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Biomedical subjects

R Esteban

Publications and source records attributed to R Esteban.

At least 127 records · Page 7Linked to original sources
PubMed1992

Long-term immunogenicity and efficacy of hepatitis B vaccine in hemodialysis patients.

Although the efficacy of hepatitis B vaccines in patients under chronic hemodialysis treatment has been well documented, the persistence of immunity in this population remains largely unknown. In this study we have followed 60 hemodialysis patients up to 3 years after primary hepatitis B vaccination (four doses of recombinant hepatitis B vaccine; Engerix B, 20 mg/dose) to evaluate the persistence of immunity (as indicated by serum levels of antibody to hepatitis B surface antigen-anti-HBs-higher than or equal to 10 mIU/ml). Fourty-four (73%) patients developed anti-HBs levels above 10 mIU/ml after vaccination; the remaining 16 (27%) vaccinees were considered nonresponders and were given a booster dose that again failed to elicit an immunoresponse. After 3 years of follow-up, 18 out of 44 (41%) responders had no detectable anti-HBs levels in the serum (antibody loss occurring within 8 and 12 months in 3 cases, within 1 and 2 years in 13, and within 2 and 3 years in 2 other cases). When compared with the responders that lost their antibodies during the follow-up period, those who remained immunoreactive 3 years after vaccination was initiated were younger and had higher anti-HBs levels at 8 months of follow-up. Two hepatitis B virus infections were detected among nonresponders during the follow-up period. Based on these data, we conclude that patients undergoing chronic hemodialysis therapy not only have lower response rates to hepatitis B vaccination than healthy adults, but also that these are frequently transient.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1991

[Primary solid hepatic sarcoma. Diagnosis by cytological puncture].

The clinical case of a 56 year old patient who developed a grafted hepatic tumoration on a year after diagnosis of liver cirrhosis of alcoholic etiology is reported. Diagnosis of the mass was made by fine needle aspiration punction ecographically guided obtaining a cellular block which, upon anatomopathological study, revealed the presence of a malignant mesenchymal tumor; a leiomyosarcoma. Not only is this type of primary hepatic tumor rare but its appearance on a liver of alcoholic cirrhosis is also of interest. It is much more common to find primary hepatic tumors of epithelial origin, concretely hepatocarcinomas. The value of this finding is discussed with the importance of the ecographically guided punction enabling the establishment of a precise histological diagnosis being underlined. The prognosis of malignant hepatic mesenchymal tumors is commented upon as well as the long survival associated to the same, which, in this case, was longer than 18 months.

Biopsy, Needle↗
PubMed1991

Molecular cloning and characterization of W double-stranded RNA, a linear molecule present in Saccharomyces cerevisiae. Identification of its single-stranded RNA form as 20 S RNA.

Most strains of the yeast Saccharomyces cerevisiae harbor a double-stranded RNA (dsRNA) molecule, called W. We obtained W cDNA clones by random priming of denatured W dsRNA followed by reverse transcription. Sequence data of W shows that only one strand ((+)-strand) has coding capacity for a protein with 829 amino acids which spans almost the entire length of the molecule (2.5 kilobases). Within this protein we found a sequence pattern characteristic of RNA dependent RNA polymerases of (+)-strand and double-stranded RNA viruses. W has no homology with other dsRNAs found in S. cerevisiae, such as L-A, L-BC or M1. However, a (+)-strand-specific probe for W hybridized with 20-S RNA. Furthermore, W (+)-strands comigrated with 20 S RNA in strand separation gels. These results suggest that 20 S RNA is a (+)-single-stranded RNA form of W dsRNA itself or a closely related molecule.

Amino Acid Sequence↗
PubMed1991

Clinical significance of two forms of IgM antibody to hepatitis delta virus.

