A large outbreak of infection and colonization with multiple genera of gram-negative bacilli carr... more A large outbreak of infection and colonization with multiple genera of gram-negative bacilli carrying the metallo- beta -lactamase gene bla(IMP-4) occurred in a 36-bed intensive care unit at a tertiary hospital in Australia. The organisms emerged rapidly, caused severe infections, and contributed to mortality. Controlling the spread of these organisms remains a challenge for all staff involved.
Phagocytosis and respiratory burst activity were measured by flow cytometry in fresh and cryopres... more Phagocytosis and respiratory burst activity were measured by flow cytometry in fresh and cryopreserved human monocytes, after ingestion of Escherichia coli and Staphylococcus aureus. Mononuclear leukocytes, isolated from 15 healthy donors, were divided into two portions, of which one was examined immediately and the other was cryopreserved for 3 weeks. Morphological characteristics and expression of receptors involved in phagocytosis were similar in fresh and cryopreserved monocytes. Furthermore, both internalization of bacteria and respiratory burst activity remained unchanged after cryopreservation. Transmission electron microscopy confirmed actual internalization of bacteria and not merely bacterial attachment to monocytes. Monocytes were demonstrated to retain integral cellular functions during cryopreservation. This may imply that the method has potential for use in basal and clinical trials.
The aim of this study was to assess the influence of growth hormone (GH) in sepsis on the immune ... more The aim of this study was to assess the influence of growth hormone (GH) in sepsis on the immune system represented by the circulating TNF-levels and the neutrophil leukocytes phagocytic capacity and respiratory burst, 22 piglets were randomized to 3 groups; pretreatment with GH (16 i.u.) before sepsis (n = 8), non-treated septic controls (n = 8), and non-septic controls (n = 6). Sepsis was induced by a standardized infusion of live E. coli. TNF was measured by a cytotoxic bioassay, while neutrophil function tests were carried out by flowcytometric assays. In brief, phagocytosis was evaluated by the neutrophils' ability to ingest FITC-labelled (fluorescein isothiocyanate) E. coli and intracellular release of oxygen metabolites was detected by the oxidation of 2',7'-dichlorofluorescin (DCFH) to the fluorescent 2',7'-dichlorofluorescein (DCF). Our data show a suppression of phagocytosis in the GH-treated group before sepsis; however, when challenged with Gram-negative bacteria, the phagocytic capacity was similar to that of the non-treated animals. The serum levels of TNF in the non-treated septic control group were twice the levels of those in the GH-treated group, 65.7 pg/ml (septic controls) vs 32.8 pg/ml (GH). Pretreatment with a single dose of GH few hours prior to sepsis does not seem to entail any further imbalance of the neutrophil function in sepsis. Lowering of the circulating TNF-levels is a presumptive favourable effect of GH in sepsis.
Insulin-like growth factor 1 (IGF-1) mediates anabolic actions in catabolic states and also influ... more Insulin-like growth factor 1 (IGF-1) mediates anabolic actions in catabolic states and also influences the immune system. Endogenous IGF-1 production is suppressed in sepsis; replacement therapy is therefore a natural approach to obtain the protein anabolic and potentially immune-stimulating effects of IGF-1. Twenty-two piglets were randomized to three groups: an IGF-1 group (n = 8) receiving a continuous infusion of 1.3 mg/h of IGF-1, a nontreated septic control group (n = 8), and a nonseptic control group (n = 6) receiving saline. Phagocytosis and respiratory burst in porcine neutrophils were evaluated by flow cytometry (FCM); tumor necrosis factor (TNF) levels were measured in serum during the septic period. In addition, human neutrophils and monocytes were primed in vitro with IGF-1 and subsequently were stimulated with phorbol myristate acetate (PMA) or Escherichia coli; phagocytosis and respiratory burst were evaluated by FCM. Under nonseptic conditions, pretreatment with IGF-1 suppressed the ability of neutrophils to ingest bacteria (ie, the level of phagocytosis) 43.4% +/- 2.7% (IGF-1-treated) vs 55.8% +/- 3.4% (nontreated septic controls) and 57.3% +/- 3.34% (nonseptic controls) (p = .01). When challenged by live E. coli infusion, phagocytosis increased in the IGF-1 group to the levels of the nontreated group. The respiratory burst showed a convincing priming effect of IGF-1. After 4 hours of sepsis, the mean fluorescence intensity was 63.1 +/- 6.9 in the IGF-1 group and 40.7 +/- 3.0 in nontreated septic controls. The serum levels of TNF-alpha in the nontreated septic control group were twice those in the IGF-1-treated group, ie, 65.7 +/- 13.1 pg/mL in the nontreated septic controls and 31.5 +/- 7.5 pg/mL in the IGF-1 group (p = .03). In vitro priming of human neutrophils and monocytes with IGF-1 and subsequent stimulation with PMA or E. coli demonstrated that IGF-1 enhanced both phagocytosis and respiratory burst. IGF-1 serves as a priming agent for biologic functions of leukocytes.
