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A Bengtsson

Publications and source records attributed to A Bengtsson.

At least 19 recordsLinked to original sources
PubMed2000

Evidence for a lipid transfer protein as the major allergen of apricot.

BACKGROUND: Apricots are widely grown in Europe, and allergic reactions are becoming more common, especially oral allergy syndrome. Apricot belongs to the botanical subfamily of Prunoideae, which includes peach, the major allergen of which was identified as a 9-kd protein, a lipid transfer protein (LTP). OBJECTIVE: The aim of the study was to evaluate the IgE reactivity pattern to an apricot extract in subjects with allergic reactions to apricot, as demonstrated by a positive oral challenge response. METHODS: Thirty patients were investigated. All the patients displayed oral allergy syndrome (2 with systemic reactions) to apricot, with positive open food challenge responses, skin prick test responses, and serum-specific IgE antibodies to apricot. The IgE reactivity pattern to apricot extract was identified by using SDS-PAGE and immunoblotting. The major allergen, a 9-kd protein, was then purified by HPLC and characterized by periodic acid-Schiff stain, isoelectric point determination, and N-terminal amino acid sequencing. RESULTS: The sera from all patients allergic to apricot recognized the 9-kd protein, whereas none of the other allergens, with molecular weights from 15 to 80 kd, acted as a major allergen. The 9-kd allergen has an isoelectric point of 8.7 and is not glycosylated. Determination of the N-terminal 34 amino acid sequence showed that it belongs to the LTP family, with a 94% homology with the LTP from peach. IgE blotting of the apricot extract was completely inhibited by the 9-kd purified LTP from peach. CONCLUSIONS: The major allergen of apricot is an LTP, which is highly cross-reactive with the LTP from peach.

Adolescent↗
PubMed2000

Gastro-intestinal complement activation during human liver transplantation: impact on postoperative liver function.

BACKGROUND: Liver transplantation elicits a systemic inflammatory response and eventually a multiple organ failure syndrome. Gastro-intestinal inflammatory activation with release of proinflammatory cytokines and complement activation may occur. This study evaluates gastro-intestinal complement activation and the association with postoperative parenchymatous liver cell injury and liver dysfunction. METHODS: In 17 patients undergoing liver transplantation, blood samples were collected from radial artery and portal vein for analysis of complement SC5b-9 and endotoxin concentration. Portal venous-arterial SC5b-9 plasma concentration gradients at 30 min after reperfusion were calculated. Outcome parameters included postoperative organ failure and serum concentrations of aspartate aminotransferase, alanine aminotransferase, bilirubin and factor II-VII-X. RESULTS: Patients with gastro-intestinal SC5b-9 release (n=7) had higher postoperative serum aspartate aminotransferase and alanine aminotransferase concentrations [49 (32-80) microkat/l vs 8 (6-14) microkat/l, P<0.01 and 33 (15-54) microkat/l vs 8 (4-23) microkat/l, P<0.04, respectively] and lower factor II-VII-X concentrations [46 (21-48)% vs 60 (47-69)%, P<0.02] compared to patients without gastro-intestinal SC5b-9 release (n=10). The ICU stay was prolonged in patients with gastro-intestinal complement release. There was no difference in number of organ failures and serum bilirubin concentration between the groups. The endotoxin concentration in arterial and portal vein blood was low and the association between endotoxaemia and complement activation was poor. CONCLUSION: Gastro-intestinal complement activation may contribute to postoperative parenchymatous liver cell injury and liver dysfunction in patients undergoing liver transplantation.

Adult↗
PubMed2000

No serological indications that systemic lupus erythematosus is linked with exposure to human parvovirus B19.