Separation of 7-8 S and 19 S forms of serum IgM antibodies to the hepatitis delta virus by rate-zonal centrifugation was carried out on serum from 24 patients with hepatitis delta virus infection: 4 patients with acute, self-limited hepatitis; 5 patients with hepatitis delta virus superinfection progressing to chronicity; and 15 patients with chronic hepatitis delta virus. The high molecular weight IgM form (19 S) was predominantly detected in acute hepatitis delta virus cases, whereas the low molecular weight (7 S) form was found in chronic hepatitis delta virus cases. The serological profile of these two forms of IgM antibody to hepatitis delta virus was investigated in serial samples from five patients with acute hepatitis delta virus superinfection that evolved to chronic hepatitis delta virus. We found that, in the acute stage of the disease, the 19 S form was predominant, whereas 6 mo later a predominance of 7-8 S IgM was observed. These results suggest that IgM antibody to hepatitis delta virus antibody forms are different in acute and chronic hepatitis delta virus infection and that their detection only helps in differentiating an acute infection from a chronic infection but not a hepatitis delta virus-hepatitis B virus-HBV coinfection from hepatitis delta virus superinfection in the acute stage of the disease.

Acute Disease↗
PubMed1991

Sleep apnoea syndrome associated with maxillofacial abnormalities.

Four cases with Obstructive Sleep Apnoea Syndrome (OSAS) are presented. They consisted of two cases with TMJ ankylosis with micrognathia, one case with Treacher Collins Syndrome, and one case with the Long Face Syndrome. Standard and specific cephalometric parameters were obtained to detect the site of the obstruction. Polysomnographic studies yielded information regarding the patient's sleep-wake state, respiratory and cardiac functioning, pre- and post-operatively. A temporary tracheostomy corrected the symptoms in one patient but the syndrome recurred when it was closed. Surgical correction of the maxillofacial anomalies will re-establish normal sleep patterns preventing OSAS.

Adolescent↗
PubMed1991

Influence of human immunodeficiency virus infection on cell-mediated immunity in chronic D hepatitis.

To determine whether the abnormalities of cell-mediated immunity described in chronic D hepatitis are associated with hepatitis D virus (HDV) infection or concomitant human immunodeficiency virus (HIV) infection, serologic and tissue hepatitis B virus (HBV) and HDV markers and T lymphocyte subsets were studied in serum samples from 38 patients with chronic D hepatitis, 26 of whom had HIV infection. Patients with chronic D hepatitis and HIV infection had significantly lower peripheral blood T4:T8 ratios resulting from a significant increase in T8+ (suppressor/cytotoxic) cells, while numbers of T lymphocyte subsets were normal in cases with chronic D hepatitis only. HIV+ patients showed an increase in HBV replication (identified by hepatitis B core antigen in liver and hepatitis B e antigen and HBV DNA in serum) and in HDV replication (tissue D antigen and HDV RNA) without evidence of more active liver disease. Probably the immunologic disturbances detected in chronic D hepatitis are secondary to HIV infection, do not contribute to the pathogenesis of liver injury, and are associated with increased viral B and D replication.

Adolescent↗
PubMed1991

Digoxygenin-labelled DNA-probe: a rapid non-radioactive method for hepatitis B virus DNA detection in serum.

The sensitivity and specificity of two non-radioactive spot hybridization assays for hepatitis B virus DNA (HBV-DNA) using biotin and digoxygenin-labelled DNA probes were investigated in parallel in 122 serum samples from patients with chronic hepatitis B and 50 controls. The results were compared with an isotopic technique using a 32P-labelled probe. HBV-DNA was detected in 56 (80%) out of 70 hepatitis B "e" antigen (HBeAg)-positive cases and in 4 (8%) out of 52 antibody to hepatitis B "e" antigen (anti-HBe)-positive cases using the digoxygenin or 32P-labelled probes. No false positives were found with either method. Using the biotin-labelled probe, 16% of sera gave discordant results, which were considered to be false positive. The time required for detection of serum HBV-DNA was 2 hours for the non-radioactive probes and 16 hours for the isotopic probes. This study suggests that the digoxygenin-labelled probe for detection of HBV-DNA is the most rapid and sensitive method for routine diagnosis of viral replication in clinical laboratories.

Alanine Transaminase↗
PubMed1991

[Pulmonary involvement in familial amyloid polyneuropathy type I].

