Search PubMed⌕ Search

Biomedical subjects

R Eckstein

Publications and source records attributed to R Eckstein.

At least 73 records · Page 4Linked to original sources
PubMed1994

Relation between leucocyte depletion and storage.

We intended to answer two questions: (1) Does storage time of platelet concentrates (PCs) influence the efficacy of leucocyte depletion by filtration? (2) Does pre-storage leucocyte depletion by filtration of PCs improve the post-storage quality? To this end we tested in parallel the halves of 10 double-sized PCs, one half stored after filtration through a polyester filter (PL 50, Pall), the other half filtered after a 5-day storage period. Efficacy of leucocyte depletion showed to be independent of the age of PCs, and pre-storage leucocyte depletion of PCs was not able to improve the quality of PCs stored for 5 days, as long as the leucocyte contamination of unfiltered PCs was lower than 0.5 x 10(8)/unit.

Adenosine Diphosphate↗
PubMed1994

Are single-needle protocols equivalent to dual-needle protocols for platelet apheresis?

In light of the increasing demands being placed on cytapheresis donors and their occasional venous problems, it has become necessary to use 1-needle in addition to 2-needle separation techniques in thrombocytapheresis. We therefore compared five 1-needle and three 2-needle programs on four different cell separators and found that meanwhile both the platelet yields and the leukopenia (controlled by Nageotte chamber counting) of the products obtained with the 1-needle technique are equivalent to those obtained using the 2-needle technique, as long as the program is suitably adjusted.

Blood Cell Count↗
PubMed1994

Automated bone marrow concentration using the Fresenius AS 104 blood cell separator.

We concentrated freshly taken bone marrow (BM) pooled from 21 patients from an original 1.265 ml (+/- 537 ml) down to 128 ml (+/- 36 ml) within 40-70 min with a modified version of the 'grancollect protocol' on the Fresenius AS 104 blood-cell separator using the P1-Y set. An average of 47% (+/- 21%) fo the initially present mononuclear cells and 68% (+/- 47%) of the colony-forming cells could be obtained in the concentrate. The erythrocyte concentration was reduced to 7% (+/- 4%) of the original amount. The technique described is very effective and makes is possible to obtain a BM cell population that is suitable for both immunomagnetic purging and cryopreservation or transplantation, e.g. in the case of blood group incompatibility.

Automation↗
PubMed1994

[Various clusters of immunoreactivity in the aged and their relation to HLA antigens and erythrocyte antigens].

In blood samples of members of the Berliner Altersstudie (BASE) (n = 427, 204 males, 223 females; mean = 85.2 years, range = 76-96 years, SD = 3.3 years), red cell, HLA-A, -B, -Cw and -Dr antigens were determined by standard methods. Lymphocyte reactivity was measured by 3H-thymidine uptake into DNA of lymphoblastic cells stimulated by 12 different mitogens and antigens. Cluster analysis, confirmed by t and F tests, defined 3 distinct clusters of lymphocyte reactivity. Clusters showed significantly different cumulations of 3 or more increased characteristic red cell and HLA antigens, and trends toward a decreased overall immunoresponsiveness in elder people. Like in middle-aged individuals, immunoresponsiveness in elder individuals can be dissected into at least 3 functionally different clusters which are not influenced by lymphocyte subsets or in vivo cell activation but by the patterns of both red cell and HLA antigens.

Aged↗
PubMed1994

[MLC reactivity demonstrates transfusion-induced immunosuppression].

The improved graft survival in preoperatively transfused renal transplant recipients led to the hypothesis that blood transfusions have an immunosuppressive effect. We examined 12 patients undergoing cardiac surgery, who received autologous red cells and one homologous HLA class-I-matched platelet concentrate. None of these patients produced red cell or lymphocytotoxic antibodies. Using the mixed lymphocyte culture (MLC) we observed a reduced lymphocyte responce to cells of the platelet donor during the first 4 days after transfusion. The MLC reactivity recovered on days 4-5 to the initial strength and reached over 200% of the initial strength from day 6 on. It must be assumed that these changes in MLC reactivity represent the early signs of the transfusion-induced immunosuppression. As intraoperative transfusions might correlate with cancer relapse, further studies must show whether this immunosuppressive effect can be avoided by the application of filtered leucocyte-depleted red cell transfusions.

