Search PubMed⌕ Search

Biomedical subjects

R Esteban

Publications and source records attributed to R Esteban.

At least 91 records · Page 5Linked to original sources
PubMed1995

Hepatitis E virus infection in acute hepatitis in Spain.

In order to study the prevalence of hepatitis E virus (HEV) infection in developed countries, IgG and IgM anti-HEV were determined in serum samples from 382 patients with acute viral hepatitis (244 hepatitis A, 48 hepatitis B and/or D, and 90 non-A, non-B, non-C hepatitis), 76 healthy subjects, 55 hemophiliacs and 50 patients on hemodialysis. IgG anti-HEV antibodies were detected and confirmed by a synthetic peptide-based EIA in 5 (5.6%) non-A, non-B, non-C acute hepatitis, in 3 (6.5%) B and D acute hepatitis, in 10 (4%) acute A hepatitis, in 3 (5.5%) of 54 healthy adults in none of the hemophiliacs and in 3 (6%) patients on hemodialysis. IgM anti-HEV antibodies were only detected in two cases of acute hepatitis B and/or D. Analysis of serial serum samples demonstrated IgG anti-HEV seroconversion in 3 of the 18 confirmed cases; one of them was also positive for IgM anti-HEV. All 3 acute anti-HEV-positive hepatitis cases occurred in adults, were community-acquired (two of them were intravenous drug addicts) and had a self-limited course. These results demonstrate that HEV is a minor cause of acute hepatitis in Spain. A similar low rate of IgG anti-HEV antibodies was detected in patients with different diseases, suggesting that HEV has a very low epidemiological impact. An apparent association of HEV infection with hepatitis B and D suggests a possible parenteral transmission of a mainly enteral pathogen.

Acute Disease↗
PubMed1995

Hepatitis C virus infection in renal transplant recipients: epidemiology, clinical impact, serological confirmation and viral replication.

The presence and significance of hepatitis C virus infection was evaluated in 241 renal transplant recipients from our hospital. Hepatitis C virus antibodies were tested by second-generation enzyme immunoassay, followed by second- and third-generation immunoblot assays (RIBA-2 and RIBA-3); hepatitis C virus RNA was measured by nested polymerase chain reaction. Hepatitis C virus antibodies, which were detected in 46.5% of patients, were mainly present before transplantation and independently associated with the total amount of transfused blood, time in hemodialysis and duration of posttransplant follow up. Liver dysfunction (alanine aminotransferase elevation) was observed in 50% of antibody-positive recipients, and 92.5% of patients with chronic liver disease without hepatitis B infection were infected with hepatitis C virus. Most antibody-positive patients (78.4%) tested positive by RIBA-2, but 21.6% were indeterminate; RIBA-3 was positive in 90% of these indeterminates. Hepatitis C virus RNA detection was positive in 96% of antibody-positive cases tested, in 20% of patients who were already anti-HCV negative before transplantation and also demonstrated persistence of HCV infection in all cases who, being antibody positive prior to transplantation, lost these antibodies during follow up (9% of transplanted patients). In conclusion, hepatitis C virus infection is extremely prevalent in renal transplant recipients from Spain and is the main cause of chronic liver disease in these patients. Confirmation by supplemental assays of anti-HCV antibodies is not necessary, but hepatitis C virus RNA testing is indispensable to detect those cases who lose or do not develop hepatitis C virus antibodies.

Adult↗
PubMed1995

Risk of hepatitis B in infancy and childhood.

