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H Sjursen

Publications and source records attributed to H Sjursen.

34 records · Page 2Linked to original sources
PubMed1991

Negative selection of human monocytes using magnetic particles covered by anti-lymphocyte antibodies.

We have developed a standardized procedure for the isolation of monocytes from peripheral blood by negative selection using magnetic polymer particles coated with monoclonal antibodies against T and B lymphocytes. The average purity of the monocyte suspension was 85%, and monocyte recovery was 72% from Ficoll-Hypaque gradient separated mononuclear cells and 32% from whole blood. In a lucigenin enhanced chemiluminescence assay there was no significant difference between cells separated immunomagnetically and those separated on a gradient. Nor did electron microscopy show any significant difference in morphology between such monocytes. Negative selection using magnetic polymer particles is an efficient method for the separation of monocytes with intact morphology and function as measured by chemiluminescence.

Antibodies, Monoclonal↗
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

[Viral infections in immunocompromised patients].

An increasing number of patients are immunocompromised due to modern treatment of cancer, organ transplantations and HIV-infections. Opportunistic viral infections are common and may cause serious disease among these patients. New vaccines, immunomodulators and antiviral drugs make it possible to prevent and treat many of these infections. We review the host defence against viral infections and the most important viral infections. We also discuss prophylaxis, diagnosis and therapy.

Antiviral Agents↗
PubMed1990

Health workers and the human immunodeficiency virus: knowledge, ignorance and behaviour.

The attitude of health personnel towards the human immunodeficiency virus (HIV) has a great influence on public opinion. Thus appropriate knowledge about HIV and its routes of transmission, plus safe and professional behaviour are crucial. A survey of 359 Norwegian health workers (75% response) revealed that factual knowledge was good. Fear of occupational transmission was substantial, but was not reflected in behaviour: 25-50% of the personnel reported not using gloves when exposed to blood. No relationship was found between knowledge and behaviour. A majority (79%) of the sample held the view that every hospital patient should be routinely tested on admission. Seventy-four per cent advocated preoperative screening, with special precautions if the results are positive. Knowledge did not seem to influence these attitudes. It is concluded that the behaviour of health personnel in relation to occupational risks is unrelated to factual knowledge, and further studies are needed to uncover behavioral determinants.

Acquired Immunodeficiency Syndrome↗
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↗
PubMed1990

Two-layer gradient separation of granulocytes for functional tests.

Two gradient separation techniques were compared with the dextran sedimentation method for the separation of granulocytes from blood. Both techniques gave adequate yield and excellent purity, and flow cytometric analysis of surface membrane markers gave no indication of subset selection during the procedure. Cells separated by the three methods behaved comparably in functional tests including random migration, chemotaxis and chemiluminescence. The gradient separation techniques are rapid and efficient methods for the preparation of near 100% pure granulocyte suspensions for functional studies.

Cell Movement↗
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

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

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↗
PubMed1982

Bacterial contamination of drops and dropper tips of in-use multidose eye drop bottles.

The type and frequency of bacterial contamination of 638 in-use multidose eye drop bottles are reported. By dripping, bacteria were recovered from 82 bottles (12.9%). Bacterial growth considered to be clinically and microbiologically significant were found in 12 cases (1.9%). The swabbings from 38 of 180 dropper tips (21.1%) yielded bacteria, while none of the pipette aspirates from 196 bottles were positive. The flora obtained by dripping and swabbing was very similar to the normal conjunctival and skin flora. It is suggested that microorganisms isolated by dripping often originate from contaminated dropper tips. The frequency of contaminated drops did not increase with increasing duration of use of the bottles. Repeated examinations and inoculation studies indicated that the solutions were self-sterilizing. This indicates that multidose eye drop bottles preserved and dispensed as in the present study may be used for more than the usual 4 weeks without increasing the risk of ocular infection.

Bacteria↗
PubMedDate not supplied

Flow cytometry for the study of phagocyte functions.

Phagocytes play a key role in host defense, and cell defects are associated with increased susceptibility to infection. Flow cytometry offers rapid and reproducible measurements of single cells in suspension and, following staining with one or more fluorochromes, simultaneous examination of several cell functions. Subpopulations of cells can be identified and sorted for morphologic, biochemical, and functional examination, and specially adapted computer systems allow storage of data for subsequent detailed analysis. Several flow-cytometric assays for the study of phagocytes and their interactions with microorganisms have been developed. These assays facilitate the study of (1) phagocyte surface receptors and regulatory molecules; (2) membrane potential; (3) phagocytosis of microorganisms, including the discrimination between attachment to the phagocyte surface and actual internalization; (4) phagosomal pH; (5) degranulation and enzymatic activity; (6) intracellular calcium; (7) oxidative metabolism; (8) intracellular killing of microorganisms; (9) degradation of microorganisms; and (10) exocytosis. In addition, the influence of serum opsonins on phagocyte-microorganism interactions can be studied. Flow-cytometric techniques are applicable to both experimental and clinical work.

Cell Separation↗
PubMedDate not supplied

Freeze induced glucose accumulation in the enchytraeid, Fredericia ratzeli from Greenland.

The tolerance of freezing and associated accumulation of cryoprotectants was studied in an Arctic population of the enchytraeid Fredericia ratzeli. At -3 and -5 degrees C specimens readily froze when slowly cooled in contact with moist soil. A small fraction of the animals (10-20 %) survived internal ice formation under these circumstances. Frozen specimens had elevated glucose concentrations as compared to unfrozen control animals acclimated at 0 degrees C. In a fraction of the animals, equal to the fraction surviving freezing, a high concentration of glucose was detected. The highest values amounted to ca. 150 microg mg(-1) dry weight, corresponding to ca. 270 mmoles L(-1). It is argued that the physiology of freeze tolerance in this enchytraeid resembles the physiology described for freeze tolerant earthworms and frogs.

Animals↗
PubMedDate not supplied

Interactions between environmental pollution and cold tolerance of soil invertebrates: a neglected field of research.

The adaptations to climatic stress of invertebrates have been extensively studied and the underlying physiology is relatively well understood. It is therefore possible to predict critical lower temperature and moisture limits at which a species will suffer increased mortality. Environmental pollution can reduce the tolerance to climatic stress considerably but it is not known how significant these synergistic effects are in polluted areas. Results are presented showing examples of synergism between toxic and climatic stress. The physiological mechanisms involved in the synergistic effects are discussed.

Journal Article↗