Biomedical subjects

H Sjursen

Publications and source records attributed to H Sjursen.

At least 19 recordsLinked to original sources

PubMed2001

[Antibiotic treatment of infectious endocarditis].

BACKGROUND: Infective endocarditis is a septic condition in which the heart valves and the endocardial surfaces are infected, causing bacteraemia. In Norway, infective endocarditis is the most common infectious disease of the heart and accounts for approximately one case per 1,000 hospital admissions. The mortality rate is 15-40%. MATERIAL AND METHODS: This article presents a review of antimicrobial treatment of infective endocarditis, based on relevant literature and the author's clinical experience. Prophylactic treatment is not described. RESULTS AND INTERPRETATION: Early start of antimicrobial treatment is extremely important in order to avoid destruction of the heart valves and should always be started as soon as endocarditis is suspected and blood cultures have been drawn. The patient must be treated with bactericidal antibiotics in high doses given intravenously for four to eight weeks, depending on the aetiologic agents and the response. Only antibiotics that have been proven effective against endocarditis should be used. The minimal inhibitory concentration (MIC) should be determined for all antibiotics used.

Anti-Bacterial Agents↗

PubMed2001

[Treatment of acute bacterial meningitis].

BACKGROUND: Acute bacterial meningitis requires immediate antimicrobial therapy. MATERIALS AND METHODS: Guidelines to antimicrobial treatment of children and adults with acute bacterial meningitis are presented. RESULTS: The most common agents causing acute bacterial meningitis are Streptococcus agalactiae in children less than one month of age, and Streptococcus pneumoniae and Neisseria meningitidis in individuals more than one month of age. If the causative bacterial agent is not known, children below one month of age should be given ampicillin and gentamicin, whereas older children and adults should be given benzylpenicillin in combination with either cefotaxime or ceftriaxone. We suggest treatment with specific antibiotic regimens in cases of known aetiology.

Acute Disease↗

PubMed2001

The effect of zanamivir treatment on the early immune response to influenza vaccination.

Zanamivir is licensed for influenza treatment, but may also play a role in prophylaxis either alone or in combination with vaccine in epidemic periods. We conducted a double blind placebo controlled trial to investigate the effect of zanamivir treatment on the humoral immune response to influenza vaccine. Forty young healthy volunteers were vaccinated with licensed trivalent influenza vaccine and received 20 mg zanamivir (24 subjects) or placebo (16 subjects) daily for a period of 14 days. No significant differences were observed in the magnitude or the time course of the antibody response to the influenza H3N2 and B strains between the two groups, in contrast the placebo group responded with higher antibody titres to the H1N1. Our results suggest that during an influenza epidemic, volunteers would only need to continue zanamivir treatment for the initial 12 days after vaccination whilst the vaccine induced protective antibody response developed.

Administration, Inhalation↗

PubMed2001

Enhanced drought tolerance of a soil-dwelling springtail by pre-acclimation to a mild drought stress.

The springtail Folsomia candida has a highly permeable cuticle, but is able to survive several weeks at 98.2%RH. This corresponds to a water potential deficit of about 17bars between the environment and the normal osmotic pressure of the body fluids of this animal. Recent studies have shown a water vapour absorption mechanism by accumulation of sugars and polyols (SP) in F. candida, which explains how this species can survive dehydrating conditions. In the present study, adult F. candida were pre-acclimated at 98.2%RH to induce the accumulation of SP, and were subsequently exposed for additional desiccating conditions from 98 to 94%RH. Activity level, water content, osmotic pressure of body fluids and SP composition were investigated. After the desiccation period, the animals were rehydrated at 100%RH and survival was assessed. The results showed that F. candida survived a more severe drought stress when it had been pre-acclimated to 98.2%RH before exposure to lower humidity. This species was able to maintain hyperosmosity to the surroundings at 95.5%RH, suggesting that it can absorb water vapour down to this limit. Below this limit, trehalose levels increased while myo-inositol levels decreased. We propose that this is a change of survival strategy where F. candida at mild desiccation levels seek to retain water by colligative means (remain hyperosmotic), but at severe desiccation levels switches to an anhydrobiotic strategy.

Journal Article↗

PubMed2001

Antibiotic susceptibility of blood culture isolates of Enterobacteriaceae. A Norwegian multicenter study.

