Search PubMed⌕ Search

Biomedical subjects

M Pardo

Publications and source records attributed to M Pardo.

At least 19 recordsLinked to original sources
PubMed2007

Comparative study between occult hepatitis C virus infection and chronic hepatitis C.

We have recently described the presence of occult hepatitis C virus (HCV) infection (HCV-RNA in liver in the absence of anti-HCV and serum HCV-RNA) in patients with persistently abnormal liver function tests of unknown aetiology. The aim of this study was to compare the characteristics of patients with occult HCV infection vs those of patients with chronic hepatitis C. We compared clinical features of 68 patients with occult HCV infection and 69 untreated chronic HCV patients (anti-HCV and serum HCV-RNA positive), matched for age, gender, duration of abnormal liver function tests and body mass index. Aspartate aminotransferase and alanine aminotransferase were higher (P < 0.001) in chronic HCV, but cholesterol and triglycerides were significantly higher in patients with occult HCV infection (P < 0.001 and P = 0.002). Chronic HCV patients had higher gamma-globulin (P = 0.005), alpha-foetoprotein (P < 0.001) and iron (P < 0.001) levels. Percentage of patients with necroinflammatory activity and fibrosis was higher (P < 0.001) in chronic HCV than in occult HCV infection. Mean percentage of infected hepatocytes was higher (P = 0.001) in chronic HCV (10.1%) than in occult HCV infection (5.3%). This occult HCV infection is a milder disease than chronic HCV, and this could be related to the significantly lower number of infected hepatocytes observed in occult HCV.

Adult↗
PubMed2006

Effect of anti-viral therapy for occult hepatitis C virus infection.

BACKGROUND: Occult hepatitis C virus infection is defined by the presence of hepatitis C virus-RNA in liver but with undetectable anti-hepatitis C virus and serum viral RNA. AIM: To study the response to anti-viral therapy in occult hepatitis C virus infection to assess the pathogenic effect of occult hepatitis C virus. METHODS: Ten patients with occult hepatitis C virus infection were treated with pegylated-interferon plus ribavirin for 24 weeks and were followed-up 24 weeks after therapy. All patients had abnormal alanine aminotransferase, hepatitis C virus-RNA positive in peripheral blood mononuclear cells and liver necroinflammation. RESULTS: At the end of treatment and follow-up, the percentage of patients with normal alanine aminotransferase was 80% (95% CI: 48-96%) and 60% (95% CI: 31-84%) respectively, and hepatitis C virus-RNA in peripheral blood mononuclear cells was negative in 80% (95% CI: 48-96%) and 70% (95% CI: 40-90%) cases. At the end of follow-up sustained response was observed in 30% (95% CI: 11-61%) of cases. Five patients underwent a second liver biopsy. In all cases, liver hepatitis C virus-RNA persisted, although hepatitis C virus-RNA load was significantly lower (3.2 x 10(4) +/- 5.1 x 10(4) copies/microg RNA) than in the basal biopsy (2.4 x 10(5) +/- 3.8 x 10(5) copies/microg RNA); (P = 0.043). Necroinflammation and fibrosis decreased in three cases. CONCLUSION: The biochemical, virological and histological response to therapy achieved in patients with occult hepatitis C virus infection demonstrates the pathologic effects of occult hepatitis C virus.

Adult↗
PubMed2005

Hepatitis C virus (HCV) and hepatitis B virus (HBV) can coinfect the same hepatocyte in the liver of patients with chronic HCV and occult HBV infection.

In this work, we have shown that hepatitis C virus (HCV) and hepatitis B virus (HBV) can coexist in the same hepatocyte using double fluorescent in situ hybridization in liver biopsy samples from patients with chronic HCV infection with occult HBV infection. Digital image analysis of hybridization signals showed that the HBV DNA levels in coinfected hepatocytes were lower than those in cells infected only with HBV. This finding supports the hypothesis of inhibition of HBV replication by HCV. Furthermore, HCV RNA levels were lower in coinfected cells than in cells infected only with HCV, suggesting that HBV may also inhibit HCV replication.

