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R Esteban

Publications and source records attributed to R Esteban.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1990

[Primary pulmonary actinomycosis: the experience in a general hospital].

Although all Actinomyces species are capable of producing primary pulmonary pathology, actinomycosis is a rare entity which is infrequently diagnosed. The clinician's lack of knowledge of the disease is frequently blamed for this, and it is estimated that its incidence in our environment is greater than suspected. We present our experience consisting of four cases of primary pulmonary actinomycosis (PPA) diagnosed at La Paz Hospital from 1974 to 1988. Its particular characteristics are emphasized as well as the need to include it in the differential diagnosis of chronic pulmonary infiltrations, cavitated lesions or pulmonary masses.

Actinomycosis↗
PubMed1990

[Sleep apnea syndrome].

The increasing importance of sleep apnea syndrome (SAS) is shown by the potentially lethal consequences of the development of apneic episodes during sleep. The presentation of SAS may be manifold, and the primary health care teams play a crucial role in the detection of their basic symptoms. The adequate approach to these patients depends on primary care teams, thus facilitating early diagnosis and the most adequate therapy in all cases. In the present study we report the features of 60 patients diagnosed of SAS in our unit for the investigation of this condition, to contribute to their diffusion among the professionals of primary health care.

Adult↗
PubMed1989

Hepatitis C virus antibodies among risk groups in Spain.

The frequency of hepatitis C virus (HCV) infection in Spain was assessed by means of a recombinant-based immunoassay for serum anti-HCV antibodies. 836 serum samples were tested from 676 patients selected according to their risk of blood-borne viral infections and presence of liver disease. Among patients at high risk of infection (with or without liver disease) anti-HCV antibodies were found in 85% of prospectively followed patients with post-transfusion non-A, non-B hepatitis, 62% of patients with chronic hepatitis or cirrhosis and a history of blood transfusion, 70% of haemophiliacs receiving replacement therapy, 70% of intravenous drug abusers, and 20% of haemodialysis patients. Only 8% of homosexual men infected with human immunodeficiency virus and 6% of female contacts of drug abusers were positive. Among patients with liver disease and no history of parenteral exposure to blood, anti-HCV antibodies were detected in 38% with cryptogenic, alcoholic, or primary biliary cirrhosis and in 44% with chronic active hepatitis. Among healthy subjects without risk factors for hepatitis the overall prevalence of anti-HCV was 1.2%.

Adolescent↗
PubMed1989

Chronic delta hepatitis: detection of hepatitis delta virus antigen in serum by immunoblot and correlation with other markers of delta viral replication.

To investigate the presence of serum hepatitis delta virus antigen by immunoblot and its correlation with other markers of active viral replication (intrahepatic hepatitis D antigen, IgM antibody to hepatitis D and serum hepatitis D virus RNA), we studied serum samples from 50 patients with chronic hepatitis D virus infection (38 with and 12 without intrahepatic hepatitis D antigen). Of the 38 patients with intrahepatic hepatitis D antigen, 27 (71%) had antigen detectable in serum by immunoblot, whereas only two were reactive by conventional enzyme-linked immunosorbent assay. Thirty-one (82%) patients were also positive for serum hepatitis D virus RNA by spot hybridization and 33 (87%) were positive for IgM anti-hepatitis D virus. All markers were simultaneously present in 24 patients. Circulating hepatitis D antigen was detected in one (8%), IgM anti-hepatitis D in seven (58%) and hepatitis D virus RNA in two (17%) of the 12 patients who had anti-hepatitis D in serum but not detectable hepatitis D antigen in liver. Hepatitis D antigen was not detected in serum of any of the 15 control patients. The results suggest that serum hepatitis D antigen as detected by immunoblot and serum hepatitis D virus RNA are similar in sensitivity for detection of active hepatitis D virus replication during chronic infection and constitute useful, sensitive and noninvasive tests for the diagnosis and monitoring of chronic hepatitis D virus infection.

Adolescent↗
PubMed1989

Internal and terminal cis-acting sites are necessary for in vitro replication of the L-A double-stranded RNA virus of yeast.

Empty particles of the L-A dsRNA virus of Saccharomyces cerevisiae bind to added viral (+) strands and convert them to dsRNA (RNA replication) in an in vitro reaction that is dependent on host factors. X dsRNA (530 bp long) is a deletion derivative of L-A dsRNA (4.5 kb). By modifying our cDNA clone of X and testing template activity of T7 RNA polymerase transcripts, we have found that both the 3' end 30 bases and an internal site on the (+) strand are necessary for optimal replication [in vitro (-) strand synthesis]. Changing any one of the 3' terminal three bases eliminates template activity, but the 3' terminal five bases of M1 (a satellite virus of L-A) can replace the 3' terminal four bases of X. A subterminal stem-loop structure is also important for template activity. The internal site that enhances replication is approximately 400 bp from the 3' end and is distinct from the site necessary for binding of (+) strands to the empty viral particles.

Base Sequence↗
PubMed1989

Serological profile of tissue autoantibodies during acute and chronic delta hepatitis.

In order to assess the serological profile in relation to other serological and histological markers of hepatitis delta virus (HDV) infection we have investigated the presence of autoantibodies during acute and chronic delta infection in 353 serum samples from different patients with acute and chronic hepatitis and autoimmune diseases. Basal cell layer antibodies (BCLA) were found in 58% acute hepatitis B, in 73% chronic hepatitis D and in 4% primary biliary cirrhosis. Stellate thymic epithelial cell antibodies (SECA) were detected in 40% acute D hepatitis and in 49% chronic D hepatitis. No tissue autoantibodies were detected in 50 acute B hepatitis, 35 autoimmune chronic liver diseases, 24 connective tissue diseases or 25 controls. In addition, two previously unreported specificities of anti-thymic antibodies reacting with reticular (TRA) and perithymocytic cells (PTA) were identified in 33% and 9% acute D hepatitis, respectively, and in 13% and 6% chronic D hepatitis cases. Among patients with acute HBV-HDV coinfection these antibodies were detected transiently (less than 4 weeks) and at low titer, whereas in those with chronic infection autoantibodies levels tend to be high and persistent throughout the follow-up. Among patients with chronic HDV infection no correlation was found between the presence of tissue autoantibodies and hepatic delta antigen expression and serum HDV-RNA which suggest that autoimmune phenomena observed during chronic delta infection are not related to the level of viral replication.

Acute Disease↗
PubMed1989

[Clinical characteristics of chronic autoimmune hepatitis. Study of 51 cases].

The clinical and histological features of the 51 patients affected with chronic autoimmuno hepatitis are analyzed. 65% of them were over 50 years old. 41% were without symptoms. The incidence of systemic symptoms was of 25.5%. 84.3% had antinuclear antibodies superior of 1/40 and 53% had positive LMA. The incidence of HCA and CH was similar. 26.7% of the patients had complications.

Adolescent↗