Biomedical subjects

J Lundahl

Publications and source records attributed to J Lundahl.

At least 19 recordsLinked to original sources

PubMed1999

The effect of in vitro activation and platelet interaction on the CD9 distribution and adhesion properties of human eosinophils.

OBJECTIVE AND DESIGN: The redistribution of CD9 in peripheral blood eosinophils was investigated with respect to the interaction with platelets during in vitro activation, and whether this interaction exerts influence on eosinophil adhesion properties. MATERIALS AND METHODS: Flow cytometry was used to investigate the CD9 expression in purified eosinophils or eosinophils from different whole blood preparations, with or without platelets present. To confirm an eosinophil/platelet interaction fluorescence microscopy was used, and to demonstrate release/shedding of CD9 molecules a biosensor technique was performed. RESULTS: Our results show that both intracellular and surface expression of CD9 decrease upon in vitro activation in the absence of platelets, a phenomenon probably caused by release/shedding of soluble forms of CD9 and not due to intracellular degradation. Increased expression of CD9 on eosinophils, stimulated in the presence of platelets, is partly a result of interacting platelets, judged by the increase in platelet specific marker CD61. In our adhesion assay a significant increase in eosinophil adhesion properties to fibronectin was obtained when eosinophils were PMA stimulated and interacting with platelets, as compared to activated eosinophils without platelets. CONCLUSIONS: Our findings, that CD9 expression on eosinophils is dynamically regulated, support our previous suggestion that CD9 may be a useful activity marker and that platelet interaction acts on eosinophil adhesion.

Adolescent↗

PubMed1998

Eotaxin increases the expression of CD11b/CD18 and adhesion properties in IL5, but not fMLP-prestimulated human peripheral blood eosinophils.

A selective recruitment of eosinophils to sites of inflammation is claimed to be controlled by regulation of cytokines, chemokines and adhesion molecules. In animal models, eotaxin has been suggested to be a potent chemokine since it in cooperation with interleukin-5 induce selective chemotaxis and infiltration of eosinophils to lung tissue after an allergen provocation. We have investigated the in vitro effect of eotaxin on human peripheral blood eosinophils with respect to CD11b/CD18 expression and adhesion properties to the matrix protein fibronectin. We did not find any effect of eotaxin per se on CD11b/CD18 expression, neither on eosinophils from healthy subjects nor from patients with asymptomatic pollen related asthma. However, eotaxin significantly upregulated the quantitative level of CD11b/CD18 and increased the adhesion to fibronectin in eosinophils from healthy subjects preincubated in vitro with interleukin-5, but not in eosinophils preincubated with fMLP. Moreover, eosinophils harvested 24 hours after an in vivo allergen inhalation provocation in asthmatics, upregulated CD11b/CD18 after in vitro incubation with eotaxin alone.

Adult↗

PubMed1998

Difference in the blood monocyte phenotype between uremic patients and healthy controls: its relation to monocyte differentiation into macrophages in the peritoneal cavity.

The phenotypic alterations between blood monocytes from 11 patients with end-stage renal disease, who had been on peritoneal dialysis for less than one week, and blood monocytes from 10 healthy controls, were analyzed. In addition, peritoneal macrophages in the dialysate effluent were enclosed. Analysis of functional receptor density was performed using immunostaining and flow cytometry. The phenotypic characterization was selected to represent various biological functions such as adhesion, phagocytosis (CD11b/CD18, CD11c/CD18, CD16), antigen-presentation (HLA-DR, ICAM-1), differentiation (transferrin receptor, CD71), receptor for LPS (CD14) and initiation of the coagulation cascade (Tissue factor, CD142). The proportion of CD16-positive blood monocytes and the quantitative level of ICAM-1 were higher in the patient group, compared to healthy controls. A significant increase in the quantitative level of CD11b/CD18, CD11c/CD18, HLA-DR and ICAM-1, transferrin receptor, CD14 and CD16, was found on peritoneal macrophages, compared to monocytes, harvested both from the corresponding patients, as well as from healthy donors. In contrast, we did not find any significant differences in the expression of tissue factor between monocytes and peritoneal macrophages. In conclusion, phenotypic differences exist between monocyte populations in the blood circulation of CAPD patients, and healthy individuals. We also show that transmigration of monocytes into the peritoneal cavity implies a selective up-regulation of functional receptors, preferentially related to adhesion, and antigen-presentation in a steady-state situation in non-infected CAPD patients.

