCV RNA was observed at the end of hemodialysis (8.6 × 105 ± 1.1 × 106 IU/ml vs. 4.4 × 105 ± 7.3 × 105 IU/ml, P = 0.003). The proportion of HCV RNA decrease was similar in patients dialyzed with both schedules and with both types of membranes. The HGF levels increased from 2,605.9 ± 1,428.7 to >8,000 pg/ml at 15 min. At the end of the session, the HGF levels decreased to 5,106.7 ± 2,533.9 pg/ml. The HGF levels at the start of the next session were similar to those at baseline (2,680.0 ± 1,209.3 pg/ml). The increase and dynamics of the HGF levels were similar in patient's hemodialyzed with both schedules and with both types of membranes. These results suggest that changes in HCV RNA and HGF levels during hemodialysis are not influenced by the schedule or type of membrane used. J. Med. Virol. 82: 763–767, 2010. © 2010 Wiley-Liss, Inc.
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- 2010
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15. Identification of different degrees of hepatitis B virus (HBV) replication by serological (HBV-DNAp, HBcAg and HBV-DNA) and histological (HBcAg) methods
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Juan Carlos Porres, Ignacio Mora, Vicente Carreño, Juan Antonio Quiroga, Carlos Hernández Guio, Julia Gutiez, and Javier Bartolomé
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Adult ,Male ,Hepatitis B virus ,DNA-Directed DNA Polymerase ,Virus Replication ,medicine.disease_cause ,Virus ,Liver Function Tests ,medicine ,Humans ,Hepatology ,biology ,business.industry ,Liver cell ,virus diseases ,Middle Aged ,biology.organism_classification ,Hepatitis B Core Antigens ,Virology ,digestive system diseases ,HBcAg ,Liver ,Hepadnaviridae ,HBeAg ,Viral replication ,DNA, Viral ,Female ,Viral disease ,business - Abstract
— The incidence of HBV-DNA polymerase, HBV-DNA and serum and liver HBcAg in 104 chronic HBsAg carriers was studied. HBV-DNA was the most frequently detected marker, followed by HBcAg and HBV-DNAp. According to their individual or combined presence, four different serological patterns of viral replication were discerned: 53 patients had all these markers, 30 had HBV-DNA but lacked HBV-DNAp (15 with and 15 without HBcAg) and 21 had no such markers detectable. The simultaneous positivity for all of those markers was observed only in HBeAg-positive patients. HBV-DNA alone or along with HBcAg was found in a similar incidence irrespective of the HBe system. Liver HBcAg was found in all but four patients with and in four without HBV-DNA. Viral DNA concentration was significantly (p < 0.001) higher when HBV-DNAp tested positive. Indeed, HBeAg rather than anti-HBe patients had higher (p < 0.005) levels of HBV-DNA. In HBeAg-positive patients, the nuclear HBcAg staining was significantly (p < 0.05) higher when HBV-DNAp tested positive. In DNA polymerase-negative patients, but positive for HBV-DNA, those with or without HBcAg had a similar percentage of core antigen staining. The same distribution was seen in anti-HBe, HBV-DNA-positive patients. However, the mean percentage of hepatocytes displaying cytoplasmic HBcAg did not differ significantly among patients with HBV-DNA, irrespective of the HBe system and the HBV-DNAp status. Such patients had significantly (p < 0.001) higher ALT levels than those without viral DNA. Active viral replication can be assessed differentially through any of these serum markers and is associated with liver cell necrosis.
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- 2008
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16. Detection of serum inhibitory factor for lymphocyte stimulation in chronic viral hepatitis: relationship with the replication level
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Juan Carlos Porres, M. Gracia Martinez, Vicente Carreño, Inmaculada Castillo, and Juan Antonio Quiroga
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Adult ,Male ,Hepatitis B virus ,Hepatitis, Viral, Human ,Lymphocyte ,Stimulation ,Lymphocyte Activation ,Virus Replication ,Inhibitory postsynaptic potential ,Hepatitis ,Immune system ,medicine ,Humans ,Glycoproteins ,Hepatitis, Chronic ,Hepatology ,business.industry ,Middle Aged ,medicine.disease ,Virology ,Neoplasm Proteins ,medicine.anatomical_structure ,HBeAg ,Viral replication ,Immunology ,Female ,Viral disease ,Hepatitis Delta Virus ,business ,Viral hepatitis - Abstract
Sera from 111 patients with chronic viral hepatitis and from 55 cases with other liver disorders were assayed for serum inhibitory factor. The prevalence of this immunosuppressive factor was very similar between chronic hepatitis B (61%), chronic hepatitis delta (57%) and chronic hepatitis C (68%). At the same time, serum inhibitory factor was never detected in the other disorders studied. The presence of this inhibitory factor was detected in a significantly higher percentage (p less than 0.05) of HBeAg, HBV-DNA positive cases (75%) than in anti-HBe positive, HBV-DNA negative cases (44.4%). In chronic hepatitis delta, this immunosuppressive factor was also related to HDV-RNA positivity. The detection of this serum immunosuppressive factor in chronic viral hepatitis and its association with a high viral replication level implies a possible role of this factor in the immune pathogenic mechanism in infectious viral hepatitis.
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- 2008
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17. Determination of isoclinics in photoelasticity with a fast regularized estimator
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Juan Antonio Quiroga, Jesús Villa, and Eduardo Pascual
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Photoelasticity ,business.industry ,Orientation (computer vision) ,Computer science ,Mechanical Engineering ,Modulo ,Isotropy ,Estimator ,Image processing ,Regularization (mathematics) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Simple (abstract algebra) ,Electrical and Electronic Engineering ,business ,Algorithm - Abstract
The determination of isoclinics from photoelastic fringe patterns is a key problem in photoelasticity. Dealing with this problem, however, is not a simple task when isotropic points are present which is common for most experimental situations. Because of this, few researchers have proposed effective and practical solutions. Visualizing this problem as the problem of the determination of the modulo 2π fringe orientation, in this paper it is proposed an efficient regularized algorithm to solve it. Experimental results show that the proposal is effective and can be used with either monochromatic or white light.
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- 2008
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18. Occult hepatitis B virus and hepatitis C virus infections
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Javier Bartolomé, Inmaculada Castillo, Vicente Carreño, and Juan Antonio Quiroga
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Hepatitis B virus ,HBsAg ,Hepatitis C virus ,Hepacivirus ,medicine.disease_cause ,Liver disease ,Virology ,medicine ,Humans ,business.industry ,virus diseases ,Hepatitis C ,Hepatitis C Antibodies ,Hepatitis B ,medicine.disease ,Occult ,digestive system diseases ,Infectious Diseases ,Liver ,DNA, Viral ,Immunology ,Hepatocytes ,RNA, Viral ,Abnormal Liver Function Test ,business - Abstract
Occult HBV infection is a well-recognised clinical entity characterised by the detection of HBV-DNA in serum and/or in liver in the absence of detectable hepatitis B surface antigen (HBsAg). Occult HBV infection has been described not only in patients who have resolved an acute or chronic HBV infection but also in patients without any serological markers of a past HBV infection. Occult HBV infection in patients with chronic HCV infection may induce more severe liver disease and lower response rate to interferon treatment. The existence of occult HCV infections has been also reported more recently. Occult HCV infection is characterised by the presence of HCV-RNA in liver and peripheral blood mononuclear cells in the absence of detectable serum HCV-RNA. Occult HCV infection may occur under two different clinical situations: in hepatitis C antibody-(anti-HCV) negative and serum HCV-RNA-negative patients with abnormal liver function tests and in anti-HCV-positive patients who have no detectable serum HCV-RNA and who have normal liver enzymes. The clinical relevance of occult HCV infections is still under investigation.
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- 2008
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19. Application of principal component analysis in phase-shifting photoelasticity
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José A. Gómez-Pedrero and Juan Antonio Quiroga
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Photoelasticity ,business.industry ,Computer science ,Noise (signal processing) ,Polarimetry ,Phase (waves) ,Astrophysics::Instrumentation and Methods for Astrophysics ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010309 optics ,Phase shifting interferometry ,Optics ,Sampling (signal processing) ,Nondestructive testing ,0103 physical sciences ,Principal component analysis ,Demodulation ,Spatial frequency ,Optica ,0210 nano-technology ,business ,Óptica - Abstract
Principal component analysis phase shifting (PCA) is a useful tool for fringe pattern demodulation in phase shifting interferometry. The PCA has no restrictions on background intensity or fringe modulation, and it is a self-calibrating phase sampling algorithm (PSA). Moreover, the technique is well suited for analyzing arbitrary sets of phase-shifted interferograms due to its low computational cost. In this work, we have adapted the standard phase shifting algorithm based on the PCA to the particular case of photoelastic fringe patterns. Compared with conventional PSAs used in photoelasticity, the PCA method does not need calibrated phase steps and, given that it can deal with an arbitrary number of images, it presents good noise rejection properties, even for complicated cases such as low order isochromatic photoelastic patterns. © 2016 Optical Society of America.