Hepatitis B virus (HBV) may be transmitted from mother to child during delivery or in the neonatal period (vertical transmission) or by direct person to person contact in teenagers and adults (horizontal transmission). Patients infected horizontally, as occurs in countries with a low prevalence of infection, achieve complete resolution in up to 95% of cases and acquire permanent immunity. On the other hand, 95% of infected newborns cannot clear the virus and remain chronic carriers. The relevance of this method of infection in newborns is twofold. First, because of persistent infection throughout life, they are at risk of developing liver cirrhosis and hepatocellular carcinoma. Second, they are permanent reservoirs of hepatitis B infection, facilitating its spread. Even in countries with low or intermediate prevalence, the importance of vertical transmission is manifest. In a study carried out in our hospital before screening of pregnant women for hepatitis B surface antigen (HBsAg) was implemented, the prevalence of HBsAg carriers among 8200 pregnant women was 1.24%, 6% of whom were HBeAg positive, for a minimum rate of transmission of HBV of 6%. From these data, there will be at least 65 children per year in Catalonia who become chronic carriers and about 1000 children at risk of acquiring HBV infection. Epidemiological studies carried out in Catalonia confirmed our results. Among children under 10 years of age in whom vertical transmission was likely, 1.7% had serum markers of HBV infection and 0.2% were HBsAg positive. These data confirm the need for universal HBV prevention in newborns, in addition to any other programme carried out in teenagers or adults.

Adult↗
PubMed1995

Implementing universal vaccination programmes: Spain.

Until 1990, the immunization policy against hepatitis B in Spain was selective high-risk vaccination. That policy failed to reduce the incidence of hepatitis B and the prevalence rates of chronic carriers. In 1991, Catalonia began a universal immunization programme targeted at 12-year-olds. Six other regions (Castilla-León, Valencia, Extramadura, Navarra, the Balearic Islands and Rioja) introduced vaccination programmes in 1992. In 1993, three more regions (Galicia, Castilla-La-Mancha and Pais Vasco) began immunizing young adolescents. This means that 12-year-olds in Spain are now included in vaccination programmes against hepatitis B.

Adolescent↗
PubMed1995

Long interval between HCV infection and development of hepatocellular carcinoma.

A high prevalence of HCV infection has been reported in patients with hepatocellular carcinoma. The progression from acute transfusion-associated hepatitis to hepatic cirrhosis and hepatocellular carcinoma has been suggested in several studies to be very long. We have investigated the prevalence of anti-HCV and the interval between HCV infection and hepatocellular carcinoma among 191 consecutive patients with cirrhosis and liver-cell carcinoma. Serum samples from 191 patients with cirrhosis and hepatocellular carcinoma, consecutively diagnosed in our hospital between 1988 and 1993, were tested for serological markers of HBV and HCV infection. One hundred and forty-eight patients (77.5%; 95% confidence interval (c.i): 76% to 80%) were anti-HCV positive by 2nd generation enzyme immunoassay (confirmed by 2nd generation recombinant immunoblot assay) and 152 patients (79.5%; 95% c.i: 76% to 80%) were anti-HCV positive by 3rd generation enzyme immunoassay, while only 14 (7.4%; 95% c.i: 5% to 10%) were HBsAg positive. Of the 29 anti-HCV positive patients with previous transfusion, the interval between the date of blood transfusion and the diagnosis of hepatic cirrhosis was 24 +/- 12.5 years and that of hepatocellular carcinoma was 26.8 +/- 12.4 years. These results confirm the high prevalence of HCV infection in patients with hepatocellular carcinoma and the slow sequential progression from HCV infection through cirrhosis and hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1995

Determination of hepatitis delta virus RNA by polymerase chain reaction in acute and chronic delta infection.

