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Biomedical subjects

J Georgsen

Publications and source records attributed to J Georgsen.

At least 37 records · Page 2Linked to original sources
PubMed1995

Preparation of white cell-reduced red cells by filtration: comparison of a bedside filter and two blood bank filter systems.

BACKGROUND: Concern has been raised about the quality of white cell (WBC)-reduced red cells (RBCs) obtained by bedside filtration. The bedside performance and workload of a routine bedside filter have been compared to the laboratory performance and workload of two blood bank filter systems. STUDY DESIGN AND METHODS: Buffy coat-depleted saline-adenine-glucose-mannitol (SAGM) RBCs (90 units) were prepared. Thirty units were filtered with each of the two blood bank filter systems, and 30 units were filtered (but not transfused) with the bedside filter in a clinical department after 8 to 24 days of storage. The RBCs lost and the postfiltration WBC content (Nageotte chamber) were determined for all filtered units, and the workload associated with filtration by each of the filter systems/filter was assessed. Units with a postfiltration content of > or = 2 x 10(6) WBCs were regarded as filtration failures. RESULTS: Four (13%) of the 30 units filtered at the bedside were filtration failures, compared to no failures with either of the blood bank filter systems. In addition, the median WBC content (0.14 x 10(6)) of the units filtered at the bedside (2 units/filter) was significantly higher than that of the units filtered in the blood bank (0.05 x 10(6)). The RBC loss was significantly higher with the filter systems than with the bedside filter, provided 2 units per filter were processed with the latter. The timed workload of the filter systems was 45 to 75 minutes per 12 units, which was similar to the time required for bedside filtration. CONCLUSION: Bedside filtration of 2 units of stored buffy coat-depleted SAGM RBCs per filter resulted in a higher incidence of filtration failure and higher postfiltration WBC content than did laboratory filtration of 1 unit of fresh buffy coat-depleted SAGM RBCs per filter with either of two blood bank filter systems.

Blood Component Removal↗
PubMed1994

Association between HLA-DRB3*0101 and immunoglobulin-E responsiveness to Bet v I.

The relationship between HLA-DRB3 antigens and specific IgE responsiveness to highly purified major allergen from white birch (Betula verrucosa), Bet v I, was studied in 43 patients, who were skin-prick test positive to birch pollen extract. Specific IgE to Bet v I was measured using an assay based on the principle of the Magic Lite method. HLA-DR and -DQ typings were performed by standard restriction fragment-length polymorphism techniques and HLA-DRB3 typing by the use of polymerase chain reaction and sequence-specific oligonucleotide. Of the 43 patients, 41 (95%) exhibited Bet v I-specific IgE. The data showed a significant association between HLA-DRB3*0101 and specific IgE to Bet v I (pc = 0.02). Furthermore, it was shown that this association was linked to the overall IgE responsiveness and not to a limited area of IgE sensitivity. The present study confirms and further identifies the association of DRB3*0101/0301 earlier described in an Austrian population to be present also in a Danish study group. This underlines the importance of this particular allele in the allergic immune response to birch pollen and emphasizes the importance of investigating the molecular basis of human allergic immune responsiveness.

Allergens↗
PubMed1994

Effect of radiographic contrast media on granulocyte phagocytosis of Escherichia coli in a whole blood flow cytometric assay.

RATIONALE AND OBJECTIVES: Earlier studies have demonstrated an adverse effect of radiographic contrast media (CM) on granulocyte phagocytosis. Most studies in the past have depended on granulocyte separative procedures that may themselves affect granulocyte functions. This study was performed to evaluate the effect of CM on phagocytosis using a flow cytometric assay allowing more physiological assay conditions. METHODS: Twenty consecutive patients were blindly randomized to receive the nonionic ratio 3.0 CM iohexol or the ionic ratio 3.0 CM ioxaglate for intravenous urography. Granulocyte phagocytic potential was measured before and at 1, 5, and 20 minutes after CM administration with a flow cytometric whole blood method evaluating the ingestion of complement- and immunoglobulin G (IgG)-opsonized fluorescent Escherichia Coli bacteria. RESULTS: The ability of granulocytes to phagocytize opsonized E. Coli was adversely affected by both CM used. Compared with baseline values, significantly decreased phagocytic activity was observed for iohexol at 1, 5, and 20 minutes and for ioxaglate at 1 and 5 minutes. The largest decrease with ioxaglate was from 85.3 +/- 10.5 to 69.3 +/- 16.3 (5 minutes), and the largest change with iohexol was from 87.1 +/- 8.5 to 74.5 +/- 15.9 (5 minutes). CONCLUSION: These results confirm earlier reports that ionic and nonionic CM adversely affect the phagocytic ability of granulocytes after intravenous administration.