OBJECTIVES: Infectious agents like parvovirus have been implicated as exogenous factors that could trigger onset of systemic lupus erythematosus (SLE). A number of case reports describing a SLE-like presentation of acute human parvovirus B19 infection have been published, but no systematic investigation of the actual seroprevalence in epidemiologically defined SLE populations has previously been reported. METHODS: Sera from 99 SLE patients from a defined area in Southern Sweden, representing 88% of all new SLE cases 1981-1995 within the Lund-Orup Health Care district with 175 000 adult inhabitants (> 15 years of age), and sera from 99 age and sex matched healthy controls were investigated for the presence of IgG parvovirus antibodies. Two different commercially available EIA kits were used; one using E coli synthesised parvovirus VP1/VP2 antigen, and one using baculovirus derived parvovirus VP2 antigen. RESULTS: The EIA using baculovirus derived antigen was more sensitive and surprisingly the controls were more often positive than the SLE patients were (79% versus 65%, chi(2) p=0.027). No difference between the groups was seen with the EIA using E coli derived antigen (46% versus 49%). Titration experiments indicated that the discordance between the two tests was a matter of sensitivity rather than specificity. CONCLUSION: No evidence was found of human parvovirus B19 infection being more prevalent among SLE patients. On the contrary, in one of the parvovirus EIAs the controls were more often positive than the SLE patients were.

Adolescent↗
PubMed2000

Novel roles of complement in systemic lupus erythematosus--hypothesis for a pathogenetic vicious circle.

We propose that impaired complement function enhances a pathogenetic vicious circle in SLE. In this process, induction and clearance of apoptotic cells is central. Apoptosis could be triggered by various etiological factors, such as infection, UV light, and drug reactions. Clearance of apoptotic material is reduced when complement function is impaired. Apoptosis leads to increased exposure of nuclear antigens to the immune system, to which estrogenic hormones could contribute. This could in turn lead to activation of autoreactive B cells, autoantibody production, and immune complex formation, all of which is accelerated by hypocomplementemia. Immune complexes may, at least partly via complement dependent mechanisms, accelerate apoptosis.

Apoptosis↗
PubMed1999

DNA levels in circulating immune complexes decrease at severe SLE flares-correlation with complement component C1q.

The objective of this study was to investigate the relationship of DNA content in circulating immune complexes with disease course and activity in SLE. The DNA content in circulating immune complexes containing anti-DNA antibodies of IgG class was determined in serial samples from 28 patients with SLE by a quantitative immunochemical assay. The patients presented various active disease manifestations over 5-55 months. Disease activity (SLEDAI-score), drug treatment and ACR-criteria were recorded. Levels of anti-dsDNA, CRP, leukocytes, complement components C3, C4 and C1q were measured. Patients with severe flares and high SLEDAI scores had low Clq levels at onset of active disease manifestations. The patients with low C1q serum levels during flare (n=13) had significantly lower amounts of DNA in immune complexes than patients with normal Clq (P=0.001). Levels of DNA in immune complexes correlated with Clq at flares (r=0.62, P<0.0001) and correlated inversely with SLEDAI scores (r=-0.47, P=0.012). In conclusion, the low levels of DNA in circulating immune complexes found in severely ill SLE patients with concomitantly low serum concentrations of Clq prior to flares might be related to tissue deposition of immune complexes.

Antibodies, Antinuclear↗
PubMed1999

Decreased respiratory depression during emergence from anesthesia with sevoflurane/N2O than with sevoflurane alone.