From May to November 1997 each of six major hospitals throughout Norway collected 72 to 104 consecutive blood culture isolates of Enterobacteriaceae, altogether 563 isolates. Escherichia coli was the predominating organism (69%), followed by Klebsiella spp. (15%), Enterobacter spp. (6%), and Proteus mirabilis (4%). The susceptibility of the isolates to ampicillin, cefuroxime, ceftazidime, imipenem, tobramycin, and ciprofloxacin was determined by the E-test. 37% and 7% of the isolates were resistant to ampicillin and cefuroxime, respectively, and 1% were resistant to ceftazidime and tobramycin. Only one isolate of P. mirabilis was imipenem resistant. All isolates were susceptible to ciprofloxacin. The prevalence of ampicillin-resistant isolates at each hospital varied from 21 to 45%, and of cefuroxime-resistant isolates from 3 to 9%. The results were compared with those of a similar study performed in 1991-1992. No significant changes in the susceptibility to the various agents could be demonstrated. The high frequency of isolates resistant to ampicillin has clearly limited the usefulness of this agent in the treatment of septicemia and other serious infections caused by Enterobacteriaceae.

Anti-Bacterial Agents↗

PubMed2001

Effects of polycyclic aromatic compounds on the drought tolerance of Folsomia fimetaria (Collembola, Isotomidae).

Drought tolerance (survival at 98.2% relative humidity and 20 degress C) was investigated for adult individuals of the springtail Folsomia fimetaria after three weeks of exposure to different polycyclic aromatic compounds (PACs). Seven PACs were investigated (acridine, dibenzofuran, carbazole, fluorene, dibenzothiophene, fluoranthene, and pyrene), with each substance used at several exposure concentrations. Sublethal concentrations of dibenzothiophene, fluorene, fluoranthene, and pyrene caused a dose-related decrease in drought tolerance in exposed adults, whereas no such relationship was found for acridine, dibenzofuran, and carbazole. The organisms used in the drought tolerance study were taken directly from standard ecotoxicity tests that had just been completed, hence the concentrations causing subsequent effects on drought tolerance and those affecting survival and reproduction in the ecotoxicity tests could be compared. Some of the tested substances significantly reduced the drought tolerance of F. fimetaria at concentrations that had little effect on survival, indicating a synergistic effect of the two stressors. However, drought tolerance was affected at concentrations below the threshold value for toxicity in standard tests (no-observed-effect concentration for reproduction) only for dibenzothiophene. In the field, soil organisms exposed to contaminants also face multiple environmental stressors such as drought and cold. Because the reduced drought tolerance is a side effect of chemical exposure, such effects should be considered when extrapolating from laboratory to field conditions.

Adaptation, Physiological↗

PubMed2000

Seasonal changes in tolerance to cold and desiccation in Phauloppia sp. (Acari, Oribatida) from Finse, Norway.

In the alpine region at Finse, Norway, Phauloppia spp. (Acari, Oribatida) inhabit lichens on top of boulders. Adult mites are about 0.5 mm in length and have a mean weight of ca. 15 µg. Temperatures in the lichens may drop below -35 degrees C in winter and increase to 55 degrees C in the summer. Large seasonal variations were recorded in supercooling points and body fluid osmolality. Mean January values of SCPs and osmolality were -35.3 degrees C and 3756 mOsm, while July values were -9.4 degrees C and 940 mOsm, respectively. Thermal hysteresis proteins were present in both summer and winter acclimated mites. In mid-winter, some of the mites survived more than 49 days in a water vapor saturated atmosphere at -19 degrees C, and more than 42 days enclosed in ice at the same temperature.The mites showed high tolerance to desiccation. Specimens collected in October survived up to 23 days at 22 degrees C and 5% RH. The tolerance to desiccation was lower in specimens collected during the winter. Some mites survived the loss of up to 90% of their total water content and were reactivated when given access to water. Length measurements of individual Phauloppia sp. showed that both male and female mites are clearly divided in two size groups, suggesting that they belong to two closely related species or different populations.

Journal Article↗

PubMed2000

Immunity to diphtheria among children in Northern Norway and North-Western Russia.