Escherichia coli↗
PubMed1994

An antibody screening test based on the antiglobulin gel technique, pooled test cells, and plasma.

The recently introduced gel technique offers significantly advances compared to traditional tube tests. The purpose of the present study was to design an antibody screening test based on the gel technique, pooled cells, and plasma and to evaluate this test by comparison with a conventional spin-tube indirect antiglobulin test (IAT) combined with a two-stage papain technique. Pilot studies were performed to establish optimal parameters during the design phase, and finally 5,446 consecutive samples were screened for irregular antibodies by the gel technique in parallel with routine techniques. Irregular erythrocyte antibodies were detected in 151 samples, and the gel technique proved equal or superior to the tube test in the detection of all antibodies except 'enzyme-only' anti-E and anti-Lea. We conclude from this study that screening for unexpected antibodies using the gel IAT in our set-up, which includes: (1) omission of enzyme technique; (2) the use of stabilized (EDTA) plasma instead of serum as test material in order to facilitate automation; and (3) pooling 2 by 2 of 4 test cells (to make the gel technique price competitive), is a fast, reliable and sensitive procedure that maintains transfusion safety and compares favourably with our previous routine of saline IAT combined with a two-stage papain technique.

ABO Blood-Group System↗
PubMed1993

Human platelet antigen-1 (Zw) typing using PCR-RFLP.

The agreement between human platelet antigen-1 typing with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and typing with a serological ELISA method was evaluated. A total of 82 individuals were typed and an absolute correlation was found between the two typing methods. The PCR-RFLP typing method could be clinically useful in a number of immunologically mediated platelet disorders, characterized by severe thrombocytopenia and in early prenatal diagnosis of neonatal alloimmune thrombocytopenia, in which serological methods are difficult to apply because of their dependency on access to platelets and access to well-characterized anti-HPA-1b antisera.

Antigens, Human Platelet↗
PubMed1992

DNA polymorphism of HLA class II genes in primary biliary cirrhosis.

We investigated the DNA restriction fragment length polymorphism of the major histocompatibility complex class II genes: HLA-DRB, -DQA, -DQB, DPA, -DPB, the serologically defined HLA-A, B, C, DR antigens, and the primed lymphocyte typing defined HLA-DP antigens in 23 Danish patients with primary biliary cirrhosis (PBC) and in healthy Danes. The following genetic markers were found with increased frequencies in PBC: HLA-B8 (relative risk, RR = 2.4, P less than 0.05, 'corrected' P greater than 0.05), HLA-DR3 (RR = 3.4, P less than 0.01, 'corrected' P less than 0.05), the DRB3*01/02/03 (DRw52) associated DRB Bgl II 9.1 kilobase (kb) fragment (RR = 2.9; P less than 0.05, 'corrected' P greater than 0.05), the DQA1*0501 associated DQA Taq I 4.8 kb fragment (RR = 3.1; P less than 0.05, 'corrected' P greater than 0.05), the DQB1*0201 (DQw2) associated DQB Hin dIII 11.5 kb fragment (RR = 3.1; P less than 0.05, 'corrected' P greater than 0.05). No DNA fragments specific for DRB1*0301 (DR3) could be identified. The frequencies in PBC of other genetic markers including DRw8, DRB1*08, HLA-DP antigens, DPA, and DPB genes did not differ significantly from those in controls. The associations between PBC and B8, DR3, DQA1*0501, and DQB1*0201, which are frequently found together on the same haplotype, are at variance with recent reports on associations between PBC and Drw8. The discrepancy suggests that PBC is genetically heterogenous.

Genes, MHC Class II↗
PubMed1992

Granulocyte adherence after intravenous and intraarterial injection of ioxaglate or iohexol.

The effect of iohexol and ioxaglate on granulocyte adherence to nylon fibers was investigated with blood from 15 patients undergoing angiography, and from 24 patients undergoing excretory urography. Decreased adherence and increased numbers of granulocytes in the circulation were observed soon after injection of iohexol or ioxaglate in the aorta, or injection of ioxaglate i.v. Increased adherence and decreased numbers of granulocytes in the circulation were observed soon after injection of iohexol i.v. The differences were small soon after the injection of contrast media (CM). More pronounced decreased adherence and increased numbers of granulocytes were detected 2 and 5 hours after injection in the aorta for both CM.