PURPOSE: To investigate ventilation and gas elimination during the emergence from inhalational anesthesia with controlled normoventilation with either sevoflurane/N2O or sevoflurane alone. METHODS: Twenty-four ASA I-II patients scheduled for abdominal hysterectomy were randomly allocated to receive either 1.3 MAC sevoflurane/N2O (n = 12) or equi-MAC sevoflurane (n = 12) in 30% oxygen (O2). Expired minute ventilation volumes (V(E)), end-tidal (ET) concentrations of O2, carbon dioxide (CO2), sevoflurane and N2O as well as pulse oximetry saturation (SpO2) and CO2 elimination rates (VCO2) were measured. The ET concentrations of sevoflurane and N2O were converted to total MAC values and gas elimination was expressed in terms of MAC reduction. Time to resumption of spontaneous breathing and extubation were recorded and arterial blood gas analysis was performed at the end of controlled normoventilation and at the beginning of spontaneous breathing. RESULTS: Resumption of spontaneous breathing and extubation were 8 and 13 min less, respectively, in the sevoflurane/N2O than in the sevoflurane group. Spontaneous breathing was resumed in both groups when pH had decreased by 0.07-0.08 and PaCO2 increased by 1.3-1.5 kPa. Depression of V(E) and VCO2 were less, and MAC reduction more rapid in the sevoflurane/N2O than in the sevoflurane group. CONCLUSIONS: Respiratory recovery was faster after sevoflurane/N2O than sevoflurane anesthesia. Changes in pH and PaCO2 rather than absolute values were important for resumption of spontaneous breathing after controlled normoventilation. In both groups, the tracheas were extubated at about 0.2 MAC.

Adult↗
PubMed1999

Perioperative gastric tonometric PCO2 and intramucosal pH in patients undergoing liver transplantation.

BACKGROUND: Extensive research has focused on the role of insufficient gastro-intestinal perfusion and inflammatory activation in the development of organ dysfunction during critical illness. In patients undergoing liver transplantation, portal and caval vein clamping leads to gastro-intestinal and lower extremity venous congestion during the anhepatic phase, and studies suggest that gastro-intestinal perfusion may be compromised. This study was performed to investigate gastro-intestinal perfusion in patients undergoing liver transplantation. METHODS: In 16 patients undergoing liver transplantation, perioperative gastric tonometry with determination of tonometric PCO2, tonometric-arterial PCO2 gradient and intramucosal pH were performed. Blood gases were obtained simultaneously from the arterial and portal vein blood. RESULTS: Tonometric PCO2 was 4.6 (4.2/5.3) kPa preoperatively and increased to 5.6 (4.5/6.0) kPa during the anhepatic phase (P<0.01), while the tonometric-arterial PCO2 gradient increased from -0.3 (-0.5/0.0) kPa preoperatively to 0.7 (0.3/1.2) kPa during the anhepatic phase (P<0.01). Intramucosal pH decreased to 7.27 (7.21/7.32) u during the anhepatic phase (P<0.01, compared to preoperatively). The portal vein PCO2 was not significantly different from arterial PCO2 or tonometric PCO2 at any measurement point. CONCLUSION: This study demonstrates that clinical liver transplantation is associated with gastro-intestinal perfusion in the range of aerobic metabolism. The results do not support the presence of gastro-intestinal perfusion in the range of anaerobic metabolism.

Adult↗
PubMed1999

Peripheral blood T-cell receptor beta-chain V-repertoire in atopic dermatitis patients after in vitro exposure to Pityrosporum orbiculare extract.

The yeast Pityrosporum orbiculare belongs to the normal cutaneous flora but is also considered to be one of the factors that may contribute to atopic dermatitis (AD). In the present study we investigated the possibility that P. orbiculare can act with superantigen activity in AD. P. orbiculare-reactive T-cell lines (TCLs) were obtained after stimulation of peripheral blood mononuclear cells (PBMC) with P. orbiculare extract. T-cell receptor beta-chain V-segment (TCRBV) usage was investigated using monoclonal antibodies and flow cytometry. We could not find any difference in TCRBV usage between AD patients (n = 10) and healthy controls (n = 5), either in fresh PBMC or in P. orbiculare-reactive TCLs. Compared with their original PBMCs the P. orbiculare-reactive TCLs showed a decreased usage of several TCRBVs, although increased usage of certain TCRBVs could be seen in some of the individuals. Further analysis of the CDR3-length polymorphism exhibited a shift in CDR3-length distribution, indicating oligoclonal expansion of T cells specific to different antigens in the P. orbiculare extract. In conclusion we have not found any evidence for superantigen activity in P. orbiculare extract, but our data support the importance of classical major histocompatibility complex (MHC)-restricted allergens in P. orbiculare.