Biopsy↗
PubMed2005

Hepatitis C virus replicates in peripheral blood mononuclear cells of patients with occult hepatitis C virus infection.

BACKGROUND: Occult hepatitis C virus (HCV) infection is characterised by the presence of HCV-RNA in the liver in the absence of anti-HCV, and serum viral RNA. Up to 70% of these patients also have HCV-RNA in peripheral blood mononuclear cells (PBMC) but it is not known if HCV is replicating in these cells. AIM: We studied possible HCV replication in PBMC of 18 patients with an occult HCV infection who were selected on the basis of HCV-RNA positivity in PBMC. METHODS: Detection of HCV-RNA positive and negative strands in PBMC was done by strand specific reverse transcriptase-polymerase chain reaction (RT-PCR) and by in situ hybridisation. RESULTS: The presence of HCV-RNA positive strand in PBMC was confirmed in all patients by strand specific RT-PCR and by in situ hybridisation. Mean percentage of PBMC which had the HCV-RNA positive strand was 3.3% (95% confidence interval (CI) 2.1-4.4) The HCV-RNA negative strand was found in the PBMC of 11/18 (61%) patients by strand specific RT-PCR and confirmed by in situ hybridisation, and the percentage of PBMC harbouring the HCV-RNA negative strand was 3.1% (95% CI 0.8-5.5). There was a significant correlation (p = 0.001, r = 0.84) between the percentage of PBMC with the HCV-RNA positive strand and that of PBMC with the HCV-RNA negative strand. CONCLUSION: HCV replicates in the PBMC of patients with occult HCV infection and thus, although these patients do not have serum HCV-RNA, they could be potentially infectious.

Adult↗
PubMed2002

Allergy after ingestion or inhalation of cereals involves similar allergens in different ages.

BACKGROUND: Cereals are among the major foods that account for food hypersensitivity reactions. Salt-soluble proteins appear to be the most important allergens contributing to the asthmatic response. In contrast, very limited information is available regarding cereal allergens responsible for allergic reactions after ingestion of cereal proteins. OBJECTIVE: The aim of this study was to evaluate the allergenic reactivity of ingested and inhaled cereal allergens in different ages, in order to investigate if the response to different allergens would depend on the sensitization route. METHODS: We included 66 patients in three groups. Group 1: 40 children aged 3 to 6 months who suffered from diarrhoea, vomiting, eczema or weight loss after the introduction of cereal formula in their diet and in which a possibility of coeliac disease was discarded. Group 2: 18 adults with food allergy due to cereals tested by prick tests, specific IgE and food challenge. Group 3: eight patients previously diagnosed as having baker's asthma. Sera pool samples were collected from each group of patients and IgE immunoblotting was performed. RESULTS: We found an important sensitization to cereal in the 40 children. The most important allergens were wheat followed by barley and rye. Among the adults with cereal allergy, sensitization to other allergens was common, especially to Lolium perenne (rye grass) pollen. Immunoblotting showed similar allergenic detection in the three groups. CONCLUSION: Clinically significant reactivity to cereal may be observed in early life. Inhalation and ingestion routes causing cereal allergy seem to involve similar allergens. The diet control was more effective in children. The possibility of cereal allergy after the introduction of cereal formula during the lactation period should not be underestimated.

Administration, Inhalation↗
PubMed2001

Analysis of the serologic response to systemic Candida albicans infection in a murine model.