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- 2016
20. Robust fitting of Zernike polynomials to noisy point clouds defined over connected domains of arbitrary shape
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Juan Antonio Quiroga, Jose I. Alonso, Diego Rodríguez Ibañez, and José A. Gómez-Pedrero
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Series (mathematics) ,business.industry ,Computer science ,Zernike polynomials ,Point cloud ,020207 software engineering ,Optoelectrónica ,02 engineering and technology ,Curvature ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Domain (mathematical analysis) ,Power (physics) ,010309 optics ,symbols.namesake ,Optics ,Unit circle ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,Óptica oftálmica ,Optica ,business ,Óptica - Abstract
A new method for fitting a series of Zernike polynomials to point clouds defined over connected domains of arbitrary shape defined within the unit circle is presented in this work. The method is based on the application of machine learning fitting techniques by constructing an extended training set in order to ensure the smooth variation of local curvature over the whole domain. Therefore this technique is best suited for fitting points corresponding to ophthalmic lenses surfaces, particularly progressive power ones, in non-regular domains. We have tested our method by fitting numerical and real surfaces reaching an accuracy of 1 micron in elevation and 0.1 D in local curvature in agreement with the customary tolerances in the ophthalmic manufacturing industry.
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- 2016
21. Ultracentrifugation of Serum Samples Allows Detection of Hepatitis C Virus RNA in Patients with Occult Hepatitis C
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Inmaculada Castillo, Juan Antonio Quiroga, Vicente Carreño, Ricardo Palacios, Javier Bartolomé, Elena Rodríguez-Iñigo, and Juan Manuel López-Alcorocho
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Male ,Hepacivirus ,Hepatitis C virus ,Immunology ,medicine.disease_cause ,Microbiology ,Virus ,Flaviviridae ,Virology ,medicine ,Humans ,In Situ Hybridization ,Phylogeny ,DNA Primers ,Base Sequence ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,virus diseases ,RNA ,Hepatitis C ,medicine.disease ,biology.organism_classification ,digestive system diseases ,Insect Science ,RNA, Viral ,Pathogenesis and Immunity ,Abnormal Liver Function Test ,Female ,Viral disease ,Ultracentrifugation - Abstract
Occult hepatitis C virus (HCV) infection of patients with abnormal liver function tests of unknown origin who are anti-HCV and serum HCV RNA negative but who have HCV RNA in the liver has been described. As HCV replicates in the liver cells of these patients, it could be that the amount of circulating viral particles is under the detection limit of the most sensitive techniques. To prove this hypothesis, serum samples from 106 patients with occult HCV infection were analyzed. Two milliliters of serum was ultracentrifuged over a 10% sucrose cushion for 17 h at 100,000 × g av , where av means average, and HCV RNA detection was performed by strand-specific real-time PCR. Out of the 106 patients, 62 (58.5%) had detectable serum HCV RNA levels after ultracentrifugation, with a median load of 70.5 copies/ml (range, 18 to 192). Iodixanol density gradient studies revealed that HCV RNA was positive at densities of 1.03 to 1.04 and from 1.08 to 1.19 g/ml, which were very similar to those found in the sera of patients with classical chronic HCV infection. Antigenomic HCV RNA was found in the livers of 56 of 62 (90.3%) patients with detectable serum HCV RNA levels after ultracentrifugation, compared to 27 of 44 (61.4%) negative patients ( P < 0.001). No differences in the median loads of antigenomic HCV RNA between patients with an those without serum HCV RNA (4.5 × 10 4 [range, 7.9 × 10 2 to 1.0 × 10 6 ] versus 2.3 × 10 4 [range, 4.0 × 10 2 to 2.2 × 10 5 ]) were found. Alanine aminotransferase and gamma-glutamyl transpeptidase levels, liver necroinflammatory activity, and fibrosis did not differ between both groups. In conclusion, HCV RNA can be detected in the sera of patients with occult HCV infection after circulating viral particles are concentrated by ultracentrifugation.
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- 2007
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22. The role of genomic and antigenomic HCV-RNA strands as predictive factors of response to pegylated interferon plus ribavirin therapy
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Vicente Carreño, Inmaculada Castillo, Juan Antonio Quiroga, Maria Eugenia Castellanos, Margarita Pardo, Javier Bartolomé, Elena Rodríguez-Iñigo, and Juan Manuel López-Alcorocho
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Hepatology ,medicine.diagnostic_test ,business.industry ,Ribavirin ,Hepatitis C virus ,Gastroenterology ,virus diseases ,RNA ,Alpha interferon ,medicine.disease_cause ,Virology ,Virus ,chemistry.chemical_compound ,chemistry ,Pegylated interferon ,Interferon ,Liver biopsy ,medicine ,Pharmacology (medical) ,business ,medicine.drug - Abstract
SUMMARY Background Hepatitis C virus replicates by the synthesis of an antigenomic HCV-RNA. As the end point of anti-viral therapy is to decrease viral replication, the amount of antigenomic HCV-RNA could influence the response. Aim To study if amounts of genomic and antigenomic HCV-RNA in the baseline liver biopsy are predictive factors of response to anti-viral therapy. Methods Eighty-eight patients with chronic HCV infection (anti-HIV-negative) treated with pegyltaed-interferon-α2b plus ribavirin for 12 months were included. Intrahepatic genomic and antigenomic HCV-RNA concentrations were determined by real-time polymerase chain reaction and percentage of infected hepatocytes by in situ hybridization. Results Of the 88 patients, 31% were responders while 69% were not. Median of antigenomic HCV-RNA in liver of responders and non-responders was 120 000 copies/μg RNA (range: 10 000–775 000) vs. 150 000 copies/μg RNA (range: 100–3 200 000; P = 0.38). Median of genomic HCV-RNA in liver of responders was 1 250 000 copies/μg RNA (range: 5000–9 000 000) and in non-responders 3 180 000 copies/μg RNA (range: 4600–18 000 000; P = 0.0191). Predictive factors of response in the logistic regression were: intrahepatic amount of genomic HCV-RNA, percentage of infected hepatocytes and previous therapy. Conclusion Response to 12 months of therapy with pegylated interferon-α2b plus ribavirin depends on the amount of genomic HCV-RNA in the pre-treatment liver biopsy.
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- 2007
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23. Serum levels of anti-NS4a and anti-NS5a predict treatment response of patients with chronic hepatitis C
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Hans Van Vlierberghe, Juan Antonio Quiroga, Geert Leroux-Roels, Vicente Carreño, Ola Weiland, Catharina Hultgren, Isabelle Desombere, and Matti Sällberg
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viruses ,Hepacivirus ,Hepatitis C virus ,Viral Nonstructural Proteins ,medicine.disease_cause ,Antiviral Agents ,Viral Proteins ,chemistry.chemical_compound ,Flaviviridae ,Antigen ,Predictive Value of Tests ,Virology ,Ribavirin ,medicine ,Humans ,Clinical significance ,NS5A ,biology ,business.industry ,Viral Core Proteins ,Intracellular Signaling Peptides and Proteins ,Interferon-alpha ,virus diseases ,Hepatitis C Antibodies ,Hepatitis C, Chronic ,biology.organism_classification ,digestive system diseases ,Treatment Outcome ,Infectious Diseases ,chemistry ,biology.protein ,RNA, Viral ,Interferons ,Antibody ,Carrier Proteins ,business ,Algorithms ,Biomarkers - Abstract
In order to understand better the clinical significance and prognostic value of antibody responses to HCV proteins and in search for parameters that may allow the early identification of non-sustained responders to therapy, antibody levels were measured against NS3, NS4a and NS5a at baseline in the serum of 120 patients chronically infected with HCV of genotype 1 that were classified as sustained responders, relapsers, or non-responders to therapy. The capacity of these antibody tests to predict therapy-outcome was evaluated. While no differences were observed in the anti-NS3 responses in these different response groups, anti-NS4a and anti-NS5a antibodies were observed more frequently and at higher titres in sustained responders versus non-responders or non-sustained responders (=non-responders + relapsers). Based on this observation, a combination of test results consisting of 'the absence of NS4a (AA 1687-1718) antibody at baseline and the presence of HCV-RNA exceeding 105 IU/ml after 1 week of treatment' was identified which predicts non-sustained response to treatment with 100% certainty. Replacing the HCV-RNA decision limit by a HCV-core antigen level of >15 pg/ml resulted in the same predictive value. The proposed algorithm also holds for patients treated with peg-interferon and ribavirin. In conclusion, in patients with chronic HCV infection, the decision to continue or stop treatment can be made after 1 week of treatment with (peg)-interferon α and ribavirin. © 2007 Wiley-Liss, Inc.
