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Biomedical subjects

C O Solberg

Publications and source records attributed to C O Solberg.

At least 55 records · Page 3Linked to original sources

Serum opsonins to group B meningococci.

The production of serum opsonins and other antibodies to serogroup B serotype 15 meningococci was examined in 7 patients with serogroup B serotype 15 meningococcal disease and 7 volunteers immunized with a vaccine containing outer membrane proteins from serogroup B serotype 2b and 15 meningococcal strains complexed with polysaccharides from serogroups A, C, Y and W-135 meningococci. Serum opsonic activity was measured by a flow cytometric phagocytosis technique, using unfixed serogroup B Neisseria meningitidis labelled with fluorescein isothiocyanate. Serum antibodies to outer membrane complexes prepared from the meningococcal test strain, B:15:P1.16, were measured by an enzyme linked immunosorbent assay. The mean number of bacteria per phagocyte increased from 9.7 to 17.3 (mean difference 7.6, p less than 0.001) when the meningococci were opsonized with convalescent sera compared to sera obtained during the acute illness, and from 8.0 to 15.4 (mean difference 7.4, p less than 0.001) when opsonized with sera from immunized versus pre-immunized volunteers. The patients had insignificant amounts of serum antibodies to the group B meningococcal test strain on admission to hospital. Two weeks later all had a marked increase in IgG, IgM and IgA serum antibodies. Vaccination caused a marked increase in serum IgG antibodies. Serum opsonic activity and IgG levels were still high 6 weeks after the acute illness/immunization. A correlation was observed between serum opsonic activity and IgG antibody levels (r = 0.883, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Infectious mononucleosis: increase of high-affinity E-receptor-bearing lymphocytes.

The increase of T lymphocytes in infectious mononucleosis (IM) is shown to be due to an increase of 'active' (early erythrocyte rosette-forming) T cells: 67.2 +/- 18.3% of IM lymphocytes were 'active' versus 34.7 +/- 14.9% of control lymphocytes. IM was also associated with an increase of lymphocytes demonstrating E receptors at 20 degrees C (E20-R). This phenomenon was not related to the heterophile antibody titre and could not be demonstrated with ox or rabbit erythrocytes. Patients with other lymphoproliferative diseases did not show an increase of E20-R-positive cells or of 'active' erythrocyte rosette-forming cells (E-RFC). Re-rosetting experiments indicated that E20-R and 'active' E-RFC belong to overlapping populations of cells. A double-gradient separation technique was shown to be superior to the conventional Ficoll-Isopaque method for the demonstration of 'active' and total T cells. A high proportion of T lymphocytes were also recovered in the granulocyte layer by this technique, indicating a selective loss of these cells by the conventional technique.

Cell Separation↗

Antimicrobial therapy and case fatality in meningococcal disease.

The effect of different initial antimicrobial treatments on the case fatality rate (CFR) was evaluated in 112 consecutive patients with meningococcal disease. The overall CFR was 9.8%. 85 patients received initial therapy with chloramphenicol in addition to benzylpenicillin or other antimicrobials, and 27 patients benzylpenicillin or other antimicrobials without chloramphenicol. Patients treated with chloramphenicol had a lower CFR than those not given chloramphenicol (5% vs. 26%; p = 0.004). However, severely ill patients were treated more often with penicillins, and adjustment for the severity of disease on admission to hospital demonstrated that this difference in favour of chloramphenicol was slight and nonsignificant (p = 0.58). High doses of benzylpenicillin and no chloramphenicol were also associated with a higher CFR than low doses. However, the difference was not significant (p = 0.22). More extensive studies should be carried out to evaluate the effect of benzylpenicillin doses and chloramphenicol on the outcome of meningococcal disease.

Adolescent↗

Case fatality of meningococcal disease in western Norway.

In the period 1976-84, 211 patients hospitalized with meningococcal disease were examined for possible relation between various epidemiological parameters and fatality. The peak incidences were in the age groups 0-4 and 13-18 years, with teenage girls peaking 2 years ahead of the boys. The overall case fatality rate was 8.5%. In septicemic patients (without meningitis) hypotension and/or ecchymoses on admission correlated strongly with a poor prognosis. Most deaths occurred during the months of March and November, and none during the summer months. There was a significant clustering of deaths among patients admitted during the morning hours, probably due to delayed diagnosis and treatment during the night. Since almost all patients who died had skin bleedings on admission, frequent examination of the skin in cases with acute unexplained fever might have saved lives.