Adolescent↗
PubMed1999

Greater increase in cytokine concentration after salvage with filtered whole blood than with washed red cells, but no difference in postoperative hemoglobin recovery.

BACKGROUND: Inflammatory mediators are released in association with intraoperative and postoperative salvage of blood. Whether these mediators (cytokines) participate in the modulation of erythropoiesis or not has been investigated. STUDY DESIGN AND METHODS: Twenty-seven patients who were to undergo total knee replacement surgery were randomly assigned to postoperative blood salvage with either filtered whole blood or washed red cells. Patients with postoperative blood loss <400 mL were considered a control group. The control group did not receive any transfusions. Plasma concentrations of the anaphylatoxin C3a, the C5b-9 terminal complement complex, and the cytokines interleukins 6 and 8, hemoglobin, reticulocytes, and red cell volume fraction in the patients were repeatedly analyzed before and after surgery. RESULTS: Significantly increased concentrations of interleukin 6 appeared in all three groups, which was interpreted as a response to the surgical trauma. The increase was significantly greater in the group that received filtered whole blood after return of shed blood. The recovery of hemoglobin levels did not differ in the groups. CONCLUSION: The transfusion of filtered whole blood leads to the formation of interleukin 6 in the circulation, but postoperative hemoglobin recovery was similar in all groups.

Aged↗
PubMed1999

[Comparative study of two methods for salvaging red blood cells: centrifugation techniques (cell-saver) versus filtration through a 100,000-dalton filter].

OBJECTIVES: Some loss of blood occurs during blood salvage. We hypothesized that plasmapheresis filtering would damage blood much less than centrifugation techniques do, thereby allowing more red blood cells to be transfused. MATERIAL AND METHODS: Laboratory study in which 16 units of whole donor blood were distributed randomly in two groups and processed either by a conventional "cell-saver" method or by hemofiltration using recirculation through a 100,000 dalton filter. We analysed hemoglobin, hematocrit, free hemoglobin, extracellular potassium, platelets, leukocytes, protein and albumin in whole blood before and after processing, and in the waste bag in each group. RESULTS: The recovery of hemoglobin and red blood cell volume was about 80% with both methods. More free plasma hemoglobin was found in the waste bag with the filtration technique. Hemolysis in processed blood was low, less than 0.1% in both groups. Platelet recovery with conventional centrifugation and filtration was 11 and 49%, respectively. Albumin, total protein and extra-cellular potassium were recovered at a rate of about 20% with the filtration technique, whereas recovery of these elements was minimal with the cell saver method. CONCLUSIONS: Both methods of autotransfusion caused moderate loss of red blood cells and low plasma levels of free hemoglobin in processed blood. Recovery of platelets, albumin, total protein and potassium was better with filtration than with the "cell-saver" method.

Blood Donors↗
PubMed1998

Formation of complement split products and proinflammatory cytokines by reinfusion of shed autologous blood.

1. The purpose of this study was to determine whether shed autologous blood collected postoperatively contains complement split products (C3a and SC5b-9) and proinflammatory cytokines (TNF-alpha, IL-1beta, IL-6 and IL-8) and whether transfusion of shed blood increases the concentrations of inflammatory mediators in the circulation. 2. Twenty consecutive patients undergoing total hip replacement surgery under spinal anaesthesia were studied. The patients were transfused with whole blood collected postoperatively. 3. The median volume shed blood returned to the patients was 350 ml (25-75% range = 300-450). Before transfusion of shed blood was filtered using a 40 microm filter (Solcotrans). Samples for complement and cytokine determinations were drawn from the collected blood. 4. Venous blood samples were drawn 1 min before transfusion, 1 and 60 min after completed transfusion. High concentrations of C3a, SC5b-9, TNF-alpha, IL-1beta, IL-6 and IL-8 were found in shed blood. The concentrations were higher than the circulating levels (P < 0.05). The filtration procedure did not significantly reduce the concentrations. 5. Transfusion of the shed blood did not significantly alter the circulating concentrations of C3a, SC5b-9, TNF-alpha, IL-1beta, and IL-8. The plasma concentrations of IL-6 were increased both 1 and 60 min after completed transfusion compared to before (P < 0.05). 6. This study shows that whole blood collected from a surgical wound contains large concentrations of complement split products and proinflammatory cytokines. Transfusion of shed blood leads to elevated plasma levels of IL-6.