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- 2007
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24. Virus-specific T-cell responses associated with hepatitis C virus (HCV) persistence in the liver after apparent recovery from HCV infection
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Margarita Pardo, Inmaculada Castillo, S. Llorente, Juan Manuel López-Alcorocho, Elena Rodríguez-Iñigo, Vicente Carreño, and Juan Antonio Quiroga
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Adult ,CD4-Positive T-Lymphocytes ,Male ,Cellular immunity ,Biopsy ,Hepatitis C virus ,Hepacivirus ,T-Cell Antigen Receptor Specificity ,CD8-Positive T-Lymphocytes ,Viral Nonstructural Proteins ,Lymphocyte Activation ,Virus Replication ,medicine.disease_cause ,Asymptomatic ,Virus ,Interferon-gamma ,T-Lymphocyte Subsets ,Interferon ,Virology ,HLA-A2 Antigen ,medicine ,Humans ,Cells, Cultured ,Aged ,biology ,Viral Core Proteins ,virus diseases ,Middle Aged ,biology.organism_classification ,Hepatitis C ,digestive system diseases ,Infectious Diseases ,Liver ,Carrier State ,Immunology ,Leukocytes, Mononuclear ,RNA, Viral ,Female ,Viral disease ,medicine.symptom ,Viral load ,Biomarkers ,medicine.drug - Abstract
Hepatitis C virus (HCV) RNA persistence in the liver has been described even after apparent resolution of HCV infection. Because T-cell reactivity plays a role in recovery from HCV infection, virus-specific T-cell responses were investigated in apparently recovered individuals in whom hepatic HCV RNA persistence was documented: 15 sustained virological responders to interferon (IFN)-treatment and 9 asymptomatic aviremic anti-HCV carriers. HCV-specific CD4(+) T-cell proliferative responses were detected significantly more often in apparently recovered individuals (sustained virological responders: 60%; asymptomatic anti-HCV carriers: 66%) compared with 50 chronic hepatitis C patients (28%; P < 0.05). However, T-cell frequencies and numbers tended to decline over time and the number of HCV proteins targeted by CD4(+) T-cell proliferative responses was limited. Interestingly, liver viral load correlated inversely with virus-specific immune responses. Thus, CD4(+) T-cell responders showed significantly lower hepatic HCV RNA levels (P < 0.05). HCV-specific IFN-gamma-secreting CD4(+) T-cells were not detected in all the apparently recovered patients although they were found significantly more often compared with chronic hepatitis C patients (P < 0.05). Also, HCV NS3-specific CD8(+) T-cells were detected in 11 HLA-A2-positive apparently recovered individuals (8 sustained virological responders and 3 asymptomatic anti-HCV carriers); T-cell frequencies tended to be greater in those patients who had lower hepatic viral levels. In conclusion, HCV-specific T-cells are detectable in apparently recovered individuals in whom HCV RNA can persist in the liver indicating that HCV replication may be prolonged in the face of an insufficient or inadequate virus-specific CD4(+) and CD8(+) T-cell response.
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- 2006
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25. Pegylated interferon-α2a kinetics during experimental haemodialysis: impact of permeability and pore size of dialysers
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F. Rodrìguez-Salvanés, G. Barril, Vicente Carreño, R. Selgas, Juan Antonio Quiroga, and P. Sanz
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Pore size ,medicine.medical_specialty ,Hepatology ,business.industry ,Kinetics ,technology, industry, and agriculture ,Gastroenterology ,Urology ,Plasma levels ,Surgery ,Pharmacokinetics ,Pegylated interferon ,Permeability (electromagnetism) ,medicine ,Pharmacology (medical) ,business ,Large pore size ,medicine.drug ,Clearance - Abstract
Summary Background : Therapeutics in end-stage renal disease (ESRD) patients undergoing haemodialysis (HD) has to consider potential drug clearance during the dialysis procedure. Pegylated interferon-α (PEG-IFN-α), a middle-size protein drug active against viral hepatitis, allows convenient once-weekly dosing due to prolonged plasma half-life. Aim : To investigate the impact of permeability and dialyser pore size on PEG-IFN-α blood levels during experimental HD. Methods : Polymethylmetacrylate (PMMA) membrane 1.6 m2 dialysers with three different permeabilities/pore sizes were selected. Results : A 40 kDa PEG-IFN-α2a (PEGASYS) was not cleared (
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- 2004
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26. Evidence for a relation between the viral load and genotype and hepatitis C virus-specific T cell responses*1
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Bo Nilsson, Ola Weiland, Isabelle Desombere, Juan Antonio Quiroga, Matti Sällberg, Vincente Carren̄o, Geert Leroux-Roels, and Catharina Hultgren
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Hepatology ,biology ,business.industry ,viruses ,T cell ,Hepatitis C virus ,Hepacivirus ,medicine.disease_cause ,medicine.disease ,biology.organism_classification ,Virology ,Virus ,medicine.anatomical_structure ,Genotype ,Immunology ,medicine ,Viral disease ,Viral hepatitis ,business ,Viral load - Abstract
Background/Aims The reason why patients with hepatitis C virus (HCV) genotype non-1 infection respond better to antiviral therapy than patients with genotype 1 infection is not known. The aim of this study is to explore the relation between the viral genotype, viral load, and the endogenous T cell response. Methods The viral genotype, the viral load, and the endogenous proliferative T cell response to the non-structural 3 protein (NS3) was analysed using serum and peripheral blood mononuclear cells from 103 patients with chronic HCV infection. Results Among 71 nontreated patients a T cell response was more common among those infected by genotype 3, as compared to those infected with genotype 1 ( P P P P P Conclusions The presence of an NS3-specific T cell response is related to the viral genotype and to a more rapid clearance of HCV RNA during antiviral therapy.
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- 2004
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27. Temporal evaluation of fringe patterns with spatial carrier with an improved asynchronous phase demodulation algorithm
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Juan Antonio Quiroga, Manuel Servin, and José A. Gómez-Pedrero
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Computer science ,Noise (signal processing) ,Asynchronous communication ,Phase (waves) ,Demodulation ,Sensitivity (control systems) ,Algorithm ,Signal ,Atomic and Molecular Physics, and Optics ,Structured-light 3D scanner ,Metrology - Abstract
A method for temporal evaluation of fringe patterns with a spatial carrier is presented. The proposed technique consists in the recording of the temporal irradiance fluctuations obtained when a linear variation of the set-up sensitivity is introduced. In this way, the use of a spatial carrier introduces a linear temporal carrier frequency. This allows the use of fast and low time consuming temporal asynchronous demodulation algorithms, similar to those employed in spatial phase shifting techniques. An existing five-step algorithm has been corrected for asynchronous demodulation. It is shown that it is possible to fix the sensitivity variation in such a way that the algorithm presents optimum behaviour against noise and nonlinearities presented by the temporal irradiance signal. Finally, the technique has been applied to measure the shape of an object, using a fringe projection set-up. ©2004 Taylor & Francis LTD.
