Nosocomial pneumonias.

The paper provides clear definitions of the basic concepts of nosocomial pneumonias. Specifically, definitions and classifications of HAP and VAP, general treatment principles and specific recommended procedures for antibiotic therapy are given as applicable in the Czech Republic.

Detection of the etiological agents of hospital-acquired pneumonia - validity and comparison of different types of biological sample collection: a prospective, observational study in intensive care patients.

BACKGROUND: There is still a lack of evidence as to which method of biological sample collection is optimal for identifying bacterial pathogens causing hospital-acquired pneumonia (HAP). Much effort has been made to find an easy and valid approach to be used in clinical practice. METHODS: The primary endpoint of this prospective, observational study was to determine the predictive value of oropharyngeal swab (OS) and gastric aspiration (GA) as simple and non-invasive methods for diagnosing HAP. Their efficacy was compared to endotracheal aspiration (ETA) and protected specimen brushing (PSB), the standard methods approved for HAP diagnosis. RESULTS: Initially, 56 patients were enrolled. Significant amounts of bacterial pathogens were detected in 48 patients (79 isolates) in Round A and in 39 patients (45 isolates) in Round B (after 72 hours). The sensitivity rates were: ETA 98%, PSB 31%, OS 64% and GA 67% in Round A and ETA 87%, PSB 32%, OS 74% and GA 42% in Round B. Strains of 12 bacterial species were identified in the samples. The three most common etiological agents (both rounds together) were Klebsiella pneumoniae (23.7%), Burkholderia multivorans (21.1%) and Pseudomonas aeruginosa (15.8%). CONCLUSIONS: Blind ETA is an optimum method for obtaining biological samples for identification of etiological agents causing HAP in intubated patients. Microbial etiological agents were more frequently detected in ETA samples than in those collected by PSB. If ETA/PSB results are negative, samples may be collected by OS and/or GA as these techniques followed ETA in terms of the frequency of pathogen detection.

Binding of the Galanthus nivalis agglutinin to thymocytes reveals alterations in surface glycosylation during T-cell development.

Surface binding of the Galanthus nivalis agglutinin (GNA) to thymocyte subsets has been studied in pigs and rodents by multicolour flow cytometry. In all the species examined, analogous staining profiles have been recorded. Counter-staining with anti-CD3epsilon, anti-CD4 and anti-CD8 monoclonal antibodies (MoAb) revealed that a significant increase of the GNA targets on the cell surface occurred during early thymocyte differentiation and reached its maximum at the level of the CD3loCD4+CD8+ small cortical thymocyte. This was followed by a decrease in the GNA binding capacity upon terminal maturation to the single positive thymocytes. PAGE analysis has revealed a dominant GNA-binding glycoprotein (molar mass approx. 90 kDa) present on thymocyte plasma membranes and absent on the surface of splenic lymphocytes, although both the whole cell lysates from both organs contained GNA ligands of the same size. Our findings are in agreement with previous data showing that immature thymocytes differ from their mature counterparts and peripheral T lymphocytes in the surface glycosylation pattern, and support the hypothesis that lectin-glycoprotein interaction plays a significant role in the cell-to-cell crosstalk in the thymic cortex.