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Biomedical subjects

K Sveen

Publications and source records attributed to K Sveen.

At least 19 recordsLinked to original sources
PubMed1992

Comparative mitogenicity and polyclonal B cell activation capacity of eight oral or nonoral bacterial lipopolysaccharides in cultures of spleen cells from athymic (nu/nu-BALB/c) and thymic (BALB/c) mice.

Optimal stimulatory doses of purified phenol-water extracted lipopolysaccharides (LPS) from 5 selected strains of 3 putative periodontopathogens (Fusobacterium nucleatum, Prevotella intermedia, and Veillonella), 3 strains of 2 nonoral bacterial species (Bacteroides fragilis and Salmonella enteritidis), and pokeweed mitogen (PWM) induced significantly higher maximum mitogenic responses and polyclonal Ig production in cultures of unfractionated spleen cells from nu/nu-BALB/c (nude) than from BALB/c (normal) mice. Compared with PWM, the LPS were stronger mitogens showing relative mitogenic capacities: B. fragilis LPS greater than F. nucleatum LPS greater than S. enteritidis LPS, Veillonella LPS, and P. intermedia LPS. B. fragilis LPS was the most and S. enteritidis LPS the least effective polyclonal B cell activator of total Ig, IgG2a, IgG2b, IgG3, IgA, and IgM secretion. IgG1 was not detected. P. intermedia LPS was the strongest IgA inducer. Kinetic observations indicated mitogenic responses and polyclonal B cell activation in a close sequential order in nude and normal cells. The LPS were potent Ag- and T cell-independent polyclonal B cell activators and LPS of subgingival plaque bacteria may therefore play a nonspecific role in the pathogenesis of periodontal diseases.

Animals↗
PubMed1991

Synergistic effect on blastogenesis in murine spleen cells of lipopolysaccharide, lipid A, and acid-degraded polysaccharide from Fusobacterium nucleatum.

Interchangeable combinations of Fusobacterium nucleatum Fev1 lipopolysaccharide (LPS) with its split products by acetic acid hydrolysis, i.e. lipid A (LA) and degraded polysaccharide (PS), amplified the blastogenic response in murine spleen cell cultures as measured by [3H]thymidine uptake. Athymic murine spleen cells precultured with LPS-Fev1 for 48 h (stage 1), washed twice and cultured together with fresh cells and either LA or PS for 72 h (stage 2) gave a synergistic response over that found in spleen cell cultures of thymic mice. Spleen cells pre-cultured with LA or PS and with fresh cells and LPS-Fev1 added to stage 2 cultures gave less significant amplification compared with precultures of LPS and either LA or PS together with fresh cells added to stage 2. Precultures with LA, PS or LPS-Fev1 and with pokeweed mitogen (PWM) and fresh cells added produced an additional increment of synergy which was most pronounced in spleen cell cultures of normal mice.

Acetates↗
PubMed1990

Blastogenesis and polyclonal immunoglobulin synthesis in murine spleen cells stimulated with lipopolysaccharide, lipid A and acid-degraded polysaccharide from Fusobacterium nucleatum.

Lipopolysaccharide of Fusobacterium nucleatum strain Fevl was split by acid hydrolysis. The split products, i.e. lipid A and degraded polysaccharide were mitogenic for murine spleen cells as measured by uptake of [3H]thymidine. The uptake of [3H]thymidine was dose-dependent. Incubation of spleen cells with stimulants for 3 days resulted in a polyclonal activation of immunoglobulin synthesis. Higher mitogenic response and immunoglobulin production were found in spleen cells of athymic mice compared to those of thymic mice. The activity of lipid A in stimulating immunoglobulin synthesis was comparable with the parent lipopolysaccharide-Fevl, the degraded polysaccharide being the less potent stimulator.

Animals↗
PubMed1987

Effect of iopentol on coagulation and platelet function in vitro and in vivo.

The effect on hemostatic parameters of two non-ionic contrast media, iopentol and iohexol in concentrations of 350 mg I/ml, were tested in vitro. The new medium iopentol had similar effects to those of iohexol, both with respect to the intrinsic coagulation system and platelet aggregation. As part of a human pharmacologic study the effects of iopentol on hemostatic parameters were tested in 8 volunteers in vivo. Iopentol induced a slightly decreased coagulability and aggregability in venous blood. It was concluded that the effects were of very little consequence for hemostasis as a whole.

