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Biomedical subjects

Holger Kiesewetter

Publications and source records attributed to Holger Kiesewetter.

At least 19 recordsLinked to original sources
PubMed2007

Moderate consumption of olive oil by healthy European men reduces systolic blood pressure in non-Mediterranean participants.

We evaluated the effects of a moderate consumption of olive oil on lipid profile, BMI, and blood pressure (BP) in a group of 160 healthy men from non-Mediterranean regions [Northern Europe (n = 50; Finland and Denmark) and Central Europe (n = 60; Germany)] and Mediterranean regions [Southern Europe (n = 45; Italy and Spain)]. The study was a randomized, cross-over trial with 3 intervention periods of 3 wk and 2 wash-out periods of 2 wk. At the intervention periods, 3 similar olive oils (25 mL/d), differing only in their phenolic concentration, were administered to the healthy volunteers. Plasma oleic acid levels increased 2-3% (P < 0.05) in men from populations with lower habitual olive oil intakes (Northern and Central Europe). General linear models showed that the administration of the sequence of the 3 olive oils was responsible for a 3% decrease in systolic BP (SBP) (P < 0.05), but not in diastolic BP, in the non-Mediterranean subjects. Multivariate analysis indicated that the lipid profile did not change in either Mediterranean or non-Mediterranean men due to the olive oil intervention. The results of this study suggest that a moderate consumption of olive oil may be used as an effective tool to reduce SBP of healthy men who do not typically consume a Mediterranean diet. However, additional longer trials are necessary for confirmation.

Adult↗
PubMed2006

Effect of olive oils on biomarkers of oxidative DNA stress in Northern and Southern Europeans.

High consumption of olive oil in the Mediterranean diet has been suggested to protect DNA against oxidative damage and to reduce cancer incidence. We investigated the impact of the phenolic compounds in olive oil, and the oil proper, on DNA and RNA oxidation in North, Central, and South European populations. In a multicenter, double-blind, randomized, controlled crossover intervention trial, the effect of olive oil phenolic content on urinary oxidation products of guanine (8-oxo-guanine, 8-oxo-guanosine and 8-oxo-deoxyguanosine) was investigated. Twenty-five milliliters of three olive oils with low, medium, and high phenolic content were administered to healthy males (n=182) daily for 3 wk. At study baseline the urinary excretion of 8-oxo-guanosine (RNA oxidation) and 8-oxo-deoxyguanosine (DNA oxidation) was higher in the Northern regions of Europe compared with Central and Southern European regions (P=0.035). Urinary excretion of the 8 hydroxylated forms of guanine, guanosine, deoxyguanosine and their nonoxidized forms were not different when comparing olive oils with low, medium, and high phenolic content given for 2 wk. Testing the effect of oil from urinary 8-oxo-deoxyguanosine changes from baseline to post-treatment showed a reduction of DNA oxidation by 13% (P=0.008). These findings support the idea that ingestion of olive oil is beneficial and can reduce the rate of oxidation of DNA. This effect is not due to the phenolic content in the olive oil. The higher DNA and RNA oxidation in Northern European regions compared with that in Central and Southern regions supports the contention that olive oil consumption may explain some of the North-South differences in cancer incidences in Europe.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2006

A novel agglutination test for antigen-specific detection of platelet antibodies.

A simple and rapid antigen-specific assay for the identification antibodies to platelets is lacking, yet. Red-dyed polystyrene microbeads were coated with monoclonal antibodies to various platelet glycoprotein complexes, and used for the detection of platelet autoantibodies and alloantibodies. The results were largely identical with those obtained by monoclonal antibody-specific immobilization of platelet antigen assay (MAIPA). The new test is reliable yet less complex and time-consuming than the currently available assays, and it can be implemented in any routine laboratory.

Agglutination Tests↗
PubMed2006

The effect of polyphenols in olive oil on heart disease risk factors: a randomized trial.

