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Biomedical subjects

B Frederiksen

Publications and source records attributed to B Frederiksen.

At least 19 recordsLinked to original sources

Eradication of early Pseudomonas aeruginosa infection.

Chronic pulmonary infection with Pseudomonas aeruginosa is responsible for most of the morbidity and mortality in cystic fibrosis (CF). Once established as a biofilm, chronic P. aeruginosa infection caused by the mucoid phenotype cannot be eradicated. However, a period of intermittent colonization with P. aeruginosa precedes the establishment of the chronic infection. This window of opportunity can be utilized to eradicate P. aeruginosa from the respiratory tract of CF patients by means of oral ciprofloxacin in combination with nebulized colistin for 3 weeks or, even better, for 3 months or by means of inhaled tobramycin as monotherapy for 4 weeks or longer. This early, aggressive eradication therapy has now been used for 15 years without giving rise to resistance to the antibiotics and without serious side effects. The therapeutic results have been very successful and have completely changed the epidemiology in the Danish Cystic Fibrosis Center and a few other centers which have used this strategy for several years. The chronic P. aeruginosa lung infection is not seen in CF infants and children anymore due to the aggressive therapy, and no other bacteria have replaced P. aeruginosa in these young patients. The aggressive therapy has been shown to very cost-effective, and a European Consensus report recommends this approach.

Anti-Bacterial Agents↗

Pseudomonas aeruginosa cross-infection among patients with cystic fibrosis during a winter camp.

Twenty-seven patients with cystic fibrosis from our Danish Cystic Fibrosis Center went to a winter camp for 1 week in November of 1990. This study is based on 22 of these patients. Prior to attending camp, 17 out of 22 patients harbored Pseudomonas aeruginosa in their sputum, but 5 patients did not. After returning from camp, all 22 patients harbored P. aeruginosa in the sputum, including the 5 patients whose sputum was free of P. aeruginosa before they went. Epidemiological typing used pulsed-field gel electrophoresis of the P. aeruginosa isolates was performed. The typing results showed that the 5 cystic fibrosis patients who were free of P. aeruginosa in their sputum prior to the winter camp had acquired P. aeruginosa isolates identical to the P. aeruginosa strains isolated from the other 17 cystic fibrosis patients. This constitutes a cross-colonization rate of 100%, the highest rate ever detected among patients with cystic fibrosis. We conclude that separate holiday camps based on the infection status of the patients with cystic fibrosis are necessary to avoid cross-infection of patients not infected with P. aeruginosa.

Adolescent↗

Changing epidemiology of Pseudomonas aeruginosa infection in Danish cystic fibrosis patients (1974-1995).

Recurrent and chronic lower airway infection with Pseudomonas aeruginosa (PA) is an important component of cystic fibrosis (CF) pulmonary disease. Different modes of treatment and control of CF patients have been introduced at the Copenhagen CF Centre over the past 20 years and have been associated with improved survival. Treatment consisted of: 1) elective antibiotics for 14 days every 3 months to patients with chronic PA infection (started in 1976), 2) cohort isolation to prevent cross-infection (patients with PA were separated from patients without PA, starting in 1981); and 3) early intensive treatment with inhaled colistin and oral ciprofloxacin from time of initial PA colonization (started in 1989). The aim of the present study was to evaluate the impact of each of these interventions on the changes in the epidemiology of PA. Based on monthly cultures of lower airway secretions in each CF patient seen during 1974-1995, significant changes in the incidence and prevalence of the PA infection were found. The monthly prevalence of chronic PA increased significantly (P < 0.0001) from below 40% before 1976 to above 60% in 1980, which was found to be due to cross-infection among the CF patients after introduction of elective antibiotic courses in 1976. To deal with this problem, cohort isolation was introduced in 1981, and since then the monthly point prevalence of chronic PA decreased slowly until 1989 (P < 0.0001), when early intensive treatment from initial PA colonization was introduced; this was associated with a further decrease in point prevalence to 45% in 1995 (P < 0.005). The annual incidence of chronic PA infection also decreased significantly (P < 0.01) from 16% to below 2% after introduction of cohort isolation and early intensive treatment from initial PA isolation. Furthermore, the time from acquisition of first PA to development of chronic PA infection increased significantly, from approximately 1 year to almost 4 years after introduction of cohort isolation (P < 0.0001). After introduction of early intensive treatment, the probability of still not having developed chronic PA infection 7 years after the first isolation of PA was above 80% (P < 0.0001). In conclusion, the introduction of cohort isolation and early intensive treatment following the initial isolation of PA resulted in a reduced incidence and prevalence of chronic PA infection. We are not aware of other studies showing a decreasing prevalence of chronic PA infection, as survival of CF patients has increased.