Aged↗
PubMed1998

Sensitization to the major allergen of Brazil nut is correlated with the clinical expression of allergy.

BACKGROUND: Only a few studies have investigated the clinical role of food allergens, especially the relationship between sensitization to a given allergen and occurrence of adverse reactions when eating the relevant food item. OBJECTIVE: This study evaluated the clinical role of the allergens of Brazil nut by comparing the patterns of IgE binding in sera from 11 patients with anaphylaxis after eating Brazil nuts with those from 10 subjects with no symptoms to this food item. Both groups had specific IgE to Brazil nut. METHODS: Allergens in the in-house extract of Brazil nut were identified by SDS-PAGE/immunoblotting, the major allergen was purified by HPLC, and its N-terminal sequence was determined by a protein sequencer. RESULTS: SDS-PAGE/immunoblotting detected a number of allergenic components with molecular weights ranging from 4 to 58 kd. All sera from symptomatic patients recognized a 9-kd allergen corresponding (as established by amino acid sequencing) to a 2S albumin already described as a major allergen of Brazil nut, whereas the other allergens each bound IgE from less than 50% of sera. No sera from asymptomatic subjects showed IgE binding to the 9-kd allergen, but they did recognize components from 25 to 58 kd, which are minor allergens. CONCLUSIONS: These findings indicate that the allergen underlying clinical reactions to Brazil nut is a 2S albumin of 9 kd and that in vitro reactivity to this allergen identifies subjects who react in vivo to ingestion of this food.

2S Albumins, Plant↗
PubMed1998

Pityrosporum orbiculare-reactive T-cell lines in atopic dermatitis patients and healthy individuals.

The yeast Pityrosporum orbiculare is one of the factors that may contribute to atopic dermatitis (AD). In the present study we compared the T-cell response to P. orbiculare in 12 AD patients with specific immunoglobulin (Ig)E antibodies (Ab) in serum against P. orbiculare with that of six non-atopic healthy controls. Freshly isolated peripheral blood mononuclear cells (PBMC) were cultured for 3 days in the presence of P. orbiculare extract. The proliferative response as measured by [3H]-thymidine incorporation was significantly higher in the AD patients than in the healthy controls (P < 0.05). Furthermore, significantly higher levels of interleukin (IL)-5 (P < 0.05), as analyzed by ELISA, were produced by PBMC from the AD patients compared to the healthy controls. Pityrosporum orbiculare-reactive T-cell lines (TCL) established by P. orbiculare stimulation of PBMC for 11 days produced significantly higher levels of IL-4 and IL-5 after stimulation with anti-CD3 Ab and showed a higher IL-4/interferon (IFN)-gamma ratio (P < 0.05) in the AD patients compared to the healthy controls. The higher proliferative PBMC response to P. orbiculare and the Th2-like cytokine production by P. orbiculare-stimulated TCL from AD patients indicate that P. orbiculare may play a role in maintaining skin inflammation in AD.

Adolescent↗
PubMed1998

Anti-TNF treatment of baboons with sepsis reduces TNF-alpha, IL-6 and IL-8, but not the degree of complement activation.