Patients with the autosomal recessive lysosomal storage disease alpha-mannosidosis suffer from re... more Patients with the autosomal recessive lysosomal storage disease alpha-mannosidosis suffer from recurrent infections. To study the mechanisms of this immunodeficiency, six patients were matched against six healthy controls and their humoral and cellular immunocompetence investigated. No differences in the number of circulating leucocytes including B-cells, levels of immunoglobulin main classes, nor IgG subclasses were observed. However, post-immunisation serum levels of specific antibodies against poliovirus, diphtheria toxin and tetanus toxin were significantly reduced. In patients, the density of the complement-binding receptor CD11b and the Fc-receptor CD16 was significantly enhanced on monocytes and polymorphonuclear neutrophils (PMN) and the number of phagocytosing PMN was significantly increased in the presence of pooled human serum. This was not observed in the presence of autologous serum, indicating altered opsonic properties. Also in normal PMN, phagocytosis was inhibited by a factor in the serum from the patients. Despite maintained oxidative burst, patient PMN demonstrated insufficient intracellular bacterial killing. Our data indicate that patients with alpha-mannosidosis have an immunodeficiency at both the humoral and cellular level.
To study the preventive effect of a milk drink fermented with multistrain probiotics on antibioti... more To study the preventive effect of a milk drink fermented with multistrain probiotics on antibiotic associated diarrhoea (AAD). Double-blind placebo controlled study. University Hospital of North Norway. Of 853 patients treated with antibiotics, 87 met the inclusion criteria, and were randomized to ingestion of a fermented milk drink containing LGG, La-5 and Bb-12 (n=46) or placebo with heat-killed bacteria (n=41), during a period of 14 days. A diary was recorded, and stool samples were collected for microbiological analyses. Sixty-three patients completed the study according to the protocol; two patients (5.9%) in the treatment group and eight (27.6%) in the placebo group developed AAD (P=0.035). The relative risk of developing AAD was 0.21 (95% confidence interval: 0.05-0.93) when given probiotic milk drink. A fermented multistrain probiotic milk drink may prevent four of five cases of AAD in adult hospitalized patients. TINE BA, Oslo, Norway.
The presence of echolucent artery plaques is associated with increased risk of cardiovascular eve... more The presence of echolucent artery plaques is associated with increased risk of cardiovascular events as compared to echogenic plaques. Whether inflammatory markers are associated with carotid plaque morphology is questioned. 5,341 individuals were examined with ultrasonography of the right carotid artery. Of these, 3,205 had carotid plaque(s), in whom plaque area (mm(2)) and plaque echogenicity, expressed as the computer-assisted gray scale median (GSM), were determined. White blood cell count (WBC), fibrinogen and C-reactive protein (CRP) were analyzed, as well as other cardiovascular risk factors. In multiple linear and logistic regression models, we determined the relationship between plaque area and echogenicity, and inflammatory markers. Women and men with carotid plaque(s) had significantly elevated levels of WBC and fibrinogen, but not CRP, as compared to subjects without plaques. All inflammatory markers were significantly associated with plaque area in men. WBC was significantly associated with plaque echogenicity in women, whereas no association was found between fibrinogen and CRP and plaque echogenicity in either gender. This cross-sectional study showed sex-dependent differences in associations between measures of carotid atherosclerosis and inflammatory markers. CRP did not discriminate echolucent from echogenic carotid plaques in either gender. Our data highlight the importance of sex-specific analyses in future studies.