Adolescent↗

Association of mannose-binding lectin gene heterogeneity with severity of lung disease and survival in cystic fibrosis.

Mannose-binding lectin (MBL) is a key factor in innate immunity, and lung infections are the leading cause of morbidity and mortality in cystic fibrosis (CF). Accordingly, we investigated whether MBL variant alleles, which are associated with recurrent infections, might be risk factors for CF patients. In 149 CF patients, different MBL genotypes were compared with respect to lung function, microbiology, and survival to end-stage CF (death or lung transplantation). The lung function was significantly reduced in carriers of MBL variant alleles when compared with normal homozygotes. The negative impact of variant alleles on lung function was especially confined to patients with chronic Pseudomonas aeruginosa infection. Burkholderia cepacia infection was significantly more frequent in carriers of variant alleles than in homozygotes. The risk of end-stage CF among carriers of variant alleles increased 3-fold, and the survival time decreased over a 10-year follow-up period. Moreover, by using a modified life table analysis, we estimated that the predicted age of survival was reduced by 8 years in variant allele carriers when compared with normal homozygotes. Presence of MBL variant alleles is therefore associated with poor prognosis and early death in patients with CF.

Adolescent↗

Epidemiologic, bacteriologic, and long-term follow-up data of children with acute hematogenous osteomyelitis and septic arthritis: a ten-year review.

A total of 69 children with acute hematogenous osteomyelitis and 48 with septic arthritis admitted in the period 1978 through 1987 were included in a retrospective review. Epidemiologic and bacteriologic data were analyzed and compared with those of an earlier study (1965 through 1975), confined to the same geographic area. Long-term outcome was evaluated by a questionnaire and clinical and radiographic follow-up. A significant increase in the admission rate for both disorders was observed. The long-term outcome was favorable: major sequelae were found in three patients (3%), minor sequelae in two patients (2%). The benign long-term outcome may well be related to rapid hospital admission and appropriate long-lasting antibiotic treatment.

Adolescent↗

[Cystic fibrosis].

Cystic fibrosis (CF), the most common life-threatening autosomal recessive disorder in Causcasian populations, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene on chromosome 7, which encodes a protein that functions as a chloride channel in the apical membrane of epithelial cells. The clinical manifestations comprise recurrent and chronic bronchopulmonary infections, pancreatic insufficiency, and hidrotic salt depletion. Such complications as diabetes, cirrhosis, and respiratory insufficiency develop, resulting in death in the absence of lung transplantation. Treatment is aggressive and comprehensive from the time of diagnosis. Early and intensive treatment of bacterial colonisation and lung infection is correlated with improved prognosis, and monthly follow-up at a CF Centre is mandatory. Mean survival among CF patients at the Danish CF Centre i Copenhagen is more than 40 years. Clinical trials of gene therapy are under way, but results to date have been disappointing.

Chromosome Aberrations↗

[Improved prognosis for patients with cystic fibrosis. A result of aggressive center-based treatment].

We report survival data for Danish centre-treated cystic fibrosis (CF) patients, covering the period 1974-1993 using cross-sectional cumulative survival probability based on annual age-specific mortality rates. No significant differences were noted in the survival probability when patients were grouped according to sex or absence/presence of meconium ileus. The annual mortality rate for 1989-1993 was 0-1.2%. Using the age-specific mortality rate for 1989-1993, we were unable to calculate the median survival probability because the curve did not fall below 50% (age up to 45 years). It was, however, possible to show that the survival probability for a CF child born after 1989 to reach his or hers 45th birthday was 80.4% (95% confidence interval 76.5-84.6%). The probability of surviving 40 years after the diagnosis of CF is made was 83.3% (95% confidence interval 80.1%-86.6%). This is considerably higher than any other published survival probability. An aggressive anti-Pseudomonas aeruginosa treatment regimen seemed important in achieving the observed improved survival.

Adolescent↗

Antibiotic treatment of initial colonization with Pseudomonas aeruginosa postpones chronic infection and prevents deterioration of pulmonary function in cystic fibrosis.