Adolescent↗

In vitro evaluation of the activity of Entamoeba histolytica studies on motility.

The tube migration test for leukocyte function studies has been modified to test the motility of Entamoeba histolytica. The test was more sensitive to the effect of antiamebic drugs than was a test for phagocytic activity. A 50% reduction in amebic motility was seen instantly after exposure to metronidazole (40 mg/l). A similar reduction of phagocytosis at the same concentration of the drug was seen only after two hours' preexposure. The extent of amebic migration in the test tube is dependent on factors such as concentration of parasites, temperature and incubation time. The tube migration test is cheap and simple and could be a valuable supplement to existing screening methods for potential antiamebic drugs.

Animals↗

Factors important for the measurement of chemiluminescence production by polymorphonuclear leukocytes.

Chemiluminescence (CL) production by phagocytosing polymorphonuclear leukocytes (PMNLs) was measured by an automatic photoluminometer with built-in mixing and temperature controls. Agitation of the vials with PMNLs and opsonized zymosan particles influenced both the lag time and the CL production. Maximal production was obtained by continuous mixing of the samples, the reaction peak occurring within 6 min. Increasing the temperature from 20 to 40 degrees C also increased the CL production, and in further experiments 37 degrees C was used. Aggregation of the PMNLs was avoided by washing the cells in PBS containing gelatin 1 g/l. Glucose, Ca2+ and Mg2+ in the final reaction mixture were necessary for maximal CL responses. The measurements of CL per s up to 4 min, the peak CL value, or the integral below the CL curve up to 6 min were all linearly proportional to the number of PMNLs in the reaction mixture. Since the lag time and the time before reaching peak CL may vary, the integral below the curve up to 6 min was chosen as the mode of CL measurement. On repeated measurements the coefficient of variation was 6.3%. The mean CL integral value for PMNLs from 14 healthy individuals was 205 +/- 19 mVs, indicating a good reproducibility of the standardized assay.

ABO Blood-Group System↗

Influence of tetracyclines and light on the release of lysozyme from human granulocytes and monocytes.

Doxycycline inhibited the release of lysozyme from human granulocytes and monocytes exposed to non-opsonized zymosan particles. This effect was more marked for granulocytes than for monocytes. Oxytetracycline, however, did not influence the release. The difference between the drugs can be explained by differences in their lipid solubilities. The divalent cation chelator, EDTA, also reduced the release of lysozyme from leukocytes exposed to non-opsonized zymosan. Accordingly, the selective release of lysozyme from human leukocytes is divalent cation dependent. The inhibition of release by doxycycline is most likely also due to binding of these ions. When the cells were exposed to UVA light in the presence of doxycycline, the inhibition of lysozyme release was potentiated. Using irradiated cells, maximal inhibition was obtained at 20 micrograms doxycycline/ml. However, it is not clear whether these results have clinical relevance.

Doxycycline↗

Granulocyte function in patients with multiple sclerosis.

Peripheral blood granulocytes and sera from patients with relapsing/remittent (group I) and chronic progressive (group II) multiple sclerosis (MS) did not differ from control cells and sera with regard to the proportion of cells bearing receptors for Fc gamma and C3b; random or directed (chemotactic) motility of granulocytes; activation as measured by chemiluminescence; opsonic activity of sera. The results of this study suggest that granulocyte function in MS is normal.

Cell Movement↗

Enhancement of leukocyte membrane receptor expression after mechanical agitation.

Granulocyte and lymphocyte suspensions were exposed to slight mechanical agitation for 30 s on a tube mixer before being examined for membrane receptors by rosette techniques. Agitation caused an increase in the proportion of granulocytes bearing receptors for sheep erythrocytes (E-R), for the Fc portion of IgG (Fc gamma-R), and for C3b (C3b-R), and of lymphocytes bearing the Fc gamma-R. The proportion of E-R-bearing lymphocytes was not enhanced, with the exception of the 'early' or 'active' E-R-bearing cells. The increase in rosette formation was specific, i.e. rosette formation with ox or rabbit E was not induced by agitation. The increased proportion of membrane receptors was not associated with an increase in granulocyte phagocytosis of preopsonized zymosan particles, as measured by chemiluminescence. Membrane perturbation thus probably increases the availability of surface receptors.