The objective of this study was to evaluate the usefulness of hepatitis delta virus (HDV) RNA detection by polymerase chain reaction (PCR) in acute and chronic D hepatitis and to correlate with HDV-RNA detection by dot blot and hepatic delta antigen. Serum samples from 33 patients with acute hepatitis B surface antigen (HBsAg)-positive hepatitis (15 with hepatitis B and D coinfection, 8 with HDV superinfection, and 10 with acute hepatitis B), 85 patients with chronic HBsAg-positive hepatitis (73 with chronic D hepatitis and 12 with chronic B hepatitis), and consecutive serum samples from nine patients with chronic D hepatitis treated with interferon alfa-2b were studied. HDV-RNA was detected by PCR in 93% of the patients with hepatitis B and D coinfection, in 100% of the patients with hepatitis D superinfection, and in 1 of the 10 patients with acute hepatitis B who subsequently seroconverted to total antibody to hepatitis delta antigen (HDAg), whereas HDV-RNA was found by dot blot technique in 60% of the hepatitis B and D coinfection cases, in 62.5% of the patients with hepatitis D superinfection, and in none of the acute hepatitis B cases. In chronic D hepatitis, HDV-RNA tested positive by PCR assay in 97% of patients with intrahepatic HDAg, in one patient with undetectable hepatic HDAg, and in none of the patients with chronic hepatitis B. In the treated patients, HDV-RNA was observed to become negative by PCR only in the three patients who had a persistent response to interferon.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Association of yeast viral 23 S RNA with its putative RNA-dependent RNA polymerase.

T double-stranded RNA (dsRNA) and its single-stranded RNA (ssRNA) counterpart, 23 S RNA, are present in some strains of the yeast Saccharomyces cerevisiae. 23 S RNA is identical with the T (+)-strand, and both are cytoplasmically inherited. The T (+)-strand encodes a protein of 104 kilodaltons (kDa) (p104) that has sequences diagnostic of RNA-dependent RNA polymerases from (+)-strand and double-stranded RNA viruses. Here we show that p104 is expressed only in yeast strains carrying T dsRNA (and 23 S RNA) and that the ability to produce p104 is co-transmitted from one strain to another by cytoplasmic mixing (cytoduction) along with T dsRNA. Neither T nor 23 S RNA is encapsidated into viral particles; however, the latter was found to be non-covalently associated with p104. This finding was based on the evidence that: (i) both 23 S RNA and p104 cosedimented in sucrose gradients and that (ii) 23 S RNA was immunoprecipitated by a p104-specific polyclonal antiserum. Consistent with this association, p104 shows single-stranded RNA-binding activity in Northwestern blots. We have localized the RNA-binding domain of p104 within its C terminus 234 amino acids.

Fungal Proteins↗
PubMed1994

Comparative analysis of serological markers of chronic delta infection: HDV-RNA, serum HDAg and anti-HD IgM.

To study the concordance, sensitivity and specificity of HDV-RNA determination by molecular hybridization, serum HDAg by immunoblot and anti-HD IgM by commercial enzyme immunoassay as compared to intrahepatic HDAg detection by an immunoperoxidase method, a statistical analysis was applied to the results of serum sample and liver biopsy determinations in 50 patients with chronic delta hepatitis (38 positive to tissue HDAg and 12 negative). Of the 38 patients with hepatic HDAg, HDV-RNA was found in 31 (82%), serum HDAg by immunoblot in 27 (71%) and anti-HD IgM in 33 (87%). Among the 12 patients without hepatic HDAg, one was found with serum HDAg using the immunoblot technique, two (17%) had HDV-RNA, and 7 (58%) had anti-HD IgM. Serum HDAg determination by immunoblot was the most specific test, followed by HDV-RNA analysis. The least specific was the anti-HD IgM technique. The anti-HD IgM test was the most sensitive, followed by HDV-RNA and serum HDAg. The concordance with intrahepatic HDAg detection was highest for HDV-RNA determination, followed by HDAg in serum. The least degree of concordance was found with anti-HD IgM determination. These results suggest that the determination of HDV-RNA by the hybridization method can be of great value for the diagnosis and monitoring of chronic delta hepatitis.

Adolescent↗
PubMed1994

Etiology of acute sporadic hepatitis in Spain: the role of hepatitis C and E viruses.

