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Biomedical subjects

K Beutel

Publications and source records attributed to K Beutel.

14 recordsLinked to original sources

Diagnosis and treatment of catheter-related infections in paediatric oncology: an update.

Otherwise unexplained clinical signs of infection in patients with long-term tunnelled or totally implanted central venous access devices (CVADs) are suspected to be CVAD-associated. Diagnostic methods include catheter swabs, blood cultures and cultures of the catheter tip or port reservoir. In the case of a suspected CVAD-related bloodstream infection in paediatric oncology patients, in-situ treatment without prompt removal of the device can be attempted. Removal of the CVAD should be considered if bacteraemia persists or relapses > or = 72 h after the initiation of (in-vitro effective) antibacterial therapy administered through the line. Timely removal of the device is also recommended if the patient suffers from a complicated infection, or if Staphylococcus aureus, Pseudomonas aeruginosa, multiresistant Acinetobacter baumannii or Candida spp. are isolated from blood cultures. Duration of therapy depends on the immunological recovery of the patient, the pathogen isolated and the presence of related complications, such as thrombosis, pneumonia, endocarditis and osteomyelitis. Antibiotic lock techniques in addition to systemic treatment are beneficial for Gram-positive infections. Although prospectively controlled studies are lacking, the concomitant use of urokinase locks and taurolidine secondary prophylaxis seem to favour catheter salvage.

Acridine Orange↗

[Bacterial infections in pediatric cancer patients].

Increased dose intensity and a better long term survival can not be reached in pediatric oncology without the judicious use of antibiotics. During periods with profound neutropenia and between intensive chemotherapy cycles are bacterial infections capable of disturbing the patients' quality of life; they may cause an acute life threatening situation and lead to a substantial increase in expenditures and consumption of ressources in supportive care. The non-judicious use of antibacterials may face the patient to an increased risk of adverse events and fosters the selection of resistant bacteria. This article provides the recommendations of the Infectious Diseases Working Party of the German Society for Pediatric Infectious Diseases (DGPI) and the German Society for Pediatric Hematology/Oncology (GPOH) for antibacterial therapy in pediatric oncology patients based upon the available literature and the clinical experience of the authors.

Antineoplastic Combined Chemotherapy Protocols↗

[Diagnostics and management of central venous line infections in pediatric cancer patients].

Otherwise unexplained clinical signs of infection in patients with tunneled or totally implanted central venous access devices (CVAD) are highly suspicious of an underlying CVAD-associated infection. Diagnostic methods include catheter swabs, blood cultures and cultures of the catheter tip or port reservoir. In case of a suspected CVAD-related blood stream infection in pediatric cancer patients in situ treatment without prompt removal of the device can be tried. The removal of the CVAD should be considered, if bacteremia persists or relapses 72 hours or longer after the initiation of an (in vitro effective) antibacterial therapy administered through the line. The CVAD should be removed even earlier, if the patient suffers from hypotension or other signs of severe organ dysfunction related to the infection. If S. aureus, Pseudomonas aeruginosa, multiresistant Acinetobacter baumannii or Candida spp.are isolated from blood cultures taken through a CVAD, patients are at a high risk for severe complications and immediate device removal is also recommended. Duration of therapy depends on the immunological recovery of the patient (neutrophils counts), the pathogen isolated and on the presence of related complications like thrombosis, pneumonia, endocarditis, osteomyelitis. Antibiotic-lock techniques in addition to systemic treatment are beneficial in Gram-positive infections. Although prospectively controlled studies are missing, the concomitant use of urokinase- or taurolidine seems to favour catheter salvage.

Antineoplastic Agents↗

[Viral infections in pediatric cancer patients].

Children with cancer or stem cell transplantation (SCT) are at considerable risk to develop life threatening viral infections. Due to both underlying disease and immunosuppressive therapy lymphocyte number and function are low and the cellular immunity against viral infections is restricted or missing. As immunosuppressive treatment regimens and mismatched or T-cell-depleted stem cell products are being used increasingly, viral infections will become an even greater problem in the future. PCR-based methods have become an indispensable tool for early recognition, preemptive therapy, and monitoring therapeutic responses by qualitative and quantitative approaches. Assays are now available that allow for parallel screening of the 16 most common viral agents. Responses to antiviral therapy are often limited in immunocompromised patients and mainly depend on the time of their initiation. Most antiviral agents have a toxicity profile that may become clinically relevant and curtail antiviral therapy. New options for treatment are therefore warranted. For the next future, these may include the transfer of specific T-cells and other immunotherapeutic approaches. This article provides the recommendations of the Infectious Diseases Working Party of the German Society for Pediatric Hematology/Oncology (GPOH) and the German Society for Pediatric Infectious Diseases (DGPI) for diagnosis and treatment of viral infections in children with cancer or post HSCT. They are based on the results of clinical trials, case series and expert opinions using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA).