Two different strains of mice with different susceptibilities to systemic candidiasis (BALB/c and CBA/H) were infected with Candida albicans SC5314. Immune sera were obtained on different days post-infection and assayed against two-dimensional polyacrylamide gel electrophoresis separation of cytoplasmic extracts obtained from protoplasts. More than 31 immunoreactive proteins were detected. Some of them were identified and found to correspond to (i) glycolytic enzymes, such as fructose biphosphate aldolase, triose phosphate isomerase (TPIS), glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase (PGK), enolase (ENO1) and pyruvate kinase, (ii) other metabolic enzymes, such as methionine synthase (METE), inosine-5'-monophosphate dehydrogenase (IMH3), alcohol dehydrogenase and aconitate hydratase and (iii) heat shock proteins: HS71 (or Ssa1p) and HS75 (or Ssb1p), both from the HSP70 family. This work reports for the first time antigenic properties for IMH3 and TPIS. Different profiles of antibody expression, depending on the mouse strain and the course of infection, were observed. ENO1 was the most immunogenic protein in infected BALB/c mice (the most resistant strain). On the other hand, sera from CBA/H mice (a more susceptible strain) showed a strong increase in reactivity along the infection against METE, HS75 and PGK. Many of these immunoreactive proteins have also been detected using sera from human patients with systemic candidiasis, thus indicating the usefulness of the murine model for studying the antibody response in systemic candidiasis. In this work we demonstrate that the combination of two-dimensional electrophoresis with immunoblotting using murine immune sera can be an important tool for the identification of C. albicans antigens and for monitoring the evolution of the disease.

Amino Acid Sequence↗
PubMed2001

TT virus detection in oral lichen planus lesions.

Epidemiological studies have demonstrated a correlation between oral lichen planus and different liver diseases. The new virus termed TT virus (TTV) is highly prevalent in patients with chronic hepatitis of different etiology and it may be speculated that TT virus may be involved in the pathogenesis of oral lichen planus. This study examined the presence of TT virus DNA in serum by PCR and in oral mucosa biopsies by in situ hybridization from 20 patients with oral lichen planus (13 with chronic hepatitis and seven without liver disease). Serum and oral mucosa biopsies from six patients all with chronic hepatitis with leukoplakia were also studied as controls. TT virus DNA was positive in the serum of 17/20 (85%) of the patients with oral lichen planus and in all the controls. TT virus DNA hybridization signals were detected in mucosa biopsies from all the patients with TT virus DNA in serum but in none of the three cases without this marker. The percentage of positive cells ranged from 1.6-80%. No differences were found in the percentage of positive cells between TT virus positive patients with and without oral lichen planus and there was no relationship between the number of positive cells and the intensity of the inflammatory infiltrate. In conclusion, TT virus infects oral epithelial cells but the results do not support a role for TT virus in causing oral lichen planus.

Aged↗
PubMed2001

Multicenter randomized study comparing initial daily induction with high dose lymphoblastoid interferon vs. standard interferon treatment for chronic hepatitis C.

One hundred fifty-five chronic hepatitis C patients were assigned at random to receive natural lymphoblastoid interferon (IFN)alpha-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 IFNalpha-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 IFNalpha-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 IFNalpha-n1 followed by intermittent or continuous maintenance therapy for 1 year does not improve the results achieved with the standard 1-year IFNalpha course in the treatment of chronic hepatitis C patients.

Adolescent↗
PubMed2001

Role of inhibitors of isoprenylation in proliferation, phenotype and apoptosis of human retinal pigment epithelium.