The aim of this study was to determine the prevalence of hepatitis viruses and analyze the epidemiological features in acute hepatitis in Spain. Consecutive serum samples from 341 patients with acute hepatitis were tested for IgM anti-hepatitis A virus, IgM anti-hepatitis B core antigen and HBsAg. The antibody to hepatitis C virus was determined using a second-generation enzyme immunoassay. In selected cases, serum was tested for antibodies for hepatitis E virus by enzyme immunoassay and hepatitis C virus-RNA by polymerase chain reaction. One hundred and fourteen (33.2%) cases of acute hepatitis were due to hepatitis A virus, 68 (20%) to hepatitis B virus, 21 (6%) to hepatitis D virus and 74 (21.8%) to hepatitis C virus infection. Of the 74 hepatitis C virus infections, 48 (65%) were anti-HCV positive at the time of diagnosis, while 26 (35%) seroconverted to anti-HCV later during follow-up. No case of hepatitis E virus infection was detected. The remaining 64 cases were negative to all acute serological markers and were classified as non-A, non-B, non-C, non-E hepatitis. Hepatitis C virus was implicated in 65/119 (54.6%) of the cases among intravenous drug users but in only in 9/199 (4.5%) of the sporadic cases (p < 0.01). Progression to chronic hepatitis was observed more frequently in anti-hepatitis C virus-positive than in antibody-negative-cases (42/70; 60% vs. 3/52 or 5.5%) (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Detection of hepatitis B precore mutants by the fluorescent linear polymerase chain reaction sequencing method.

To evaluate the presence of precore mutants, serum samples from 25 patients with chronic hepatitis B, HBV-DNA positive (5 HBeAg and 20 anti-HBe positive) were studied. The complete precore-core region of HBV-DNA was directly sequenced after polymerase chain reaction amplification by a fluorescent linear polymerase chain reaction sequencing method. Precore variants were detected in one HBeAg positive and in all 20 anti-HBe positive patients: in 19 cases, G to A at position 1896, with or without the substitution G to A at position 1899, in two cases C to T substitution at position 1817 which also produces a stop codon (CAA to TAA), one accompanied by the mutation G to A at position 1896. The only mutation observed in the patient who was initially HBeAg positive patient was a G to A substitution at position 1899. Consecutive serum samples from a patient with chronic hepatitis B, initially had the simultaneous presence of wild type and variant strains. Elimination of the wild-type strain was associated with reactivation of liver disease. Analysis of the sequences obtained demonstrated the heterogeneity of the hepatitis B virus genome in the precore-core region. These results indicate that the main cause of non-expression of HBeAg in chronic hepatitis B in our country is the substitution of G to A at nucleotide 1896, alone or accompanied by other variants. Fluorescent linear polymerase chain reaction is a fast and sensitive method to study heterogeneity in the precore-core region.

Amino Acid Sequence↗
PubMed1994

Incidence and outcome of hepatitis C virus infection after liver transplantation.

The objective of this study was to determine the incidence and outcome of hepatitis C virus (HCV) infection after liver transplantation (OLT). Fifty-two transplanted patients were studied. Serum samples were examined for antibodies to HCV (anti-HCV) and HCV-RNA by PCR, before and after OLT. Patients were distributed into two groups: group 1 consisted of 24 patients (pretransplant anti-HCV positive) and group 2 consisted of 28 patients (pretransplant anti-HCV negative). One year after OLT, HCV-infected patients were evaluated by liver biopsy. HCV-RNA was detected in 28 of the 52 (53.9%) patients after OLT. Twenty-two patients in group 1 (96%) were reinfected. In group 2, acquired HCV infection was detected in six (21.4%) patients. At 6 and 12 months, one and five of six patients had seroconverted, respectively. Liver biopsy in 23 HCV-infected patients showed chronic hepatitis in 18 (78%) cases (2, chronic persistent hepatitis; 3, chronic lobular hepatitis and 13, chronic active hepatitis). Fourteen of the 23 (60.8%) patients were asymptomatic. Most symptomatic patients had chronic hepatitis with cholestasis. Overall, 18 of 20 cases of chronic hepatitis diagnosed in OLT recipients were HCV related. Mortality beyond 6 months after OLT was slightly higher in the HCV-infected group (P = 0.055). In conclusion, HCV reinfection is almost universal. Acquired HCV infection post-OLT is frequent. HCV-infected patients frequently develop chronic hepatitis. Most chronic hepatitis after transplantation are HCV related.