Animals↗

Influence of fever temperatures and of some cytoactive drugs on in vitro lysozyme release from monocytes and granulocytes.

The selective in vitro release of lysozyme from human monocytes and granulocytes was not greatly influenced by temperatures above 37 degrees C and up to 40 degrees C. The release was markedly inhibited by preincubation with phenylbutazone, oxyphenylbutazone, colchicine and vincristine. A water-soluble hydrocortisone complex also inhibited lysozyme release, but at high concentrations, lysis of the cells occurred. Although methotrexate had a weak inhibiting effect, no appreciable influence on release was observed with cyclophosphamide or cytarabine. Thus, release of lysozyme from blood leukocytes is likely to be dependent on cellular functions involving the stability of both microtubules and membranes.

Body Temperature↗

The influence of antimicrobial agents on macrophage-associated Staphylococcus aureus.

Macrophages obtained by culturing human blood monocytes were incubated with Staphylococcus aureus for phagocytosis to occur and exposed to gentamicin, rifampin, clindamycin or trimethoprim/sulphamethoxazole. The macrophage-associated bacteria were protected against gentamicin at low concentrations (1 mg/l) and trimethoprim/sulphamethoxazole. However, high concentrations of gentamicin and clindamycin reduced the number of bacteria, indicating that these drugs penetrated into human macrophages and killed phagocytosed bacteria. Rifampin, even at low concentrations (0.5 mg/l), caused a marked reduction in macrophage-associated bacteria, implying that the drug penetrated into the phagocytes and retained its effect in the cells most effectively.

Anti-Bacterial Agents↗

Granulocyte and lymphocyte membrane receptors in aseptic meningitis, infectious mononucleosis and other viral infections.

Granulocytes and lymphocytes from 44 patients with acute viral infections were examined for membrane receptors for sheep erythrocytes (E-R), for the Fc portion of IgG (Fc gamma-R) and for complement component C3b (C3b-R). Aseptic meningitis was associated with a decrease in Fc gamma-R and C3b-R bearing granulocytes but an increase in the proportions of lymphocytes bearing the same receptors. Patients with infectious mononucleosis (IM) had a decreased percentage of C3b-R bearing granulocytes, an increase of E-R bearing T lymphocytes and a slight decrease in the proportion of Fc gamma-R and C3b-R bearing lymphocytes. Cerebrospinal fluid from IM patients contained 92-98% T lymphocytes. The group of patients with other viral infections showed a decreased percentage of granulocytes bearing Fc gamma-R and C3b-R, and of E-R bearing lymphocytes. The decrease of Fc gamma-R and C3b-R bearing granulocytes in viral infections may be of importance in relation to the increased risk of bacterial superinfection in these patients.

Cell Membrane↗

Leukocyte membrane receptors in meningitis and other bacterial infections.

Blood leukocytes from 37 patients with acute bacterial infections, and cerebrospinal fluid (CSF) granulocytes from 12 patients with bacterial meningitis, were examined for the distribution of membrane receptors (R) for (1) untreated sheep erythrocytes (E), (2) the Fc portion of IgG (Fc gamma), and (3) complement component C3b. We found a decreased percentage of granulocytes bearing Fc gamma-R in the CSF from patients with meningitis, and in blood from patients with respiratory tract infections. This group also had a decreased percentage of C3b-R bearing granulocytes on admission, whereas meningitis patients had lower levels of C3b-R and Fc gamma-R bearing granulocytes in the 2nd and 3rd week and even later. Several patients with meningitis and gastroenteritis had granulocytes bearing the E-R, previously considered specific for T lymphocytes. Such cells were also found in the CSF. Meningitis and respiratory tract infections were associated with a decreased percentage of 'active' T lymphocytes. The total percentage of T lymphocytes was also decreased in meningitis. Conversely the proportion of Fc gamma-R bearing lymphocytes (consisting mostly of B lymphocytes) was increased in most infections. During the first 3 weeks of bacterial meningitis, the percentages of Fc gamma- and C3b-R bearing granulocytes, and of Fc gamma-R bearing lymphocytes, gradually decreased, while the T lymphocyte percentage increased from the initial low values.