Blood Transfusion↗
PubMed1994

[Effect of various rabbit complement batches of HLA class I antigen determination in lymphocytotoxicity testing].

HLA class I lymphocytotoxicity testing is strongly complement-dependent. We tested 13 commercially available rabbit complement batches (7 distributors) using a panel of 14 donors with decisive patterns of HLA antigens. We defined a scoring system that weights the different possible faulty reactions. The rating score ranged from 12.45 to 46.55 (median 16.09). Comparing the reactions in batches with low and high rating scores gave statistically significant differences (chi 2 test, p < 0.05). Our complement reaction score may be helpful to find the optimal complement batch for HLA class I lymphocytotoxicity testing.

Animals↗
PubMed1994

[Flow cytometry quality control in stem cell separation].

Peripheral blood-derived haematopoietic stem cells (PBSC) are used as an alternative to bone marrow stem cells for autologous transplantation. One of the most important prerequisites for successful PBSC separation is the precise determination of the optimal separation days. As we previously demonstrated that neither PLT counts nor WBC counts in the peripheral blood (PB) are of predictive value for the amount of colony-forming cells (CFC) in the patients' PB, we started a daily monitoring of CD-34-positive cells to determine the beginning of the separation series. In addition to routine cell counts and CFU testing we assessed the number of CD 34+ in the PBSC concentrates to ascertain the number of separations needed for each patient. Due to the strong correlation of CD 34+ cells to CFC it is possible to predict the number of CFC collected within 2 h after finishing the PBSC separation and to calculate the efficiency of the separation for quality control.

Colony-Forming Units Assay↗
PubMed1994

[Screening for markers of transfusion-associated infections in autologous blood donation].

Autologous blood donation is increasingly used in preparing patients for elective surgical procedures. The aim is to diminish the transmission of transfusion-associated infections, to avoid transfusion-related immunosuppression and to relieve the general blood supply. However, autologous blood donation programs do not necessarily incorporate serologic donor screening. From June 1990 to January 1993 we examined 4,038 consecutive autologous donations from 1,708 patients. The median age was 61 years (range 10-88), the sex ratio was 1/1.5 male/female. We tested each unit for serum ALT, anti-HIV1 + 2, HBsAG, anti-HBc, anti-HCV, and Treponema pallidum antibodies (TPHA test). The overall rates of positive test results were: ALT > 45 U/l 0.64%, anti-HBc 15.9%, BHsAG 0.72% and TPHA test 0.32% of all units; anti-HCV (1st gen.) 4.26% of 1,948 and anti-HCV (2nd gen.) 2.34% of 2,090 donations. With respect to the sex-related normal range of the local laboratory, 332 (8.2%) of all components had an elevated serum ALT level. No donation was positive for anti-HIV1/2. The overall rate of components with pathological findings in tests for ALT, HCV antibodies, HBs antigen and/or Treponema antibodies was 11.7%. We conclude from these data that a substantial proportion of autologous blood is potentially harmful in cases of mistake solely with respect to serologic screening results. Procedures to minimize the risk of mistake of autologous blood should routinely include serologic screening and marking of units with pathological findings.

Adolescent↗
PubMed1993

Cellular immunity, HLA-class I antigens, and family history of psychiatric disorder in endogenous psychoses.