A large outbreak of infection and colonization with multiple genera of gram-negative bacilli carr... more A large outbreak of infection and colonization with multiple genera of gram-negative bacilli carrying the metallo- beta -lactamase gene bla(IMP-4) occurred in a 36-bed intensive care unit at a tertiary hospital in Australia. The organisms emerged rapidly, caused severe infections, and contributed to mortality. Controlling the spread of these organisms remains a challenge for all staff involved.
Phagocytosis and respiratory burst activity were measured by flow cytometry in fresh and cryopres... more Phagocytosis and respiratory burst activity were measured by flow cytometry in fresh and cryopreserved human monocytes, after ingestion of Escherichia coli and Staphylococcus aureus. Mononuclear leukocytes, isolated from 15 healthy donors, were divided into two portions, of which one was examined immediately and the other was cryopreserved for 3 weeks. Morphological characteristics and expression of receptors involved in phagocytosis were similar in fresh and cryopreserved monocytes. Furthermore, both internalization of bacteria and respiratory burst activity remained unchanged after cryopreservation. Transmission electron microscopy confirmed actual internalization of bacteria and not merely bacterial attachment to monocytes. Monocytes were demonstrated to retain integral cellular functions during cryopreservation. This may imply that the method has potential for use in basal and clinical trials.
The aim of this study was to assess the influence of growth hormone (GH) in sepsis on the immune ... more The aim of this study was to assess the influence of growth hormone (GH) in sepsis on the immune system represented by the circulating TNF-levels and the neutrophil leukocytes phagocytic capacity and respiratory burst, 22 piglets were randomized to 3 groups; pretreatment with GH (16 i.u.) before sepsis (n = 8), non-treated septic controls (n = 8), and non-septic controls (n = 6). Sepsis was induced by a standardized infusion of live E. coli. TNF was measured by a cytotoxic bioassay, while neutrophil function tests were carried out by flowcytometric assays. In brief, phagocytosis was evaluated by the neutrophils' ability to ingest FITC-labelled (fluorescein isothiocyanate) E. coli and intracellular release of oxygen metabolites was detected by the oxidation of 2',7'-dichlorofluorescin (DCFH) to the fluorescent 2',7'-dichlorofluorescein (DCF). Our data show a suppression of phagocytosis in the GH-treated group before sepsis; however, when challenged with Gram-negative bacteria, the phagocytic capacity was similar to that of the non-treated animals. The serum levels of TNF in the non-treated septic control group were twice the levels of those in the GH-treated group, 65.7 pg/ml (septic controls) vs 32.8 pg/ml (GH). Pretreatment with a single dose of GH few hours prior to sepsis does not seem to entail any further imbalance of the neutrophil function in sepsis. Lowering of the circulating TNF-levels is a presumptive favourable effect of GH in sepsis.
Insulin-like growth factor 1 (IGF-1) mediates anabolic actions in catabolic states and also influ... more Insulin-like growth factor 1 (IGF-1) mediates anabolic actions in catabolic states and also influences the immune system. Endogenous IGF-1 production is suppressed in sepsis; replacement therapy is therefore a natural approach to obtain the protein anabolic and potentially immune-stimulating effects of IGF-1. Twenty-two piglets were randomized to three groups: an IGF-1 group (n = 8) receiving a continuous infusion of 1.3 mg/h of IGF-1, a nontreated septic control group (n = 8), and a nonseptic control group (n = 6) receiving saline. Phagocytosis and respiratory burst in porcine neutrophils were evaluated by flow cytometry (FCM); tumor necrosis factor (TNF) levels were measured in serum during the septic period. In addition, human neutrophils and monocytes were primed in vitro with IGF-1 and subsequently were stimulated with phorbol myristate acetate (PMA) or Escherichia coli; phagocytosis and respiratory burst were evaluated by FCM. Under nonseptic conditions, pretreatment with IGF-1 suppressed the ability of neutrophils to ingest bacteria (ie, the level of phagocytosis) 43.4% +/- 2.7% (IGF-1-treated) vs 55.8% +/- 3.4% (nontreated septic controls) and 57.3% +/- 3.34% (nonseptic controls) (p = .01). When challenged by live E. coli infusion, phagocytosis increased in the IGF-1 group to the levels of the nontreated group. The respiratory burst showed a convincing priming effect of IGF-1. After 4 hours of sepsis, the mean fluorescence intensity was 63.1 +/- 6.9 in the IGF-1 group and 40.7 +/- 3.0 in nontreated septic controls. The serum levels of TNF-alpha in the nontreated septic control group were twice those in the IGF-1-treated group, ie, 65.7 +/- 13.1 pg/mL in the nontreated septic controls and 31.5 +/- 7.5 pg/mL in the IGF-1 group (p = .03). In vitro priming of human neutrophils and monocytes with IGF-1 and subsequent stimulation with PMA or E. coli demonstrated that IGF-1 enhanced both phagocytosis and respiratory burst. IGF-1 serves as a priming agent for biologic functions of leukocytes.