Adult↗

PubMed1998

Alterations in adhesion molecule (CD11b/CD18 and CD62L) expression on granulocytes after chemotherapy.

BACKGROUND: Infections during chemotherapy-induced granulocytopenia constitute a major threat to patients with malignant disorders. The aim of this study was to evaluate whether circulating granulocytes after chemotherapy have a normal expression of adhesion molecules or if the granulocytes, in addition to being present in low number, also present signs of qualitative alterations. METHODS: We have investigated the time course of adhesion molecule expression (CD11b/CD18 and CD62L) and in vitro mobilization [responsiveness against N-formyl-methionyl-leucyl-phenylalanine (fMLP) for CD11b/CD18] by flow cytometry in circulating granulocytes after chemotherapy in 12 patients with haematological malignancies. Blood samples for analysis were drawn before chemotherapy and at time points when granulocyte counts were < 0.5, 0.5-1.0 and > 1.0 x 109 L-1. RESULTS: The quantitative level, expressed as mean fluorescence intensity (MFI), of CD11b/CD18 was significantly higher and of CD62L significantly lower at granulocyte nadir than before chemotherapy. The in vitro responsiveness to fMLP was significantly reduced at the same time point. These alterations were restored to pretreatment values at the time of granulocyte count recovery. Granulocytes from patients with bacteraemia (n = 6) exhibited lower CD11b/CD18 MFI values after fMLP stimulation than non-bacteraemic patients after granulocyte count recovery. In addition, the MFI of CD62L was significantly lower both before chemotherapy and after granulocyte recovery in the bacteraemic group. CONCLUSION: Chemotherapy induces qualitative alterations in circulating granulocytes with respect to adhesion molecule expression and mobilization, and these alterations are more pronounced in patients with accompanying bacteraemia.

Adolescent↗

PubMed1998

The lymphocytic alveolitis in sarcoidosis is associated with increased amounts of soluble and cell-bound adhesion molecules in bronchoalveolar lavage fluid and serum.

OBJECTIVES: Pulmonary sarcoidosis is a chronic inflammatory disorder of unknown aetiology accompanied by a lymphocytic alveolitis. It is likely that a selective and temporal expression of adhesion molecules plays a crucial role in the recruitment of cells to the inflammatory site. We investigated the expression of adhesion molecules on alveolar T-lymphocytes and in bronchoalveolar lavage (BAL) fluid and serum to elucidate mechanisms behind the accumulation of cells in the lung in sarcoidosis. DESIGN: In a cross-sectional study in patients with active and inactive sarcoidosis and in healthy volunteers, we examined, in serum and in BAL fluid, the soluble adhesion molecules, VCAM-1, ICAM-1, and P-, E- and L-selectin. In addition, the expressions of alpha4-beta1 (VLA-4) and alpha5-beta1 (VLA-5) integrins on alveolar T-lymphocytes were analysed. SETTING: The subjects attended the outpatient clinic at the Division of Respiratory Medicine, Karolinska Hospital, Stockholm, Sweden. SUBJECTS: Nineteen sarcoidosis patients, nine with clinically active disease, and 13 healthy volunteers were included in the study. The sarcoidosis diagnosis was based on a typical histological and/or clinical (symptoms, radiograph, lung function) picture. RESULTS: In sarcoidosis patients, particularly in those with active disease, an increase of the expressions of beta1-integrins was accompanied by elevated concentrations in BAL fluid of soluble VCAM-1. In serum, the levels of E-selectin and ICAM-1 were significantly higher in patients with active disease than in those with inactive disease and controls. CONCLUSIONS: The findings offer some mechanistic explanations as to how the cell-rich alveolitis in sarcoidosis occurs, and furthermore suggest additional markers, such as s-ICAM-1, for assessment of disease activity.

Adult↗

PubMed1998

Elutriation of human alveolar macrophages: influence on cell surface receptor expression.