Blood Coagulation↗
PubMed1985

Clearance of Bacteroides fragilis lipopolysaccharide in vivo.

The clearance of bacterial lipopolysaccharide (LPS) from Bacteroides fragilis was studied, using wound chambers implanted subcutaneously in rabbits. The primary skin inflammatory reaction, the Limulus amoebocyte lysate test and the haemagglutination inhibition test all demonstrated a more rapid elimination of LPS from the wound chambers after the second injection, compared to the elimination rate after the first injection given three days earlier. The clearance rate of LPS was significantly higher (0.003 greater than or equal to p greater than or equal to 0.0006) and the number of accumulated leukocytes in the inflammatory exudate significantly lower (p less than or equal to 0.05) after the second injection. Antibodies to B. fragilis LPS in the exudate before the second endotoxin injection was of the 19S IgM class. This suggests that phagocytes in the granulation tissue lining the chamber walls may be of importance in the elimination of endotoxin.

Animals↗
PubMed1985

Intravascular studies with iohexol (Omnipaque). Results from the first 49 clinical trials.

In order to assess the vascular clinical trial program of iohexol (Omnipaque) in Europe, the results from the first 49 vascular trials are collectively reported. The included iohexol material comprises 1742 patients. In 40 comparative trials, other contrast media like metrizamide (Amipaque), ioxaglate (Hexabrix) and various monomeric ionic media were administered in 1292 patients included in this analysis. No severe or unexpected adverse reactions related to iohexol were encountered. No clinically significant differences in radiographic image quality between the media were documented. The overall tolerability of iohexol was superior to that of monomeric ionic media and seemed to be as good as that of metrizamide.

Adolescent↗
PubMed1979

Effect of the addition of a vasoconstrictor to local anesthetic solution on operative and postoperative bleeding, analgesia and wound healing.

A clinical study of local anesthetic solutions with and without epinephrine was conducted involving 32 healthy adults requiring removal of bony impacted mandibular third molars. The time elapsing from the administration of the anesthetic solution until analgesia was obtained was significantly shorter in the vasoconstrictor group (P less than 0.001). Additional anesthetic was necessary in 44% of the patients in the control group. The blood loss in the vasoconstrictor group was significantly lower (P less than 0.001) than in the group receiving anesthetic solution without the vasoconstrictor. No statistically significant difference in operation time between the groups was found, although the profuse bleeding in the control group impeded to some extent the surgical procedure. A positive correlation coefficient between operation time and blood loss of r = 0.65 in the vasoconstrictor group (P less than 0.006) and r = 0.77 in the control group (P less than 0.001) was found. Hemorrhage occurring 24 h postoperatively was recorded in 37% of the subjects in the vasoconstrictor group, and of these 83% revealed a healing of the socket by second intention.

Adolescent↗
PubMed1979

Incomplete branchial arch syndromes, branchial cleft cyst and vascular hamartoma in a patient with multiple neurofibromatosis.

A case report with simultaneous occurrence of neurofibromatosis, incomplete branchial arch syndromes, a branchial cleft cyst and a pseudocyst in connection with a vascular hamartoma anterior to the right ear of a 38-year-old woman is presented. A possible common pathogenesis of the vascular hamartoma and the incomplete branchial arch syndromes as well as that of the neurofibromatosis is suggested. The pseudocyst is interpreted as a branchial cleft cyst showing inflammatory changes due to a pharyngitis shortly before the preauricular tumor appeared.

Adult↗
PubMed1979

Chemotaxis or migration inhibition of rabbit peritoneal polymorphonuclear leukocytes caused by chemoattractants at various concentrations.

