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Biomedical subjects

K Koerner

Publications and source records attributed to K Koerner.

At least 19 recordsLinked to original sources
PubMed1992

Cryopreserved autologous platelet transfusions in alloimmunized patients with acute leukemia.

Autologous platelets of 5 alloimmunized patients with acute leukemia in remission were cryopreserved with 5% dimethylsulfoxide in liquid nitrogen and retransfused in the following therapy-induced thrombocytopenic phase. The mean platelet recovery after freezing, thawing and washing was 85 +/- 6%. The mean corrected 1-hour increment in platelet counts was 11 (4-27) x 10(9)/l, i.e. 61% in comparison with fresh platelet transfusions in other patients. In vivo function of frozen platelets was documented by improvement of the posttransfusion bleeding time. Cryopreserved autologous platelets function hemostatically and can be used even for completely refractory patients and thus permit curative antileukemic therapy.

Adult↗
PubMed1991

Investigating the presence of HIV sequences and the distribution of virological markers in hemophiliacs and their sexual partners.

In this study, we report the investigation of a hemophiliac cohort, in which the last HIV-1 seroconversion occurred in 1985. We wanted to evaluate whether 5 years later the results of serological screening and polymerase chain reaction (PCR) technology would match. We examined 61 German patients with congenital deficiencies of factors VII, VIII-c, and IX, and 16 sexual partners (15 partners of anti-HIV-1-negative hemophiliacs). Patients' and partners' anti-HIV-1 status was determined by ELISA and Western blot. Further, we applied the PCR to investigate the possible presence of HIV sequences in anti-HIV-1-negative individuals. Four sets of primers were used in four separated reactions to avoid false-negative results due to genetic variation, as well as false-positive results due to DNA carryover. The data by PCR were not different from the data attained by conventional serological methods. The prevalence of serological markers for HBV and HCV was determined.

HIV↗
PubMed1991

[HIV study of German Red Cross blood banks in Germany and Berlin].

In the HIV study of the German Red Cross blood banks the overall rate has remained constantly low, with less than two Western blot positive donors in 100,000 donors since 1987. However, the rate of HIV positivity tends to increase in male first time and in male repeat blood donors. Despite this fact, the overall rate stays constant since the number of young first time donors has decreased with increasing donations by women. Therefore the blood banks once again have to take newly intensified but also sophisticated measures to guarantee further as well a sufficient number of blood products as their HIV safety.

Berlin↗
PubMed1990

[Confidential donor self-exclusion for raising the safety of blood preparations].

Since July 1987 the German Red Cross Baden-Württemberg has practised confidential and anonymous self-exclusion of potential blood donours. The answers given by all donours of the Red Cross Blood Donour Service in Baden-Württemberg (n = 297,648) between 23. 2. 1988 and 31. 1. 1989 were analysed. Virological data of self-exclusion donours (n = 1910) and of a control group (n = 1856) were compared. No donour who had excluded himself was anti-HIV positive, but two of the donours who had designated their blood for transfusion. Those that had excluded their blood donation had a significantly higher prevalence of hepatitis B markers. There was no significantly higher prevalence than among other blood donours with respect to anti-CMV antibodies, syphilis and increased GPT levels. The proportion of male first-time donours was twice as high among self-excluders than among those who released their blood for subsequent donation.

Antibodies, Viral↗
PubMed1990

Risk of HIV infection from former blood donations of donors found to be HIV antibody-positive in blood bank routine testing. "Look-back" study in German Red Cross Blood Banks in the FRG.

Recipients of blood given by 52 repeat blood donors found to be positive by Western blot analysis for anti-HIV from April 1985 to December 1987, among a total of 1.6 million blood donors in the German Red Cross Blood Banks in the FRG, were investigated. Of 149 recipients identified, 76 (51%) had died. Ten recipients refused to be tested. Of those recipients who were tested at least 5 months after transfusion, 46 were HIV antibody negative and 17 were Western blot-positive. In 14 of the HIV antibody-positive recipients, transfusion was given during the period from 1982 to the begin of routine testing in 1985. Three recipients of HIV antibody-negative donations were subsequently identified as HIV positive. The blood had been donated a median of 3 months before HIV antibodies were detected in the donors. From a total of 3 million donations since testing has been introduced, the risk of HIV transmission in tested blood is 1:1 million in our donor population where the HIV antibody prevalence (in Western blot) is about 1 per 100,000 donations/donors.

AIDS Serodiagnosis↗
PubMed1990

[HIV study of the German Red Cross of West Germany 1985-1989: prevalence/incidence and mode of infection, retrospective studies].

All German Red Cross Blood Banks in the FRG cooperate in a study on prevalence and epidemiology of HIV-antibodies in blood donors. The prevalences of 1 to 2 Western blot positive donors per 100,000 donors/donations quarterly since 1987 are constantly low. The measures undertaken to defer persons at risk seem to be effective. The "look back" data confirm the "rest risk" of HIV-infections by blood products in the FRG which is estimated to be about 1:1 million on the basis of the epidemiologic data. More than 90% of the donors infected are members of risk groups of heterosexual partners to persons at risk. Until today, in blood donors there is no indication of an increasing number of unaware heterosexually acquired HIV-infections.

