Molecular Characterization of Podoviral Bacteriophages Virulent for Clostridium perfringens and Their Comparison with Members of the Picovirinae

Clostridium perfringens is a Gram-positive, spore-forming anaerobic bacterium responsible for human food-borne disease as well as non-food-borne human, animal and poultry diseases. Because bacteriophages or their gene products could be applied to control bacterial diseases in a species-specific manner, they are potential important alternatives to antibiotics. Consequently, poultry intestinal material, soil, sewage and poultry processing drainage water were screened for virulent bacteriophages that lysed C. perfringens. Two bacteriophages, designated ΦCPV4 and ΦZP2, were isolated in the Moscow Region of the Russian Federation while another closely related virus, named ΦCP7R, was isolated in the southeastern USA. The viruses were identified as members of the order Caudovirales in the family Podoviridae with short, non-contractile tails of the C1 morphotype. The genomes of the three bacteriophages were 17.972, 18.078 and 18.397 kbp respectively; encoding twenty-six to twenty-eight ORF's with inverted terminal repeats and an average GC content of 34.6%. Structural proteins identified by mass spectrometry in the purified ΦCP7R virion included a pre-neck/appendage with putative lyase activity, major head, tail, connector/upper collar, lower collar and a structural protein with putative lysozyme-peptidase activity. All three podoviral bacteriophage genomes encoded a predicted N-acetylmuramoyl-L-alanine amidase and a putative stage V sporulation protein. Each putative amidase contained a predicted bacterial SH3 domain at the C-terminal end of the protein, presumably involved with binding the C. perfringens cell wall. The predicted DNA polymerase type B protein sequences were closely related to other members of the Podoviridae including Bacillus phage Φ29. Whole-genome comparisons supported this relationship, but also indicated that the Russian and USA viruses may be unique members of the sub-family Picovirinae

Artéria femoral profunda: uma opção como origem de fluxo para derivações infrageniculares Deep femoral artery: an option as inflow site in infragenicular bypasses

CONTEXTO: Na isquemia crítica, a artéria femoral profunda pode tornar-se a opção mais distal como origem de fluxo para derivações distais em casos de oclusão da origem da artéria femoral superficial associada a prega inguinal hostil. OBJETIVO:Avaliar, retrospectivamente, a artéria femoral profunda como doadora de fluxo para derivações infrageniculares. MÉTODOS: De 2000 a 2005, 129 derivações infrageniculares apresentaram anastomose proximal nas artérias femorais, comum (40), superficial (72) e profunda (17). O presente estudo teve como foco a artéria femoral profunda, e suas indicações foram: prega inguinal hostil (seis casos), limite da extensão do substituto (seis casos) e ambos os fatores (outros cinco casos). Foram abordadas a primeira e a segunda porção em 12 casos e a terceira porção em cinco casos. As cirurgias foram secundárias em 47% dos casos, e os substitutos utilizados foram veias do membro superior em 11 casos, safena interna em cinco e safena externa em um caso. RESULTADOS: No total dos enxertos (129), as estimativas de perviedade primária e salvamento do membro foram: 68,0% e 84,7%, respectivamente, com erro padrão (EP) aceitável (0,1) em 36 meses. Quando o grupo foi estratificado, as artérias femorais comum, superficial e profunda apresentaram resultados comparáveis de perviedade primária (63,3, 70,2 e 64,7%; p = 0,63) e salvamento do membro (83,1, 82,4 e 92,3%; p = 0,78). A perviedade dos enxertos com origem nas porções proximal e distal da artéria femoral profunda, bem como das cirurgias primárias e secundárias, foram comparáveis, sem diferença estatística significante (p = 0,89 e p = 0,77, respectivamente). CONCLUSÃO: A artéria femoral profunda mostrou ser acessível e efetiva como origem de fluxo de enxertos infrageniculares, com resultados satisfatórios de perviedade e salvamento do membro.<br>BACKGROUND: Deep femoral artery can be the most distal technical option as donor site in patients with critical limb ischemia presenting superficial artery occlusion and hostile groins. OBJECTIVE: To retrospectively assess the deep femoral artery as an inflow site for infragenicular bypass grafts. METHODS: From 2000 to 2005, 129 infragenicular bypass grafts with proximal anastomosis located in femoral arteries were performed. Forty were located in the common femoral artery (CFA), 72 in the superficial femoral artery (SFA) and 17 in the deep femoral artery (DFA). Indications for using the DFA as inflow were hostile groin (six cases), limited arterial substitute length (six cases) or both (five cases). Anastomosis site was located in the first or second portion in 12 cases, and in the third in five cases. The surgery was secondary in 47% of the cases, and the arterial substitutes used were arm veins (11), greater saphenous vein (five) and lesser saphenous vein (one). RESULTS: Primary patency and limb salvage rates were 68.0 and 84.7%, respectively, with acceptable standard error (0.1) in 36 months. The results of patency divided by inflow artery were similar (CFA, 63.3%; SFA, 70.2%; DFA 64.7%; p = 0.63), as well as limb salvage rates (CFA, 83.1%; SFA, 82.4%; DFA 92.3%; p = 0.78). Analyzing the deep femoral group, no difference of patency rates was observed when the anastomotic site was compared (proximal vs. distal portions of the DFA) or between patients with or without previous grafts. (p = 0.89 and 0.77, respectively). CONCLUSION: Deep femoral artery is a feasible and effective option as donor site for infragenicular bypass grafts, with satisfactory patency and limb salvage rates

Emerging Tools to Assess the Risk of Rupture in AAA: Wall Stress and FDG PET

Abdominal aortic aneurysm (AAA) rupture is a significant cause of mortality in developed countries. The growth rate and the rupture of AAA may be unpredictable. This chapter places a special emphasis on evaluating patient-specific approaches to the risk of rupture of AAA, using imaging. Specifically, we describe two pathways of assessing this risk: one being the use of morphologic imaging data to compute wall stress (and wall stress-related parameters) via finite element simulation (FES) and the other, the use of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to assess biological processes in the aortic wall components. Both methods are described, along with the limits preventing their widespread use. Nevertheless, the current diameter-based clinical scenarios could be yet impacted by the reported value of FES and FDG PET to predict the risk of AAA rupture. Lastly, the relationship between wall stress and the biological activities as described by FDG PET points at least partially to genetic or acquired alterations of the arterial wall response to wall stress, which can be found in familial aneurysms or in smokers, for example. An integrated patient-specific risk assessment strategy that would include imaging parameters along with personal and heritable risk factors is becoming increasingly suitable.</p