Antigens, Surface↗

In vivo and in vitro effects of doxycycline on leucocyte membrane receptors.

Tetracyclines, particularly doxycycline, have adverse effects on granulocyte function in vitro. We have examined the effects of doxycycline on membrane receptors for IgG (Fc gamma-R) and C3b (C3b-R) on granulocytes and lymphocytes, as well as on the sheep erythrocyte receptor (E-R) on T lymphocytes. Acne patients given doxycycline orally had a lower percentage of Fc gamma-R positive granulocytes (57%) than before treatment (80%) or compared to healthy controls (81%). Following in vitro doxycycline incubation, normal granulocytes showed decreased levels of Fc gamma-R positive cells. This effect was counteracted by the addition of magnesium during incubation. The deleterious effect of doxycycline on granulocyte functions may be due to decreased levels of Fc gamma-R bearing granulocytes. Doxycycline in vivo or in vitro had no significant effect on the proportion of C3b-R bearing granulocytes or lymphocytes or the T lymphocyte percentage. After in vitro irradiation with light at 340-380 nm, however, both granulocytes and lymphocytes preincubated with doxycycline showed up to 50% decrease in Fc gamma-R bearing cells, while control cells without doxycycline were unaffected.

Acne Vulgaris↗

Treatment of anaerobic septicemia.

Septicemia caused by anaerobic bacteria is indistinguishable from septicemia caused by aerobic bacteria. High age, origin in the gastrointestinal or genitourinary tract, malignancies and surgery or invasive, diagnostic procedures are indicative of anaerobic etiology. Between 5% and 15% of all septicemias are anaerobic. Benzylpenicillin is active against most anaerobic bacteria, and nitroimidazoles, clindamycin and chloramphenicol are dependable drugs in the treatment of bacteroides septicemias. Surgical drainage and debridement are of major importance, and proper measures to prevent circulatory failure are mandatory. Hyperbaric oxygen therapy may have a dramatic effect. The use of corticosteroids and endorphin antagonists is controversial. Exchange transfusions have been attempted, but further clinical trials are necessary to establish their place in the management of anaerobic septicemia.

Adult↗

Budd-Chiari syndrome with obstruction of the inferior caval vein: successful treatment by cavosplenoatrial shunt.

A 27-year-old man had a 10-month history of recurrent ascites, massive edema, and extreme fatigue. The diagnosis of Budd-Chiari syndrome with severe stenosis of the retrohepatic part of the inferior caval vein had been established. Medical treatment had failed to prevent further deterioration. A single 14 mm Gore-Tex graft (W.L. Gore & Associates, Inc. Elkton, Md.) was used to establish a cavosplenoatrial shunt. The postoperative recovery was uneventful. All signs of ascites and edema disappeared within 8 weeks after surgery. In connection with repair of a ventral hernia 8 months later, a liver biopsy specimen revealed partial normalization of liver histology and an angiography demonstrated a patent shunt. Two and a half years after the initial operation he developed a bleeding peptic ulcer demanding emergency surgery. The shunt was again found patent. Three years after the first operation the patient is free of symptoms and working full time.

Adult↗

Granulocytes are more sensitive than lymphocytes to changes in EA and EAC indicator cell quality.

Granulocytes were more sensitive to age variation of EAC3b indicator cells than lymphocytes, and showed a significant decrease in rosette formation with EAC3b indicator cells more than 2 weeks old; whereas lymphocytes showed unchanged EAC3b rosette formation with indicator cells up to 4 weeks old. EAIgG rosette formation by granulocytes was less affected by the age of the indicator cells than by their degree of sensitization, with a 25% loss of rosettes after 1 dilution of the sensitizing antibody. Thus optimal sensitization is essential for granulocyte EAIgG rosette formation, and relatively fresh indicator cells for EAC3b rosette formation. Hemolysis of contaminating erythrocytes did not influence EAIgG or EAC3b rosette formation.

Complement System Proteins↗