Centrifugal elutriation has turned out to be a quick and easy to handle method to separate alveolar macrophages with high purity in bronchoalveolar lavage fluid. However, less is known about the influence of elutriation on the expression of cell surface receptors and cell function. We investigated whether the elutriation procedure or different temperatures affect the expression of some surface receptors. These were selected to reflect different aspects of cell function such as phagocytosis (Fc gamma-receptor), antigen presentation (HLA-DR) and proliferation (transferrin receptor). We conclude that the centrifugal elutriation procedure has no influence on the expression of these functional receptors on resting alveolar macrophages. Heat stimulation, however, increased the expression of HLA-DR and the transferrin receptors. Summarizing, when working with alveolar cells at +4 degrees C elutriation is a quick method which yields a high purity of macrophages that are phenotypically unaltered.

Adult↗

PubMed1998

The myelin basic protein gene in multiple sclerosis: identification of discrete alleles of a 1.3 kb tetranucleotide repeat sequence.

Myelin basic protein (MBP) is a potential autoantigen in multiple sclerosis (MS) and its gene therefore is an attractive candidate to confer genetic susceptibility to this disease. Linkage and association with certain alleles of a 1.2 kb tetranucleotide repeat region 5' to the MBP gene with MS have been reported in Finnish patients, and an association has been reported from Denmark. However, these findings have not been confirmed in subsequent analyses in other populations. A limitation of previous studies has been the low resolution of the typing procedure. We have investigated the same polymorphism in thirty-four Swedish nuclear families with 2 or 3 MS patients. and in 149 unrelated Swedish MS patients and 95 healthy controls using a fluorescence-based semi-automated technique which allowed the identification of discrete tetrarepeat numbers. Neither parametric two-point linkage analysis nor a nonparametric affected pedigree members analysis showed any sign of linkage. In addition, the distribution of alleles was similar in patients and controls. We conclude that the MBP gene does not influence susceptibility to MS in Swedish patients.

Alleles↗

PubMed1998

No evidence for increased frequency of autoantibodies during interferon-beta1b treatment of multiple sclerosis.

Interferon-beta1b (IFN-beta1b) is a widespread therapy of multiple sclerosis (MS), reducing the numbers and severity of exacerbations and the total lesion load measured by magnetic resonance imaging of the brain. Since IFN-beta1b has potent immunomodulatory properties, a potential side-effect of IFN-beta1b treatment could be the development of autoimmune responses. The frequencies of antinuclear and smooth muscle antibodies, antibodies against microsomal antigen of thyroid epithelial cells as well as a group of heterophilic antibodies were determined in 26 MS patients treated with IFN-beta1b for 3-20 months. No elevation of antibody titres was found for any of the antibodies studied when compared with paired samples obtained from most of the patients before the initiation of treatment. Although examined on a rather small group of patients, the results show no evidence of increased frequency of autoantibodies during interferon-beta1b treatment of multiple sclerosis.

Adjuvants, Immunologic↗

PubMed1998

Differences between rat alveolar and interstitial macrophages 5 wk after quartz exposure.

Macrophages play an essential role in pulmonary host defense. We investigated differences between rat alveolar (AM) and interstitial (IM) macrophages after exposure in vivo to quartz, an inducer of intensive alveolitis. Rats were exposed to 0.5 ml of saline without (n = 8) or with (n = 8) 10 mg of quartz by intratracheal instillation. In a third group (n = 8), 10 mg of surfactant were added to the quartz mixture. Five weeks later, AM were recovered by bronchoalveolar lavage and IM by mechanical fragmentation of the lung, followed by enzymatic treatment. Contamination of AM to the IM fraction was calculated to be 12-15%. After quartz exposure, the expression of major histocompatibility complex class Ia was increased in both AM and IM fractions. The receptor corresponding to human complement receptor 3 increased in AM after quartz exposure, and AM from quartz-exposed animals had a lower metabolic activation. Our findings indicate that IM are immunocompetent cells and that differences between AM and IM fractions occur upon quartz-induced inflammation. This response is not affected by addition of surfactant.

Animals↗

PubMed1998

Complement activation during blood sampling procedures alters the expression of CD11b/CD18 on human neutrophils.

