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Biomedical subjects

B Kubanek

Publications and source records attributed to B Kubanek.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Effect of preparation and preservation modality on thrombocyte quality].

In patients with acute leukemia, chemotherapy leads to subsequent aplasia-associated thrombocytopenia requiring the substitution of platelets to avoid and treat bleeding complications. A multitude of tests to assess the quality of platelet concentrates is available to date. In this study, we investigated the quality of platelet concentrates prepared by two different methods, preparation from platelet-rich plasma versus preparation from buffy coat, and stored under varying conditions, namely horizontal versus vertical rotation, by measuring the binding rate of corresponding antibodies to platelet membrane glycoproteins GPIb, GPIIb-IIIa, GPIa-IIa and GPIV using flow cytometry. Expression of platelet surface antigens was well maintained during platelet preparation and storage for 7 days. Preparation and storage modalities showed no significant effect on the expression of membrane glycoproteins. These results indicate that platelet function as represented by antibody binding is well maintained during platelet preparation and storage leading to sufficient hemostasis following transfusion.

Acute Disease↗
PubMed1993

[Recombinant antibodies in serologic diagnosis].

In this paper we discuss the value of a new methodology for the production of monoclonal antibodies by recombinant techniques. This approach is especially useful for human monoclonal antibodies due to instability of human antibody-producing cell lines. As an example, we present a recombinant human antibody to the hepatitis C virus (HCV) core protein.

Antibodies, Monoclonal↗
PubMed1993

Influence of graft-versus-host disease on the eradication of minimal residual leukemia detected by polymerase chain reaction in chronic myeloid leukemia patients after bone marrow transplantation.

To evaluate the remission quality of Philadelphia chromosome (Ph)-positive, BCR/ABL-positive CML patients after allogeneic bone marrow transplantation (BMT) we used the polymerase chain reaction (PCR) to detect BCR-ABL specific RNA in addition to Southern blotting, cytogenetic, and hematological investigation. Fifty-five bone marrow samples of 27 patients in clinical remission were studied by PCR, 0.5 to 99 months (median 8 months) after BMT. The median clinical follow-up of this cohort of patients is 24 months (1-109) after BMT. BCR-ABL transcripts could be detected in 16 out of 27 patients (59%). Risk factors for minimal residual leukemia (MRD) as defined by PCR were the kind of graft-versus-host disease (GvHD) prophylaxis (patients with T-cell-depleted grafts had a higher rate of MRD in comparison to patients treated with methotrexate/cyclosporin A) and the presence or absence of GvHD after BMT (patients without GvHD had a higher incidence of MRD than patients with GvHD). Moreover, the detection of minimal residual leukemia had prognostic significance. Out of 16 patients with minimal residual leukemia as detected by PCR, four patients relapsed clinically and two further cases relapsed cytogenetically. In contrast none of the patients lacking evidence of minimal residual leukemia relapsed. Serial PCR analysis may prove helpful in deciding about further therapeutic interventions (e.g. interferon therapy or adoptive immunotherapy) before leukaemic relapse becomes manifest after BMT.

Adult↗
PubMed1993

[Risk of infection transmission by blood components].

OBJECTIVE: Assessment of the present risk of blood-borne infection associated with homologous blood transfusion in Central Europe with particular emphasis on HIV and HCV infections. DATA SOURCES: The relevant literature in the English and German language and the authors' data. STUDY SELECTION: No special study has been carried out for the present paper. RESULTS: The recognition of the risk for transmitting HIV by transfusion has led to a bundle of measures which have improved the safety of blood supply in Germany. A stricter donor selection as well as screening for HIV 1 and HIV 2 have reduced the risk to transmit HIV to the order of 1 per 1 million units transfused. The transmission of hepatitis B is estimated to be in the order of 1:50,000. The anti-HCV testing, introduced in 1990, has markedly reduced the transmission of HCV to less than 1:5,000 per unit as judged from our own data. A further reduction is expected by an improved HCV screening in the near future. Fatal disease from bacterial contamination is rare, with an estimated risk of one in a million units. Syphilis transmitted by transfusion is virtually not occurring anymore. However, increased efforts should continue to enhance the safety of blood, bearing in mind that a zero risk is not achievable for effective therapies. The estimation of risks is a dynamic, time-dependent value which has to be estimated for a geographically defined population for a given time period. CONCLUSIONS: The risk of transfusion-associated infection has been markedly reduced in recent years. Albeit there is a small but definitive risk, which is often overestimated. The risks have to be defined to estimate the risk/benefit ratio of the homologous as well as the autologous transfusion for the individual patient.

Blood Banks↗
PubMed1992

A sensitive sandwich ELISA for measuring erythropoietin in human serum.

