Stimulation of B lymphocytes by lipopolysaccharides from anaerobic bacteria.

Lipopolysaccharides (LPSs) from anaerobic gram-negative bacteria, including those of low endotoxic activity that are isolated from Bacteroides, Prevotella, and Porphyromonas are potent inducers of DNA replication and polyclonal immunoglobulin production in murine B lymphocytes. The activation is dose-dependent and T cell-independent. Replication of DNA and production of immunoglobulins were also stimulated by lipid A and by the LPS heteropolysaccharide that were isolated by mild acid hydrolysis of the LPSs of Bacteroides fragilis and Fusobacterium nucleatum. Combinations of LPS, lipid A, and acid-degraded polysaccharide amplified the blastogenic response. Antibodies that react with the polysaccharide part of LPSs isolated from members of the Bacteroidaceae are present in healthy human serum.

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.

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.

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.

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.

High dose urography in patients with renal failure. A double blind investigation of iohexol and metrizoate.

The new non-ionic contrast medium iohexol 350 mg I/ml was compared with the ionic contrast medium metrizoate 350 mg I/ml in a double blind, two-group urographic study performed on 20 patients with stable, impaired renal function. A dose of contrast medium of 500 mg I/kg body weight was given to each patient. Iohexol resulted in significantly fewer subjective adverse reactions than metrizoate. A similar image quality was obtained with the two contrast media. No clinically significant difference existed between the two contrast media with respect to influence on blood pressure, pulse or clinical chemical parameters. A tendency to deterioration of renal function after urography was found in both groups, but no difference of statistical significance existed between the two contrast media with respect to possible nephrotoxicity. Inadequate hydration may have been partly responsible for the nephrotoxic effect of the urographic procedure.

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.

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.

Summary of U.S. and European intravascular experience with iohexol based on the clinical trial program.

The nonionic contrast medium, iohexol, was released by Nyegaard, Oslo, in 1980 for clinical testing. Results of a three-phase clinical trial program carried out in Europe and the U.S. through December 1983 are summarized. Evaluation of phase I studies of human tolerance and excretion--and phase II studies of effects on pharmacologic and physiologic parameters--indicated that iohexol was well tolerated and effective. Phase III consisted mainly of controlled parallel and crossover studies comparing iohexol with conventional ionic media and with other nonionic agents in a variety of radiographic studies. Image quality was as good or better with iohexol than with ionic media. Iohexol was tolerated significantly better than ionic agents. Patients consistently reported fewer and less intense pain and heat sensations. Iohexol had less effect on blood pressure, blood flow, heart rate, and electrophysiologic parameters, and caused fewer adverse reactions than ionic media for all types of reactions observed.

Phase II studies in urography, cardioangiography and cerebral angiography with iohexol. An evaluation of the clinical trial program and the clinical findings.

The first experience in patients (phase II studies) with iohexol (Omnipaque) - a new non-ionic contrast medium - in intravenous urography (34 patients), cardioangiography (45 patients) and cerebral angiography (38 patents) is collectively reported. A non-comparative, multicentre design was used in all 3 applications. The objective was to assess the efficacy (the opacity to X-rays) and the tolerability of iohexol using routine contrast medium doses in a well defined adult population. No unexpected or severe reactions occurred in the 117 included or 9 excluded patients. Good efficacy was confirmed, and the contrast medium was well tolerated. The results warrant advancing iohexol into comparative phase III trials. The iohexol phase II studies and initial research in patients with contrast media in general are discussed.

Randomized double-blind cross-over study of iohexol and Amipaque in cerebral angiography.

Iohexol was compared with Amipaque (metrizamide) in a double-blind study in one pair of injections in each of 20 patients referred for routine cerebral angiography. Catheter position, patient position, injection pressure, contrast medium volume, and concentration (300 mg l/ml) were the same in the two injections, with iohexol and Amipaque being used alternately. Except for these two injections iohexol was used throughout. The parameters studied included diagnostic information obtained (quality of the examination), circulation time, and comparison of patient reactions to the pair of injections (e.g., electrocardiogram, heart rate, and subjective reactions). The patients' reactions to the noncomparative part of the examination were evaluated also, and the patients were observed for possible adverse reactions after the examination. No difference could be detected between the two contrast media in this series. No serious adverse reactions occurred.

Human pharmacokinetics of iohexol. A new nonionic contrast medium.