BACKGROUND: Isoprenoid biosynthesis is known to be essential for diverse cellular functions, including cell proliferation. The aim of this work was to study the effects caused by the addition of different inhibitors of isoprenylation (lovastatin, manumycin A, farnesyltransferase inhibitor III and N-acetyl-S-farnesyl-L-cysteine) to human retinal pigment epithelium (RPE) in culture, as potential coadjunctive-to-surgery treatments applicable to proliferative vitreoretinopathy. METHODS: Human RPE cell cultures were established from adult corneal donors. Proliferation levels were evaluated using the incorporation of 5-bromo-2'-deoxyuridine into the DNA. Cell viability was measured by tetrazolium bromide transformation. Apoptosis was determined by DNA fragmentation assay, TdT-mediated d-UTP-X nick-end labeling (TUNEL) and phosphatidylserine exposure assessment. Changes in cell morphology and actin cytoskeleton were evaluated using a phase-contrast microscope and by fluorescent staining of actin cables with TRITC-phalloidin. RESULTS: We found that lovastatin showed an important antiproliferative effect on human RPE cells in culture. This effect was clearly dose-dependent, and adding mevalonate could reverse it. We also found that lovastatin induced changes in the distribution of actin cytoskeleton and, finally, that it also induced RPE apoptosis. Manumycin A, farnesyltransferase inhibitor III and N-acetyl-S-farnesyl-L-cysteine also showed antiproliferative effects in RPE. However, they do not have any effect on cell morphology or induction of apoptosis. DISCUSSION: We identified various effects of lovastatin on human RPE cultures: inhibition of cell proliferation, modifications of the phenotype and induction of apoptosis. Interestingly, the addition of different inhibitors of protein isoprenylation only affected the proliferation of the cells. There was no evidence that isoprenylated proteins inhibition is related to lovastatin-induced RPE apoptosis.

Actins↗
PubMed2001

In situ detection of hepatitis C virus RNA in salivary glands.

Chronic hepatitis C virus (HCV) infection has been associated with several extrahepatic manifestations, among these, to diseases with oral manifestations such as Sjögren's syndrome or sialadenitis. HCV-RNA has been detected in saliva and in salivary glands from patients with sialadenitis by polymerase chain reaction. However, morphological evidence of HCV replication in salivary gland cells is needed to support a role for HCV in causing sialadenitis or Sjögren's syndrome. We have used in situ hybridization and immunohistochemistry to analyze the presence of HCV-RNA of sense and antisense polarity and HCV core antigen, respectively, in salivary gland biopsies from 19 patients with chronic sialadenitis or Sjögren's syndrome (eight anti-HCV-positive; 11 anti-HCV-negative). HCV-RNA of both positive and negative polarity as well as HCV core antigen were detected in the epithelial cells of the salivary gland biopsies from all of the anti-HCV-positive patients but in none of the anti-HCV-negative cases. The percentage of HCV-infected cells ranged from 25 to 48.8% in the patients studied. In conclusion, we have shown that HCV infects and replicates in the epithelial cells from salivary glands of patients with Sjögren's syndrome or chronic sialadenitis. However, its implication in the pathogenesis of these diseases deserves future research.

Adult↗
PubMed2001

Extended follow-up of anti-HBe-positive patients with chronic hepatitis B retreated with ribavirin and interferon-alpha.

In a pilot study of combination therapy with ribavirin and IFN alpha conducted in anti-HBe-positive individuals with chronic hepatitis B, 21% of patients achieved a sustained ALT normalization and clearance of hepatitis B virus (HBV) DNA as measured by PCR. The present work has assessed whether these sustained responses are lasting long-term. In addition, IFN gamma levels were tested serially in serum as a measure of the immune system activation during treatment. By extending the post-treatment follow-up period 2 years the occurrence of delayed HBV DNA relapses was observed. A low serum level of IFN gamma was detected during and after treatment. IFN gamma demonstrated a multiphasic time-course: the amount of IFN gamma increased in parallel with reductions in HBV DNA but also with ALT flare-ups. In conclusion, the extended follow-up study of anti-HBe-positive patients after combined treatment with ribavirin and IFN alpha has shown that sustained responses are lasting in 17% patients but also that a late onset HBV DNA relapse may occur.

Adult↗
PubMed2001

Hepatitis B virus-specific T-cell proliferation and cytokine secretion in chronic hepatitis B e antibody-positive patients treated with ribavirin and interferon alpha.

