Biomedical subjects

Holger Hebart

Publications and source records attributed to Holger Hebart.

41 records · Page 3Linked to original sources

PubMed2002

Cellular immunity to viral and fungal antigens after stem cell transplantation.

Cellular immunity to viral and fungal antigens is often suppressed after stem cell transplantation. Viral infections, in particular infections with cytomegalovirus and Epstein-Barr virus, are often reactivated after allogeneic stem cell transplantation. Pathogenetic factors are immune deficiency and T-cell stimulation in the course of graft-versus-host reactions. Fungal infections are opportunistic infections derived with ubiquitous microorganisms. Immune deficiency, neutropenia, steroid treatment, and antibiotic treatment contribute to the pathogenesis. The study of viral and fungal immunity after allogeneic stem cell transplantation gives insight into the reconstitution of the immune system and tolerance.

Antigens, Fungal↗

PubMed2002

Automated extraction of genomic DNA from medically important yeast species and filamentous fungi by using the MagNA Pure LC system.

A fully automated assay was established for the extraction of DNA from clinically important fungi by using the MagNA Pure LC instrument. The test was evaluated by DNA isolation from 23 species of yeast and filamentous fungi and by extractions (n = 28) of serially diluted Aspergillus fumigatus conidia (10(5) to 0 CFU/ml). Additionally, DNA from 67 clinical specimens was extracted and compared to the manual protocol. The detection limit of the MagNA Pure LC assay of 10 CFU corresponded to the sensitivity when DNA was extracted manually; in 9 of 28 runs, we could achieve a higher sensitivity of 1 CFU/ml blood, which was found to be significant (p <or= 0.004). DNA from all fungal species analyzed could be extracted and amplified by real-time PCR. Negative controls from all MagNA Pure isolations remained negative. Sixty-three clinical samples showed identical results by both methods, whereas in 4 of 67 samples, discordant results were obtained. Thus, the MagNA Pure LC technique offers a fast protocol for automated DNA isolation from numerous fungi, revealing high sensitivity and purity.

DNA, Fungal↗

PubMed2002

High variability between results of different in-house tests for cytomegalovirus (CMV) monitoring and a standardized quantitative plasma CMV PCR assay.

A total of 2,718 blood samples were analyzed in five virological laboratories for the presence of cytomegalovirus (CMV) by in-house tests and one standardized plasma PCR assay. Results from in-house tests showed remarkable variability. Detection of CMV pp65 antigen or DNA from cells was more sensitive than that by plasma CMV PCR assay.

Culture Media↗

PubMed2000

Molecular methods in the diagnosis of infections in the immunocompromised host.

Despite recent developments, infection remains a major obstacle to a successful outcome in transplantation. Molecular methods have allowed for earlier diagnosis and have proven to be powerful tools for analysing the epidemiology of infectious diseases. More recently, some of these molecular methods have been commercialized, enabling standardized diagnostic techniques to be used in multicentre trials.

Journal Article↗

PubMed2000

CMV Infection in Bone Marrow and Solid Organ Transplant Patients in the Era of Antiviral Prophylaxis.

Recent developments in the diagnosis and therapy of cytomegalovirus (CMV) infection have helped to reduce CMV-associated morbidity and mortality following allogeneic bone marrow and solid organ transplantation. The clinical symptoms of active CMV infection and the prevalence of life-threatening CMV disease vary widely between different patient populations according to the type of transplant and the intensity of immunosuppression employed. Antiviral prophylaxis with aciclovir, valaciclovir and ganciclovir has been shown to reduce CMV infection and disease following organ transplantation. Antiviral drugs, in particular ganciclovir and foscarnet, have varying sideeffects, however, and antiviral resistance due to prolonged administration of ganciclovir and foscarnet has been reported recently. Short courses of pre-emptive antiviral therapy for documented CMV infection help to reduce the duration and sideeffects of therapy, offering an alternative strategy to antiviral prophylaxis. Studies are required to compare the efficacy and costs of antiviral prophylaxis with pre-emptive therapy.

Journal Article↗