We found an increased lymphocyte proliferation after stimulation with an antigen "cocktail" in 49 schizophrenic patients and 37 patients suffering from affective psychosis, compared with 45 healthy control subjects. On the basis of this and other findings such as increased numbers of CD3+ and CD4+ cells, an increased ratio of CD4+/CD8+ cells, and a reduced level of suppressor cell activity in schizophrenia and endogenous depression, we investigated the influence of the human leukocyte antigen-Class I (HLA-A, HLA-B, HLA-C) system on the altered immune function and evaluated the relationship to immune function of a family history of psychiatric disorders. A cluster analysis of cases with regard to the HLA-Class I antigens was first performed in a group of 133 healthy control subjects, and two immunogenetically different clusters were found; then 86 patients (49 schizophrenics, 37 affective psychoses) for whom immune functional data were available were assigned to the two HLA-I clusters that had been determined in the control subjects. Analyses of variance (ANOVAs) showed no differences in immune function between the two clusters. With respect to the cluster assignment and the family history of psychiatric diseases, a two-way ANOVA revealed significant differences in the lymphocyte response to the antigen cocktail, in the number of CD8+ cells, and in one suppressor cell assay. When patients were compared by ANOVA on the basis of family history of psychiatric disorder, patients with a positive family history showed a significantly higher number of CD4+ cells and a higher CD4+/CD8+ ratio. Moreover, certain HLA genes, especially HLA-A1, HLA-B8, HLA-B16, and HLA-C2 seemed to be related to the immune function and/or to the immune function and the family history.

Adolescent↗
PubMed1993

Investigations of the cellular immunity during depression and the free interval: evidence for an immune activation in affective psychosis.

1. Results of investigations of the immune function in affective disorders are conflicting. Some authors described an immune suppression, others an immune activation in major depression. The authors performed a study of cellular immunity in the MDD subtype endogenous depression. 23 patients suffering from endogenous depression were investigated during the depressive state, the results were compared with a group of 14 patients during the free interval and 51 healthy controls. 2. The lymphocyte proliferation after incubation with diphtheria- and tetanus toxoid, mainly stimulating T-cells, was reduced but after incubation with an antigen-cocktail, stimulating both, T- and B-cells, was increased in patients during depression and during the free interval compared to controls. 3. The CD3(+)- and CD4(+)-cells were significantly enhanced in both groups of patients while the CD8(+)-cells showed no differences to the controls. The ratio CD4+/CD8+ was increased in patients, too, as described in some autoimmune disorders. 4. The suppressor cell activity was significantly reduced in the PWM-assay and in the PHA-assay. The mixed lymphocyte culture showed a tendency to reduced suppressor cell activity as well. 5. The results point to an immune activation and to a disturbed control of the proliferative activity in affective psychosis. A T-cell related defect, not compensated by an increased number of CD3+- and CD4+ -cells is discussed. 6. From our point of view, the conflicting results of psychoneuroimmunological investigations in depressive disorders may be related to etiologically different subgroups of depression. The diagnostic category of MDD is possibly one of the traps in psychoneuroimmunology.

Adult↗
PubMed1993

Automated processing of human bone marrow grafts for transplantation.

Prior to purging or cryopreservation, we concentrated 21 bone marrow (BM) harvests using a modification of the 'grancollect-protocol' of the Fresenius AS 104 cell separator with the P1-Y set. Within 40-70 min, the initial marrow volume of 1,265 ml (+/- 537 ml) was processed two to three times. A mean of 47% (+/- 21%) of the initial mononuclear cells was recovered in a mean volume of 128 ml (+36 ml). The recovery of clonogenic cells, measured by CFU-GM assays, was 68% (+/- 47%). Red blood cells in the BM concentrates were reduced to 7% (+/- 4%) of the initial number. The procedure was efficient and yielded a BM cell fraction suitable for purging, cryopreservation and transplantation. At this time, 10 of the 21 patients whose BM was processed using this technique have been transplanted. Seven of these 10 patients have been grafted using the BM alone. Three of the 10 patients showed reduced cell viability and colony growth in the thawed BM samples, and therefore obtained BM and peripheral blood-derived stem cells. All transplanted patients showed an evaluable engraftment, achieving 1,000 granulocytes per microliter of peripheral blood in a mean of 18 days.

Automation↗
PubMed1993

T-cells and psychopathology in schizophrenia: relationship to the outcome of neuroleptic therapy.

