Clinical application of MRI in children for the assessment of pulmonary diseases.

The standard examination technique for the chest in children is an X-ray examination - it is fast, cheap and provides a good overview of anatomy and pathology. In cases with an unclear pathology or if more details are needed (i. e. pre-therapeutically), computed tomography is most often performed with the well known drawbacks of limited soft tissue contrast and radiation. Radiation should be avoided in children, especially if follow-up examinations are needed. Recent magnetic resonance (MR) techniques allow for fast and reliable assessment of pulmonary diseases in children. Due to the inherent soft tissue contrast, diagnosis can be frequently performed without contrast media application. This review provides an exemplary MR examination protocol for routine application in pediatric patients. The diagnostic value of MRI is shown in patients with infectious diseases, patients with immunodeficiency, anatomic abnormalities, acquired chronic diseases, and pulmonary tumors. Since MRI is especially suitable for functional imaging, an MR protocol is provided for the examination of thoracic deformities. This review summarizes the use of thoracic MRI in the clinical pediatric setting with special focus on the clinical indications as a radiation-free method.

Differential effects of the combination of caspofungin and terbinafine against Candida albicans, Candida dubliniensis and Candida kefyr.

The activity of caspofungin (CSP) combined with terbinafine (TRB) against Candida dubliniensis, Candida kefyr and azole-resistant Candida albicans was evaluated in vitro by checkerboard analysis. The combination of CSP with TRB resulted in positive interactive effects in vitro against C. albicans and C. kefyr but not against C. dubliniensis. Moreover, true synergism was observed only against TRB resistant strains which became susceptible to this drug in the presence of CSP. In contrast, indifference was observed against strains that were already sensitive to TRB indicating that CSP may inhibit resistance to TRB.

Combined surgical and antifungal treatment of a subcutaneous infection due to Paecilomyces lilacinus.

Paecilomyces lilacinus was the causal agent of a case of subcutaneous infection in a patient with liver cirrhosis. Surgical treatment in combination with systemic amphotericin B therapy led to complete recovery. Retrospectively performed microdilution testing revealed dose dependent in vitro susceptibility of the isolate to voriconazole (MIC = 2 g/ml) and terbinafine (MIC = 1 microg/ml).

Molecular typing for fungi--a critical review of the possibilities and limitations of currently and future methods.

Invasive fungal infections represent an increasing problem in patients with inherited and acquired immunodeficiencies. Molecular biotyping techniques, such as DNA fingerprinting, are useful tools to increase our knowledge of the pathogenic organisms that cause them, and thus to improve their treatment and develop prevention strategies. In the present review, we evaluate and discuss the possibilities and limitations of the methods currently used for biotyping strains of fungal species. These include techniques based on restriction fragment length polymorphism (RFLP) with or without hybridization to probes (Southern), PCR-based techniques, electrophoretic karyotyping (EK), and multilocus enzyme electrophoresis (MLEE). Additionally, we discuss newer techniques that are being developed for the fingerprinting of fungal strains. Among them, we review conformation-based polymorphism scanning methods, such as single-strand conformation polymorphism analysis (SSCP) and heteroduplex mobility assays, sequencing strategies such as multilocus sequence typing (MLST) and DNA microarrays.

Case Reports. Pulmonary cryptococcosis associated with cryptococcal meningitis in non-AIDS patients.

We report four cases of pulmonary cryptococcosis associated with cryptococcal meningitis in non-HIV infected patients. All four patients had no apparent symptoms and signs of focal lesions that necessitate evaluation for the pulmonary lesion. Two out of four patients had radiologic evidence of pulmonary cavitation and mass lesions simultaneously, an uncommon finding in non-AIDS patients. Diagnostic and therapeutic problems of pulmonary cryptococcosis associated with cryptococcal meningitis are discussed.

Antimicrobial peptides as potential new antifungals.

Ribosomally synthesized natural antimicrobial peptides (AP) and their synthetic derivatives are small, cationic, amphipathic molecules of 12-50 amino acids with unusually broad activity spectra. These peptides kill microorganisms by a common mechanism, which involves binding to the lipid bilayer of biological membranes, forming pores, and ultimately followed by cell lysis. Several AP from mammals, amphibians, insects, plants and their synthetic derivatives demonstrate promising in vitro activity against various pathogenic fungi including azole-resistant Candida albicans strains. In addition to their antimicrobial activity, some AP such as lactoferrin, interact with a variety of host cells and can increase the activity of natural killer and lymphokine activated killer cells. Pretreatment of polymorphonuclear neutrophil leukocytes (PMN) or monocytes with these AP also may upregulate superoxide release. AP as potential new antifungal agents offer some advantages, such as rapid killing of pathogenic fungi and the difficulty to raise mutants resistant to these peptides. AP are limited by their nonselective toxicity, stability, immunogenicity and their costs of production. Potential clinical applications of AP in the future have to be further explored in preclinical and clinical studies to assess their impact as a new class of antifungals.

Standardized molecular typing.

Molecular typing methods are useful tools in molecular mycology. The results of these biotyping procedures may help to identify pathogenic strains in order to detect sources of nosocomial infection and for the investigation of epidemiological relationships. With respect to the facultative pathogen, Candida albicans, various methods such as pulse-field gel electrophoresis (PFGE), restriction fragment length polymorphism (RFLP), DNA fingerprinting methods and hybridization with repetitive DNA elements have been described as useful tools in molecular epidemiology. The previously described hybridization method with the Candida albicans specific CARE-2 probe and subsequent rehybridization with a molecular size marker is a standardized reproducible typing method for comparison of results obtained in different laboratories. In a larger epidemiological study conducted at the University Hospital of Würzburg analysing clinical C. albicans isolates, we were able to describe relationships between sequential patient isolates. These findings demonstrate that standardized molecular typing methods are a powerful tool in molecular mycology studies.