BACKGROUND AND OBJECTIVES: Differences in blood sampling and separation techniques can affect the quantitative levels of activation markers on different leukocyte subsets. We examined the effect of two sampling procedures of EDTA blood on the quantitative levels of two markers, the CD11b/CD18 antigen and the EG2 epitope on intracellular eosinophilic cationic protein (ECP), in neutrophils and eosinophils, respectively. MATERIALS AND METHODS: Sample I was collected directly after completion of blood donation by an open technique and constant flow from the transfer tube directly into EDTA tubes. After sampling, the transfer tube was manually closed with a clamp. Sample II was collected 45 s later by the same technique by opening the clamp. RESULTS: We found a significantly (p < 0.01) higher expression of CD11b/CD18 on neutrophils collected by sampling procedure II than on those collected by sampling procedure I. In contrast, we did not find any difference in the intracellular ECP expression between sampling procedures I and II. To further explore the mechanisms for the observed upregulation of CD11b/CD18, fragments of a transfer tube were incubated with normal human serum (NHS) and heat-inactivated NHS (NHS56), respectively, for 60 min at +37 degrees C. Leukocytes from healthy blood donors were then incubated for 15 min at +37 degrees C with these serum preparations. The CD11b/CD18 expression was significantly higher (p < 0.01) on neutrophils incubated with transfer-tube-activated NHS compared with NHS alone. However, when leukocytes were incubated with transfer tube activated NHS56, no difference was observed compared with incubation with NHS alone. In addition, by using confocal laser scanning microscopy, we could identify complement (C3c) deposits on the inner surface of the transfer tube fragments incubated in NHS, but not in NHS56, CONCLUSIONS: The quantitative level of the activation marker CD11b/CD18 on neutrophils, but not the EG2 epitope on intracellular ECP in eosinophils is significantly increased by a slight modification of the blood sampling procedure. It is suggested that the observed upregulation of CD11b/CD18 is caused by complement activation within the transfer tube. The results emphasize the importance of in-house data on the effect of variations in sampling procedures, particularly when data from healthy blood donors are included in clinical studies.

Blood Proteins↗

PubMed1998

Kinetics of bradykinin levels during and after leucocyte filtration of platelet concentrates.

OBJECTIVE: To measure bradykinin levels in platelet concentrates during and after leucocyte filtration. METHODS: Platelet concentrates were leukocyte depleted using three different leucocyte-depletion filters selected to represent filters with negative, positive or neutral charge, respectively. Bradykinin levels were analysed before, during and up to 90 min post-filtration. RESULTS: Significant levels of bradykinin were generated when negatively charged leucocyte depletion filters were used. However, we found a high variation between platelet concentrates prepared from different donors as well as within the same concentrate when this was divided into three aliquots. Generated bradykinin was rapidly degraded in the collection bag and no bradykinin was detectable 60 min post-filtration. CONCLUSION: Bradykinin generation is more pronounced when negatively charged leucocyte removal filters are used. Due to a rapid degradation of bradykinin in the storage bag, pre-storage filtration should minimise the risk of bradykinin related adverse reactions during transfusion with some filters.

Adolescent↗

PubMed1997

Effects of grapefruit juice ingestion--pharmacokinetics and haemodynamics of intravenously and orally administered felodipine in healthy men.

OBJECTIVE: To examine the effect of grapefruit juice on the metabolism of felodipine following intravenous and oral administration. METHODS: The study had a randomised, four-way, crossover design in 12 healthy males. Single doses of felodipine were given as an intravenous infusion for 1 h (1.5 mg) or as an oral extended release (ER) tablet (10 mg). Grapefruit juice (150 ml) or water was ingested 15 min prior to drug intake. RESULTS: Intake of grapefruit juice did not significantly alter the intravenous pharmacokinetics of felodipine compared to control treatment, whereas after oral drug administration it did lead to an increase in the mean AUC and Cmax by 72% and 173%, respectively, and the mean absolute bioavailability was increased by 112%. The fraction of the oral felodipine dose reaching the portal system was increased from 45% to 80% when intake of drug was preceded by grapefruit juice ingestion. The pharmacokinetics of the primary metabolite, dehydrofelodipine, was affected by the intake of juice, resulting in a 46% increase in Cmax. Juice intake immediately before oral felodipine resulted in more pronounced haemodynamic effects of the drug as measured by diastolic blood pressure and heart rate. However, the haemodynamic effects of the intravenous administration were not altered by juice intake. Vascular-related adverse events were reported more frequently when oral drug administration was preceded by juice intake compared with control treatment. Taking grapefruit juice immediately prior to intravenous felodipine administration did not cause any alteration in the adverse event pattern. CONCLUSION: The main acute effect of the grapefruit juice on the plasma concentrations of felodipine is mediated by inhibition of gut wall metabolism.