The pharmacokinetics of iohexol, a new nonionic, water-soluble contrast medium, have been determined after intravenous injection in 20 healthy volunteers, at four different dose levels (125-500 mg I/kg). The apparent volume of distribution was 0.27 1/kg, indicating distribution in the extracellular water. The biologic half-life was 121 minutes, comparable with that of other intravascular contrast media. Iohexol was excreted completely unmetabolized in the urine, with a 100% recovery 24 hours after injection. A comparison of iohexol and chromium-51 (51Cr)-EDTA clearances indicates that iohexol is mainly excreted by glomerular filtration. The 51Cr-EDTA clearance was the same when injected separately and concomitantly with iohexol, indicating that glomerular filtration rate is not affected by iohexol. No dose dependency was observed in the investigated parameters t1/2 alpha, t1/2 beta, Vd, ClT or ClR. Iohexol pharmacokinetics are in correspondence with previously reported data on intravascular contrast media.

Tolerability of iohexol after injection into healthy volunteers.

The effects of iohexol, a new non-ionic contrast medium, after intravenous injection into humans are reported. After injection of small doses into 2 subjects, iohexol was injected intravenously into 20 healthy male volunteers in doses of 125 to 500 mg I/kg body weight. A large number of physiologic, biochemical, hematologic and pharmacokinetic parameters were analysed. The results indicated that iohexol was well tolerated and that clinical trials in patients could be undertaken.

Induction of leukochemotaxis, primary skin inflammation and local Shwartzman reaction by Neisseria gonorrhoeae extract.

The leukochemotactic activity of ultrasonicate of the N. gonorrhoeae strain 8551 was studied by in vitro and in vivo experiments. No chemotactic activity was observed with extract incubated in Gey's solution alone or with heat-inactivated rabbit serum. Activity attracting polymorphonuclear cells was generated on injection of the extract into chambers implanted subcutaneously in rabbits, and in vitro when incubated with fresh rabbit serum, normal guinea pig serum or serum deficient in C4. Chemotactic activity was not observed on incubation with mouse serum deficient in C5. The extract showed pronounced activity in the preparing of rabbits for the local Shwartzman reaction and in inducing primary skin inflammatory reaction. Gonococci this contain chemotaxigens that induce chemotaxin production by means of complement activation via the alternative pathway, and these or other components initiate strong inflammatory responses in vivo.

Tolerability and diagnostic usefulness of iohexol in urography. An open multicentre clinical trial.

The first experience with iohexol in urography in humans is reported. Injection of iohexol in a dose of 200 mg I/kg body weight into 34 patients with normal renal function was followed by only few and slight subjective adverse effects. A large number of laboratory tests revealed no toxic effects. High radiographic contrast was obtained.

Amipaque (metrizamide) in vascular use and use in body cavities: a survey of the initial clinical trials.

A review of the initial 76 clinical trials with Amipaque in vascular radiology and in examinations of the body cavities, mostly performed in the Scandinavian countries, is given. The clinical material presented comprises a total of 2,661 Amipaque examinations, 1,784 examinations performed intravascularly and 515 in body cavities. In addition, 362 vascular examinations with Amipaque in children are presented. Generally, no difference in visualization compared to ionic media was found. However, improved visualization was reported in some few angiographic studies and higher contrast density was indicated in the urograms. Compared to ionic media, Amipaque caused considerably less subjective reactions and less hemodynamic effects. A remarkable reduction in post-phlebographic thrombosis following leg phlebography was found with Amipaque. No death related to Amipaque occurred, and few contrast medium reactions have been recorded. Thus, the good tolerability of the non-ionic Amipaque shown in animal studies has also been confirmed clinically outside the subarachnoid space.

Changes of lateral soft tissue profile after surgical correction of mandibular prognathism.

The lateral soft tissue profile was recorded in 10 patients with slight to moderate degrees of mandibular prognathism, preoperatively, and 6 weeks after subcondylar sliding osteotomy had been performed. The recording method was mechanical. Only small and insignificant profile changes were found in the submandibular and occlusal plane regions as well as in the ramus region. The only significant change of profile was found in the mandibular body region, probably as a result of firm connection between soft tissue and underlying distally moved bone. The lack of significant profile change in the osteotomy region was in accordance with subjective observations and was probably due to local remodelling and adaptation processes. The facial width was thus found to be unaltered 6 weeks postoperatively.

A polypeptide antigen from a strain of Staphylococcus simulans. 2. Antigenic and biological properties.

A purified polypeptide antigen from Staphylococcus simulans CCM 2705 produced one precipitation line by double diffusion in agar with rabbit antiserum against homologous whole bacteria. The purified antigen did not induce antibody production in rabbits. However, when the antigen was complexed with methylated bovine serum albumin, antibodies with specificity against the polypeptide were produced. The antigen did not sensitize normal or tanned erythrocytes for agglutination in antiserum. The polypeptide antigen induced a primary skin reaction and was toxic for mice. It also induced production of MIF as demonstrated by the migration inhibition test. The polypeptide was found to be a leukotaxigen. No difference between C4 normal and C4 deficient serum was noted. C5 was found to be necessary for the induction of chemotaxis.