BACKGROUND: Virgin olive oils are richer in phenolic content than refined olive oil. Small, randomized, crossover, controlled trials on the antioxidant effect of phenolic compounds from real-life daily doses of olive oil in humans have yielded conflicting results. Little information is available on the effect of the phenolic compounds of olive oil on plasma lipid levels. No international study with a large sample size has been done. OBJECTIVE: To evaluate whether the phenolic content of olive oil further benefits plasma lipid levels and lipid oxidative damage compared with monounsaturated acid content. DESIGN: Randomized, crossover, controlled trial. SETTING: 6 research centers from 5 European countries. PARTICIPANTS: 200 healthy male volunteers. MEASUREMENTS: Glucose levels, plasma lipid levels, oxidative damage to lipid levels, and endogenous and exogenous antioxidants at baseline and before and after each intervention. INTERVENTION: In a crossover study, participants were randomly assigned to 3 sequences of daily administration of 25 mL of 3 olive oils. Olive oils had low (2.7 mg/kg of olive oil), medium (164 mg/kg), or high (366 mg/kg) phenolic content but were otherwise similar. Intervention periods were 3 weeks preceded by 2-week washout periods. RESULTS: A linear increase in high-density lipoprotein (HDL) cholesterol levels was observed for low-, medium-, and high-polyphenol olive oil: mean change, 0.025 mmol/L (95% CI, 0.003 to 0.05 mmol/L), 0.032 mmol/L (CI, 0.005 to 0.05 mmol/L), and 0.045 mmol/L (CI, 0.02 to 0.06 mmol/L), respectively. Total cholesterol-HDL cholesterol ratio decreased linearly with the phenolic content of the olive oil. Triglyceride levels decreased by an average of 0.05 mmol/L for all olive oils. Oxidative stress markers decreased linearly with increasing phenolic content. Mean changes for oxidized low-density lipoprotein levels were 1.21 U/L (CI, -0.8 to 3.6 U/L), -1.48 U/L (-3.6 to 0.6 U/L), and -3.21 U/L (-5.1 to -0.8 U/L) for the low-, medium-, and high-polyphenol olive oil, respectively. LIMITATIONS: The olive oil may have interacted with other dietary components, participants' dietary intake was self-reported, and the intervention periods were short. CONCLUSIONS: Olive oil is more than a monounsaturated fat. Its phenolic content can also provide benefits for plasma lipid levels and oxidative damage. International Standard Randomised Controlled Trial number: ISRCTN09220811.

Adult↗
PubMed2006

Detailed analysis of the variability of peptidylarginine deiminase type 4 in German patients with rheumatoid arthritis: a case-control study.

Peptidylarginine deiminase type 4 (PADI4) genotypes were shown to influence susceptibility to rheumatoid arthritis (RA) in the Japanese population. Such an association could not previously be confirmed in different European populations. In the present study, we analysed exons 2-4 of PADI4 in 102 German RA patients and 102 healthy individuals to study the influence of PADI4 variability on RA susceptibility by means of haplotype-specific DNA sequencing. Analyses of the influence of PADI4 and HLA-DRB1 genotypes on disease activity and on levels of anti-cyclic citrullinated peptide antibodies were performed. Comparing the frequencies of PADI4 haplotype 4 (padi4_89*G, padi4_90*T, padi4_92*G, padi4_94*T, padi4_104*C, padi4_95*G, padi4_96*T) (patients, 14.7%; controls, 7.8%; odds ratio = 2.0, 95% confidence interval = 1.1-3.8) and carriers of this haplotype (patients, 27.5%; controls, 13.7%; odds ratio = 2.4, 95% confidence interval = 1.2-4.8), a significant positive association of PADI4 haplotype 4 with RA could be demonstrated. Other PADI4 haplotypes did not differ significantly between patients and controls. Regarding the individual PADI4 variants, padi4_89 (A-->G), padi4_90 (C-->T), and padi4_94 (C-->T) were significantly associated with RA (patients, 49.5%; controls, 38.7%; odds ratio = 1.6, 95% confidence interval = 1.1-2.3). Considering novel PADI4 variants located in or near to exons 2, 3, and 4, no quantitative or qualitative differences between RA patients (8.8%) and healthy controls (10.8%) could be demonstrated. While the PADI4 genotype did not influence disease activity and the anti-cyclic citrullinated peptide antibody level, the presence of the HLA-DRB1 shared epitope was significantly associated with higher anti-cyclic citrullinated peptide antibody levels (P = 0.033). The results of this small case-control study support the hypothesis that variability of the PADI4 gene may influence susceptibility to RA in the German population. Quantitative or qualitative differences in previously undefined PADI4 variants between patients and controls could not be demonstrated.