Chronic pulmonary infection with Pseudomonas aeruginosa (PA) develops in most patients with cystic fibrosis (CF) and is associated with a poor prognosis. Much effort has been directed toward treating the chronic infection, but it is almost impossible to eradicate it once established; therefore, prevention is preferable. Since 1989 CF patients at the Danish CF Center in Copenhagen have been treated with an intensive three-step-protocol consisting of colistin inhalations and oral ciprofloxacin at the time of initial PA colonization. This study compares 48 patients treated according to this intensive protocol with 43 historic controls. The study was carried out over 44 months and included 218 patient-years. Only 16% of the treated patients developed chronic PA infection after 3 1/2 years compared with 72% of the control patients (Kaplan Meier estimate, P < 0.005, log rank test). This indicates that aggressive treatment prevented or delayed chronic PA infection in 78% of the patients for 3 1/2 years. Furthermore, aggressive treatment maintained or increased pulmonary function (forced vital capacity and forced expiratory volume in 1 second in percent of predicted values) during the year after inclusion compared with the control group, in which pulmonary function declined (P < 0.01, Mann-Whitney test). Although some of the treated patients eventually developed chronic PA infection, these patients had significantly better pulmonary function at the onset of chronic PA infection compared with control patients (P < 0.001, Mann-Whitney test). When the different steps in the intensive three-step-protocol were analyzed, there was a trend suggesting that 3 months of high-dose treatment with colistin inhalation and oral ciprofloxacin produced the best results in terms of postponement or prevention of chronic PA infection (P < 0.05).

Adolescent↗

Improved survival in the Danish center-treated cystic fibrosis patients: results of aggressive treatment.

We report survival data for Danish center-treated cystic fibrosis (CF) patients, covering the period 1974-1993 and using cross-sectional cumulative survival probability based on annual age-specific mortality rates. Analyses by age and by years after diagnosis were made. No significant differences were noted in the survival probability when patients were grouped according to sex or absence/presence of meconium ileus. The annual mortality rate for 1989-1993 was 0-1.2%. Using the age-specific mortality rate for 1989-1993, we were unable to calculate the median survival probability because the curve did not fall below 50% (age up to 45 years); however, it was possible to show that the survival probability for a newborn CF child to reach his 45th birthday was 80.4%(confidence interval 76.5-84.6%). The median age at diagnosis was 0.63 years with no sex difference. The probability of surviving 40 years after the diagnosis of CF was made was 83.3% (confidence interval 80.1-86.6%). This is considerably higher than any other published survival probability. An early anti-Pseudomonas aeruginosa treatment regimen seemed important in achieving the observed improved survival.

Adolescent↗

Acute osteomyelitis and septic arthritis in the neonate, risk factors and outcome.

Twenty-two neonates with acute osteomyelitis (AO) or septic arthritis (SA) were included in a study based on a review of medical reports and a long-term clinical and radiological follow up. Clinical symptoms, bacteriology, risk factors, and outcome are discussed. The diagnoses were difficult, the clinical symptoms vague, fever rare and white cell count normal. Detection by plain radiological films was more efficient than by radionuclide bone scan. Staphylococcus aureus was the predominant causative organism and a shift towards group B Streptococcus in recent years was not identified. Risk factors for AO and SA were prematurity (13/22), respiratory distress syndrome (15/22) and perhaps most important: umbilical artery catheterisation (15/22). Severe sequelae were found in only 1 patient, while 3 patients had slight asymptomatic changes. The relatively favourable long-term outcome is unexplained, but may be related to early and appropriate, long lasting antibiotic treatment.

Acute Disease↗

Polymorphism in ospC gene of Borrelia burgdorferi and immunoreactivity of OspC protein: implications for taxonomy and for use of OspC protein as a diagnostic antigen.

The nucleotide sequences of the ospC gene from five Danish human Borrelia burgdorferi isolates representing all three B. burgdorferi genospecies (B. burgdorferi sensu stricto, Borrelia garinii sp. nov., and group VS461) and from the American type strain B31 were determined and compared with the published ospC sequence from the German B. burgdorferi isolate PKo (R. Fuchs, S. Jauris, F. Lottspeich, V. Preac-Mursic, B. Wilske, and E. Soutschek, Mol. Microbiol. 6:503-509, 1992). The ospC gene was present in all isolates, regardless of the presence or absence of its product, OspC. The deduced amino acid sequences of OspC from the seven isolates were aligned and revealed pairwise sequence identities ranging from 60.5 to 100%. Differences were scattered throughout the amino acid sequences. A phylogenetic tree was constructed and revealed three distinct phenotypic groups OspCI to OspCIII corresponding to the three delineated genospecies. Immunoblot analysis revealed that the seven OspC proteins tested have both common and specific epitopes. There is significant epitope diversity, since even polyclonal antisera showed serotype-restricted specificity. Therefore, a serodiagnostic assay for Lyme borreliosis utilizing OspC as a test antigen should include all three OspC phenotypes in order to obtain a species-wide sensitivity.

Amino Acid Sequence↗

Feto-maternal listeriosis in Denmark 1981-1988.

