Molecular detection and species-specific identification of medically important Aspergillus species by real-time PCR in experimental invasive pulmonary aspergillosis.

Diagnosis of invasive pulmonary aspergillosis (IPA) remains a major challenge to clinical microbiology laboratories. We developed rapid and sensitive quantitative PCR (qPCR) assays for genus- and species-specific identification of Aspergillus infections by use of TaqMan technology. In order to validate these assays and understand their potential diagnostic utility, we then performed a blinded study of bronchoalveolar lavage (BAL) fluid specimens from well-characterized models of IPA with the four medically important species. A set of real-time qPCR primers and probes was developed by utilizing unique ITS1 regions for genus- and species-specific detection of the four most common medically important Aspergillus species (Aspergillus fumigatus, A. flavus, A. niger, and A. terreus). Pan-Aspergillus and species-specific qPCRs with BAL fluid were more sensitive than culture for detection of IPA caused by A. fumigatus in untreated (P < 0.0007) and treated (P ≤ 0.008) animals, respectively. For infections caused by A. terreus and A. niger, culture and PCR amplification from BAL fluid yielded similar sensitivities for untreated and treated animals. Pan-Aspergillus PCR was more sensitive than culture for detection of A. flavus in treated animals (P = 0.002). BAL fluid pan-Aspergillus and species-specific PCRs were comparable in sensitivity to BAL fluid galactomannan (GM) assay. The copy numbers from the qPCR assays correlated with quantitative cultures to determine the pulmonary residual fungal burdens in lung tissue. Pan-Aspergillus and species-specific qPCR assays may improve the rapid and accurate identification of IPA in immunocompromised patients.

Diagnostic imaging of experimental invasive pulmonary aspergillosis.

Pulmonary infiltrates in neutropenic hosts with invasive aspergillosis are caused by organism-mediated tissue injury, vascular invasion, and hemorrhagic infarction. Ultrafast computed tomography (UFCT) scanning reproducibly measures these lesions in experimental invasive pulmonary aspergillosis in persistently neutropenic rabbits. The pulmonary lesion score from UFCT scanning is a useful outcome variable for measuring differences in efficacy of antifungal compounds alone and in combination, as well as the virulence of different strains and species of Aspergillus. Several studies demonstrate that the course of pulmonary lesions treated with amphotericin B, lipid formulations of amphotericin B, triazoles, echinocandins, and combination therapy measured by serial UFCT scans correlate with those measured by survival, histopathological resolution of lesions, microbiological clearance of Aspergillus fumigatus, and resolution of galactomannan index. We further developed a multidimensional volumetric imaging (MDVI) method for analysis of the volume of pulmonary infiltrates over time in response to antifungal therapy. Volumetric data by MDVI correlate with UFCT pulmonary lesion scores and validated biological endpoints. A recent pilot clinical study demonstrated the applicability of MDVI to human pulmonary fungal infections. MDVI also improves objectivity of radiological assessment of therapeutic response to antifungal therapy and merits more extensive evaluation in patients with invasive aspergillosis, as well as other fungal and bacterial pneumonias.

Sex- and age-specific effects of anabolic androgenic steroids on reproductive behaviors and on GABAergic transmission in neuroendocrine control regions.

Illicit use of anabolic androgenic steroids (AAS) has become a prevalent health concern not only among male professional athletes, but, disturbingly, among a growing number of women and adolescent girls. Despite the increasing use of AAS among women and adolescents, few studies have focused on the effects of these steroids in females, and female adolescent subjects are particularly underrepresented. Among the hallmarks of AAS abuse are changes in reproductive behaviors. Here, we discuss work from our laboratories on the actions of AAS on the onset of puberty and sexual behaviors in female rodents, AAS interactions and sex- and age-specific effects of these steroids on neural transmission mediated by gamma-aminobutyric acid receptors within forebrain neuroendocrine control regions that may underlie AAS-induced changes in these behaviors.