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Biomedical subjects

U Bäcker

Publications and source records attributed to U Bäcker.

15 recordsLinked to original sources
PubMed1992

Abbott HCV EIA 2nd generation: a new screening assay.

An enzyme immunoassay for the detection of antibodies against structural and nonstructural domains of the hepatitis C virus (EIA-2) was compared to a first generation test (EIA-1) that can only detect antibodies against one nonstructural antigen (c100). EIA-2 revealed elevated detection rates as assessed in high risk and patient populations as well as lower repeat reactive rates in volunteer blood donors. Research test systems proved an increase in apparent specificity.

Blood Donors↗
PubMed1991

[HTLV-I antibody screening of blood donors].

Routine screening of 344,266 blood donations of approximately 200,000 donors for anti-HTLV-I was done by enzyme immuno assay (EIA). Repeatedly reactive samples were confirmed by Western Blot (WB) and radio immuno precipitation assay (RIPA). The prevalence of anti-HTLV-I in Bavarian blood donors is 0.02-0.026%. The specificity of HTLV-I-EIA is 99.95%.

Blood Donors↗
PubMed1990

Erythrocyte antibodies in AIDS are associated with mycobacteriosis and hypergammaglobulinemia.

Positive direct antiglobulin results prior to transfusion in some of our AIDS patients, as well as some reports in the literature on red cell antibodies in AIDS patients, prompted us to investigate the prevalence of erythrocyte antibodies in AIDS patients with transfusion requiring anemia. In addition we studied the question of relevant correlations with clinical diagnosis and with hematological and immunological laboratory parameters. Of 145 consecutive hospitalized AIDS patients (CDC criteria), 34 (23%) presented with anemia requiring transfusion. With each cross-match a routine antibody screening was performed. In cases of positive reaction additional antibody differentiation was done. Diagnoses, hematologic parameters, and therapy were studied retrospectively. Agglutination was positive in at least one test for 41% (14/34) (group 1). C3d, anti I, cold agglutinins, and IgG occurred most frequently (n = 9/8/7/6 out of 14). Seventy-five per cent (12/14) had leukopenia (less than 4000/microliters), 57% (8/14) had thrombocytopenia (less than 150,000/microliters), and 43% (6/14) showed both. Average values for leukocytes, thrombocytes, and CD4-positive lymphocytes did not differ significantly in patients with (group 1) and without (group 2) erythrocyte antibodies. Average gamma globulin levels were significantly increased in group 1 (23.2 g/l versus 16.9 g/l; p less than 0.001). In group 1, 64% (9/14) had proven mycobacteriosis (6 atypical), in contrast to only 15% (3/20) in group 2 (p less than 0.05). There were no significant differences between the two groups in prevalence of other opportunistic infections, malignant lymphoma, and Kaposi's sarcoma. Autoimmune versus infectious pathogenesis of pathologic erythrocyte antibodies in AIDS has been discussed in the literature.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Initial results of the anti-HIV-1/2 combined ELISA].

Between March 30 and July 31, 1989, 117,874 blood donations were tested for anti-HIV-1 and in a combined ELISA for anti-HIV-1/HIV-2 (both Abbott). On each repeat reactive (14 = 0.01% for anti-HIV-1 and 400 = 0.34% for anti-HIV-1/HIV-2), a Western blot (WB) was performed. Two donors, who tested repeatedly reactive in both ELISAs, were confirmed anti-HIV-1 positive by WB. As the specificity of anti-HIV-1/HIV-2 ELISA is considerably lower (99.66%) than of anti-HIV-1 (99.99%), introduction of a different HIV-2 specific ELISA should be discussed to prevent loss of too many blood donations and donors through anti-HIV screening.

AIDS Serodiagnosis↗
PubMed1989

[Erythrohepatic protoporphyria with rapidly progressing liver cirrhosis].

A 49-year-old man, known to have had an increased light sensitivity since childhood, was admitted to hospital because of jaundice. Biochemical and morphological examination revealed cirrhosis of the liver with cholestasis. There was a 70-fold increase of protoporphyrin content in the erythrocytes, increased fecal protoporphyrin excretion as well as secondary coproporphyrinuria. Despite symptomatic treatment with ursodeoxycholic acid and cholestyramine hepatic failure ensued for which orthotopic liver transplantation was performed five months after the diagnosis had been made. The patient died two months later of treatment-resistant septicaemia and multiorgan failure. This case demonstrates the need for annual monitoring of liver functions and porphyrin parameters to ensure earliest possible diagnosis of hepatic involvement in erythrohepatic protoporphyria.

Cholestyramine Resin↗
PubMed1988

A new second-generation anti-HIV-1 enzyme immunoassay using recombinant envelope and core proteins.

