PubMed Health⌕ Search

Biomedical subjects

G Wegner

Publications and source records attributed to G Wegner.

At least 19 recordsLinked to original sources
PubMed1991

Influence of white blood cells on the filterability of human erythrocytes: modelling of the filtration process and experimental results.

In medical research and clinical practice, the increasing application of filtration measurements, to characterize the erythrocyte deformability has aroused an intensive discussion about possible erroneous interpretations of measured values (filterability indices). In the present paper the influence of white blood cells (WBC) on these indices is described and discussed in relation to a mathematical model of the filtration process. We found for two gravity filtration systems, using cellulose filters and concentrated erythrocytes suspensions sensitivities of their filterability indices of (1 +/- 0.1)% per 100 WBC/microliter (initial filtration rate measurement) and (3 +/- 0.3)% per 100 WBC/microliter (hemofiltrometer). In comparison to Nuclepore filtration systems with sensitivities of 5-12% per 100 WBC/microliters, cellulose filters were much less sensitive to WBC. The necessity, advantages and disadvantages of additional procedures for WBC removal are discussed. A standardization of residual WBC-count in limits of 500 +/- 300 WBC/microliters at a hematocrit of 60% is proposed. Fitting of the filtration curves of the hemofiltrometer to a model function may either improve the accuracy of estimation of filterability indices or divide them into two model parameters with different WBC-sensitivities: the initial filtration rate parameter having a low WBC-sensitivity ((0.9 +/- 0.2)% per 100 WBC/microliter) and the occlusion related parameter having a 12 times higher sensitivity ((11 +/- 1)% per 100 WBC/microliter). Interpretation, advantages and disadvantages of the model parameters are discussed also in comparison to the filterability index.

Cellulose↗
PubMed1991

[Characterization of erythrocyte deformability by filtration technics. 5. The effect of leukocytes on the filterability of erythrocytes].

Filterability measurements have been used widely in medical research and clinical practice to characterize erythrocyte deformability. In the present paper the influence of white blood cells (WBC) on the of filterability indices is investigated and discussed. We found for two gravity filtration systems using cellulose filters and concentrated erythrocyte suspensions sensitivities of their filterability indices of 1% per 100 WBC/microliters (initial) filtration rate measurement) and 3% per 100 WBC/microliters (hemofiltrometer). The necessity, advantages and disadvantages of additional methods for WBC removal are discussed in comparison to nuclepore filtration systems with sensitivities of 5-12% per 100 WBC/microliters. The standardization of residual WBC-count in limits of 500 +/- 300 WBC/microliters at a hematocrit of 60% is proposed.

Erythrocyte Deformability↗
PubMed1990

[Interpretation of the estrogen receptor content of breast cancer].

The biochemical analysis of estrogen receptor (ER) content, using the DCC (dextran-coated charcoal) method, was compared with different plotting methods of the estrogen-receptor immunocytochemical assay (ER-ICA) in 80 primary breast cancers including 9 metastases under routine conditions. It was evident, that the determined content of estrogen receptors depends on the technique of measurement, as well as the microscopic organizations of the individual carcinomas and should be interpreted in respect of their content of stroma and if possible of tumour heterogeneity.

Antibodies, Monoclonal↗
PubMed1989

Investigations on the deformability of human red blood cells stored in different preservative solutions: relation between cellular hemoglobin concentration and in vivo survival.

In continuation of earlier studies (Kucera, W. et al.: Biomed. Biochim. Acta 44, 1459-1467, (1985); Wegner, G. et al.: Biomed. Biochim. Acta 46, 605-609 (1987] the in vivo of human red blood cells (RBC) stored for 35 or 42 days in different anticoagulant and preservative media was analyzed with regard to the main influencing factors. We found a significant partial correlation (2 alpha = 0.001; n = 75) between the in vivo survival and the mean cellular hemoglobin concentration (MCHC; rp = -0.70) as well as on a lower level (2 alpha = 0.01; n = 75) with the ATP content (rp = 0.35). By calculating the internal viscosity as a determinant of RBC deformability from MCHC values and non-linear fitting an equation for the survival prediction for known MCHC values of stored RBC was found. Low pressure filterability through cellulose filters characterizing cellular deformability is interpreted in relation to viability of stored RBC.

Blood Preservation↗
PubMed1989

Histological classification of synovitis.