Immune elimination of hepatitis B virus (HBV) during antiviral therapy depends on the activation of T-cell responses, which are generally impaired in chronic hepatitis B. HBV-specific T helper (Th)-cell reactivity has been assessed post-treatment in liver and peripheral blood of 18 anti-HBe-positive patients with chronic hepatitis B administered combined ribavirin/interferon alfa (IFN-alpha) therapy. The results showed that patients with undetectable HBV DNA by quantitative polymerase chain reaction under combination therapy were able to mount an HBV-specific CD4(+) Th-cell proliferative response and such T-cell reactivity is detectable 1 year after HBV DNA clearance. Hepatitis B virus core (HBcAg) and e (HBeAg) antigen-specific Th-cell proliferation was found more frequently in the liver and peripheral blood in those patients who sustained the alanine aminotransferase (ALT) normalization together with HBV DNA loss. However, HBV-specific IFN-gamma production in vitro in peripheral blood mononuclear cells augmented in 4 of 5 sustained responders and all 13 nonresponders, interleukin 10 (IL-10) production decreased in all 5 sustained responders but increased in 7 of 13 nonresponders. Furthermore, intrahepatic HBcAg plus HBeAg-specific Th-cell proliferation only occurred in sustained responders (2 of 3, 67%, vs. 0 of 9; P =.045) whose cells showed in vitro significantly increased productions in HBcAg/HBeAg-specific IFN-gamma and IL-12 compared with nonresponders in whom IFN-gamma and IL-12 productions decreased together with increased IL-10 secretion. In conclusion this study indicates that combined therapy with ribavirin and IFN-alpha for chronic hepatitis B not only significantly reduces viremia levels but also induces lasting CD4(+) T-cell proliferation and Th1 cytokine release at the site of infection, which may lead to sustained eradication of the HBV.

Adult↗
PubMed2001

Population kinetics of tobramycin in neonates.

The population kinetics of tobramycin were studied in 140 neonates (100/40 patients for the index/validation groups, respectively) of 30 to 42 weeks' gestational age and 0.8 to 4.25 kg current body weight in their first 2 weeks of life, undergoing routine therapeutic drug monitoring of their tobramycin serum levels. The 365 tobramycin concentration measurements obtained were analyzed by use of NONMEM according to a one-compartment open model with zero-order absorption and first-order elimination. The effect of a variety of demographic, developmental, and clinical factors (gender, height, birth weight, current weight, gestational age, postnatal age, postconceptional age, and serum creatinine concentration) on clearance and volume of distribution was investigated. Forward selection and backward elimination regression identified significant covariates. The final pharmacostatistical model with influential covariates was as follows (full population): clearance (L/h) = 0.0508 x current weight (kg), multiplied by 0.843 if birth weight was 2.5 kg or less (low-birthweight infants), and volume of distribution (L) = 0.533 x current weight (kg). Using the proportional error model for the random-effects parameters, interindividual variability for clearance and for volume of distribution was determined to be 25.8% and 21.9%, respectively, and the residual variability was 19.2%. In this study, the use of the NONMEM gave significant and consistent information on the pharmacokinetics and the determinants of the pharmacokinetic variability of tobramycin in neonates when compared with available bibliographic information. Moreover, the final population pharmacokinetic model may be used to design a priori recommendations for tobramycin and to improve the dosing readjustments through Bayesian estimation.

Anti-Bacterial Agents↗
PubMed2001

Association of HLA-DR genes with mild idiopathic adulthood biliary ductopenia.