Until recently, attention has been focused on the pathogenetic aspects of immunological findings in schizophrenic patients. There has been no mention of the relationship between such findings and schizophrenic symptoms. To study the probable relationship between T-cells and T-cell subgroups in the course and prognosis of schizophrenia, immunological and psychopathological parameters were correlated in 55 patients suffering from schizophrenia (ICD-9: 295.0-295.6) or schizoaffective psychosis (ICD-9: 257.7) before neuroleptic treatment. The correlations were performed for a second time in 24 of these patients after clinical improvement at a reinvestigation. Positive correlations of the Brief Psychiatric Rating Scale and the Scale for Assessment of Negative Symptoms with the numbers of CD3+ and CD4+ T-cells (total T- and T-helper cells), which were enhanced compared with controls, were found at the reinvestigation after clinical improvement, whereas no significant correlation could be detected at the pretreatment investigation. These results show that the cellular immune parameters are related to the course of the psychopathological symptoms in schizophrenia and, possibly, are a marker of the therapeutic outcome or neuroleptic treatment.

Adolescent↗
PubMed1993

Sporadic occurrence of Diego A antigens and antibodies in Berlin.

BACKGROUND: The antigen Dia is common among Mongols (5-12%), but rare in Caucasians (< 1%). OBJECTIVE: The accidental discovery of Diego A (Dia) antibodies in a South American tourist and in an elderly German patient prompted us to investigate the frequency of Dia antigens in the German population. DESIGN: 1,352 German random blood donors, all living in Berlin or in the areas around, were tested for the presence of the Dia antigen on their red blood cells. All donors were Caucasians. RESULTS: Dia was found in 12 individuals (0.89%). CONCLUSIONS: We think that Dia is a low-frequency antigen in the European population. The admixture of Mongol genes following wars or migration is only of low or no importance.

Aged↗
PubMed1993

[Mobilization of hematopoietic stem cells in peripheral blood by leukapheresis].

To improve the separation results of peripheral blood stem cells (PBSC), cytokines (GM-CSF, G-CSF or IL3) can be administered to patients. The most important prerequisites for successful PBSC separation are daily monitoring of CD-34-positive cells to determine the separation days and the use of optimized separation programs. To improve the performance of the cell separation, we increased the process volume to more than patients' blood volume and obtained increased MNC and CFU recoveries. In most cases, we collected more cells than the preseparation number of circulating cells. We therefore conclude that large-volume PBSC separation itself mobilizes hematopoietic progenitor cells.

Antigens, CD↗
PubMed1993

[Optimizing leukocytapheresis for collection of circulating hematopoietic stem- and precursor cells by multiparameter flow cytometry].

Peripheral blood stem cells are an alternative to bone marrow-harvested stem cells. We report on the feasibility of predicting optimal timing for leukapheresis by means of blood monitoring for CD34-positive cells by flow cytometry. In addition to monitoring, determinations of CD34-positive cells also are predictive for the hemopoietic potency of cells harvested by leukapheresis, as close correlations of numbers of CFU-GM and of CD34-positive cells, respectively, in leukapheresis samples are determined. Our data are indicating that flow-cytometrical determinations of CD34-positive cells are helpful in the setting of blood stem cell harvesting by leukapheresis, both for optimal timing of the procedure and for real-time estimation of the hemopoietic potency of cells harvested.

Antigens, CD↗
PubMed1993

[Quality assurance in preoperative autologous blood collection from the viewpoint of the transfusion medicine physician].

The overall risk of autologous hemotherapy, consisting of the risks due to donation and transfusion, has to be lower than that of homologous hemotherapy. To maintain the advantage of autologous blood, for example preoperative blood deposit, it has to be collected and prepared according to the guidelines on the production of homologous blood, except some obvious deviations concerning donor criteria. In this paper we recommend measures for the quality assurance in autologous predeposits from the point of view of transfusion medicine.

AIDS Serodiagnosis↗