Familial amyloid polyneuropathy type 1 or Corino Andrade's disease (FAP 1) is classified amongst the hereditary systemic amyloidosis, being autosomically dominant and preferably affecting the peripheral nervous system. Our country is the fourth world focus with regard to incidence, preceded only by Portugal, Japan, and Sweden. Amyloid involvement is rare, generally following primary forms. There are only three cases described of these hereditary forms, none of which is of the FAP type 1. Our goal is to present a patient diagnosed of FAP type 1 who developed hemoptysis during the course of her disease, observing an amyloid bronchial infiltrate in the samples obtained by bronchoscopy. This is the first case described of pulmonary involvement in this type of amyloidosis according to the literature reviewed.

Adult↗
PubMed1991

[Long term follow-up of non-symptomatic HBsAg carriers].

232 asymptomatic HBsAg carriers were controlled between May/1986 and May/1990. The were detected in our blood bank between 1974 and 1976 or during pregnancy or delivery period after 1981. 23 of 232 (10%) became negative during the follow-up, this happening more frequently in carriers after 5 years of follow-up. Only 2 of 209 carriers with HBsAg were HBeAg positive and 1 of these was also DNA-VHB positive. None of the HBeAg negative carriers showed DNA-VHB; only 5 had increased transaminases. 7 were anti-VHC positive, these individuals experiencing more frequent increases in transaminases. The results of this study suggests that the determination of transaminases, viral activity markers, anti-HD, anti-VHC in HBsAg carriers are enough to identify those with hepatic disease.

Adolescent↗
PubMed1990

Evaluation of antibodies to hepatitis C virus in a study of transfusion-associated hepatitis.

BACKGROUND: The hepatitis C virus (HCV) is now known to be the chief cause of transfusion-associated non-A, non-B hepatitis, but the prevalence of HCV among blood donors and the frequency of transmission by blood transfusion are unknown. METHODS: To assess the sensitivity and specificity of a test for antibody to HCV, we tested serum samples from participants in a large study of transfusion-associated hepatitis. Samples were obtained prospectively from consecutive adults undergoing open-heart surgery in Spain, but were tested retrospectively, after the antibody enzyme immunoassay for anti-HCV became available. RESULTS: Of 280 transfusion recipients given a total of 1109 units of blood, 27 (9.6 percent) had transfusion-associated non-A, non-B hepatitis (mean follow-up, 52 weeks) and 24 of the 27 seroconverted to anti-HCV-positive, whereas only 2 (0.8 percent) of the remaining transfusion recipients seroconverted. Among the 1044 donor specimens available for testing, 16 (1.5 percent) had anti-HCV antibody. Only 1 additional seropositive donor was found when 44 implicated donors who had been seronegative were retested 9 to 12 months later. Of the 16 recipients of anti-HCV-positive blood, 14 (88 percent) had transfusion-associated hepatitis and seroconverted to anti-HCV-positive. The remaining two recipients had neither hepatitis nor anti-HCV antibody. Among 25 patients with non-A, non-B hepatitis for whom all transfused blood was tested, 14 had received blood positive for anti-HCV. CONCLUSIONS: About 90 percent of blood donors with antibody to HCV have infectious virus in their blood. The screening of blood donors for anti-HCV antibody should prevent about half the cases of transfusion-associated hepatitis, but the donors with infectious virus who are anti-HCV-negative may remain seronegative for prolonged periods.

Adult↗
PubMed1990

[A study of 158 cases of acute delta hepatitis].