Administration, Oral↗

PubMed1997

Dialysis-induced serum factors inhibit adherence of monocytes and granulocytes to adult human endothelial cells.

In patients on hemodialysis, the sequences of events required for adhesion molecule-mediated adherence of monocytes and granulocytes to endothelial cells are pathophysiologically disrupted because activation of the cells with subsequent alterations in adhesion molecule phenotypes takes place in the extracorporeal circuit far away from the respective endothelial cell ligand. As a consequence, the host defense to infections may be affected. We analyzed the expression of CD62L and CD11b/CD18 on monocytes and granulocytes and the adherence of these cells, collected before, during, and after cuprophan hemodialysis, to resting and interleukin-1 beta (IL-1 beta)-stimulated adult human saphenous vein endothelial cells (HSVECs). Monocytes collected before dialysis adhered more avidly to HSVECs than did granulocytes. Adherence of both cell types increased to IL-1 beta-stimulated HSVECs (P < 0.05). Granulocytes obtained at 180 minutes adhered less to resting HSVECs than granulocytes harvested before hemodialysis (P < 0.05), despite an increase in CD11b/CD18 expression. To study if serum factors inhibiting adherence accumulate during hemodialysis, we incubated leukocytes harvested before hemodialysis in the same patients' serum collected before, during, and after dialysis. Serum collected at 180 minutes of cuprophan hemodialysis exerted inhibitory effects on both monocyte and granulocyte adhesion to HSVECs (P < 0.05). By contrast, serum collected during polysulfone hemodialysis of the same patients did not have any significant impact on the adherence of inflammatory cells to HSVECs. These findings contribute to an increased understanding of the factors involved in the impaired immune response observed in dialysis patients.

Adult↗

PubMed1997

Surfactant prevents quartz induced down-regulation of complement receptor 1 in human granulocytes.

Quartz is known to induce an inflammatory response in the alveolar space by recruitment of different effector cells. We investigated the interaction between granulocytes and quartz with respect to expression of complement receptor type 1 (CR1) and CR3, with and without the presence of surfactant. Granulocytes from hemolyzed blood were stimulated by N-formyl-methionyl-leucyl-phenylalanine (fMLP), which mobilize the intracellular pool of CR1 to the surface, and the mean fluorescence intensity (MFI) measured by cytofluorometry was 47.4 (46-63.6) (median; interquartile range). Quartz exposure reduced the CR1 expression to 23.2 (22.8-30.6) MFI units (P < 0.01), a porcine surfactant preparation added during quartz exposure abolished the down-regulation completely, 47.7 (43.2-62.3) MFI units (P < 0.001). Similar results were obtained after preincubation of the cells with surfactant followed by quartz exposure. No significant influence on CR1 expression was found by a synthetic lipid mixture, nor was the CR3 expression affected. In conclusion, this study demonstrates that the presence of surfactant inhibits quartz induced down-regulation of CR1 on activated granulocytes.

Adolescent↗

PubMed1997

Impaired leucocyte rolling, adhesion and transendothelial migration following cuprophane haemodialysis.

In this study, we investigated how different steps in the extravasation process of leucocytes, i.e. rolling, adhesion and transendothelial migration, are affected by haemodialysis with cuprophane membranes. Human leucocytes obtained from whole blood prior to clinical haemodialysis and from the afferent blood line (post-dialyser) 15 min after the initiation of dialysis were injected into the mesenteric microcirculation of urethane anaesthetized rabbits and analysed for their ability to roll in the microvessels by use of intravital fluorescence microscopy. Moreover, neutrophils from the two leucocyte populations were compared with respect to chemoattractant-induced adhesion and transmigration across confluent monolayers of bovine aortic endothelial cells. Our results show that, as compared with pre-dialysis leucocytes, 15 min of cuprophane haemodialysis impaired leucocyte rolling by 78 +/- 7%, reduced N-formyl-methionyl-leucyl-phenylalanin (fMLP)-induced adhesion by 34 +/- 9%, and abolished transendothelial migration. These findings demonstrate that intradialytical activation of leucocytes during cuprophane haemodialysis severely affects leucocyte functions that are critical in the extravasation process of these cells at inflammatory tissue sites, and thus may help explain the increased susceptibility to infections observed in patients on chronic haemodialysis.