A sandwich, non-competitive enzyme-linked immunosorbent assay (ELISA) for erythropoietin (EPO) is described. The ELISA utilizes a monospecific, polyclonal antibody raised in rabbits against human recombinant EPO (rhu EPO) and purified over a rhu EPO affinity chromatography column. The ELISA procedure can be summarized as follows: Anti-EPO is coated onto 96-well ELISA microtitre plates; standard EPO or sample is added and left to bind to this catching antibody; this is followed by the addition of the same antibody which has been biotinylated; finally, anti-biotin conjugated to alkaline phosphatase is added and the enzyme reaction developed and read at 405 nm. All parameters of the assay have been optimized. Recombinant human EPO was standardized against the World Health Organization 2nd International Reference Preparation for erythropoietin. The minimal detectable concentration of rhu EPO was 0.3-0.5 mU/ml, which corresponded to 1.2-2 mU/ml of EPO in serum (serum diluted 1:4). No reaction was obtained with a variety of blood components and cytokines, indicating that the anti-EPO antibody did not cross-react with those substances to produce false-positive results. The intra-assay variation ranged from 3% to 10%, while the inter-assay variation ranged from 8.5% to 24%. Serum dose-response curves were parallel to the standard dose-response curve. The assay is easy to use, rapid, reproducible, but above all quantitative, specific and sensitive to measure the EPO content in all serum samples.

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

[The critical hemoglobin value in the therapy of chronic anemia].

Adequate oxygen delivery to the tissues can usually be assured until the hemoglobin concentration falls below 7-8 g/dl in patients with chronic anemia provided their compensatory mechanisms are not impaired. Such a reduction of hemoglobin concentration is usually tolerated without symptoms at rest. Under increased physical activity or by an underlying impaired function of the lung or the cardiovascular system, adaptation to anemia may not be sufficient. For this reason the impact of anemia and the resulting hypoxemia must be assessed by determining oxygen needs at various levels of physical activity. The clinical assessment for adequate oxygenation of tissues can be sufficiently estimated by simple parameters as tachycardia, dyspnea etc. Benefits from replenishing O2 carrying capacity by transfusion must be always balanced against transfusion-associated risks. Below a hemoglobin concentration of 7 g/dl oxygen transport is impeded and transfusions are necessary to avoid jeopardizing the patient by additional stressful illnesses such as fever.

2,3-Diphosphoglycerate↗
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

Comparison of plateletpheresis with two different cell separators using 100 identical donors.

Plateletpheresis with the cell separator COBE Spectra and Fenwal CS 3000 was compared in 100 identical donors. The Spectra was significantly superior with regard to collection efficiency (53% vs. 42%, p less than .001) and leukocyte contamination of the platelet products (.1 x 10(8) vs. 1.4 x 10(8), p less than .001). Additionally, it offers a selectable volume of the concentrate and a better control of the ACD infusion. The Spectra standard procedure needs more ACD, resulting in more citrate dependent donor reactions (5% vs. 1%). In conclusion, the Spectra system shows a more efficient and pure platelet separation compared with the CS 3000.

Adolescent↗
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

HIV prevalence in blood donors in urban and in rural areas of the Federal Republic of Germany.

HIV infection rates in blood donors from the FRG were compared with the prevalence in donors from Berlin to obtain information on the HIV infections in donors of rural versus urban origin. The HIV prevalences decrease similarly in the first years of testing, although on different levels. They are lower in rural areas by a factor of 15 in the first year and of 10 thereafter. The modes of infectivity in both groups are similar although drug abuse seems to be more frequent amongst infected donors of urban areas. Ninety percent of the infected donors are either persons at risk or sexual partners of risk persons. During the observed time period there seems to be a trend from homo-/bisexuality and i.v. drug abuse to heterosexual contacts with persons at risk as the mode of infection. In conjunction with the stabile low and constant rates of infection for the last two years, these data indicate that the risk of HIV infection by blood transfusion is reduced to an acceptable minimum even in urban areas.

Adult↗
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

Anti-lipopolysaccharide-immunoglobulin (IgG-anti-LPS) therapy in intensive care patients following surgery from infectious disease.

In 18 intensive care patients the effect of a IgG-Anti-Lipopolysaccharide (Anti-LPS), was investigated in a randomized study following surgery after bacterial infections, mostly peritonitis. Fresh frozen plasma was administered during the first 5 postoperative days, containing either more than 65 micrograms/ml Anti-LPS in the therapy group or less than 12.5 micrograms/ml in the control group. The serum level of Anti-LPS was monitored. Clinical and chemical parameters were recorded to evaluate infectious complications and outcome of the patients. The mortality in the treatment group was not different from the control group with 30% (3 out of 10) and 25% (2 out of 8), respectively. No beneficial effect was observed either from the administration of Anti-LPS or from endogenously produced Anti-LPS on any clinical parameter in our patients.

Adult↗