The activation of complement and the release of TNF-alpha, IL-6 and IL-8 are important pathogenic factors behind organ dysfunction in sepsis. The aim of this study was to determine whether infusion of anti-TNF antibodies alters complement activation and plasma concentrations of pro-inflammatory cytokines at high doses of Escherichia coli. Six baboons received intravenously 2 x 10(9) live E. coli bacteria per kg body weight (group 1), in addition five received pretreatment with 1 mg per kg body weight anti-TNF antibodies (group 2), and seven received 5 x 10(8) live E. coli bacteria per kg body weight (group 3). Two hours after the start of infusion of the bacteria, plasma concentrations of C3 activation products, C5a and the terminal SC5b-9 complement complex were increased in groups 1 and 2 (P < 0.05), but there was no significant difference between the groups. At 2 h the levels of TNF-alpha, IL-6 and IL-8 were lower in group 2 compared with group 1 (P<0.05). In group 2 compared with group 1 the TNF-alpha concentrations were, however, higher at 4, 8 and 24 h. The explanation for this phenomenon is probably that TNF-alpha binds to the anti-TNF antibody complex and is released slowly after it has been bound. The study showed that infusion of anti-TNF antibodies reduced the concentrations of TNF-alpha, IL-6 and IL-8, without any detectable influence on complement activation.

Animals↗
PubMed1998

Effects of intravenous regional administration of methylprednisolone plus mepivacaine in rheumatoid arthritis.

To evaluate the subjective and objective response to intravenous regional administration of a glucocorticoid (IVRAG) on rheumatoid arthritis (RA), twenty RA-patients received, in a randomised, double-blind crossover and placebo-controlled fashion, either 50 mg methylprednisolone in mepivacaine 0.25% or mepivacaine (placebo) in one hand only using a Bier-block technique. The other hand was given the opposite. One week later the procedure was repeated but the previous placebo hand was now treated with the glucocorticoid. About 50% of the patients experienced a subjective improvement at 1 and 6 weeks. After one week a significant reduction was recorded in grip diastasis with no difference between the glucocorticoid and the placebo. In the other outcome measures (grip strength, handvolume, rest pain, and movement provoked pain) no differences were recorded between the glucocorticoid and placebo. At six weeks a significant reduction in grip diastasis and movement provoked pain as well as a significant increase in grip strength were noted. Hand volume was unchanged. IVRAG is a safe, easy and well-tolerated technique. The beneficial results are probably due to both a systemic and a regional effect. The findings of benefit in both hands at the end of one week seem to suggest that mepivacaine can give some short term improvement.

Adult↗
PubMed1998

Extracorporeal ("ex vivo") connection of pig kidneys to humans. III. Studies of plasma complement activation and complement deposition in the kidney tissue.

The complement system is one of the important factors involved in the hyperacute rejection of xenografts. This report deals with the activation of the complement system in a clinical trial where pig kidneys were extracorporeally connected to two volunteer dialysis patients who were pretreated with plasmapheresis in order to substantially reduce anti-pig xenoantibodies. The clinical data of the perfusion experiments and the patients humoral immune response to pig xenoantigens have been reported in detail (Xenotransplantation 1996; 3:328-339, 340-353). Three consecutive daily plasmapheresis treatments of the patients reduced the plasma complement protein (C3, C4, and C5) concentrations to 8-27% of the baseline values. The perfusion of the pig kidney connected to patient 1 was terminated at 65 min due to graft rejection and this patient was not hemodynamically affected by the experiment. The second experiment was terminated at 15 min due to an anaphylactic like reaction of the patient. In patient 1 a slight reduction of plasma C3, C4, and C5 and an increase of C5a and SC5b-9 occurred, while C3a decreased during the perfusion. Patient 2 had an increase of all complement parameters, most prominent for C4d and SC5b-9, which occurred concomitant with the appearance of the anaphylactic like side effects. In general, plasma levels of PMN elastase, IL6 and IL8 increased in both patients during the perfusion. Immunohistochemical investigation of the kidney tissues revealed deposition of human complement factors C1q, C4c, and C3c in a congruent pattern with the vasculature of the kidney in patient 1. In kidney 2 only trace amounts of C1q and C3c were found. Both kidneys were negative for properdin. Therefore, in this experimental set up with extracorporeal connection of pig kidneys to the human circulation the human complement cascade is activated mainly through the classical pathway.

Adult↗