Patients with the autosomal recessive lysosomal storage disease alpha-mannosidosis suffer from re... more Patients with the autosomal recessive lysosomal storage disease alpha-mannosidosis suffer from recurrent infections. To study the mechanisms of this immunodeficiency, six patients were matched against six healthy controls and their humoral and cellular immunocompetence investigated. No differences in the number of circulating leucocytes including B-cells, levels of immunoglobulin main classes, nor IgG subclasses were observed. However, post-immunisation serum levels of specific antibodies against poliovirus, diphtheria toxin and tetanus toxin were significantly reduced. In patients, the density of the complement-binding receptor CD11b and the Fc-receptor CD16 was significantly enhanced on monocytes and polymorphonuclear neutrophils (PMN) and the number of phagocytosing PMN was significantly increased in the presence of pooled human serum. This was not observed in the presence of autologous serum, indicating altered opsonic properties. Also in normal PMN, phagocytosis was inhibited by a factor in the serum from the patients. Despite maintained oxidative burst, patient PMN demonstrated insufficient intracellular bacterial killing. Our data indicate that patients with alpha-mannosidosis have an immunodeficiency at both the humoral and cellular level.
To study the preventive effect of a milk drink fermented with multistrain probiotics on antibioti... more To study the preventive effect of a milk drink fermented with multistrain probiotics on antibiotic associated diarrhoea (AAD). Double-blind placebo controlled study. University Hospital of North Norway. Of 853 patients treated with antibiotics, 87 met the inclusion criteria, and were randomized to ingestion of a fermented milk drink containing LGG, La-5 and Bb-12 (n=46) or placebo with heat-killed bacteria (n=41), during a period of 14 days. A diary was recorded, and stool samples were collected for microbiological analyses. Sixty-three patients completed the study according to the protocol; two patients (5.9%) in the treatment group and eight (27.6%) in the placebo group developed AAD (P=0.035). The relative risk of developing AAD was 0.21 (95% confidence interval: 0.05-0.93) when given probiotic milk drink. A fermented multistrain probiotic milk drink may prevent four of five cases of AAD in adult hospitalized patients. TINE BA, Oslo, Norway.
The presence of echolucent artery plaques is associated with increased risk of cardiovascular eve... more The presence of echolucent artery plaques is associated with increased risk of cardiovascular events as compared to echogenic plaques. Whether inflammatory markers are associated with carotid plaque morphology is questioned. 5,341 individuals were examined with ultrasonography of the right carotid artery. Of these, 3,205 had carotid plaque(s), in whom plaque area (mm(2)) and plaque echogenicity, expressed as the computer-assisted gray scale median (GSM), were determined. White blood cell count (WBC), fibrinogen and C-reactive protein (CRP) were analyzed, as well as other cardiovascular risk factors. In multiple linear and logistic regression models, we determined the relationship between plaque area and echogenicity, and inflammatory markers. Women and men with carotid plaque(s) had significantly elevated levels of WBC and fibrinogen, but not CRP, as compared to subjects without plaques. All inflammatory markers were significantly associated with plaque area in men. WBC was significantly associated with plaque echogenicity in women, whereas no association was found between fibrinogen and CRP and plaque echogenicity in either gender. This cross-sectional study showed sex-dependent differences in associations between measures of carotid atherosclerosis and inflammatory markers. CRP did not discriminate echolucent from echogenic carotid plaques in either gender. Our data highlight the importance of sex-specific analyses in future studies.
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Papers by Dag Halvorsen