Adult↗
PubMed1994

Dynamic behavior of hepatitis C virus quasispecies in patients undergoing orthotopic liver transplantation.

We have studied the distribution of viral sequences from the 5' noncoding region and from a fragment of the E2/NS2 region of the hepatitis C virus (HCV) genome in samples obtained before and after liver transplantation in two patients with HCV cirrhosis. The population of viral sequences in both regions were established by sequencing cloned PCR products. In both cases, the complexity of the viral quasispecies decreased after transplantation, although the consensus nucleotide and amino acid sequences remained unchanged. It is suggested that both positive and negative selection and random sampling events contribute substantially in shaping the genetic composition of HCV quasispecies and that recurrence of HCV infection may occur under equilibrium conditions.

Amino Acid Sequence↗
PubMed1994

Synthesis of a non-radioactive hepatitis B virus DNA probe from human serum by the polymerase chain reaction.

A method for synthesizing probes for detecting hepatitis B virus DNA in serum was developed. It uses DNA extracted from the serum of an hepatitis B virus carrier as target, and digoxigenin-11-dUTP incorporated in DNA sequences during the polymerase chain reaction as tracer. Using a spot hybridization assay, the sensitivity and specificity of the digoxigenin-labelled DNA probe were compared with two standard hepatitis B virus DNA probes, synthesized with cloned hepatitis B virus DNA and labelled either with digoxigenin or 32P by random priming. Data obtained from the three methods showed an excellent correlation. Thus, hepatitis B virus DNA extracted from human serum and labelled by polymerase chain reaction may be considered a suitable alternative to cloned DNA. It provides reliable probes and eliminates the need for facilities and personnel dedicated to the manipulation of clones. These advantages will allow a wider application of hepatitis B virus DNA testing in clinical practice.

Base Sequence↗
PubMed1993

[Hepatocellular carcinoma: clinical aspects, diagnosis, and survival in 140 cases].

BACKGROUND: Hepatocellular carcinoma (HCC) constitutes a frequent clinical problem in the follow up of patients with liver cirrhosis. The clinical features and diagnoses and survival in a group of 140 cases of HCC are reviewed. METHODS: All the clinical histories of the patients diagnosed of HCC between 1987 and 1991 in the Unit of Hepatology of the General Hospital of the Vall d'Hebron were retrospectively reviewed. The clinical, analytical, diagnostic, therapeutic and evolutive data were collected. RESULTS: One hundred forty patients (121 males and 19 females) were included. In 92% of the cases the HCC was established on liver cirrhosis in which alcohol was the most frequent etiologic factor. According to the Pugh-Child classification 31% of the patients were in group A, 32.5% in group B and 36.4% in group C. Clinically, diagnosis was carried out in the course of periodic out patient follow up in 21% of the cases. HBsAg was positive in 8.5% of the cases and anti HCV was 55% and in 78% by ELISA 1 and ELISA 2, respectively. Alphafetoprotein (AFP) was greater than 500 ng/dl in 37% of the cases. The treatment received was: surgical resection in 18 cases, liver transplantation in 3, intraarterial chemotherapy in 11 and intratumoral alcoholization in 8. Symptomatic treatment was administered in 71% of the cases. Global mean survival was 4.4 +/- 0.5 months. Mean survival was greater in patients with better liver function and smaller tumor size in the patients surgically treated and in those diagnosed in the periodic controls. CONCLUSIONS: Hepatocellular cancer is normally established in patients with liver cirrhosis. The high prevalence of infection by the hepatitis C virus and the low prevalence by hepatitis B virus is of note. The patients with greater survival were those surgically treated and those diagnosed in periodic controls.

Aged↗