Purified lipopolysaccharide (LPS) from Veillonella incubated in normal rabbit serum was tested for chemotactic activity on rabbit polymorphonuclear leukocytes (PMNs) in modified Boyden chambers. In doses above those giving optimal response (over-optimal dose), a decrease of the PMN migration activity was found. This decrease also correlated well with an increase in the migration inhibition of the PMNs as demonstrated with the capillary tube assay. The PMN chemotactic factor isolated from LPS-induced inflammatory exudate (LPS-CF) in rabbits, produced both a decrease in chemotactic response and a migration inhibition of PMNs in over-optimal doses. This inhibitory effect was not due to cytotoxicity, proved by the trypan blue exclusion test. Also, a reduced locomotion of PMNs first preincubated with chemoattractants and then reactivated, was shown when the same PMNs were restimulated to migration using the same chemoattractants. This was interpreted as a deactivation of the cells. A cross-deactivation was demonstrated between LPS-CF and casein. The results from the experiments reported show that the Boyden chamber may be used to disciminate directional chemotaxis and migration inhibition. It may also be concluded from the study that the reduced migration activity of PMNs at over-optimal doses of chemoattractants is not due to cytotoxicity, but most probably is caused by a deactivation of the cells.

Animals↗
PubMed1979

The influence of specific antibodies and cellular immunity in the induction of tolerance of chemotactic activity caused by Bacteroides fragilis lipopolysaccharide.

Exudate aspirated from wound chambers implanted subcutaneously on rabbits at different time intervals after local lipopolysaccharide (LPS) injection, showed a peak of chemotactic mediator concentration in vitro about two hours before the peak of polymorphonuclear lekocytes accumulated in vivo was demonstrated. Injection of LPS locally into the wound chambers three days after the first injection of LPS showed a reduced number of PMNs accumulated in the exudate. Antibodies to the LPS preparation were demonstrated in the exudate and serum by indirect haemagglutination of sheep erythrocytes before the second LPS injection. This antibody titre increased up to two weeks after the first LPS injection, and was slightly higher in the serum than in the exudate. Also, a migration inhibition factor (MIF) activity was demonstrated in the exudates formed. This MIF activity of the exudates increased after the second LPS injection. The increased titre of specific antibody may indicate an accelerated clearance of LPS, and the MIF activity may indicate a reduced response of PMNs to chemotactic mediators. However, the involvement of other biological mechanisms contributing to the decreased response, cannot be excluded.

Animals↗
PubMed1979

[Autotransplantation of teeth: indication, technic and prognosis].

An account is given of the most important indications for tooth transplantation. The developmental stage of the tooth most suitable for transplantation and the special demands to the recipient site, are considered. Each main group of indication is illustrated with case reports. Finally, factors influencing the prognosis of the transplant are discussed.

Adolescent↗
PubMed1979

Endotoxins of anaerobic gram-negative rods.

Endotoxic lipopolysaccharides (LPS) isolated from Fusobacterium are similar to those of Salmonella with respect to chemical composition, O-antigenic specificity and endotoxic activity. Bacteroides LPS are highly atypical with respect to the chemical composition, and their endotoxic activity is low. O-Antigenic specificity is present. B. fragilis LPS is chemotactic for polymorphonuclear leukocytes in vitro and in vivo. The chemotactic activity is brought about by activation of the alternative complement pathway.

Animals↗
PubMed1978

Giant ranula causing mandibular prognathism.

This is a case report of a 20-year-old man with ranula, the size of an orange, in the floor of the mouth causing mandibular prognathism with fan-shaped mandibular teeth anterior to the premolars. The tumor was extirpated. The pathogenesis, differential diagnosis and treatment of ranulas are discussed.

Adult↗
PubMed1978

The importance of C5 and the role of the alternative complement pathway in leukocyte chemotaxis induced in vivo and in vitro by Bacteroides fragilis lipopolysaccharide.

Chambers implanted subcutaneously in C5 normal (C5 N) and C5 deficient (C5 D) mice were used to examine the migration of polymorphonuclear leukocytes (PMNs) into the wound chamber fluid in response to injected Bacteroides fragilis lipopolysaccharide (LPS). The difference in PMN migration was highly significant between the two mouse strains, the C5 D mice showing no initial, but a low, delayed migration. The results from the study indicated that chemotaxis plays a major role in the accumulation of PMNs in the acute inflammatory response. Intraperitoneal endotoxin stimulation also showed a significantly lower total number of leukocytes in the exudate from C5 D mice as well as a delayed migration of cells compared to C5 N mice. No leukotactic mediators were elaborated in C5 D serum or exudate upon incubation with LPS when tested in a modified Boyden chamber. However, endotoxin-induced wound chamber fluid in C5 D mice showed an increasing leukotactic activity at the same time as the acute inflammatory response subsided in C5 N mice. Incubation of B. fragilis LPS in C4 deficient (C4 D) guinea pig serum indicated that the LPS was able to activate complement components to generated split products chemotacic for rabbit PMNs via the alternative complement pathway.