A simple system of synovitis classification is proposed based on histomorphological evaluation of 400 random specimens of synovial tissue. It discriminates between two types of diagnosis: 1) one with a high degree of information, being called C-synovitis (synovitis with a characteristic or diagnostic histomorphological pattern), where the clinical diagnosis can be predicted on the basis of the histomorphological pattern, 2) a second type of diagnosis with a lower degree of information, being called NC-synovitis (synovitis with non-characteristic or non-diagnostic morphological findings in the synovial membrane). We subdivided NC-synovitis into 4 subgroups and determined the RA-probability of each subgroup in order to permit clinical use of the proposed histomorphological classification. In addition, by using immunoperoxidase staining methods for immunoglobulins the subgroups were shown to have different quantities of extravasally deposited immunoglobulins in the synovial membrane. The subgroup with the highest RA-probability also turned out to have the highest amount of extravasally deposited immunoglobulins.

Fibroblasts↗
PubMed1988

Use of lectin-immunohistochemistry in joint diseases.

The lectin binding pattern of the inflamed synovial tissue of patients with OA (osteoarthritis) and RA (rheumatoid arthritis) were examined with 18 different lectins. The synovial lining cells are heavily stained by PHA-L, WGA, PNA, Con A, MPA and RCA. In the subsynovial layer, WGA, PHA-L and RCA were found to be fairly good monocytic markers. The lectin binding pattern of the lectins under study, however, failed to discriminate between patients with OA and RA.

Arthritis↗
PubMed1987

[Changes in erythrocyte deformability in blood preservation].

The deformability changes of erythrocytes during storage were characterized by a filtration procedure for blood units mainly used for erythrocyte substitution in the GDR. Following order of maintaining deformability properties were measured: 1. At-196 degrees C cryopreserved erythrocytes; 2. whole blood units; 3. at-28 degrees C cryo-preserved erythrocytes (in clinical examination); 4. buffy-coat free erythrocyte concentrates resuspended with CDS-AG medium. The drastic deformability loss of CDS-AG resuspended erythrocytes (75% of all erythrocyte transfusions!) is caused by an increase of the internal viscosity due to a practically irreversible shrinkage of erythrocytes as an effect of low ionic strength. In contrast to former data a reinvestigation of in vivo survival resulted in values 20% below the limit of 70% 24 h p.i. In comparison to this the abroad used CPDA-1 whole blood units and SAGM resuspensions showed only small deformability changes during storage. By a change of composition of the GDR-resuspension medium the drastic deformability loss is avoided. This new resuspension medium is concerning the deformability loss comparable to the SAGM medium. A comparison of deformability changes during storage in plastic bags and glass bottles as well as in media with various hemolysis reducing agents did not show any differences.

Blood Preservation↗
PubMed1987

Deformability investigations of erythrocytes stored at different temperatures.

The deformability changes of erythrocytes stored at different temperatures were characterized by a filtration procedure. The filterability index (FI) of erythrocytes cryopreserved at either -196 degrees C or -28 degrees C increased (deformability decreased) by about 9% and 40% respectively. For comparison with the cryopreserves the filterability of erythrocytes stored in liquid state at +4 degrees C were investigated. The filterability changes are discussed in comparison with the changes of MCHC during storage.

Blood Preservation↗
PubMed1987

Deformability characterization of erythrocytes stored in different resuspension media.

The deformability changes of erythrocytes during 35 days of storage in different resuspension media were characterized by a filtration procedure. The filterability of erythrocytes stored in CDS-AG medium decreased drastically, whereas the filterability of erythrocytes stored in SAGM and SAGS medium decreased only slightly. The MCHC change of stored erythrocytes were discussed in relation to filterability effects.

Blood Preservation↗
PubMed1987

Immunophotometric analysis of immunoglobulin synthesis and deposition in synovial membranes of patients with rheumatoid arthritis.

Immunophotometrical measurements of the Ig synthesis of plasma cells in joint capsules of patients with rheumatoid arthritis and osteoarthritis were compared. Patients with rheumatoid arthritis showed higher mean values in the single plasma cell than patients with osteoarthritis for all Ig isotypes except IgG. These results are indicative for a B cell activation with increased synthesis of Ig in RA.

Arthritis, Rheumatoid↗
PubMed1987

Deformability of human red blood cells stored for different periods at subzero temperatures.

