Prevalence of genes encoding extracellular proteases in Staphylococcus aureus - important targets triggering immune response in vivo

Proteases of Staphylococcus aureus have long been considered to function as important virulence factors, although direct evidence of the role of particular enzymes remains incomplete and elusive. Here, we sought to provide a collective view of the prevalence of extracellular protease genes in genomes of commensal and pathogenic strains of S. aureus and their expression in the course of human and mouse infection. Data on V8 protease, staphopains A and B, aureolysin, and the recently described and poorly characterized group of six Spl proteases are provided. A phylogenetically diverse collection of 167 clinical isolates was analyzed, resulting in the comprehensive genetic survey of the prevalence of protease-encoding genes. No correlation between identified gene patterns with specific infections was established. Humoral response against the proteases of interest was examined in the sera derived from human patients and from a model mouse infection. The analysis suggests that at least some, if not all, tested proteases are expressed and secreted during the course of infection. Overall, the results presented in this study support the hypothesis that the secretory proteases as a group may contribute to the virulence of S. aureus.

„Neko bi pomislio da se barem delimično sačuva dogma o monarhiji”: Antilatinski traktati Varlaama Kalabrijskog u srpskoslovenskom prevodu 14. veka

Die antilateinischen Traktate von Gregorios Palamas und Barlaam von Kalabrien stellten für die serbischen Übersetzer des 14. Jahrhunderts eine grosse Herausforderung dar – nicht nur wegen ihres dogmatischen Inhalts, sondern auch wegen des ausgeprägt polemischen Charakters ihrer Argumentation. In diesem Aufsatz wird die argumentative Form der zwei Traktate („opuscula“ ) Barlaams von Kalabrien analysiert, die in cod. Dečani 88 enthalten sind (fol. 38r-81r). Der zweite von ihnen (fol. 69v-81r) richtet sich an ein griechisches (orthodoxes) Auditorium; die Anreden an die Lateiner, die sich darin finden, haben rein rhetorischen Charakter. Der erste Traktat (fol. 39r-69r), der während der Unionsverhandlungen des Jahres 1334/1335 entstand, hat jedoch eine für die byzantinische Unionspolemik eher ungewöhnliche Form: der Dialog mit der Gegenseite ist hier keine rhetorische Fiktion, sondern ein ernstes Anliegen des Autors. Dies hat bereits bei der Rezeption des Traktats im griechisch-athonitischen Milieu den Verdacht geweckt, Barlaam habe den Lateinern unzulässige Zugeständnisse gemacht. Barlaam hat versucht, diesen Verdacht durch metakommunikative Kommentare zu entkräften, die ausschliesslich in der serbisch-kirchenslavischen Übersetzung von Dečani 88 enthalten sind. Der Übersetzer der Traktate hat deren argumentative Form im wesentlichen nicht angetastet und nur gelegentlich versucht, die Zugehörigkeit der einzelnen Argumente dem Leser durch Marginalscholien deutlich zu machen.

Partikule kao izazov - za prevodioce i izdavače (na primerlu srpskoslovenskog prevoda antilatinskih traktata Gregorija Palame i Varlaama Kalabrijskog)

Die Übersetzung der antilateinischen Traktate der byzantinischen Theologen Gregorios Palamas (1296-1359) und Barlaam von Kalabrien (1290-1348) Über den Ausgang des Heiligen Geistes entstand in den 60er Jahren des 14. Jahrhunderts. Die älteste Abschrift dieser Übersetzung, die Handschrift Dečani 88, ist zugleich die Arbeitshandschrift der Übersetzer. Sie enthält auf jeder Seite Korrekturen, die einen unmittelbaren Einblick in den Übersetzungsprozess bieten. Aus diesen Korrekturen ist ersichtlich, dass die Übersetzer bei der Wiedergabe nicht nur der theologischen Termini, sondern auch der Partikeln geschwankt haben. Der Autor verbindet diese Schwankungen mit dem Problem der Erhaltung der Argu-mentationsform der Traktate von Gregorios Palamas und Barlaam von Kalabrien in der Über-setzung und analysiert ein konkretes Beispiel: die altserbische Partikel daj.