We collected clinical information about 30 cases of Listeria monocytogenes infections in pregnancy, which occurred in Denmark between 1981 and 1988. The incidence of feto-maternal listeriosis was approximately one case per 100,000 live births in the early 1980s but increased to 25.3 cases per 100,000 live births in 1986. Listeriosis in Denmark occurred in two different patterns: endemic, in which the feto-maternal cases were a small proportion of the total, and epidemic: cases due to strains which were indistinguishable by phage-typing, and having a higher proportion of feto-maternal cases, as was seen in the outbreak of 1985-1987. The study group comprised 11 cases of intra-uterine death, three of maternal septicaemia without infection of the fetus and 16 cases of neonatal infection. Most neonates were ill at birth or became so within the first 24 h. The overall mortality rate among liveborn infants was 10.5% (2/19).

Abortion, Spontaneous↗

[Familial infection caused by Haemophilus influenzae].

A three-year-old girl developed purulent arthritis and her nine-month-old younger brother meningitis with Haemophilus influenzae type b, after an interval of 43 days. Attention should be drawn to the spread of Haemophilus disease other than meningitis.

Arthritis, Infectious↗

Antibody response to pneumococcal vaccine in patients with early stage Hodgkin's disease.

Antibody response to pneumococcal vaccination was studied in 76 patients with Hodgkin's disease (HD) before, during and at different time intervals after cessation of therapy. All patients were in pathological stage I and II following explorative laparatomy with splenectomy. The increase in antibody response was compared to the findings in 12 healthy volunteers with the aim of establishing the optimal time for vaccination. Serum antibodies against 6 of the pneumococcal polysaccharide antigens (types 1, 4, 7F, 14, 18C and 23F) contained in the vaccine were determined by an ELISA. Antibody response to pneumococcal type antigens was similar in healthy adults and in patients with early stage HD before therapy. After treatment, postvaccination antibody response became negligible. Even up to 7 years after cessation of therapy patients were not able to raise a significant antibody response.

Adolescent↗

Prognostic value of immunologic abnormalities and HIV antigenemia in asymptomatic HIV-infected individuals: proposal of immunologic staging.

The prognostic value of various immunologic tests was investigated in 150 HIV-seropositive homosexual men, who were initially without HIV-related symptoms or AIDS and who were followed for a median of 12 months (range 3-28 months). The laboratory investigations included HIV antigen in serum, total lymphocyte count, T-helper (CD4) and T-cytotoxic/suppressor (CD8) counts, and lymphocyte transformation responses to the mitogens phytohemagglutinin (PHA) and pokeweed mitogen (PWM), and to antigenic extracts from Candida albicans and cytomegalovirus. 24 individuals developed HIV-related symptoms or AIDS (11 cases). All parameters except the CD8 count were of prognostic value, but a multivariate analysis of symptom-free survival showed that HIV antigenemia, a CD4 count less than 0.5 x 10(9)/l, and relative response to PWM below 25% of controls contained all the prognostic information. Individuals abnormal at entry for these 3 variables had a theoretical 36 times as high hazard of developing symptoms within the observation period as had individuals with normal parameters. There was no significant covariation between HIV antigenemia on the one hand and CD4 count and response to PWM on the other. Although, the latter 2 variables covaried, each of them provided independent information, and both were used to classify the degree of the immunodeficiency in 3 stages: Im-0 with normal values, Im-1 with one, and Im-2 with both tests abnormal. Individuals in stage Im-2 had a 10 times increased risk of developing symptoms. The immunologic staging correlated significantly with the clinical grouping (CDC criteria). This staging improved in only 1, but deteriorated in half of 36 individuals observed for at least 18 months. Thus, the staging is likely to prove useful when attempts to arrest the immunodeficiency of HIV-infected individuals has to be monitored.

Biomarkers↗

Independent clinical significance of HIV antigen determination and CD4 counts in anti-HIV positive patients.

HIV antigenemia was found in 52/243 HIV antibody positive individuals attending 2 AIDS-screening clinics, giving a prevalence of 13, 25 and 76% in CDC groups II, III and IV, respectively. No correlation was found to decreased CD4 lymphocyte values in the individual groups. HIV antigen therefore identified a separate subpopulation. For 138 asymptomatic patients followed prospectively both laboratory parameters predicted HIV-related events, the relative risk factor being 4 for low CD4 value and 6 for presence of HIV antigen. Individuals presenting with HIV antigen and decreased CD4 count all developed disease within 18 months, the relative risk factor being 24. Thus the 2 markers, when measured together, effectively separated asymptomatic HIV-infected patients into 1 of 3 risk categories.

Antigens, Differentiation, T-Lymphocyte↗