Animals↗

PubMed1997

Phenotypic alterations in circulating monocytes induced by open heart surgery using heparinized and nonheparinized cardiopulmonary bypass systems.

In this study of 31 patients with coronary bypass surgery, we used flow cytometry to compare heparin-coated and noncoated cardiopulmonary bypass systems on leukocyte activation. We found significant differences between the groups during bypass, with activation of the complement system, measured as elevated levels of C3a desArg, upregulation of granulocyte beta2 integrin (CD11b), and a loss of circulating monocytes when noncoated systems were used. In both groups an early increase in the monocyte cell surface CD62L expression was obvious while the percentage of human leukocyte antigen (HLA)-DR positive monocytes did not alter. The morning after the operation, leukocytosis was present, together with a highly significant reduction in the monocyte expression of CD11b and HLA-DR, indicating the recruitment to the peripheral blood of cells with altered phenotypes. This alteration in phenotype on potent inflammatory cells may be one part of the impaired function of the immunological system reported after major surgery.

Adult↗

PubMed1997

Different expression and mobilisation of the complement regulatory proteins CD35, CD55 and CD59 in neonatal and adult neutrophils.

We investigated the expression and the N-formyl-methionyl-phenylalanine (fMLP)- and interleukin-8 (IL-8)-induced mobilisation of the complement regulatory proteins CR1 (CD35), decay-accelerating factor (CD55) and CD59 on neutrophils in neonates and adults. The expression of CD35 on resting neonatal neutrophils was significantly higher than in adults. Both fMLP and IL-8 increased CD35 expression more markedly in adults. CD55 on resting neutrophils in neonates was significantly higher than in adults, but did not further increase upon fMLP stimulation as opposed to adults. The increase in CD59 expression was more pronounced in adult neutrophils and was significantly higher than in neonates after fMLP activation. The addition of the protease inhibitor phenylmethanesulphonyl fluoride during fMLP activation improved the upregulation of CD35 significantly more in neonates, but not CD55 or CD59. This effect could be replaced by human normal sera. These data demonstrate that differences exist between neonatal and adult neutrophils with respect to the expression and mobilisation of functional receptors related to protection from autologous complement lysis and may indicate differences in the efficiency to circumvent complement-mediated cell damage at the inflammatory site.

Adult↗

PubMed1997

Functional, morphological, and phenotypical differences between rat alveolar and interstitial macrophages.

Alveolar macrophages (AM) and interstitial macrophages (IM) from rat lungs were characterized with respect to morphology, phagocytosis, adhesion properties, and phenotype. AM were recovered by lung lavage and IM by treatment of the lung tissue with DNAse and collagenase. The AM were enzyme treated in the same way as the IM. The IM were smaller than AM and had a higher nuclear to cytoplasm ratio. They had markedly lower phagocytic capacity. The attachment of particles to the cell surface was significantly lower in IM than in AM, but the capacity to ingest the particles was the same. Adherence to vitronectin- as well as fibronectin-coated surfaces was significantly higher in AM. The phagolysosomal pH was similar in IM and AM, around pH 5, indicating that dissolution of inorganic particles can take place effectively also in IM. Five surface receptors were studied, and the expression differed significantly in all five between AM and IM. The expression of OX-1 (CD 45), a common leukocyte antigen, was significantly higher on AM as was the expression of CD 71 (transferrin receptor). The receptor density for OX-42 was higher on a fraction of IM. This might be compatible with a stronger interaction between these cells and, for example, matrix components. IM had more surface antigen expressing MHC class Ia (OX-6) and CD 54. Both receptors are important for the antigen presentation capacity of macrophages. These findings show profound differences in phenotype between AM and IM and indicate that IM is a highly immunocompetent cell and should not be regarded only as a precursor to AM.

Animals↗