In 1990, diphtheria re-emerged in Russia and during the following four-year period the resulting epidemic reached all the Newly Independent States (NIS) of the former Soviet Union. Several neighbouring countries of NIS, Norway included, have experienced sporadic imported cases. A sero-epidemiological study among children in Northern Norway and North-Western Russia was performed in order to evaluate protection against diphtheria and how differences in vaccination programmes affect immunity. A total of 664 sera, 400 from Norwegian and 264 from Russian children, were examined for antibodies against diphtheria, using an in vitro toxin neutralisation method. The Russian children studied had satisfactory protection in all age groups examined. The Norwegian children had poor protection against diphtheria from the age of 7 years until they received the booster dose at the age of 11. Therefore, a revision of the Norwegian vaccination programme, including a booster dose at school-entry age, seems warranted.

Antibodies, Bacterial↗

PubMed2000

Immunodeficiency in alpha-mannosidosis: a matched case-control study on immunoglobulins, complement factors, receptor density, phagocytosis and intracellular killing in leucocytes.

UNLABELLED: Patients with the autosomal recessive lysosomal storage disease alpha-mannosidosis suffer from recurrent infections. To study the mechanisms of this immunodeficiency, six patients were matched against six healthy controls and their humoral and cellular immunocompetence investigated. No differences in the number of circulating leucocytes including B-cells, levels of immunoglobulin main classes, nor IgG subclasses were observed. However, post-immunisation serum levels of specific antibodies against poliovirus, diphtheria toxin and tetanus toxin were significantly reduced. In patients, the density of the complement-binding receptor CD11b and the Fc-receptor CD16 was significantly enhanced on monocytes and polymorphonuclear neutrophils (PMN) and the number of phagocytosing PMN was significantly increased in the presence of pooled human serum. This was not observed in the presence of autologous serum, indicating altered opsonic properties. Also in normal PMN, phagocytosis was inhibited by a factor in the serum from the patients. Despite maintained oxidative burst, patient PMN demonstrated insufficient intracellular bacterial killing. CONCLUSION: Our data indicate that patients with alpha-mannosidosis have an immunodeficiency at both the humoral and cellular level.

Adolescent↗

PubMed1999

[Once-daily dosage of aminoglycosides--a therapeutic simplification and an economical benefit].

Conventionally, aminoglycosides have been administered in two or three daily doses. Numerous in-vitro and animal experiments and several clinical trials favour a once-daily dosage regimen of aminoglycosides, which provides a more rapid concentration-dependent bacterial killing and is probably less toxic than two or three dosage regimens. In this article the pharmacological and microbiological background for once-daily aminoglycoside administration is reviewed, and some controlled trials are discussed. Recommendations for clinical practice are given.

Anti-Bacterial Agents↗

PubMed1999

Leukocyte adhesion deficiency in a Norwegian boy.

A Norwegian boy suffering from recurrent urinary and respiratory tract infections was examined. It was found that granulocyte random migration, respiratory burst activity and the proportions of CD11/CD18 receptor positive leukocytes were reduced, consistent with a diagnosis of leukocyte adhesion deficiency. An increased proportion of Fc gammaI-receptor-bearing granulocytes did not compensate for the CR3 deficiency.

Adolescent↗

PubMed1999

Detection of diphtheria antitoxin by four different methods.

OBJECTIVE: To investigate the reliability of the different methods used in Norway and Russia for detection of diphtheria antitoxin. METHODS: One hundred and twenty-two sera were selected among Russian serum samples previously collected for seroepidemiologic studies of diphtheria antitoxin. The sera were selected to cover the total antitoxin range and were analyzed by four different antidiphtheria toxin assays: an in vitro toxin neutralization test using Vero cells (in vitro NT), an in vivo neutralization test using rabbit skin inoculation (in vivo NT), an indirect enzyme immunoassay (EIA) and a passive hemagglutination assay (PHA). The results were expressed according to the international standard as: not protected (<0.01 IU/mL), relatively protected (0.01-0.1 IU/mL) or protected (≥0.1 IU/mL). The sensitivity, specificity and inter-rater agreement (K or Kw) of each method were related to the in vitro NT selected as the reference method. RESULTS: The in vivo NT test corresponded very well with the in vitro NT in its ability to differentiate between protection/relative protection and no protection (sensitivity 97%, specificity 87% and K=0.84). The EIA test showed a high sensitivity (96%), but since many sera were categorized as protected rather than not protected, the specificity (30%) and inter-rater agreement (K=0.29) were low. The PHA test had a very high specificity (100%) but a low sensitivity (86%). CONCLUSIONS: The agreement between the two neutralization tests was high. If none of the neutralization assays is routinely available, the PHA test can be used to predict the need for vaccination on an individual basis but should not be used for seroepidemiologic studies, since the protection rate for diphtheria would be falsely too low, due to the lower sensitivity. The indirect EIA test used in this study should not be used routinely.