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- 2004
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28. Virus-specific effector CD4+T-cell responses in hemodialysis patients with hepatitis C virus infection
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Rafael Selgas, Secundino Cigarrán, Guillermina Barril, Dolores Subirá, Miguel A. Rico, Juan Antonio Quiroga, Susana Castañón, Sara Ruiz, and Vicente Carreño
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Cellular immunity ,biology ,medicine.medical_treatment ,Hepatitis C virus ,virus diseases ,Hepatitis C ,medicine.disease_cause ,medicine.disease ,Virology ,Peripheral blood mononuclear cell ,Virus ,Infectious Diseases ,Immunology ,medicine ,biology.protein ,Cytokine secretion ,Hemodialysis ,Antibody - Abstract
Patients with chronic renal failure undergoing hemodialysis who are infected with hepatitis C virus (HCV) may test consistently anti-HCV negative. Because CD4(+) T-cells provide help for antibody production virus-specific effector CD4(+) T-cell responses were investigated in relation to anti-HCV positivity in 15 hemodialysis patients grouped according to HCV antibody and viremia. CD4(+) T-cell reactivity was studied in peripheral blood mononuclear cells by standard lymphocyte proliferation assay and phenotypic/functional characterization (cell-surface staining/cytokine secretion) by flow cytometry. HCV-specific CD4(+) T-cell proliferation in viremic hemodialysis patients was weak or absent independently of their anti-HCV status. Virus-specific CD4(+) T-cells displayed a memory phenotype and showed low to undetectable capacity to secrete effector interferon (IFN)-gamma. Impaired activation-induced cytokine secretion appeared to be Th1 (IFN-gamma) but not Th2 (interleukin-4)-directed and was virus-specific as cytomegalovirus responses were preserved. The frequency ex vivo of CD3(+)CD4(+)IFN-gamma(+) T-cells was independent of the HCV antibody status and comparable between viremic (range: 0.08-1.54%) or non-viremic (0.11-3.2%) hemodialysis patients and healthy donors (0.13-1.10%; P = 0.58). The numbers of CD3(+)CD4(+)IFN-gamma(+) T-cells augmented slightly (P = 0.047) in HCV-infected hemodialysis patients but markedly in only one (greater than ninefold) after HCV stimulation. In conclusion, hemodialysis patients show limited HCV-specific effector CD4(+) Th1-cell responses which nonetheless seem unrelated to the anti-HCV status and are not more impaired due to the ongoing hemodialysis.
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- 2003
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29. Evaluation of Rotation and Visual Outcomes After Implantation of Monofocal and Multifocal Toric Intraocular Lenses
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Nuria Garzón, Francisco Poyales, Begoña Ortíz de Zárate, Juan Antonio Quiroga, and Jose Luis Ruiz-García
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Adult ,Male ,medicine.medical_specialty ,Visual acuity ,Distance visual acuity ,Pseudophakia ,Rotation ,genetic structures ,medicine.medical_treatment ,Visual Acuity ,Lentes de contacto ,Artificial Lens Implant Migration ,Prosthesis Design ,Cataract ,Lens Implantation, Intraocular ,Cirugía ,Ophthalmology ,medicine ,Humans ,Prospective Studies ,Aged ,Aged, 80 and over ,Lenses, Intraocular ,Phacoemulsification ,business.industry ,Astigmatism ,Mean age ,Middle Aged ,eye diseases ,Alcon Laboratories ,Intraocular lenses ,Multifocal IOLs ,Oftalmología ,Female ,Surgery ,Óptica oftálmica ,sense organs ,medicine.symptom ,business ,Rotational stability ,Follow-Up Studies - Abstract
PURPOSE: To evaluate rotational stability and its influence on postoperative visual acuity of different monofocal and multifocal toric intraocular lenses (IOLs). METHODS: A prospective interventional study was designed. Ninety-one patients with a mean age of 71.65 ± 11.82 years were implanted with toric IOLs after phacoemulsification. Three monofocal toric IOLs (the Lentis LT [Oculentis, Berlin, Germany], enVista [Bausch & Lomb, Rochester, NY], and AcrySof IQ [Alcon Laboratories, Inc., Fort Worth, TX]) and one multifocal toric IOL (AcrySof IQ ReSTOR; Alcon Laboratories, Inc.) were implanted. Preoperative and postoperative images were taken to calculate the misalignment due to the marking method. To evaluate rotation in the different follow-up visits, another photograph was taken 1 hour and 1, 7 and 30 days postoperatively. Refraction, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity were measured 30 days postoperatively. RESULTS: Postoperative UDVA was 0.1 logMAR or better in 64.6% of eyes implanted with monofocal IOLs and 46.4% of eyes implanted with multifocal IOLs. The enVista toric IOL showed the best UDVA compared to the other monofocal IOLs, with 81% of eyes with 0.1 logMAR or better. The mean misalignment in the total group studied was 0.07° ± 0.60°; 69.6% of monofocal IOLs and 67.9% of multifocal IOLs showed less than 5° of rotation. A correlation was found between postoperative UDVA and rotation in the monofocal and multifocal IOLs implanted ( r = 0.439 [ P < .011] and = 0.787 [ P = .001], respectively). CONCLUSIONS: At 1 month postoperatively, UDVA was slightly more affected by IOL rotation in multifocal than monofocal toric IOLs. The marking method was also effective. [ J Refract Surg . 2015;31(2):90–97.]
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- 2015
30. Sinusoidal least-squares fitting for temporal fringe pattern analysis
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J. Villa, José A. Gómez-Pedrero, and Juan Antonio Quiroga
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Noise immunity ,business.industry ,Irradiance ,Atomic and Molecular Physics, and Optics ,symbols.namesake ,Optics ,Fourier transform ,Fourier analysis ,Fringe pattern ,Fitting algorithm ,symbols ,Sensitivity (control systems) ,Sine ,business ,Algorithm ,Mathematics - Abstract
A sinusoidal least-squares fitting algorithm (SLSF) is applied to temporal evaluation of fringe patterns. The least-squares fitting of a sine function directly with the irradiance fluctuations due to a linear sensitivity variation of the optical set-up avoids the problems inherent to Fourier analysis. Experiments show that the proposed method has a better noise immunity than the temporal Fourier method. An application of this technique to Deflectometry is also presented.
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- 2002
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31. Features of the CD4+ T-cell response in liver and peripheral blood of hepatitis C virus-infected patients with persistently normal and abnormal alanine aminotransferase levels
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Ola Weiland, Vicente Carreño, Susana Castañón, Dolores Subirá, Juan Antonio Quiroga, Miguel A Rico, Matti Sällberg, Margarita Pardo, Esteban Garcia, and Geert Leroux-Roels
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Adult ,CD4-Positive T-Lymphocytes ,Male ,Hepatitis C virus ,Hepacivirus ,Population ,medicine.disease_cause ,Virus ,Interferon-gamma ,Liver disease ,T-Lymphocyte Subsets ,Interferon ,medicine ,Humans ,Viremia ,education ,Cells, Cultured ,education.field_of_study ,Hepatology ,biology ,Alanine Transaminase ,Hepatitis C, Chronic ,Middle Aged ,Viral Load ,medicine.disease ,biology.organism_classification ,Interleukin-10 ,Liver ,Immunology ,Female ,Viral disease ,Viral load ,Cell Division ,medicine.drug - Abstract
The liver is the primary site of hepatitis C virus (HCV) replication; intrahepatic T-cell responses may influence liver disease severity.HCV-specific CD4(+) T-cell reactivity was investigated ex vivo in paired liver tissue and peripheral blood from 42 chronic HCV patients.The frequencies with which HCV-specific HLA class-II-restricted CD4(+) T-cell proliferation were observed were 29% in liver and 36% in peripheral blood. Among responses, non-structural-3 protein (NS3)-specific T-cell proliferation was dominant but non-exclusive and did rarely occur concurrently in liver infiltrate and peripheral blood suggesting liver compartmentalization of a CD4(+) T-cells population. Compared with 24 patients with abnormal ALT levels, 18 HCV carriers with persistently normal ALT levels had similar serum and liver viral loads but showed: (i) a low-activity grade and stage chronic hepatitis (P0.001); (ii) less intrahepatic CD4(+) T-lymphocytes (P0.01); (iii) less frequent intrahepatic (17 vs. 33%) and peripheral (17 vs. 38%) NS3-specific CD4(+) T-cell proliferation; (iv) less often in vitro T-helper (Th)1 (interferon-gamma) cytokine production (2 vs. 18%; P0.001).Our data show a low frequency of intrahepatic HCV-specific HLA class-II-restricted CD4(+) Th1 responses in patients with chronic HCV. However, these Th1 responses are detected more often in those patients with overt clinical and histological disease.