We have prospectively studied 158 cases of acute hepatitis delta observed during the last 7 years in a general hospital. Among them 136 were male and 22 female. The mean age was 22.7 years with a range between 16 and 61 years. The epidemiologic factors were drug addiction by parenteral route in 145 cases (92%), sexual transmission in 5 (3%), post transfusional in 2 (1%) and unknown in 6 (4%). With respect to the delta type infection, 105 cases (66%) were coinfections with type B and delta, and 53 patients had a type delta superinfection (34%). The clinical course was a fulminant hepatitis in three cases (two cases of coinfection B and delta an one case of delta superinfection), and an acute benign hepatitis in 155 patients. The follow-up of 118 patients revealed that 96% of coinfections by type B and delta evolved to the chronicity showing findings of active chronic hepatitis or hepatic cirrhosis. It should be noted that in 4 cases of superinfection delta type (11%) the HBsAg was negative after several months of positivity. In these patients the level of transaminases normalized and the hepatic histology evidenced alterations of chronic active hepatitis (2 cases) and hepatic cirrhosis (2 cases) without identification of tissular delta antigen.

Acute Disease↗
PubMed1990

Portable encapsidation signal of the L-A double-stranded RNA virus of S. cerevisiae.

The (+) single-stranded RNA (ssRNA) of the L-A virus is the species packaged to form new viral particles. Empty L-A viral particles specifically bind viral (+) ssRNA, and a sequence 400 bases from the 3' end is necessary for this activity. We show that its stem-loop structure, the A residue protruding from the stem, and the loop sequence are all important for the binding, and that this 34 base region is sufficient for the binding. M1, a satellite virus of L-A, has a similar structure on its (+) strand that is likewise sufficient for the binding. Heterologous RNA with the binding sequence from L-A or M1, when expressed in vivo, was packaged in L-A viral particles. Thus, the sites necessary to bind to empty particles are encapsidation signals for the L-A virus. Since the pol domain of the 180 kd minor coat protein appears to be responsible for the binding, this result suggests that the RNA polymerase molecule recognizes the viral genome for packaging.

Base Sequence↗
PubMed1990

[Diagnosis of acute hepatitis caused by herpes simplex virus using in situ hybridization].

A 50-year-old male without relevant past history was admitted because of fever lasting for 23 days. Physical examination showed hepatomegaly and splenomegaly without other findings. Laboratory studies only revealed mildly abnormal hepatic enzymes. The remaining investigations (markers, serologies, antinuclear antibodies, blood and urine cultures) were negative. Chest and abdomen X-ray films were normal. In abdominal echogram a homogeneous liver without space occupying lesions was seen, and computed tomography disclosed enlarged liver, spleen and lymph nodes. Needle hepatic biopsy was reported as showing reactive hepatitis. Although clinically meningeal antibody seroconversions were not found, DNA chains of cytomegalovirus, Epstein-Barr virus, hepatitis B virus and herpes virus simplex were investigated with the in situ hybridisation technique. Its result was a strongly positive hybridisation for herpes virus and negative for the other investigated viruses.

Acute Disease↗
PubMed1990

Hepatitis B virus and hepatitis D virus replication in HBsAg-positive fulminant hepatitis.

Hepatitis B virus DNA and hepatitis D virus RNA, the most sensitive markers of hepatitis B and hepatitis D virus replication, were sought by molecular hybridization with radioactive probes in serial serum samples from 29 consecutive patients with HBsAg-positive fulminant hepatitis. Nineteen patients had evidence of hepatitis D virus infection, as assessed by the presence in serum of delta antigen, anti-delta antibodies, or both. Hepatitis B virus DNA was found in only two patients: one was a chronic HBsAg carrier with hepatitis D virus superinfection and the other had fulminant hepatitis caused by hepatitis B and hepatitis D coinfection. Hepatitis D virus RNA was detected in three patients: two with hepatitis B and hepatitis D coinfection and also in the HBsAg carrier with positive hepatitis B virus DNA and hepatitis D virus superinfection. None of 10 patients with hepatitis B virus infection alone had detectable viral nucleic acids in serum. Overall, viral nucleic acids were detected in the sera of 4 of the 29 patients (14%). Hepatitis D virus antigenemia did not indicate hepatitis D virus replication because hepatitis D virus RNA was not detected in 9 of 12 patients with hepatitis D virus antigen in their sera. The low frequency of viral replication found in fulminant hepatitis B or D may explain the low recurrence rate of viral hepatitis in patients with fulminant hepatitis who have received liver transplantations.

Adolescent↗