Adolescent↗

Oral mature teratoma containing epididymal tissue in a female neonate.

We describe a female neonate with an oral teratoma showing bone, teeth, and epidermis, but also epididymal (male) tissue. PCR amplification of Y-chromosomal DNA clearly showed male DNA from paraffin-embedded tumour tissue. The girl had a normal female karyotype without abnormalities of the genital organs. There are at least three hypotheses for the origin of teratomas: parthenogenesis, incomplete twinning, and totipotent somatic-cell origin. This case supports the hypothesis of an included dizygotic twin, and might contribute to the elucidation of the pathogenesis of extragonadal teratomas.

DNA↗

New LightCycler PCR for rapid and sensitive quantification of parvovirus B19 DNA guides therapeutic decision-making in relapsing infections.

Detection of parvovirus B19 DNA offers diagnostic advantages over serology, particularly in persistent infections of immunocompromised patients. A rapid, novel method of B19 DNA detection and quantification is introduced. This method, a quantitative PCR assay, is based on real-time glass capillary thermocycling (LightCycler [LC]) and fluorescence resonance energy transfer (FRET). The PCR assay allowed quantification over a dynamic range of over 7 logs and could quantify as little as 250 B19 genome equivalents (geq) per ml as calculated for plasmid DNA (i.e., theoretically >or=5 geq per assay). Interrater agreement analysis demonstrated equivalence of LC-FRET PCR and conventional nested PCR in the diagnosis of an active B19 infection (kappa coefficient = 0.83). The benefit of the new method was demonstrated in an immunocompromised child with a relapsing infection, who required an attenuation of the immunosuppressive therapy in addition to repeated doses of immunoglobulin to eliminate the virus.

Child↗

The interaction of buccal mucosal epithelial cells with E. coli bacteria enhances the intraepithelial calcium flux and the release of prostaglandin E2 (PgE2).

Mucosal epithelial cells contribute significantly to host defense mechanisms. Uroepithelial cells (UEC) from healthy donors suppress bacterial growth in vitro. Bacterial adherence to UEC has been shown to be a prerequisite. Similar results have been shown for buccal epithelial cells (BEC). The host response triggered by the host-parasite interaction seems to involve signal transduction and intracellular activation of second messengers. In this study the intraepithelial calcium flux was analyzed in individual BEC after bacterial contact. BEC were derived from scrapes of the buccal mucosa and labelled with fluo-3 (a calcium indicator). Thereafter the cells were analyzed immediately with a FACscan flowcytometer. The intracellular events were evaluated before and after the addition of viable E. coli bacteria (strain 4389, K1O1H7, pili II pos.). For control, the influence of prostaglandins, histamine, PMA, LPS and opsonized avital E. coli on the epithelial calcium flux was investigated. Additionally, supernatants of BEC-E. coli cocultures were analyzed with respect to their PgE2 content. PgE2 concentrations in supernatants of BEC, cultured alone or together with E. coli, were measured by a commercial PgE2 ELISA kit. The addition of vital E. coli to BEC was promptly answered by a significant intracellular calcium flux. PgE2, histamine and PMA, but not PgF2alpha, PgE1, LPS and opsonized E. coli, increased intracellular calcium. BEC alone did not release PgE2. After coculture with E. coli increased levels of PgE2 were measured in the supernatants. PgE2 release was still enhanced by coactivation of the BEC with phorbolester (PMA). Our results confirm that calcium flux in mucosal epithelial cells is stimulated by the cell-bacteria contact. We suggest that the increased PgE2 release amplifies the stimulation of intraepithelial second messengers. The resulting cell activation may lead to the secretion of antimicrobial peptides, thereby contributing to the regulation of mucosal host resistance to bacterial infections.

Adult↗

Immunogenicity and reactogenicity of a Haemophilus influenzae type b tetanus conjugate vaccine when administered separately or mixed with concomitant diphtheria-tetanus-toxoid and acellular pertussis vaccine for primary and for booster immunizations.