Animals↗
PubMed1978

Rabbit polymorphonuclear leukocyte chemotactic factor generated in vivo by Bacteroides fragilis lipopolysaccharide. I. Isolation and physico-chemical characterization.

By chromatographic separation on Sephadex gels a peptide, termed the lipopolysaccharide-induced chemotactic factor (LPS-CF), has been isolated from inflammatory exudate. The exudate was obtained from Teflon chambers implanted subcutaneously in rabbits 3 h after LPS from Bacteroides fragilis ss. fragilis had been injected. Three chemotactic peaks were eluted by fractionation of the exudate on Sephadex G-200 columns; one major peak with molecular weight of approximately 16,000 and two minor peaks with molecular weights of approximately 68,000 and 7,000. Refiltration of the major peak on G-75 showed the same elution profile as that found on G-200 columns. By addition of 8 M urea to the elution fluid only the major and the low molecular weight peaks appeared. The molecular weight of the major chemotactic peak was calculated to 16,000 on Sephadex gels, and also using SDS-polyacrylamide gel electrophoresis and equilibrium centrifugation. The chemotactic factor was quite heat-stable and was also non-dialyzable, and freezing and thawing as well as storage at 4 degrees C for several weeks did not impede its activity. This chemotactic factor is probably identical to the cytotaxic fragment split off from C5 upon interaction with LPS.

Animals↗
PubMed1978

Rabbit polymorphonuclear leukocyte chemotactic factor generated in vivo by Bacteroides fragilis lipopolysaccharide. II. Antigenic and biologic properties.

Preparations of the polymorphonuclear leukocyte (PMN) chemotactic factor isolated from lipopolysaccharide (LPS)-induced inflammatory exudate in rabbits were immunogenic in guinea pigs. Complete fusion of the precipitation lines produced against anti-CF by LPS-CF (molecular weigth 16,000) and material eluted on Sephadex G-200 columns with molecular weights (MW) of 68,000, 16,000 and 7,000 was found. Also, the chemotactically active material with MW of 68,000 and 7,000 eluted on G-75 columns after fractionation of the fraction of MW 16,000 from the G-200 eluate was antigenically identical to LPS-CF in double diffusion in agar. Normal rabbit serum (NRS) incubated with LPS, LPS-induced wound chamber exudate and NRS alone gave lines of precipitation against the anti-LPS-CF sera identical to that of LPS-CF. The capacity of LPS-CF to attract PMNs was significantly higher than that of LPS, and a peak in the number of PMNs in the exudate of wound chambers implanted in rabbits was found 4 h after the local injection of LPS-CF. When injected intraperitoneally in C5 deficient mice, LPS-CF stimulated a PMN migration which was only slightly below that in C5 normal mice. Antisera to LPS-CF inhibited the chemotactic activity of LPS-CF as well as that of LPS-NRS when the supernatants were tested using the Boyden's technique. Also, preincubation of PMNs with LPS-CF suppressed the migration towards a chemotactic gradient of LPS-CF molecules of these PMNs.

Animals↗
PubMed1978

Induction of leukochemotaxis by protein A of Staphylococcus aureus.

The mechanism of the leukochemotactic activity of staphylococcal protein A (pA) has been studied by in vitro and in vivo experiments. Protein A alone or mixed with heat-inactivated serum induced no migration of polymorphonuclear leukocytes, demonstrating that pA is not a cytotaxin, but a cytotaxigen. Protein A, activating both pathways of the C system, induced chemotaxis in a C4 deficient serum, but not in a C5 deficient serum. This shows that the chemotactic mediator elaborated is a split product of C5, i.e. C5a. The chemotactic activity of pA observed in the presence of normal sera (in vitro) and in wound chambers (in vivo) was exclusively caused by C activation via reaction with Fc.

Animals↗