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- 2002
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32. Impact of Isolated Hepatitis C Virus (HCV) Core-Specific Antibody Detection and Viral RNA Amplification among HCV-Seronegative Dialysis Patients at Risk for Infection
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María Dolores Arenas, Yésica Amézquita, Adoración Martín-Gómez, Jose M. Alcazar, Gloria del Peso, Rebeca García-Agudo, Inmaculada Castillo, Guillermina Barril, Secundino Cigarrán, José Antonio Herrero, Vicente Carreño, Nuria Garcia-Fernandez, Juan Antonio Quiroga, Pilar Caro, Pilar Martínez-Rubio, Javier Bartolomé, Ana Blanco, Emilio González-Parra, and Mario Espinosa
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Microbiology (medical) ,Adult ,Male ,medicine.medical_treatment ,Hepatitis C virus ,Biology ,medicine.disease_cause ,Dialysis patients ,Liver Function Tests ,Renal Dialysis ,Virology ,medicine ,Humans ,Viral rna ,Dialysis ,Aged ,Aged, 80 and over ,medicine.diagnostic_test ,Viral Core Proteins ,RNA ,virus diseases ,Hepatitis C ,Hepatitis C Antibodies ,Middle Aged ,medicine.disease ,digestive system diseases ,Peptide Fragments ,Enzymes ,Specific antibody ,Immunology ,RNA, Viral ,Female ,Liver function tests - Abstract
Amplification of hepatitis C virus (HCV) RNA from blood detected occult HCV infections in 30.9% of 210 HCV-seronegative dialysis patients with abnormal liver enzyme levels that had evaded standard HCV testing practices. Isolated HCV core-specific antibody detection identified three additional anti-HCV screening-negative patients lacking HCV RNA amplification in blood who were considered potentially infectious. Together, these findings may affect management of the dialysis setting.
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- 2014
33. Demodulation of carrier fringe patterns by the use of non-recursive digital phase locked loop
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Manuel Servin, Juan Antonio Quiroga, and Francisco Cuevas
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Carrier signal ,Computer science ,business.industry ,Noise (signal processing) ,Phase (waves) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Phase-locked loop ,TheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGES ,Optics ,Signal-to-noise ratio ,Demodulation ,Optica ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Phase retrieval ,business ,Phase modulation ,Óptica - Abstract
First- and second-order recursive Digital Phase Locked Loops (DPLLs) have been used recently in fringe data processing because it is the fastest way to obtain the unwrapped phase of a carrier frequency fringe pattern due to its minimal computational overhead. Nevertheless these simple DPLLs cannot cope with fringes having high noise and very wide band phase modulation. In this work we present a highly improved DPLL. The system presented is a non-recursive DPLL which is far more robust than previously presented recursive DPLL. The advantage of this newer technique with respect to recursive DPLL is its higher gain in the signal to noise ratio on the detected phase and higher stability. Unfortunately this is obtained at a higher computational cost.
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- 2001
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34. Temporal phase evaluation by fourier analysis of fringe patterns with spatial carrier
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José A. Gómez-Pedrero and Juan Antonio Quiroga
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Materials science ,business.industry ,Irradiance ,Phase (waves) ,Measure (mathematics) ,Atomic and Molecular Physics, and Optics ,symbols.namesake ,Fourier transform ,Optics ,Distribution (mathematics) ,Fourier analysis ,symbols ,Moire deflectometry ,Sensitivity (control systems) ,business - Abstract
A new method is presented for the temporal evaluation of fringe patterns with spatial carrier. The proposed technique involves recording the irradiance fluctuations obtained when a linear variation of the set-up sensitivity is introduced. In this condition, the use of a spatial carrier introduces a linear temporal carrier frequency. In this way, Fourier analysis can be performed to obtain the phase and, finally, the quantity to be measured. The optimum conditions for the sensitivity variation have been studied in order to minimize the errors associated with the Fourier analysis. The technique has been applied to measure the distribution of ray deflections on the surface of two ophthalmic lenses using a deflectometric set-up.
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- 2001
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35. Multicenter randomized study comparing initial daily induction with high dose lymphoblastoid interferon vs. standard interferon treatment for chronic hepatitis c
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Luis García-Villarreal, Juan A. del Olmo, José Aguilar, Vicente Carreño, Juan Antonio Quiroga, Agustín Domínguez, Moisés Diago, Francisco Pérez-Hernández, Angeles Castro, Dolores Suárez, and Margarita Pardo
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business.industry ,Leukocyte Counts ,Virology ,law.invention ,Infectious Diseases ,Maintenance therapy ,Chronic hepatitis ,Randomized controlled trial ,law ,Interferon ,Induction therapy ,Medicine ,In patient ,Lymphoblastoid Interferon ,business ,medicine.drug - Abstract
One hundred fifty-five chronic hepatitis C patients were assigned at random to receive natural lymphoblastoid interferon (IFN)α-n1, s.c., for 13 months in one of three treatment regimens: initial daily induction with 10 million units (MU) followed (group 1, n = 50) or not (group 2, n = 52) by 1 month of rest and then three times weekly 10 MU (2 months), 5 MU (2 months), and 3 MU (8 months); group 3 (n = 53) received tiw 5 MU (2 months) followed by 3 MU (11 months). By intention-to-treat analysis, ALT normalization at completion of treatment was greater in patients who received continuous IFNα-n1 therapy with initial daily induction (group 2: 24/52, 46%) compared with those given intermittent therapy with initial daily induction (group 1: 17/50, 34%) and those who received standard IFNα-n1 therapy (group 3, 18/53, 34%; P not significant). The sustained ALT response was 26%, 27% and 21% and the sustained virological response was 20%, 27%, and 19%, in groups 1, 2, and 3, respectively. A trend was observed towards a higher biochemical and virological end-of-treatment response in patients given induction therapy (17%) compared with standard therapy (6%, P = 0.053). Sustained biochemical and virological responses were 20%, 27%, and 17% in groups 1, 2, and 3, respectively. Platelet and leukocyte counts decreased following daily high-dose treatment and remained low until therapy cessation (P < 0.001). The data suggest that daily s.c. induction with 10 MU IFNα-n1 followed by intermittent or continuous maintenance therapy for 1 year does not improve the results achieved with the standard 1-year IFNα course in the treatment of chronic hepatitis C patients. J. Med. Virol. 64:460–465, 2001. © 2001 Wiley-Liss, Inc.
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- 2001
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36. Association of HLA-DR genes with mild idiopathic adulthood biliary ductopenia
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María Luisa Gutiérrez, Manuel Esteban García-Jiménez, Juan Antonio Quiroga, Vicente Carreño, and Margarita Pardo
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Adult ,Male ,medicine.medical_specialty ,Intrahepatic bile ducts ,Cholestasis, Intrahepatic ,Immunogenetics ,Severity of Illness Index ,Asymptomatic ,Gastroenterology ,Genetic determinism ,Pathogenesis ,Ductopenia ,Internal medicine ,HLA-DR ,Humans ,Medicine ,Genetic Predisposition to Disease ,Prospective Studies ,Allele ,Hepatology ,business.industry ,HLA-DR Antigens ,Middle Aged ,Immunology ,Female ,medicine.symptom ,business - Abstract
OBJECTIVE: Mild idiopathic adulthood ductopenia (MIAD) is an asymptomatic chronic cholestatic liver disease characterized by the loss of interlobular bile ducts in
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- 2001
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37. Isochromatics demodulation from a single image using the regularized phase tracking technique
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Juan Antonio Quiroga and Manuel Servin
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Photoelasticity ,business.industry ,Computer science ,Large dynamic range ,Astrophysics::Instrumentation and Methods for Astrophysics ,Phase (waves) ,Tracking (particle physics) ,GeneralLiterature_MISCELLANEOUS ,Atomic and Molecular Physics, and Optics ,Low noise ,Optics ,Demodulation ,Computer vision ,Artificial intelligence ,Spatial frequency ,Single image ,business - Abstract
In this work we propose a robust fringe demodulation technique applied to the analysis of a single isochromatics fringe pattern produced in photoelasticity. The method used is a regularized phase tracking algorithm with a new sequential scanning technique specifically adapted for the characteristics of the isochromatic fringe patterns: possible apparition of closed fringes, large dynamic range in its spatial frequency content and low noise. The performance of the method is discussed and experimental results are presented.