UNLABELLED: With an increasing number of new vaccines available for routine childhood immunization, combination vaccines are needed in order to maintain or achieve a high compliance with recommended immunization programmes. In a prospective, randomized, comparative, multi-centre study, 822 healthy infants were enrolled to receive three doses of either a candidate or a commercially available Haemophilus influenzae type b (Hib) vaccine concomitantly with diphtheria-, tetanus- acellular pertussis (DTaP) vaccine. Study subjects were randomly allocated to one of the following groups: (1) separate, or (2) mixed injection of DTaP and candidate Hib vaccine, or (3) separate injection of DTaP and commercial Hib vaccine. One year later the first 189 study subjects received either separate or mixed injections of the same Hib and DTaP vaccines as booster doses. Evaluation of reactogenicity was based on diary cards completed by parents. Immunogenicity was documented by measuring IgG antibody concentrations in serum samples taken before and 4 weeks after primary and booster vaccination. No serious adverse events occurred and most local and systemic reactions were mild to moderate. Booster doses were more reactogenic than primary doses with all groups. Antibody concentrations against pertussis antigens were similar to those seen with DTaP alone. All but one subject had protective antibody concentrations against diphtheria and tetanus. Primary immune response to the Hib vaccine was significantly lower in the group receiving the mixed Hib-DTaP vaccine, however, > or = 95% of vaccinees had anti-Hib antibody concentrations > or = 0.15 microg/ml and there was a marked booster response (> 100-fold) in all groups. CONCLUSIONS: Mixing DTaP and Hib vaccines for primary immunization caused a decrease in anti-Hib antibody response, although after primary immunization as after booster doses, all subjects showed antibody concentrations considered to be protective for invasive Hib disease. Mixing of the vaccines did not result in increased reactogenicity.

Analysis of Variance↗

Reactogenicity and immunogenicity of a booster dose of a combined diphtheria, tetanus, and tricomponent acellular pertussis vaccine at fourteen to twenty-eight months of age.

OBJECTIVES: The primary objective was to assess the nature and incidence of adverse events after a fourth dose of a tricomponent acellular pertussis-diphtheriatetanus vaccine given in the second year of life after primary vaccination with the same vaccine at 3, 4, and 5 months of age. A secondary objective was to analyze the immunogeniecity of the booster vaccination. DESIGN: Of the 5361 children enrolled (aged 14 to 28 months), adverse reactions were specifically solicited from the first 1863 enrollees for the first 4 days after vaccination and then were unsolicited for the remainder of the 4 weeks of follow-up (group 1). In the next 3498 subjects, safety and reactogenicify were entirely unsolicited for this 4-week period (group 2). Immunogenicity was analyzed by means of prebooster and postbooster serum antibody titers for all vaccine components in a random subgroup of 197 children from group 1. RESULTS: Soliciting symptoms elicited reports of at least one symptom in 1314 of 1809 children in group 1 (72.6%), including 993 (54.9%) with local and 885 (48.9%) with general symptoms during the first 4 days after vaccination. When symptoms were gathered in an unsolicited fashion, only 580 of 3498 children in group 2 (16.6%) had a reported symptom during this time, consisting of 344 (9.8%) local and 319 (9.1%) general symptoms, respectively. An unsolicited symptom, areactive edematous swelling of the whole thigh, occurred in 62 children (1.1%), with 45 and 17 reports in groups 1 and 2, respectively. The vast majority of all reported symptoms were mild to moderate, and all children recovered without sequelae. Fourteen serious adverse events were reported, but none was considered to be related to the vaccination. Immunogenicity analysis showed a vaccine response to pertussis toxin in 99.5% of subjects, to filamentous hemagglutinin in 98.5%, and to pertactin (69 kd outer membrane protein) in 99%. All subjects had postvaccination antibody titers of 0.1 IU/ml or greater against diphtheria and tetanus toxoids.

Antibody Formation↗

Safety and efficacy of acellular pertussis vaccines: the Mainz study and other recent studies.