OBJECTIVE: Mild idiopathic adulthood ductopenia (MIAD) is an asymptomatic chronic cholestatic liver disease characterized by the loss of interlobular bile ducts in <50% of the portal tracts. Although the underlying cause of MIAD is unknown, the host factors may contribute to the patient's susceptibility to the disease. The aim of this work was to investigate the immunogenetics in the pathogenesis of MIAD. METHODS: We prospectively studied 22 Caucasian patients with MIAD. Peripheral blood was collected, and HLA-DR typing was performed by polymerase chain reaction with sequence-specific primers followed by sequencing for subtyping. Results were compared with those from 140 age- and sex-matched controls. RESULTS: There was no significant association between HLA-DRB1 alleles and the disease, although a trend was found in MIAD patients with the DRB1*1502 allele (five of 44 vs four of 280 in controls; p corrected = 0.055; chi2 = 13.9). Multiple HLA-DRB1 alleles (*04, *11, *15) showed increased frequencies in MIAD patients. Further subtyping revealed a motif (positions 25-32 of the beta1 chain) present in 17 (77.3%) patients, which was significantly associated with MIAD (p = 0.049; chi2 = 3.87). Seven patients (31.8%) and 21 (15%) controls coded for this motif in their two alleles (p = 0.068; chi2 = 3.76). Among MIAD patients, those seven had abnormal ALT levels (p = 0.017) and their gamma-glutamyltransferase and ALT values tended to be more increased. CONCLUSIONS: These results provide evidence of an immunogenetic basis of susceptibility to MIAD in Caucasian individuals.

Adult↗
PubMed2001

[Mammary carcinoma ine ectopic breast tissue. A case report].

Ectopic breast tissue, that includes supernumerary breasts and aberrant breast tissue, develops along the mammary line. Malignancies rarely develop in this tissue. We report a 44 years old female subjected to a resection of a 3 cm Ø tumor located 2 cm below the right lower mammary sulcus. The pathological study reported an infiltrating ductal carcinoma. The patient was operated again and a metastatic carcinoma was detected in three resected axillary lymph nodes. Adjuvant chemotherapy and radiotherapy was indicated.

Adult↗
PubMed2000

Fluorescent "in situ" hybridization of hepatitis C virus RNA in peripheral blood mononuclear cells from patients with chronic hepatitis C.

Although the liver is the main target for hepatitis C virus (HCV) infection, HCV RNA of positive and negative polarity has also been detected in peripheral blood mononuclear cells (PBMCs) by polymerase chain reaction. However, no data have been published on the relationship between the number of HCV-infected PBMCs and serum viremia levels. To address this issue, PBMC samples from 20 patients with chronic hepatitis C were examined by fluorescent "in situ" hybridization. Serum viremia levels and viral load in infected PBMC were measured using the Amplicor Monitor test. HCV was detected in all PBMC samples corresponding to the HCV-positive patients. Fluorescent signals were found mainly in the cytoplasm of the cell. The percentage of positive cells ranged from 0.08% to 4%, with a statistical correlation with the viral load in PBMC (r = 0.69; p =. 001) but not with the serum viremia levels (r = 0.23). It was demonstrated that HCV infection of PBMCs is a common feature of HCV chronic carriers. The results suggest that HCV infection of PBMCs does not contribute significantly to HCV viremia.

Hepacivirus↗
PubMed2000

Cross-species identification of novel Candida albicans immunogenic proteins by combination of two-dimensional polyacrylamide gel electrophoresis and mass spectrometry.

We have previously reported the usefulness of two-dimensional gel electrophoresis followed by Western blotting with sera from patients with systemic candidiasis in the detection of the major Candida albicans antigens (Pitarch et al., Electrophoresis 1999, 20, 1001-1010). The identification of these antigens would be useful for the characterization of good markers for the disease, and for the development of efficient diagnostic strategies. In this work we have used nanoelectrospray tandem mass spectrometry to obtain amino acid sequence information from the immunogenic proteins previously detected. We report here the cross-species identification of these antigens by matching of tandem mass spectrometry data to Saccharomyces cerevisiae proteins. Using this approach, we unambiguously identified the four C. albicans immunogenic proteins analyzed, namely aconitase, pyruvate kinase, phosphoglycerate mutase and methionine synthase. Furthermore, we report for the first time that aconitase, methionine synthase and phosphoglycerate mutase have antigenic properties in C. albicans.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