Journal Article↗

PubMed1997

Antibiotic susceptibility of blood culture isolates of Enterobacteriaceae from six Norwegian hospitals 1991-1992.

From August 1991 to February 1992, each of the six largest hospitals throughout Norway collected 84 to 107 consecutive blood culture isolates of Enterobacteriaceae, altogether 571 isolates. The distribution of various species and genera at the different hospitals was uniform; Escherichia coli being most prevalent (57-67%), followed by Klebsiella spp. (12-18%) and Proteus mirabilis (7-11%). Twenty-one and 4% of E. coli isolates were resistant to ampicillin and cefuroxime, respectively, and 11% of Klebsiella isolates were cefuroxime resistant. Five Enterobacter isolates and one Citrobacter isolate were resistant to ceftazidime, and one Salmonella isolate was resistant to imipenem. All isolates were susceptible to ciprofloxacin and tobramycin. These results were compared with the antibiotic consumption in each hospital region. Although hospitals in the regions with the highest consumption of ampicillin tended to have a higher percentage of isolates resistant to this agent, no significant differences were found. There was no significant difference between hospitals regarding prevalence of cefuroxime-resistant isolates.

Anti-Bacterial Agents↗

PubMed1997

The influence of growth hormone on tumour necrosis factor and neutrophil leukocyte function in sepsis.

The aim of this study was to assess the influence of growth hormone (GH) in sepsis on the immune system represented by the circulating TNF-levels and the neutrophil leukocytes phagocytic capacity and respiratory burst, 22 piglets were randomized to 3 groups; pretreatment with GH (16 i.u.) before sepsis (n = 8), non-treated septic controls (n = 8), and non-septic controls (n = 6). Sepsis was induced by a standardized infusion of live E. coli. TNF was measured by a cytotoxic bioassay, while neutrophil function tests were carried out by flowcytometric assays. In brief, phagocytosis was evaluated by the neutrophils' ability to ingest FITC-labelled (fluorescein isothiocyanate) E. coli and intracellular release of oxygen metabolites was detected by the oxidation of 2',7'-dichlorofluorescin (DCFH) to the fluorescent 2',7'-dichlorofluorescein (DCF). Our data show a suppression of phagocytosis in the GH-treated group before sepsis; however, when challenged with Gram-negative bacteria, the phagocytic capacity was similar to that of the non-treated animals. The serum levels of TNF in the non-treated septic control group were twice the levels of those in the GH-treated group, 65.7 pg/ml (septic controls) vs 32.8 pg/ml (GH). Pretreatment with a single dose of GH few hours prior to sepsis does not seem to entail any further imbalance of the neutrophil function in sepsis. Lowering of the circulating TNF-levels is a presumptive favourable effect of GH in sepsis.

Animals↗

PubMed1995

Retention of phagocytic functions in cryopreserved human monocytes.

Phagocytosis and respiratory burst activity were measured by flow cytometry in fresh and cryopreserved human monocytes, after ingestion of Escherichia coli and Staphylococcus aureus. Mononuclear leukocytes, isolated from 15 healthy donors, were divided into two portions, of which one was examined immediately and the other was cryopreserved for 3 weeks. Morphological characteristics and expression of receptors involved in phagocytosis were similar in fresh and cryopreserved monocytes. Furthermore, both internalization of bacteria and respiratory burst activity remained unchanged after cryopreservation. Transmission electron microscopy confirmed actual internalization of bacteria and not merely bacterial attachment to monocytes. Monocytes were demonstrated to retain integral cellular functions during cryopreservation. This may imply that the method has potential for use in basal and clinical trials.