Blood Banks↗
PubMed1990

[Current data on the prevalence and epidemiology of HIV from the HIV study by the German Red Cross of West Germany].

From the multicenter study of the Red Cross Blood Banks in the FRG HIV-antibody prevalences and incidences are documented since July 1985. Constantly low prevalences and incidences since 1987 of less than 2 Western blot (Wb)-positive donors and less than 1 Wb-positive donor per 100,000 donors respectively confirm our estimate of the rest risk of an HIV-infection by blood products of 1:500,000 to 1:3 million donations. In the epidemiologic details there seems to be a trend to an increase of the incidence in male repeat blood donors. The modes of HIV-infection in blood donors have changed to an increasing number of infections acquired in heterosexual contacts to persons at risk.

AIDS Serodiagnosis↗
PubMed1989

[Blood donor selection in providing anticytomegalovirus-negative blood components].

Sera of 1731 blood donors of the Ulm blood bank were screened for cytomegalovirus (CMV) antibodies. Prevalence of these antibodies was 37%. The seroconversion rate among 1090 anti-CMV-negative blood donors was 13 per thousand per year for the whole donor population over a period of 27 months and depended on age. It was 16 per thousand per year for donors aged 18-40 years, but only 7 per thousand for those over 41 years old. Seropositivity was higher in women than men. To provide anti-CMV-negative blood requires a prescreened anti-CMV-negative donor group and the rescreening of each further donated blood component.

Adolescent↗
PubMed1989

Unsatisfactory specificities and sensitivities of six enzyme immunoassays for antibodies to hepatitis B core antigen.

To examine the consistency and comparability of anti-hepatitis B core antigen (anti-HBcAg) assays, four blood donation centers of the Red Cross in the Federal Republic of Germany tested 4,080 unselected blood donors with six different tests in parallel. Confirmation testing of reactive samples was done in the National Reference Center for Viral Hepatitis. Depending on the test kit used, 4.1 to 9.9% of serum samples were initially positive and 2.9 to 7.5% were repeatedly positive. Sixteen percent of serum samples were positive in at least one test but only three percent were positive in all six tests. Statistical analysis of frequency distribution of optical densities for each test suggested that there should be a correction of the cutoff values. This reduced the number of false-positive results by half, but a significant proportion of discrepant results could not be resolved. The lack of specificity and consistency requires cautious interpretation of isolated anti-HBcAg results in clinical specimens. Screening of predominantly anti-HBcAg-negative populations (e.g., blood donors) by the current anti-HBcAg test kits will almost necessarily give unsatisfactory results.

Blood Donors↗
PubMed1989

Preparation of leukocyte-poor platelet concentrates for transfusion by filtration through a new cellulose acetate filter.

The preparation of leukocyte-poor platelet concentrates using a new cellulose acetate filter was evaluated. The platelet loss was 9% when freshly prepared platelet concentrates were filtered. The platelet loss was more variable and about 16% (p less than 0.05) when 5 day old platelets were filtered. The leukocyte removal was not influenced by storage time. The mean absolute number of leukocytes was about 1 x 10(7) and 3 x 10(7) for freshly prepared or 5 day old platelet concentrates, respectively (p less than 0.05). The leukocyte-poor platelet concentrate prepared by the described filtration procedure may be used as a blood component in transfusion therapy to prevent or delay platelet alloimmunization.

Blood Preservation↗
PubMed1989

[Comparative studies of rheologic properties of erythrocyte concentrates in relation to a 6-week storage period in various preservative solutions].

Buffycoat free red cell concentrates were stored at 4 degrees C for 42 days in CPD-A1 and two new red cell preservation solutions, PAGGS-Sorbitol and SAG-Mannitol. The rheological behaviour of the red cells was measured by viscometry of red cell suspensions (hematocrit 45%) at steady flow at various intervals during the storage period. The viscoelastic properties of the red cells were studied at oscillatory flow using an oscillation rheometer. The deformability of the red cells during storage was determined by measurement of the viscosity of hard packed cells at steady flow. The results show better red cell deformability during the entire storage period using the new solutions PAGGS-Sorbitol or SAG-Mannitol compared to the standard blood bank preservation solution CPD-A1.

Blood Preservation↗
PubMed1988

[Epidemiology of HIV in blood donors in West Germany].

Of a total of 5.6 million blood donations by 1.6 million German Red Cross donors between July, 1985 and December, 1987 tested for HIV antibodies 210 were found to be positive in at least one Western blot. Calculated per quarter, the prevalence (for first-time donors) of 10 per 100,000 in 1985 decreased to 4 per 100,000 in 1986, while the incidence (for multiple donors) was a constant 2 per 100,000 for each quarter in 1987. This indicates that new HIV infections were rare in blood donors and there was no exponential increase. Further analysis revealed that over 90% of those with confirmed Western blot positive results were members of risk groups or their direct contacts. The age and sex distribution conformed to the known pattern for AIDS cases in the Federal Republic of Germany. The data demonstrate that there is at present no indication of a rapid spread of HIV infections transmitted heterosexually among blood donors.

Acquired Immunodeficiency Syndrome↗