Following concerns about the safety and reactogenicity profile of diphtheria, tetanus and whole cell pertussis vaccines (DTwP), new and less reactogenic alternatives were developed over the last two decades. The new diphtheria, tetanus and acellular pertussis vaccines (DTaP) no longer consist of the whole bacterial cell but of either extracts or of a few highly purified components. While it soon became clear that DTaP vaccines are significantly less reactogenic than DTwP vaccines, their efficacy was disputed and remained unproven. First studies and epidemiological data from Japan suggested vaccine efficacy rates (VE) of about 80%; however, the first blinded clinical trial from Sweden documented a much lower VE. Worldwide, seven large DTaP efficacy trials have recently been completed. Our own efforts included a large safety trial with 22505 vaccinees and, nested in this setting, a prospective household contact study. Typical WHO-defined pertussis developed in 7 of 112 DTaP vaccinated children following household exposure as compared to 96 cases in 173 children not vaccinated against pertussis. Thus, vaccine efficacy was calculated to be 88.7% (95% CI 76.6 to 94.6). The median duration of spasmodic cough in the few children vaccinated with DTaP who did start coughing was 17 days as compared to 35 days in unvaccinated children. No waning of protection was observed. None of the confounding variables analyzed influenced study results in favour of DTaP. Following administration of more than 67000 DTaP doses, 153 serious adverse events were reported. Eight events were considered possibly related and five were considered related to the study vaccine. According to additional study results from the other trials it can be concluded that DTaP vaccines, like DTwP vaccines, are safe and effective. The choice between DTwP and DTaP should be based on acceptance of the reactogenicity profile, coverage rates achieved, costs and other factors in each individual country.

Clinical Trials as Topic↗

Clinical experience of a tricomponent acellular pertussis vaccine combined with diphtheria and tetanus toxoids for primary vaccination in 22,505 infants.

OBJECTIVES: To assess the safety and tolerability of 12 lots of SmithKline Beecham Biologicals' diphtheria-tetanus-tricomponent acellular pertussis vaccine (DTaP) in a large cohort of 22,000 vaccinees, with detailed analyses of reactivity, immunogenicity, and immune response to pertussis toxin in subsets. METHODS: In a prospective, double-blind, multicenter trial in Germany, 22,505 healthy infants received three vaccinations of DTaP at age 3, 4, and 5 months. Serious adverse events were followed for 1 month after each vaccination, and neurologic events for 1 year or longer. Serum IgG antibodies were assayed before vaccination and 1 month after vaccination. RESULTS: After 67,000 doses, 153 serious adverse events (0.23%) were reported, 8 considered possibly related, and 5 related to vaccination, including 1 hypotonic-hyporesponsive episode. Incidence rates of sudden infant death syndrome (7; 0.01%) or acute neurologic events (20; 0.030%) were no higher than expected and not considered to be related to vaccination. Redness and swelling of 20 mm or greater occurred after 44 (0.6%) and 40 (0.6%) of the 7270 doses, respectively, and high fever (> 39.5 degrees C) in 6 (0.08%) subjects within 48 hours of vaccination. In the immunogenicity analysis of 580 infants, 98% responded to pertussis toxin, 96% to filamentous hemagglutinin, and 98% to pertactin. In an additional 5712 infants, the response rate to pertussis toxin was 99%. CONCLUSIONS: In a large cohort of 22,505 infants vaccinated, SmithKline Beecham Biologicals' tricomponent DTaP vaccine was shown to be safe, well-tolerated, and immunogenic for all component antigens.

Diphtheria-Tetanus-Pertussis Vaccine↗

Acellular pertussis vaccines: the rationale for an efficacy trial in Germany.

After concern about the safety of diphtheria-tetanus toxoid-whole cell pertussis vaccines (DTPw), the recommendation to vaccinate children with DTPw was withdrawn in 1974 in the former West Germany. This led pertussis cases to increase to an estimated 100,000 annually. Despite renewal of the vaccination recommendation in 1991, vaccine use remained low. The German health care structure assures regular contact between most children and pediatricians. This enabled the conduct of a large efficacy trial with a diphtheria-tetanus toxoid-acellular pertussis (DTPa) vaccine. Because a placebo-controlled trial was not ethically possible, a prospective household contact study with a blinded clinical follow-up was done. Possible study participants were screened by their pediatrician, who also initiated diagnostic procedures. Clinical follow-up was done by another locally based but independent and blinded physician. Vaccine efficacy was calculated to be 89% (95% confidence interval, 76.6%-94.6%). None of the identified confounding factors biased results in favor of the DTPa vaccine.

Clinical Trials as Topic↗