Deformability changes of human red blood cells (RBC) stored for different periods at +4 degrees C, -28 degrees C and -196 degrees C were characterized by a filtration procedure. The filterability index (FI) of RBC stored at -196 degrees C increased (deformability decreased) by about 8%, whereas FI of RBC, liquid stored at +4 degrees C as whole blood, increased by about 25%. In contrast to both the FI of RBC cryopreserved at -28 degrees C for different periods showed an increase of about 40% after 62 days and seemed to be constant for some further months (up to 240 days). A further FI increase was measured after 485 days. Mean cellular hemoglobin concentration changes during storage are excluded to be the cause for deformability loss in this case. An estimation illustrates the osmotic effect of the residual glycerol content after routine deglycerolization procedure and the differences of osmotic and ionic strength effects on RBC deformability in stored blood.

Blood Preservation↗
PubMed1987

Investigations on the deformability of human red blood cells stored in different preservative solutions: influence of changed medium composition.

In continuation of a former paper (W. Kucera, G. Wegner, D. Lerche: Biomed. Biochim. Acta 44, 1459 to 1467, 1985) the deformability changes of human red blood cells (RBC) during 35 days of storage in different resuspension media of changed composition were characterized by a filtration procedure. The filterability of RBC stored in CDS-AG medium (high sucrose content) decreased drastically (increase of the filterability index to more than the 6-fold). This deformability loss is caused by an increase of the internal viscosity (at least 4-fold) due to shrinkage of red blood cells by more than 20% as an effect of low ionic strength. In contrast, the filterability loss of RBC stored in SAGM medium was slight. The cell volume showed a slight increase with unchanged mean cellular hemoglobin concentration. By changing the composition of CDS-AG medium by reduction of the sucrose content from 234 mM to 30 mM and addition of 150 mM NaCl (SAGS medium) the drastic deformability loss was avoided. From the viewpoint of deformability this SAGS medium is comparable to the internationally accepted SAGM resuspension medium.

Blood Preservation↗
PubMed1986

In situ evaluation of immunoglobulin synthesis of synovial plasma cells in rheumatoid arthritis and osteoarthritis by plug photometry.

Synovial membranes of patients with osteoarthritis--a disease with unaltered immunoregulation--and rheumatoid arthritis were immunostained for the different immunoglobulin isotypes using the PAP-method and a two-layer alkaline phosphatase technique. Randomly selected plasma cells with positive immunostaining were measured by plug photometry. The average extinction of the single plasma cell is considered to be indicative of the immunoglobulin synthesis of the measured plasma cell and the isotype under study. When we compared both disease entities, patients with rheumatoid arthritis were characterized (i) by higher average extinction values for all Ig-isotypes except IgG (ii) by a higher rate of high producer plasma cells. From this data, we conclude that immunophotometry is a new in vivo method for discriminating two types of synovitis (i) one without increased Ig-synthesis at the single cell level and (ii) a second one with increased Ig-synthesis.

Antibody-Producing Cells↗
PubMed1986

[Deformability of stored erythrocytes as a criteria for their in vivo survival rate].

The loss of deformability observed in erythrocytes stored as whole blood for 36 days (ACD-AG) or as buffy-coat free erythrocyte concentrate (EK) was characterized by measuring their filterability. During the first 3 weeks the index of filterability for ACD-AG erythrocytes increased only slightly and rose to about 140% of its initial value on the 36th day. In contrast, a heavy loss of deformability (increase of the filterability index to more than 600%) was detected for erythrocytes from EK, which, from a rheological point of view, is apt to raise doubts of using this stored blood. An incubation of 1 hour at 37 degrees C in fresh plasma did not result in improving the deformability. A cell volume loss of more than 20% connected with an increase of the inner viscosity to more than 400% was found to be the cause of this decrease of deformability. These rheological differences are also reflected in the 24 hours in vivo survival rate (SR), if the "early loss" of damaged erythrocytes immediately after transfusion is taken into account. Whereas the SR values of 80% for whole blood erythrocytes do not change significantly, the SR values for EK values can be found to reach 54% approximately.

Blood Transfusion↗
PubMed1985

Comparison between continuous and intermittent administration of Estracyt in the treatment of carcinoma of the prostate.

Ninety-five patients with prostatic carcinoma, stages A-D and of all histological grades were randomized between a continuous and an intermittent treatment regimen of Estracyt (estramustine phosphate). 77 patients were evaluated (46 with continuous and 31 with intermittent therapy). Remissions were seen in 13 (28%) and (13%), respectively. Stable disease was recorded in 30 (65%) and 24 (77%), respectively. Progression experienced 3 (6%) and 3 (10%) respectively. 19% were unable to continue therapy due to intolerable gastrointestinal side effects (7 patients receiving continuous and 8 patients receiving intermittent therapy).

Aged↗