Disruption of Bcchs4, Bcchs6 or Bcchs7 chitin synthase genes in Botrytis cinerea and the essential role of class VI chitin synthase (Bcchs6).

Chitin synthases play critical roles in hyphal development and fungal pathogenicity. Previous studies on Botrytis cinerea, a model organism for necrotrophic pathogens, have shown that disruption of Bcchs1 and more particularly Bcchs3a genes have a drastic impact on virulence (Soulié et al., 2003, 2006). In this work, we investigate the role of other CHS including BcCHS4, BcCHS6 and BcCHS7 during the life cycle of B. cinerea. Single deletions of corresponding genes were carried out. Phenotypic analysis indicates that: (i) BcCHS4 enzyme is not essential for development and pathogenicity of the fungus; (ii) BcCHS7 is required for pathogenicity in a host dependant manner. For Bcchs6 gene disruption, we obtained only heterokaryotic strains. Indeed, sexual or asexual purification assays were unsuccessful. We concluded that class VI chitin synthase could be essential for B. cinerea and therefore BcCHS6 represents a valuable antifungal target.

Predictors and Consequences of Sac Shrinkage after Endovascular Infrarenal Aortic Aneurysm Repair.

Background: Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). We evaluated the impact of sac shrinkage on secondary interventions, on survival and its association with endoleaks, and on compliance with instructions for use (IFU). Methods: This observational retrospective study was conducted on all consecutive patients receiving EVAR for an infrarenal abdominal aortic aneurysm (AAA) using exclusively Endurant II/IIs endograft from 2014 to 2018. Sixty patients were entered in the study. Aneurysm sac shrinkage was defined as decrease ≥5 mm of the maximum aortic diameter. Univariate methods and Kaplan-Meier plots assessed the potential impact of shrinkage. Results: Twenty-six patients (43.3%) experienced shrinkage at one year, and thirty-four (56.7%) had no shrinkage. Shrinkage was not significantly associated with any demographics or morbidity, except hypertension (p = 0.01). No aneurysm characteristics were associated with shrinkage. Non-compliance with instructions for use (IFU) in 13 patients (21.6%) was not associated with shrinkage. Three years after EVAR, freedom from secondary intervention was 85 ± 2% for the entire series, 92.3 ± 5.0% for the shrinkage group and 83.3 ± 9% for the no-shrinkage group (Logrank: p = 0.49). Survival at 3 years was not significantly different between the two groups (85.9 ± 7.0% vs. 79.0 ± 9.0%, Logrank; p = 0.59). Strict compliance with IFU was associated with less reinterventions at 3 years (92.1 ± 5.9% vs. 73.8 ± 15%, Logrank: p = 0.03). Similarly, survival at 3 years did not significantly differ between strict compliance with IFU and non-compliance (81.8 ± 7.0% vs. 78.6 ± 13.0%, Logrank; p = 0.32). Conclusion: This study suggests that shrinkage ≥5 mm at 1-year is not significantly associated with a better survival rate or a lower risk of secondary intervention than no-shrinkage. In this series, the risk of secondary intervention regardless of shrinkage seems to be linked more to non-compliance with IFU. Considering the small number of patients, these results must be confirmed by extensive prospective studies.

Innovative Technique for Below the Knee Arterial Revascularisation Using Porcine Self Made Stapled Pericardial Tube Grafts.

INTRODUCTION: When no autologous vein is available for distal bypass in the setting of chronic limb threatening ischaemia (CLTI), new alternatives are required to solve the problems of availability, patency, and resistance to infection. An innovative technique of below the knee bypass for CLTI using a porcine self made stapled pericardial tube graft is reported. REPORT: An 84 year old man, admitted with right CLTI with foot infection due to long occlusion of the femoropopliteal segment, required urgent revascularisation. In the absence of autologous vein and cryopreserved vessels, a 4 mm self made stapled porcine pericardial tube graft 56 cm long was created from two 14 × 8 cm patches, to perform a femorotibioperoneal trunk bypass. On day 10, bypass thrombectomy and balloon angioplasty of the distal anastomosis were needed to treat early occlusion. Oral anticoagulation was then started. Right toe pressure increased from 0 to 70 mmHg, and no infection was reported. Complete wound healing was achieved. At six months, the bypass was still patent. DISCUSSION: The use of porcine self made stapled pericardial tube grafts could offer new options for revascularisation in CLTI. Larger cohort studies with longer follow up are needed to confirm this successful preliminary experience.