Aorta↗
PubMed1992

Radiographic contrast media and release of neutrophil specific proteins in vitro and after intravenous injection.

The neutrophil granulocytes contain granules in which different proteins are present. When activated the neutrophils degranulate and thereby release some of these proteins to the surroundings. Some of these proteins are specific for this type of cell, e.g., lactoferrin and elastase. To investigate the influence of contrast media (CM) on this release, blood was incubated with diatrizoate, ioxaglate, iohexol, iodixanol, hyperosmolar saline, and hyperosmolar mannitol at different concentrations, and the amount of the neutrophil specific proteins lactoferrin and elastase were measured. Decreasing protein concentrations were observed for increased medium concentrations, suggesting that the degranulation process of the neutrophils was inhibited by the CM. The protein concentrations were lowest after incubation with the two ionic media diatrizoate and ioxaglate. Significantly decreased values of plasma lactoferrin were observed one min after i.v. injection of iohexol or ioxaglate in 82 patients undergoing urography. There was no significant difference between the two CM.

Contrast Media↗
PubMed1992

Granulocyte chemotaxis before and after urography. Influence of four different radiographic contrast media.

Granulocytes isolated from whole blood of 10 volunteers with Hypaque/Ficoll or Percoll gradient centrifugation showed a significant inhibition of their chemotactic response when incubated with diatrizoate. The influence of 4 different i.v. injected radiographic contrast media (CM) on granulocyte chemotaxis was evaluated using the under agarose assay. Each CM was injected in 10 consecutive outpatients referred for urography. Cells and serum were obtained before and 20 min after the injection of CM. Autologous serum was used as chemoattractive agent, and the cell suspensions from both samples were tested against serum drawn both before and after the injection of CM. No significant changes in granulocyte chemotaxis or the chemotactic potential of serum were seen. Furthermore, there was no change in the chemotactic response towards homologous serum or N-fmlp after injection of diatrizoate or iohexol. In conclusion, the investigation did not unveil any change in granulocyte chemotaxis 20 min after the injection of CM in the 40 subjects studied.

Cell Separation↗
PubMed1992

Phagocytic properties of granulocytes after intravenous injection of ioxaglate or iohexol.

To evaluate the influence of radiographic contrast media (CM) on human granulocytes, the ability of these cells to ingest latex particles after intravenous injection of ioxaglate and iohexol was investigated. Both CM inhibited the phagocytic properties of granulocytes; the inhibition was the most pronounced immediately after the injection, but inhibition was also observed 60 min after injection of ioxaglate. The inhibition 1 and 5 min after injection of CM was more pronounced after injection of ioxaglate than after injection of iohexol. However, this difference between the 2 CM was not significant. Significant inhibition of phagocytosis was found for mannitol solutions with osmolalities higher than 369 mOsm/l. Significant inhibition of phagocytosis was observed when granulocytes were isolated with either Hypaque/Ficoll or Percoll gradient centrifugation and then incubated with diatrizoate. Thus the ability of granulocytes to phagocytize latex particles was inhibited after i.v. injection of 50 ml ioxaglate or iohexol. Part of this inhibition may be due to hyperosmolality.

Granulocytes↗
PubMed1992

Granulocyte adherence is inhibited by radiographic contrast media in vitro.

Different amounts of diatrizoate, ioxaglate, iohexol, iodixanol, NaCl 1,000 mOsm/kg, mannitol 1,098 mOsm/kg, and meglumine (meglumine concentrations corresponding to the content in the diatrizoate solutions) were added to either whole blood or a suspension of granulocytes in autologous plasma, and the adherence to nylon fibers was determined. At high concentrations all the investigated contrast media (CM) inhibited granulocyte adherence. The degree of inhibition was significantly greater when the ionic CM diatrizoate and ioxaglate were used, as compared with the nonionic media. Meglumine solutions at high concentrations also inhibited adherence but significantly less than diatrizoate solutions containing the same amount of meglumine. Diatrizoate showed the greatest inhibitory effect on granulocyte adherence, and significant inhibition could be detected even with a 1.25% solution.

Cell Adhesion↗