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- 2001
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38. Pilot study of combination therapy with ribavirin and interferon alfa for the retreatment of chronic hepatitis B e antibody-positive patients
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Teresa Cotonat, Félix Manzarbeitia, Vicente Carreño, Rosa Clouet, Juan Manuel López-Alcorocho, Margarita Pardo, and Juan Antonio Quiroga
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medicine.medical_specialty ,HBsAg ,Hepatology ,biology ,Combination therapy ,business.industry ,Ribavirin ,virus diseases ,Alpha interferon ,medicine.disease ,Gastroenterology ,digestive system diseases ,chemistry.chemical_compound ,Liver disease ,chemistry ,Alanine transaminase ,Internal medicine ,Immunology ,biology.protein ,medicine ,business ,Viral load ,Interferon alfa ,medicine.drug - Abstract
Twenty-four patients with chronic hepatitis B virus (HBV), antibody to hepatitis B e antigen (anti-HBe), HBV DNA positivity, and alanine transaminase (ALT) elevation who failed previous interferon alfa (IFN-α) therapy were included in a pilot study of combination therapy with ribavirin and IFN-α. The patients received daily oral ribavirin (1,000-1,200 mg according to body weight) plus 5 million units (MU) IFN-α2b three times a week for 12 months and were followed-up for 12 months. The median viremia level decreased significantly at the end of treatment (1.2 × 103copies/mL) and follow-up (4.0 × 102 copies/mL) compared with the baseline (3.0 × 106 copies/mL; P < .05). After 12 months, 8 of 24 (33%) patients had cleared HBV DNA and 12 (50%) had normal ALT levels. At the end of the study virological and biochemical response was 50% and 21%, respectively. Thus, virological and biochemical response sustained in 5 of 24 (21%) patients retreated with ribavirin and IFN-α; none of them lost hepatitis B surface antigen (HBsAg). Liver histology improved in 2 of 4 sustained responders but in none of the 12 nonresponders with paired biopsies (P = .05). The response was independent of dose and duration of previous treatment, viral load, or the distribution of HBV precore wild-type/mutant variants. However, sustained responders had significantly higher necroinflammation (P = .036) and fibrosis (P = .007) scores. IFN-α–related side effects were mild and reversible on discontinuation. In 4 (17%) patients who suffered nausea and diarrhea the ribavirin dosage was reduced by 50% after 1 month of therapy and finally discontinued in all of them. No patient had liver disease decompensation. In summary, combination therapy with ribavirin and IFN-α may be efficacious to treat viremic anti-HBe–positive patients with chronic hepatitis B who have failed previous IFN therapy.
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- 2000
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39. RANDOMIZED CONTROLLED TRIAL OF RECOMBINANT HUMAN GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR FOR THE TREATMENT OF CHRONIC HEPATITIS C
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Carlos Arocena, Pedro Anchı́a, Alvaro Brotons, Juan Antonio Quiroga, M N Fernández, Vicente Carreño, Margarita Pardo, Julio Martín, and Sonia Navas
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Hepatitis C virus ,Immunology ,Alpha interferon ,Viremia ,Interferon alpha-2 ,medicine.disease_cause ,Antiviral Agents ,Biochemistry ,Gastroenterology ,law.invention ,Randomized controlled trial ,Interferon ,law ,Internal medicine ,medicine ,Humans ,Immunology and Allergy ,Molecular Biology ,Aged ,biology ,business.industry ,Granulocyte-Macrophage Colony-Stimulating Factor ,Interferon-alpha ,Hematology ,Hepatitis C, Chronic ,Middle Aged ,Eosinophil ,medicine.disease ,Recombinant Proteins ,medicine.anatomical_structure ,Granulocyte macrophage colony-stimulating factor ,Alanine transaminase ,biology.protein ,Drug Therapy, Combination ,Female ,Drug Eruptions ,business ,medicine.drug - Abstract
Granulocyte-macrophage colony-stimulating factor (GM-CSF) was administered subcutaneously to 45 chronic hepatitis C patients, randomly assigned to receive 0.5, 1 or 2 microg GM-CSF/kg b.w. daily/6 weeks (n=30), or no treatment (n=15). Alanine transaminase (ALT) values normalized in four out of 10 (40%) patients administered 2 microg GM-CSF [1 cleared hepatitis C virus (HCV) RNA] but in none given 0.5 or 1 microg or untreated controls (P=0.0079). Following 4 weeks of rest, patients received 5 million units of interferon (IFN)alpha2b every other day/6 months, alone (n=30), or combined with 2 microg GM-CSF/daily for 3 months (n=15). At treatment end, ALT levels in patients administered the combination normalized more frequently than in those given monotherapy (73% vs 47%, P=0.089). Viraemia decreased significantly in 11/15 (73%) patients administered GM-CSF/IFNalpha2b combination (mean log HCV RNA copies/ml+/-SEM: 4.13+/-0.40 vs 5.29+/-0.23;P=0.011), and in 20/30 (67%) receiving IFNalpha2b monotherapy (4.27+/-0.28 vs 5. 31+/-0.14;P=0.004); 27% and 20% of patients given the combination and monotherapy, respectively, cleared HCV RNA. One patient in each regime had a sustained response after 12 months. 2', 5'-Oligoadenylate synthetase activity (2-5AS) increased during GM-CSF therapy (P=0.033 with the 2 microg dose). 2-5AS increased more in the GM-CSF/IFN-alpha2b combination than with IFNalpha2b monotherapy (P
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- 2000
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40. Retreatment of chronic hepatitis B e antigen-positive patients with recombinant interferon alfa-2a
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Vicente Carreño, Solko W. Schalm, Moisés Diago, Friederike Zahm, Félix Manzarbeitia, Irene Vafiadis, Juan Antonio Quiroga, Patrick Marcellin, F. Javier Jiménez, Geoge E. Kitis, Javier Salmerón, and Stephanos J. Hadziyannis
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Hepatitis ,Hepatitis B virus ,Piecemeal necrosis ,medicine.medical_specialty ,HBsAg ,Hepatology ,business.industry ,Alpha interferon ,medicine.disease ,medicine.disease_cause ,Gastroenterology ,Discontinuation ,HBeAg ,Internal medicine ,Immunology ,medicine ,business ,Interferon alfa ,medicine.drug - Abstract
Fifty-seven patients with chronic hepatitis B, hepatitis B virus (HBV) e antigen (HBeAg) and HBV DNA positivity, and aminotransferase elevation despite a previous course of any type of adequate interferon alfa (IFN-α) therapy were included in a multicenter prospective randomized controlled trial. The objective of the study was to compare a second course of IFN-α therapy (9 million units [MU] of IFN-α-2a, Roferon-A, thrice weekly for 6 months) versus no therapy in terms of loss of HBV DNA and HBeAg. At the end of the study, a sustained clearance of HBV DNA and HBeAg was observed in 9 of the 27 (33.3%) patients who had received retreatment with IFN-α compared with 3/30 (10%) patients who spontaneously cleared these markers in the untreated control group (χ2 = 4.66, P = .031; odds ratio: 4.5, 95%; confidence interval: 1.1-18.9). None of the responders lost HBsAg. Patients retreated with IFN-α were more likely to have biochemical remission in association with HBV clearance (5/27, 18.5%) compared with untreated patients (1/30, 3.3%; Fisher's exact test P = .09). Histological improvement in the liver necroinflammatory activity was observed among sustained responders to IFN-α retreatment, consisting of regression of the portal and periportal inflammation and of the piecemeal necrosis; there was no change in the degree of liver fibrosis. Side effects were similar to those previously reported during IFN-α treatment; these were mild and reversible on IFN-α discontinuation. None of the baseline features were associated with response by Cox's regression analysis. In summary, viremic patients with chronic HBeAg-positive hepatitis may experience disease remission following retreatment with IFN-α. Thus, retreatment with IFN-α may be considered a therapeutic option
- Published
- 1999
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41. Does Occult Hepatitis C Virus Infection Exist?
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Javier Bartolomé, Inmaculada Castillo, Vicente Carreño, and Juan Antonio Quiroga
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Adult ,Male ,Vasculitis ,Microbiology (medical) ,Hepacivirus ,Hepatitis C virus ,Virus Replication ,medicine.disease_cause ,Polymerase Chain Reaction ,Sensitivity and Specificity ,Liver Function Tests ,medicine ,Humans ,In patient ,Letters to the Editor ,Connective Tissue Diseases ,Aged ,biology ,medicine.diagnostic_test ,Liver Diseases ,Hepatitis C antibody ,virus diseases ,Hepatitis C ,Middle Aged ,medicine.disease ,biology.organism_classification ,Virology ,Occult ,digestive system diseases ,Liver ,Leukocytes, Mononuclear ,RNA, Viral ,Female ,Abnormal results ,Liver function tests - Abstract
Occult hepatitis C infection is regarded as a new entity that should be considered when diagnosing patients with a liver disease of unknown origin. Using an ultrasensitive real-time PCR assay, we demonstrated that occult hepatitis C virus (HCV) infection cannot be found in peripheral blood mononuclear cells of patients with cryptogenic liver diseases, HCV--associated systemic vasculitis, or connective tissue diseases. The significance of such occult infection must be elucidated.