Adolescent↗
PubMed2006

Misdiagnosis in patients with diclofenac-induced hemolysis: new cases and a concise review.

Diclofenac has been implicated in many cases of life-threatening immune hemolytic anemia (IHA). Nevertheless, confusion still occurs at the bedside and in the laboratory. Herein we report nine new patients and summarize all published cases (total, n = 61). Direct and indirect antiglobulin tests were performed according to standard procedures. Tests for drug-dependent antibodies were performed in the presence and absence of the target drugs and their ex vivo antigens (in the urine of patients treated with the drug). Diclofenac- and/or ex-vivo-antigen-dependent red cell antibodies were detected in all new cases. We identified nine new cases with diclofenac-dependent IHA. All cases were initially suspected to have an abdominal illness and/or autoimmune hemolytic anemia of warm type. Acute renal failure was present in three of the 9 new patients and in 20 of 37 published patients. Seven of the 46 patients died (15%), and clinical information is lacking in 15 other published cases. Diclofenac-dependent and/or ex-vivo-antigen-dependent IHA should always be considered when a patient on diclofenac develops acute renal failure and/or IHA.

Acute Kidney Injury↗
PubMed2006

Differences in the transmigration of different dendritic cells.

OBJECTIVE: Although several methods for the generation of dendritic cells (DCs) exist, little is known about the transmigration capacities of the cells developed. Their ability to migrate to the adjacent lymphatic system is relevant since their efficacy does also rely on their potential to interact with lymphocytes. METHODS: We studied the transmigration of DCs derived from hematopoietic progenitor cells (HPC), from peripheral blood monocytes, and from leukemic cells. DCs from monocytes and leukemic cells could be generated within 1 week, whereas DCs from HPC needed 2 weeks for maturation. RESULTS: While DCs from all sources showed similar morphologic features and allostimulatory capacities, their transmigration capacities varied: HPC-derived DCs showed the highest migratory response to macrophage inflammatory protein (MIP)-3alpha and beta. Monocyte-derived DCs were equally attracted to MIP-3beta and stroma-derived factor (SDF)-1alpha. Only few leukemic DCs migrated in response to SDF-1. Other chemoattractants tested included MIP-1alpha and RANTES. Replacement of fetal bovine by human serum did not change the DC's overall migratory capacities. It did, however, influence the responsiveness to certain chemokines. CONCLUSION: Although DCs from all three sources are immunocompetent antigen-presenting cells, our findings suggest that HPC and monocyte-derived DCs can be administered subcutaneously and intravenously, but that leukemic DCs should be injected into the lymph node.

Cell Communication↗
PubMed2006

A simple and practical assay for the antigen-specific detection of platelet antibodies.

BACKGROUND: The antigen-specific assays currently used for characterization of platelet (PLT)-reactive auto- and alloantibodies are too technically complex and impracticable for most routine laboratories. Here, a novel antigen-specific particle assay (ASPA) for PLTs similar to that of red blood cells is described. STUDY DESIGN AND METHODS: PLTs were solubilized and then incubated with red-dyed polystyrene particles coated with monoclonal antibodies (MoAbs) to various PLT glycoprotein complexes. These particles were directly tested for coating with autoantibodies (n = 8) or indirectly tested for serum autoantibodies (n = 33) or alloantibodies against HPA-1a (n = 4) or HPA-5b (n = 5). Serum samples from healthy blood donors (n = 100) served as negative controls. RESULTS: Negative reactions were clearly distinguishable from positive reactions, and the results of the particle assay were in concordance with those obtained by the standard MoAb-specific immobilization of PLT antigen assay (MAIPA) in all cases with alloanti-bodies. In three patients, only the ASPA was able to detect autoantibodies that were completely undetectable by the MAIPA. In contrast, in only one patient, the MAIPA detected autoantibodies that the ASPA failed to detect. CONCLUSION: In our opinion, the new ASPA is reliable, yet less complex and time-consuming than the currently available assays, and it can be implemented in any routine laboratory.

