Search PubMed⌕ Search

Biomedical subjects

A Halstensen

Publications and source records attributed to A Halstensen.

At least 55 records · Page 3Linked to original sources
PubMed1991

Immunization against serogroup B meningococci. Opsonin response in vaccinees as measured by chemiluminescence.

One hundred and thirteen healthy volunteers were immunized twice (six weeks apart) with four different doses (12.5, 25, 50 and 100 micrograms, measured as protein content) of an outer membrane vesicle vaccine from a serogroup B meningococcal strain (44/76, B:15:P1.16) complexed to serogroup C meningococcal polysaccharide and/or Al(OH)3 i.e. 12 different vaccines. Serum opsonic activity against the serogroup B strain was measured using a chemiluminescence method. A significant rise in serum opsonic activity was demonstrated in 84 volunteers (74%) six weeks after the first injection and in 97 (86%) six weeks after the second. All vaccinees with low preimmunization values (less than 25 mVs) experienced a significant increase in opsonic activity. A dose-related response was most evident for the vaccines containing adjuvant, and these vaccines were associated with a maximum response six weeks after the second injection, while the vaccines without Al(OH)3 induced a peak response six weeks after the first injection. The postimmunization opsonic activity was similar to that found in convalescent sera, indicating that the vaccines may protect against serogroup B meningococcal disease.

Adolescent↗
PubMed1990

[Treatment of infections caused by group A beta-hemolytic streptococci].

Since 1987 the number of severe and fatal cases of group A-beta-hemolytic streptococci (GAS) infections has increased in Scandinavia. It therefore seems reasonable to stress the monitoring, diagnosis and treatment of infections caused by GAS. Treatment with phenoxymethylpenicillin for ten days is recommended for patients with uncomplicated disease. Patients with severe disease should be treated with benzylpenicillin intravenously. We discuss alternative antibiotics, treatment of immunological complications, and general hygienic precautions.

Adult↗
PubMed1990

[The challenges of differential diagnosis of infections caused by beta-hemolytic streptococci].

Infections due to Streptococcus pyogenes are varied and often difficult to diagnose. During the last few years the clinical manifestations of these infections and the treatment rationale have changed. New diagnostic tests have been introduced. The present article reviews the diagnostic possibilities based upon clinical findings, the doctor's own laboratory and the microbiological laboratory. Rapid immunological tests, differential leukocyte count and C-reactive protein are pointed out as potentially useful laboratory tools for the clinician.

C-Reactive Protein↗
PubMed1990

IgG subclass antibodies to serogroup B meningococcal outer membrane antigens following infection and vaccination.

IgG and IgG subclass antibodies to the outer membrane antigens from Neisseria meningitidis (serogroup B, serotype 15:P1.16) were quantitated by an enzyme-linked immunosorbent assay (ELISA) in sera from 40 patients with group B:15:P1.16 meningococcal disease and 24 volunteers immunized with a serotype 15:P1.16 outer membrane vesicle vaccine. A second injection was given 6 weeks after the first immunization. Patient sera obtained two and six weeks after onset of the disease had significantly higher levels of total IgG, IgG1, IgG2, and IgG3 antibodies to the outer membrane antigens than acute sera, convalescent sera from patients with systemic non-meningococcal bacterial infections and sera from healthy controls. The levels of total IgG and IgG1 remained high one and three years later. Sera from the vaccinees showed high levels of total IgG and IgG1 6, 12 and 26 weeks after the first immunization and high levels of IgG3 6 weeks after the second immunization. No increase of IgG2 or IgG4 levels was observed in the postimmunization sera. Immunoblotting of three convalescent sera demonstrated individual patterns of IgG subclass binding to various outer membrane antigens with most distinct binding of IgG1 and IgG3 antibodies to the class I protein, the H.8 lipoprotein and the lipopolysaccharide. Since IgG1 and IgG3 are the most effective antibodies for complement activation and phagocytosis, group B meningococcal disease and immunization with the serotype 15:P1.16 outer membrane vesicle vaccine stimulate production of those IgG subclasses which have the strongest opsonic and bactericidal activity.

Adolescent↗
PubMed1989

Local production of tumor necrosis factor alpha, interleukin 1, and interleukin 6 in meningococcal meningitis. Relation to the inflammatory response.

We examined the cerebrospinal fluid (CF) taken on admission from 60 patients with infections caused by Neisseria meningitidis for presence of TNF-alpha, IL-1, and IL-6. TNF-alpha was detected in CF in 55 and 19% (p = 0.03), IL-1 in 50 and 15% (p = 0.05), and IL-6 in 98 and 100% of patients with meningitis and septic shock/bacteremia, respectively. The median IL-6 concentration in CF in patients with meningitis was 154 ng/ml, and in patients with septic shock/bacteremia it was 42 ng/ml (p = 0.001). The level of LPS in CF correlated with the level of TNF-alpha (r = 0.91, p less than 0.001), but not with the level of IL-1 and IL-6. CF levels of TNF-alpha, IL-1, and IL-6 correlated with each other (r = 0.34-0.54, p less than 0.01), with the protein concentration (r = 0.34-0.62, p less than 0.01) and inversely with the CF/blood glucose ratio (r = -0.34 to -0.67, p less than 0.01). Only the Il-6 level correlated with the leukocyte count (r = 0.37, p less than 0.01). In rabbits TNF-alpha, IL-1, and IL-6 activities sequentially appeared in CF within 3 h of injection of meningococcal LPS or viable meningococci, whereas the main infiltration of granulocytes started after 4 h. TNF-alpha was detected in serum at concentrations less than 1/100 of those in CF after administration of LPS into the subarachnoid space, and conversely, TNF-alpha was detected in CF at concentrations 1/100 of those in serum after intravenous injection of LPS. The results demonstrate that TNF-alpha, IL-1, and IL-6 are sequentially produced in the initial phase of the local inflammatory response caused by meningococci, and that the subarachnoid space and systemic circulation are separate compartments with respect to production of TNF-alpha, IL-1, and IL-6.