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- 2008
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42. EFFECTS OF THE RIBAVIRIN-INTERFERON α COMBINATION ON CULTURED PERIPHERAL BLOOD MONONUCLEAR CELLS FROM CHRONIC HEPATITIS C PATIENTS
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Julio Martín, Vicente Carreño, Sonia Navas, Juan Antonio Quiroga, and Margarita Pardo
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Adult ,CD4-Positive T-Lymphocytes ,Mononuclear cell proliferation ,Hepatitis C virus ,medicine.medical_treatment ,Immunology ,Alpha interferon ,Hepacivirus ,CD8-Positive T-Lymphocytes ,Interferon alpha-2 ,medicine.disease_cause ,Antiviral Agents ,Biochemistry ,Peripheral blood mononuclear cell ,chemistry.chemical_compound ,Interferon ,Ribavirin ,2',5'-Oligoadenylate Synthetase ,Humans ,Immunology and Allergy ,Medicine ,Drug Interactions ,Molecular Biology ,Cells, Cultured ,Aged ,business.industry ,Interferon-alpha ,virus diseases ,Hematology ,Hepatitis C, Chronic ,Middle Aged ,Recombinant Proteins ,digestive system diseases ,Enzyme Activation ,Cytokine ,chemistry ,Leukocytes, Mononuclear ,Cytokines ,RNA, Viral ,Cytokine secretion ,business ,Cell Division ,medicine.drug - Abstract
The effects of ribavirin and interferon (IFN) alpha have been investigated on cultured peripheral blood mononuclear cells, obtained from 15 patients with chronic hepatitis C virus (HCV) infection. At clinically relevant serum concentrations achieved during therapeutic administration, ribavirin did inhibit moderately the mitogen-stimulated mononuclear cell proliferation and growth of the CD4+ and CD8+ T cell subsets without apparent cytolysis. The ribavirin-IFN-alpha combination showed activity against HCV with disappearance of HCV RNA in 27% of cases, and a synergy in the inducibility of the intracellular enzyme 2',5'-oligoadenylate synthetase. Such ribavirin concentrations induced modest increases in the T helper 1-like cytokine production by mononuclear cells. Higher ribavirin concentrations markedly inhibited IFN-gamma production, but augmented interleukins (IL) 2, 4, and 12 secretion. Conversely, IFN-alpha tended to suppress IL 2, 4 and 12, but enhanced IFN-gamma and IL-10 secretion. Thus, ribavirin and IFN-alpha appear to cause diverse effects on immunoregulatory cytokine secretion, and when combined, counteracted for production of IL-2 and IL-12, while upregulated mononuclear cell secretion of IFN-gamma and that of the anti-inflammatory cytokine IL-10. These findings suggest a non-cytolytic modulation of inflammatory responses induced by the drug combination, that may be relevant in the pathophysiology of chronic HCV infection.
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- 1998
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43. Genetic Diversity and Tissue Compartmentalization of the Hepatitis C Virus Genome in Blood Mononuclear Cells, Liver, and Serum from Chronic Hepatitis C Patients
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Sonia Navas, Vicente Carreño, Julio Martín, Inmaculada Castillo, and Juan Antonio Quiroga
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Adult ,Male ,Hepacivirus ,Hepatitis C virus ,Molecular Sequence Data ,Immunology ,Genome, Viral ,medicine.disease_cause ,Microbiology ,Peripheral blood mononuclear cell ,Virology ,Genetic variation ,medicine ,Humans ,Genetic variability ,Genetic diversity ,biology ,Genetic Variation ,Hepatitis C, Chronic ,biology.organism_classification ,Virus-Cell Interactions ,Hypervariable region ,Liver ,Genetic distance ,Insect Science ,Leukocytes, Mononuclear ,Female - Abstract
The degree of genetic variability in the hypervariable region 1 of hepatitis C virus (HCV) was analyzed by cloning and sequencing HCV genomes obtained in paired samples of serum, liver tissue, and peripheral blood mononuclear cells (PBMC) from four chronic hepatitis C patients. Genetic variability in serum was higher than in liver tissue or PBMC at the level of complexity (the number of different sequences obtained from each type of tissue) as well as at the level of genetic distance between all pairs of sequences within each tissue (compared by the Student t test; P < 0.001 for two patients and P < 0.01 for another). The spectrum of viral genomes differed among the three types of tissue, as shown by segregation of sequences according to their tissue of origin in phylogenetic analysis and by statistical analysis of mean genetic distances observed between sequences obtained from different tissues ( P < 0.001), but sequences from liver tissue and PBMC were more closely related to each other than to those from serum.
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- 1998
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44. Multicenter Randomized, Controlled Study of Intramuscular Administration of Interferon-β for the Treatment of Chronic Hepatitis C
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Vicente Carreño, José Pedreira, Arturo Pérez-Mota, Juan Antonio Quiroga, Luis Inglada, Dolores Suárez, Angeles Castro, José Such, Esther Carballo, Juan Angel del Olmo, Moisés Diago, and Agustín Domínguez
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Adult ,Male ,medicine.medical_specialty ,Immunology ,Viremia ,Anorexia ,Antiviral Agents ,Injections, Intramuscular ,Gastroenterology ,Transaminase ,law.invention ,Randomized controlled trial ,Weight loss ,law ,Virology ,Internal medicine ,medicine ,Humans ,Transaminases ,Aged ,business.industry ,Interferon-beta ,Cell Biology ,Hepatitis C ,Middle Aged ,medicine.disease ,Surgery ,Treatment Outcome ,Hair loss ,Chronic Disease ,Female ,medicine.symptom ,Headaches ,business - Abstract
The intramuscular administration of interferon-beta (IFN-beta) at a dosage of 6 million units three times per week for 6 months has been evaluated in 90 patients included in a multicenter, randomized, controlled trial for the treatment of chronic hepatitis C. Transaminase levels were significantly reduced in IFN-beta-treated patients (p = 0.015) and were significantly lower with respect to those of the untreated controls (p = 0.040 at 6 months). Four treated (8%) and one untreated (2.5%) patients had normal transaminase values after 6 months. At study end (12 months), three quarters of the IFN-beta-treated patients had sustained transaminase normalization, whereas the untreated case had relapsed. Hepatitis C viremia was cleared in 6 (12%) treated patients but in none of the untreated controls (p = 0.058). Side effects of IFN-beta were infrequent (a mild flu-like syndrome in < 10%, asthenia in 16%, anorexia in 8%, headaches and weight loss in 8%, and hair loss in 4%). Leukocyte and platelet counts decreased during IFN-beta treatment, but no dose modifications were necessary. Such decreases were not statistically significant when compared with the levels in the untreated controls. Intramuscular IFN-beta at the dosage used has little efficacy in the treatment of chronic hepatitis C. Because of IFN-beta tolerance, higher doses and alternate routes of injection might prove beneficial for the treatment of this disease.
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- 1997
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45. Concordance of hepatitis C virus typing methods based on restriction fragment length polymorphism analysis in 5' noncoding region and NS4 serotyping, but not in core PCR or a line probe assay
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Sonia Navas, Vicente Carreño, Javier Bartolomé, Juan Antonio Quiroga, J. Martín, and Inmaculada Castillo
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Microbiology (medical) ,Base Sequence ,Sequence analysis ,Hepatitis C virus ,Molecular Sequence Data ,Hepacivirus ,Biology ,medicine.disease_cause ,Hepatitis C ,Polymerase Chain Reaction ,Virology ,Molecular biology ,Virus ,Genotype ,medicine ,Typing ,Restriction fragment length polymorphism ,Line Probe Assay ,Sequence Alignment ,Genotyping ,Polymorphism, Restriction Fragment Length ,Research Article - Abstract
Data from sequence analysis, genotyping by restriction fragment length polymorphism in the 5' noncoding region, and NS4 serotyping of the sera of 20 patients with chronic hepatitis C virus infection have shown 100% concordance, while core-based methods and a line probe assay have shown several missing or wrong results.