Comparison of freehand-navigated and aiming device-navigated targeting of liver lesions

BACKGROUND Accurate needle placement is crucial for the success of percutaneous radiological needle interventions. We compared three guiding methods using an optical-based navigation system: freehand, using a stereotactic aiming device and active depth control, and using a stereotactic aiming device and passive depth control. METHODS For each method, 25 punctures were performed on a non-rigid phantom. Five 1 mm metal screws were used as targets. Time requirements were recorded, and target positioning errors (TPE) were measured on control scans as the distance between needle tip and target. RESULTS Time requirements were reduced using the aiming device and passive depth control. The Euclidian TPE was similar for each method (4.6 ± 1.2-4.9 ± 1.7 mm). However, the lateral component was significantly lower when an aiming device was used (2.3 ± 1.3-2.8 ± 1.6 mm with an aiming device vs 4.2 ± 2.0 mm without). DISCUSSION Using an aiming device may increase the lateral accuracy of navigated needle insertion.

Cone-beam computed tomography-guided stereotactic liver punctures: a phantom study

PURPOSE Images from computed tomography (CT), combined with navigation systems, improve the outcomes of local thermal therapies that are dependent on accurate probe placement. Although the usage of CT is desired, its availability for time-consuming radiological interventions is limited. Alternatively, three-dimensional images from C-arm cone-beam CT (CBCT) can be used. The goal of this study was to evaluate the accuracy of navigated CBCT-guided needle punctures, controlled with CT scans. METHODS Five series of five navigated punctures were performed on a nonrigid phantom using a liver specific navigation system and CBCT volumetric dataset for planning and navigation. To mimic targets, five titanium screws were fixed to the phantom. Target positioning accuracy (TPECBCT) was computed from control CT scans and divided into lateral and longitudinal components. Additionally, CBCT-CT guidance accuracy was deducted by performing CBCT-to-CT image coregistration and measuring TPECBCT-CT from fused datasets. Image coregistration was evaluated using fiducial registration error (FRECBCT-CT) and target registration error (TRECBCT-CT). RESULTS Positioning accuracies in lateral directions pertaining to CBCT (TPECBCT = 2.1 ± 1.0 mm) were found to be better to those achieved from previous study using CT (TPECT = 2.3 ± 1.3 mm). Image coregistration error was 0.3 ± 0.1 mm, resulting in an average TRE of 2.1 ± 0.7 mm (N = 5 targets) and average Euclidean TPECBCT-CT of 3.1 ± 1.3 mm. CONCLUSIONS Stereotactic needle punctures might be planned and performed on volumetric CBCT images and controlled with multidetector CT with positioning accuracy higher or similar to those performed using CT scanners.

Angiographic C-arm CT- versus MDCT-guided stereotactic punctures of liver lesions: nonrigid phantom study

OBJECTIVE Angiographic C-arm CT may allow performing percutaneous stereotactic tumor ablations in the interventional radiology suite. Our purpose was to evaluate the accuracy of using C-arm CT for single and multimodality image fusions and to compare the targeting accuracy of liver lesions with the reference standard of MDCT. MATERIALS AND METHODS C-arm CT and MDCT scans were obtained of a nonrigid rapid prototyping liver phantom containing five 1-mm targets that were placed under skin-simulating deformable plastic foam. Target registration errors of image fusion were evaluated for single-modality and multimodality image fusions. A navigation system and stereotactic aiming device were used to evaluate target positioning errors on postinterventional scans with the needles in place fused with the C-arm CT or MDCT planning images. RESULTS Target registration error of the image fusion showed no significant difference (p > 0.05) between both modalities. In five series with a total of 25 punctures for each modality, the lateral target positioning error (i.e., the lateral distance between the needle tip and the planned trajectory) was similar for C-arm CT (mean [± SD], 1.6 ± 0.6 mm) and MDCT (1.82 ± .97 mm) (p = 0.33). CONCLUSION In a nonrigid liver phantom, angiographic C-arm CT may provide similar image fusion accuracy for comparison of intra- and postprocedure control images with the planning images and enables stereotactic targeting accuracy similar to that of MDCT.