Adolescent↗
PubMed1989

Flow cytometric assay for the measurement of serum opsonins to Neisseria meningitidis serogroup B, serotype 15.

A flow cytometric phagocytosis assay has been developed for the measurement of human serum opsonins to serogroup B meningococci. Live bacteria and bacteria inactivated by heat, formalin or ethanol were labelled with fluorescein-isothiocyanate (FITC). The bacteria were opsonized with sera from patients with group B meningococcal disease and sera from healthy controls, and phagocytosis determined by combined measurements of FITC-fluorescence and forward angle light scatter. Optimal sensitivity was obtained using viable bacteria, 5% serum, 20 bacteria per leukocyte capable of phagocytosis, 7.5 min opsonization time, 5 min phagocytosis time, 37 degrees C, and continuous agitation during opsonization and phagocytosis. The opsonic activity of sera from convalescent patients was markedly higher than that of sera from patients with acute illness. Only minor day-to-day and interindividual variations were observed. The flow cytometric phagocytosis technique is a rapid and reproducible method for the measurement of serum opsonins to meningococci.

Blood Bactericidal Activity↗
PubMed1989

The complex pattern of cytokines in serum from patients with meningococcal septic shock. Association between interleukin 6, interleukin 1, and fatal outcome.

Serum samples from patients with meningococcal disease were examined for the presence of IL-6, TNF-alpha, and LPS. Median serum concentration of IL-6 was 1,000 times higher in patients with septic shock (189 ng/ml) than in patients with bacteriaemia, meningitis, or combined septic shock and meningitis. 11 of 21 patients with serum levels greater than 3.0 ng/ml died, whereas all 58 patients with serum levels at less than or equal to 3.0 ng/ml, survived. All four patients with serum IL-6 levels greater than 750 ng/ml, died. IL-1 was detected in serum from three patients who also had high serum levels of IL-6, TNF-alpha, and LPS, and rapidly fatal courses. IL-6 appeared to be released into serum later than TNF-alpha, and was detected in serum for up to 36 h. The half-life of IL-6 and TNF-alpha was calculated to be 103 +/- 27 min and 70 +/- 11 min, respectively. These data indicate that a complex pattern of cytokines exists in serum from patients with meningococcal septic shock, and that the release of IL-6 and IL-1, in addition to TNF-alpha, is associated with fatal outcome.

Humans↗
PubMed1989

Serum opsonins to serogroup B meningococci in meningococcal disease.

The opsonic activity to serogroup B meningococci (B:15:P1.16) was measured in sera from 101 patients with meningococcal disease using a chemiluminescence method. On admission to hospital the opsonic activity was lower in 12 patients who died than in survivors (p = 0.0007). A close association was observed between the opsonic activity and the duration of symptoms before admission, the severity of the disease, and the levels of IgG antibodies to the outer membrane complex (15:P1.16). The opsonic activity was low in 2 premorbid sera compared to healthy controls. The mean opsonic activity peaked 2 weeks after admission and was still high 3-5 years later. Meningococcal strains of different serogroups, serotypes and subtypes induced a similar increase in opsonic activity to B:15:P1.16 meningococci. No increase in activity was observed in sera from patients with meningitis and septicemia caused by other bacteria. Serum opsonins seem to be of significant importance in the host defence against serogroup B meningococci.

Adolescent↗
PubMed1987

Association between tumour necrosis factor in serum and fatal outcome in patients with meningococcal disease.

Serum samples taken on admission from 79 patients with meningococcal meningitis, septicaemia, or both, were examined in a highly sensitive bioassay for tumour necrosis factor (TNF). TNF was detected in samples from 10 of 11 patients who died but from only 8 of 68 survivors. All 5 patients with serum TNF levels over 440 units/ml (corresponding to 0.1 ng/ml recombinant TNF) died.

Adolescent↗
PubMed1987

Standardization of a chemiluminescence method for the measurement of meningococcal opsonins using ethanol fixed meningococci.

A chemiluminescence (CL) method using polymorphonuclear leukocytes (PMNLs) and an automatic photoluminometer was used to measure serum opsonins to viable and inactivated group B meningococci. Continuous mixing at 37 degrees C both during opsonization and phagocytosis was essential for optimal CL responses. The CL response increased rapidly during an opsonization time up to 7.5 min, and with PMNL and bacteria concentrations up to 37.5 X 10(5) and 3.8 X 10(7) cells/ml, respectively. Opsonized ethanol fixed meningococci gave CL responses similar to those of viable meningococci, but had a better reproducibility. Using the ethanol fixed bacteria, the variation of PMNLs from different donors, the day-to-day variation, and the coefficient of variation of the CL responses, were all less than 10%. The opsonic activity of convalescent sera from 10 patients with meningococcal disease was markedly higher than that of sera obtained during the acute phase of the disease. Thus, this standardized CL assay using ethanol fixed bacteria is a highly reproducible and sensitive method for measuring serum opsonins to meningococci.

Ethanol↗
PubMed1987

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↗
PubMed1987

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↗
PubMed1987

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↗
PubMed1986

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↗
PubMed1986

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↗