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- 1997
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46. High prevalence of occult hepatitis C virus infection in patients with primary and secondary glomerular nephropathies
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Ana Aguilar, Carmen Bernis, Rafael Selgas, Vicente Carreño, Jorge Martínez-Ara, Inmaculada Castillo, Juan Antonio Quiroga, E. Hernandez, Teresa Olea, Javier Bartolomé, and Rosario Madero
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Adult ,Male ,Hepatitis C virus ,Nephritis, Hereditary ,Hepacivirus ,medicine.disease_cause ,Peripheral blood mononuclear cell ,Serology ,chemistry.chemical_compound ,Glomerulonephritis ,Risk Factors ,medicine ,Prevalence ,Humans ,Prospective Studies ,Aged ,Hepatitis ,Creatinine ,business.industry ,virus diseases ,Odds ratio ,Hepatitis C Antibodies ,Middle Aged ,medicine.disease ,Occult ,Hepatitis C ,digestive system diseases ,chemistry ,Nephrology ,Immunology ,Leukocytes, Mononuclear ,RNA, Viral ,Female ,business - Abstract
The association of hepatitis C virus (HCV) infection and glomerulonephritis is well known. However, the relationship between immune-mediated glomerulonephritis and occult HCV, characterized by the presence of HCV-RNA in liver or in peripheral blood mononuclear cells in the absence of serological markers, is unknown. We tested this in 113 anti-HCV-negative patients; 87 with immune-mediated glomerulonephritis and 26 controls with hereditary glomerular nephropathies. All patients were serum HCV-RNA negative by conventional real-time PCR. Significantly, occult HCV-RNA (detectable viral RNA in peripheral blood mononuclear cells or in serum after ultracentrifugation) was found in 34 of 87 patients with immune-mediated glomerulonephritis versus 1 of 26 control patients. The serum creatinine levels were significantly higher in patients with immune-mediated glomerulonephritis with than in those without occult HCV (1.5 versus 1.1 mg/dl, respectively). A multivariate analysis adjusted for gender showed a significantly increased risk of occult HCV in patients with immune-mediated glomerulonephritis versus the controls (odds ratio of 13.29). Progression to end-stage renal disease tended to be faster in patients with immune-mediated glomerulonephritis and occult HCV than in the negative cases. Thus, occult HCV is strongly associated with immune-mediated glomerulonephritis and may have a role in the progression of the disease.
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- 2013
47. Recombinant human granulocyte colony-stimulating factor reduces hepatitis c virus replication in mononuclear cells from chronic hepatitis c patients
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Sonia Navas, Vicente Carreño, Juan Antonio Quiroga, and Julio Martín
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Hepatitis B virus DNA polymerase ,Hepatitis C virus ,medicine.medical_treatment ,Immunology ,Drug Evaluation, Preclinical ,Hepacivirus ,Granulocyte ,Virus Replication ,medicine.disease_cause ,Antiviral Agents ,Biochemistry ,Peripheral blood mononuclear cell ,Granulocyte Colony-Stimulating Factor ,medicine ,Humans ,Immunology and Allergy ,Interleukin 6 ,Molecular Biology ,Cells, Cultured ,biology ,business.industry ,Hematology ,Hepatitis C ,medicine.disease ,Virology ,Recombinant Proteins ,Granulocyte colony-stimulating factor ,medicine.anatomical_structure ,Cytokine ,Chronic Disease ,Leukocytes, Mononuclear ,biology.protein ,business - Abstract
Hepatitis C virus infects mononuclear leukocytes of patients with chronic hepatitis C. Treatment with rhG-CSF led to a dose-related reduction in the genomic and antigenomic hepatitis C viral strands in cultures of mitogen-stimulated, naturally-infected peripheral blood mononuclear cells from patients with chronic hepatitis C. Hepatitis C virus genomic strand of subtype 1b was suppressed in 5 of 11 cases, and concurrently with suppression of the viral antigenomic strand in two of them. The treatment also resulted in a significantly increased release of interleukin 6, but not of other cytokines. However, the biological response of hepatitis C virus-infected mononuclear cells to treatment with recombinant human granulocyte colony-stimulating factor was unrelated to any particular pattern of cytokine production.
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- 1996
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48. Squareness error calibration of a CMM for quality control of ophthalmic lenses
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Juan Antonio Quiroga, Diego Rodríguez-Ibañez, and Jose I. Alonso
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Engineering ,business.industry ,Mechanical Engineering ,Control (management) ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Quality (physics) ,Volumetric error ,Optics ,Ophthalmic lenses ,Control and Systems Engineering ,Calibration ,Reference surface ,Computer vision ,Artificial intelligence ,Optica ,business ,Software ,Óptica - Abstract
This paper proposes a calibration procedure for the squareness error of small-sized coordinate measuring machines like those used for ophthalmic lenses quality control. The proposed procedure only requires a spherical lens as a reference surface and it only needs to be measured once making this calibration method faster and cheaper than the existing ones.
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- 2013
49. Sequence of non-structural regions 3 and 5 of hepatitis C virus genomes from Spanish patients: existence of a predominant variant related to type 1b
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Vicente Carreño, Margarita Pardo, Juan Antonio Quiroga, Inmaculada Castillo, Maria Pernas, and Javier Bartolomé
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viruses ,Hepatitis C virus ,Molecular Sequence Data ,Pcr assay ,Genome, Viral ,Hepacivirus ,Viral Nonstructural Proteins ,Biology ,medicine.disease_cause ,Polymerase Chain Reaction ,Genome ,Homology (biology) ,Virology ,Complementary DNA ,medicine ,Humans ,Amino Acid Sequence ,Genetics ,NS3 ,Base Sequence ,virus diseases ,Hepatitis C ,medicine.disease ,Serum samples ,digestive system diseases - Abstract
Several hepatitis C viruses (HCV) have been described. In this study, the prevalence of HCV subtypes 1a, 1b, 2a and 2b has been studied by means of specific PCR in 93 serum samples of Spanish patients. Among these, the HCV-1b subtype was the most frequently detected (62%). Complementary DNA fragments from non-structural region 3 (NS3) and 5 (NS5), obtained from serum samples of three Spanish patients, were amplified by PCR and the products were cloned and sequenced. Comparison of the sequence obtained with those previously published shows the highest homology (91.7% in NS3 and 91.8% in NS5) with the HCV-1b subtype. The incidence of the local variant was analysed among the HCV-1b-infected patients. In order to distinguish between the local and HCV-1b prototype subtype, a new specific PCR assay was designed using primers from NS5. In the majority of the 76 HCV-1b-infected patients, the local variant was the only subtype detected (53%). These findings support the existence of a local variant, belonging to the HCV-1b subtype.
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- 1995
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50. New perspectives in occult hepatitis C virus infection
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Javier Bartolomé, Inmaculada Castillo, Vicente Carreño, and Juan Antonio Quiroga
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Cirrhosis ,Hepatitis C virus ,Hepacivirus ,medicine.disease_cause ,Antiviral Agents ,Liver disease ,chemistry.chemical_compound ,medicine ,Humans ,Serologic Tests ,Asymptomatic Infections ,business.industry ,Ribavirin ,Gastroenterology ,virus diseases ,General Medicine ,Hepatitis C ,medicine.disease ,Occult ,digestive system diseases ,Editorial ,chemistry ,Liver ,Hepatocellular carcinoma ,Immunology ,Etiology ,Leukocytes, Mononuclear ,RNA, Viral ,business - Abstract
Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occult hepatitis C has been found not only in anti-HCV positive subjects with normal values of liver enzymes or in chronic hepatitis of unknown origin but also in several groups at risk for HCV infection such as hemodialysis patients or family members of patients with occult HCV. This occult infection has been reported also in healthy populations without evidence of liver disease. Occult HCV infection seems to be less aggressive than chronic hepatitis C although patients affected by occult HCV may develop liver cirrhosis and even hepatocellular carcinoma. Thus, anti-HCV negative patients with occult HCV may benefit from antiviral therapy with pegylated-interferon plus ribavirin. The persistence of very low levels of HCV RNA in serum and in PBMCs, along with the maintenance of specific T-cell responses against HCV-antigens observed during a long-term follow-up of patients with occult hepatitis C, indicate that occult HCV is a persistent infection that is not spontaneously eradicated. This is an updated report on diagnosis, epidemiology and clinical implications of occult HCV with special emphasis on anti-HCV negative cases.
- Published
- 2012
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