Antibodies, Monoclonal↗
PubMed2006

Thawing procedures and the time course of clotting factor activity in fresh-frozen plasma: a controlled laboratory investigation.

BACKGROUND: In this study, we evaluated the effects of the thawing process of 2 commercially available devices on the activity of clotting factors, inhibitors and activation markers of the hemostatic system in fresh-frozen plasma (FFP). In an experimental procedure, FFP was thawed under running warm water at 42 degrees C. METHODS: Plasma of 20 healthy donors was sampled, separated, and distributed in 3 plasma bags. Within 2 h after sampling plasma bags was frozen at a temperature of -30 degrees C to -40 degrees C and stored for at least 8 wk. After sampling (baseline) as well as immediately and 1, 2, 4, and 6 h after thawing, the activity of FV, FVII, FVIII, fibrinogen, fibrin monomers (FM), d-dimers (DD), alpha2-antiplasmin (alpha2-AP), and protein S (PS) was determined from each plasma bag. RESULTS: From 1 h to 6 h after thawing, no significant differences in the activity of the investigated coagulation markers dependent on the thawing procedure were found. However, immediately after thawing and independent of the thawing procedure, the activity of FVII was significantly decreased (P < 0.01), whereas FM were significantly increased (P = 0.001). CONCLUSION: The thawing procedures studied exhibited no significant influence on activity and stability of the investigated markers of coagulation over the study period. The decreased activity of FVII and the clinical significance of the increase in FM require further research.

Adult↗
PubMed2006

Gene polymorphisms implicated in influencing susceptibility to venous and arterial thromboembolism: frequency distribution in a healthy German population.

Evolvement and progression of cardiovascular diseases affecting the venous and arterial system are influenced by a multitude of environmental and hereditary factors. Many of these hereditary factors consist of defined gene polymorphisms, such as single nucleotide polymorphisms (SNPs) or insertion-deletion polymorphisms, which directly or indirectly affect the hemostatic system. The frequencies of individual hemostatic gene polymorphisms in different normal populations are well defined. However, descriptions of patterns of genetic variability of a larger extent of different factors of hereditary hypercoagulability in single populations are scarce. The aim of this study was i) to give a detailed description of the frequencies of factors of hereditary thrombophilia and their combinations in a German population (n = 282) and ii) to compare their distributions with those reported for other regions. Variants of coagulation factors [factor V 1691G>A (factor V Leiden), factor V 4070A>G (factor V HR2 haplotype), factor VII Arg353Gln, factor XIII Val34Leu, beta-fibrinogen -455G>A, prothrombin 20210G>A], coagulation inhibitors [tissue factor pathway inhibitor 536C>T, thrombomodulin 127G>A], fibrinolytic factors [angiotensin converting enzyme intron 16 insertion/deletion, factor VII-activating protease 1601G>A (FSAP Marburg I), plasminogen activator inhibitor 1-675 insertion/deletion (5G/4G), tissue plasminogen activator intron h deletion/insertion], and other factors implicated in influencing susceptibility to thromboembolic diseases [apolipoprotein E2/E3/E4, glycoprotein Ia 807C>T, methylenetetrahydrofolate reductase 677C>T] were included. The distribution of glycoprotein Ia 807C>T deviated significantly from the Hardy-Weinberg equilibrium, and a comparison with previously published data indicates marked region and ethnicity dependent differences in the genotype distributions of some other factors.

Arterial Occlusive Diseases↗
PubMed2005

Hemoglobin screening in prospective blood donors: comparison of different blood samples and different quantitative methods.