Adult↗

PubMed1995

Immunity to diphtheria in northern Norway and northwestern Russia.

A case of diphtheria, which has not been seen in Norway for 30 years, was reported in 1992 in the northern part of the country bordering Russia. An increasing number of cases of diphtheria has been reported in the former USSR, including the northwestern part of Russia. In order to elucidate the potential of an epidemic spread across the Norwegian-Russian border, a seroepidemiological study was performed. A total of 470 sera, 243 from Finnmark, Norway, and 227 from Arkhangelsk, Russia, were examined for antibodies against diphtheria toxin, using an in vitro toxin neutralisation method. No statistically significant difference in the presence of diphtheria antitoxin between the Norwegian and the Russian populations was found. The presence of neutralising antibodies decreased by age, and this decrease was most pronounced among the Russians. Individuals aged 40 to 70 years, and Norwegian women in particular, seem to have an increased risk for diphtheria as judged by the diphtheria antitoxin levels.

Adolescent↗

PubMed1995

Safety and efficacy of meropenem in patients with septicaemia: a randomised comparison with ceftazidime, alone or combined with amikacin.

Meropenem is a new broad spectrum carbapenem antibiotic which can be administered as monotherapy for serious infections. The efficacy and safety of meropenem was compared with that of ceftazidime (alone or in combination with amikacin) in 153 patients with septicaemia who were enrolled into identical, prospective, randomised studies. Forty-five patients with infections arising from the urinary or lower respiratory tracts were given either meropenem 500 mg or ceftazidime 250-1000 mg intravenously every 8 h; 108 patients with more serious infections were given meropenem 1 g or ceftazidime 2 g every 8 h +/- amikacin 15 mg/kg/day. Overall, 71 patients received meropenem, 47 ceftazidime and 35 ceftazidime plus amikacin. Comparable clinical response rates were achieved in the meropenem and ceftazidime/amikacin groups (92% vs 94% at the end of therapy respectively). Furthermore, a satisfactory bacteriological response was obtained in all evaluable patients. The most common pathogens isolated were Escherichia coli, Streptococcus pneumoniae and Pseudomonas aeruginosa. Relapse occurred in one patient in the ceftazidime/amikacin group, who had a mixed infection of E. coli and P. aeruginosa. There were no relapses in the meropenem group. Both treatments were well tolerated and only one patient had to withdraw from the trial because of an adverse effect (rash associated with ceftazidime). In conclusion, these data confirm that meropenem monotherapy is well tolerated and is as effective as ceftazidime (alone or combined with amikacin) in the empirical treatment of septicaemia. It should prove to be a useful addition to the drugs currently available for this life-threatening disease.

Adult↗

PubMed1992

Monocyte phagocytosis of opsonized Neisseria meningitidis serogroup B.

The chemiluminescence (CL) was examined when peripheral blood monocytes were incubated with opsonized Neisseria meningitidis, serogroup B, serotype 15:P1.16 or serotype 2a:P1.2. The monocytes were separated from a mononuclear cell suspension by an immunomagnetic negative selection technique using magnetic polystyrene microspheres coated with monoclonal antibodies specific for T and B lymphocytes. More than 90% of the lymphocytes were removed, yielding a suspension containing 93% monocytes. Optimal sensitivity for phagocytosis was obtained using 1% serum (10 microliters), 72 bacteria per monocyte cell, and 7.5 min opsonization and incubation time during continuous agitation at 37 degrees C. The CL was amplified by lucigenin. Preliminary experiments suggest that convalescent sera from patients with group B meningococcal disease induced increased CL responses compared to acute sera. Sera from volunteers immunized with an outer membrane complex vaccine from serogroup B, serotype 15:P1.16 or 2a:P1.2 meningococci also induced increased CL activity compared to preimmune sera. No such response was shown when a group B capsular polysaccharide vaccine was given. This response pattern was also demonstrated by a flow cytometric phagocytosis technique (FCM). Internalization of meningococci by monocytes was demonstrated by a FCM quenching technique and by transmission electron microscopy. CL and FCM represent rapid and reproducible methods for the measurement of opsonophagocytosis of meningococci by monocytes and may be performed with minute amounts of sera.

Adult↗