In a multicenter collaborative study a new second-generation HIV-1 antibody enzyme immunoassay (Abbott recombinant HIV-1 EIA) using Escherichia coli-expressed recombinant p24 and p41 proteins as solid-phase antigens was compared with the first-generation H9 cell-line-based Abbott HIV-1 EIA. The results of the confirmatory assays (Western blot, immunofluorescence), combined with clinical information, were used as the reference standard for the detection of HIV-1 antibodies in 10,676 random blood donor serum specimens, in a panel of 840 specimens from symptomatic and asymptomatic patients and a total of 63 serial blood specimens from 23 people at risk. With fresh blood donor sera, the specificity of the first-generation assay ranged between 99.54 and 99.76% (95% confidence limits, CL) compared with 99.81-99.95% (95% CL) for the second-generation EIA. With panel specimens the recombinant HIV-1 EIA achieved an overall sensitivity of 100% and a specificity range of 98.3-99.7% (95% CL); the corresponding sensitivity and specificity ranges observed for the first-generation EIA were 98.0-99.5% (95% CL) and 94.3-96.8% (95% CL), respectively. The improved sensitivity for the second-generation assay was confirmed by testing serial samples from seroconverting patients. The use of recombinant proteins eliminated non-specific reactions due to class II human leukocyte antigen (HLA)-directed antibodies.

Blood Donors↗
PubMed1987

[Therapeutic lymphapheresis in leukostasis-induced priapism].

Priapism occurred as a result of leukostasis due to an extreme rise in leukocyte count (503,000/microliter, 96% lymphocytes) in a 46-year-old man with chronic lymphatic leukaemia. In addition to surgical treatment, anticoagulant administration and cytostatic treatment several courses of lymphapheresis were performed using a cell separator. This latter procedure quickly reduced the number of lymphocytes and improved the patient's operability.

Combined Modality Therapy↗
PubMed1983

Oral acetylcysteine reduces exacerbation rate in chronic bronchitis: report of a trial organized by the Swedish Society for Pulmonary Diseases.

This multicentre trial was undertaken to confirm previous results indicating that long-term treatment with oral acetylcysteine reduces the exacerbation rate in patients with chronic bronchitis. Two hundred and eighty-five patients, smokers or ex-smokers, with chronic bronchitis started a pre-trial placebo-period of 1 month. After this run-in period 259 patients were included in the trial and randomized into two parallel groups. The patients were treated in a double-blind way either with acetylcysteine 200 mg b.i.d. or placebo b.i.d. for 6 months. The trial was completed by 98 patients in the acetylcysteine group and by 105 patients in the placebo group. Initially, there were no significant differences between the groups. Twice weekly, the patients filled in a diary card concerning symptoms. The number of exacerbations was assessed from these cards and at visits 2, 4 and 6 months after institution of therapy. The exacerbation rate was significantly lower in the acetylcysteine group in which 40% of the patients remained free from exacerbations compared to 19% in the placebo group. Sick-leave due to acute exacerbation was significantly less common in the acetylcysteine group. The drug was well tolerated.

Acetylcysteine↗
PubMed1982

Diagnostic significance of quantitative determination of hepatitis B surface antigen in acute and chronic hepatitis B infection.

HBsAg was determined quantitatively by radioimmunoassay and by Laurell electrophoresis in sera of 90 patients with acute hepatitis B, 57 patients with chronic hepatitis B, and 154 HBsAg positive blood donors. Of 55 patients with clearance of HBsAg from the circulation within six months, 54 (98%) showed an at least 50% reduction in concentration within 16 days. All 55 patients had such a decrease within 20 days. No such decrease was found in seven patients with acute hepatitis B who became HBsAg carriers. Therefore, quantitative HBsAg concentration in paired sera seems to be a reliable and early prognostic marker in acute hepatitis B. In patients with clearance of HBsAg most of the antigen is already present in the circulation at hospitalization and is eliminated with a mean half-life of 8.8 days. Patients with chronic hepatitis exhibit on average nearly the same HBsAg concentration (about 40,000 ng/ml) as patients with acute hepatitis B at hospitalization (about 39,000 ng/ml) and HBsAg positive blood donors on average a lower HBsAg concentration (about 8,000 ng/ml).

Blood Donors↗
PubMed1982

[Synthesis and properties of nuclear hydroxylated derivatives of flufenamic acid and etofenamate (author's transl)].

Synthesis of six nuclear hydroxylated derivatives of flufenamic acid and etofenamate (5-OH-, 4'-OH and 5,4'-(OH2) on a preparative scale is described. All compounds show low toxicity, but only weak anti-inflammatory activity in the rat paw kaolin edema test as compared to 2-(2-hydroxyethoxy)ethyl-N-(a,a,a-trifluoro-m-tolyl)-anthranilate (etofenamate, active substance of Rheumon Gel).

Animals↗
PubMed1980

[Prevalence of serological hepatitis A and B markers in Bavarian blood donors (author's transl)].

Sera from 1966 Bavarian blood donors were investigated by radioimmunoassay for serological markers of past hepatitis A and B infections. The prevalence of hepatitis A antibody increased with age and was higher in the urban than in rural populations. More than 80% of persons above 40 years of age had antibody whereas only few young adults showed previous exposure to hepatitis a virus. 20 of 1093 random persons (1.8%) were HBsAg positive at first blood donation. In all age groups anti-HBc was the best marker for previous hepatitis B exposure. There was no correlation between the frequency of hepatitis A and B markers.

Adult↗