Portable photometers are increasingly used for hemoglobin screening in blood centers. In a total of 500 unselected prospective blood donors, venous hemoglobin concentrations were measured using a hematology analyzer, and fingerstick hemoglobin concentrations were measured on both a HemoCue B and a Biotest hemoglobin photometer. In 100 of the donors, earstick hemoglobin levels were also measured on the HemoCue system. The mean hemoglobin levels in the fingerstick samples were slightly higher than those in the venous samples. The deviation exceeded the limit of +/-10g l(-1) in 9% of samples tested by HemoCue and in 20% of those investigated by Biotest. The use of earstick samples led to considerable overestimation of the actual hemoglobin concentration.

Blood Donors↗
PubMed2005

Failure of bedside ABO testing is still the most common cause of incorrect blood transfusion in the Barcode era.

BACKGROUND AND OBJECTIVES: ABO-incompatible red blood cell (RBC) transfusions are a major risk in transfusion medicine. Identification of factors leading to this hazard is important to improve transfusion safety. MATERIAL AND METHODS: All consecutive erroneous ABO-incompatible transfusions occurring from January 1997 to December 2004 at the Charité University Hospital in Berlin, Germany were analysed. RESULTS: A total of 343,432 RBC units were transfused, and eight patients erroneously received 13 ABO-incompatible RBC concentrates. The most frequent error was incorrect bedside testing (n=7). Intensive care treatment was required in two cases, but there were no fatal mistransfusions. Four patients had no or only mild reactions. CONCLUSION: Mistransfusions are still a considerable risk in transfusion medicine despite quality control systems and electronic data processing. An increase in transfusion safety may require the introduction of further systems, e.g. radio-frequency identification (RFID) tags.

ABO Blood-Group System↗
PubMed2005

Use of the platelet reactivity index by Grotemeyer, platelet function analyzer, and retention test Homburg to monitor therapy with antiplatelet drugs.

In 1974, Wu and Hoak described a method for determining circulating platelet aggregates. This method was modified by Grotemeyer in 1983. The platelet reactivity index (PR) is based on the ratio of platelet aggregates in blood samples obtained in different buffer solutions. Platelet aggregates are resolved when blood is sampled in EDTA-buffer, but remain fixed when EDTA-formalin-buffer is used. Generally, the PR is preferred, because in vitro manipulations of platelets are not necessary, and the results are calculated. PR values above 1.05 are suspicious for elevated platelet aggregation. PR values above 1.2 indicate pathological changes in platelet aggregation. The PR is inexpensive (4.0 euro dollars) and rapid to perform. PR values were used successfully to identify nonresponders to secondary prophylaxis with acetylsalicylic acid (ASA), that is, patients suffering from stroke (33%) and patients after cardiac ischemia (18%). Furthermore, elevated PR values correlated significantly with the incidence of arterial thromboembolic complications. The PR correlated well in our prospective study with values received from the retention test Homburg (RT-H) and the platelet function analyzer (PFA-100). The data indicate that the values of the PR seem to be highly predictive for the evaluation of the ASA therapy. However, the PR is not feasible for the determination of the ASA overdosage.

Aspirin↗
PubMed2005

Rapid identification of iron deficiency in blood donors with red cell indexes provided by Advia 120.

BACKGROUND: A new generation of automated hematology analyzers allows the rapid determination of various red cell (RBC) indexes, including the percentage of hypochromic mature RBCs (HYPOm) and the hemoglobin (Hb) content of reticulocytes (CHr). These indexes have not yet been validated as measures for the detection of iron deficiency in blood donors. STUDY DESIGN AND METHODS: Iron status was evaluated in a total of 1142 unselected prospective blood donors based on measurement of serum ferritin, soluble transferrin receptor, and Hb compared to RBC indexes provided by an automated hematology analyzer (Advia 120, Bayer HealthCare) including HYPOm and CHr. RESULTS: Assuming that the most precise measure for body iron storage is related to the logarithm of the ratio of soluble transferrin receptor to ferritin, the sensitivity of ferritin for the diagnosis of iron depletion was 89 percent compared to 57 percent for HYPOm and CHr, respectively, to 69 percent for the combination of both RBC indexes, and to 26 percent for Hb concentration. CONCLUSION: The RBC indexes HYPOm und CHr are significantly better screening measures for identification of iron depletion in blood donors than Hb.

Adolescent↗