OBJECTIVETo investigate α-toxin-induced apoptosis of umbilical vein endothelial cells and explore its role in vertical infection of Staphylococcus aureus L-form.

METHODSHUV-EC-C cells exposed to different concentrations (0, 10, 30, 90, and 270 ng/ml) of α-toxin for different time lengths (0, 2, 4, 6, and 8 h) were examined for apoptosis using flow cytometry with Annexin V-PI staining. The levels of tumor necrosis factor-α (TNF-α) and the activities of, caspase-3 and caspase-8 in the cell culture were detected by ELISA and colorimetric method, respectively. α-Toxin-induced cell apoptosis was also analyzed in HUV-EC-C cells treated with a neutralizing antibody of TNF-α or with the inhibitory peptides of caspase-3 (zDEVD-FMK) and caspase-8 (zIETD-fmk).

RESULTSα-Toxin induced apoptosis of HUV-EC-C cells in a dose- and time-dependent manner and caused significantly enhanced expression of TNF-α and the activation of both caspase-3 and caspase-8. Inhibition of TNF-α with its neutralizing antibody and the inhibitory peptides of caspase-3 or -8 all significantly decreased α-toxin-induced cell apoptosis, and the caspase-3 inhibitor completely blocked α-toxin-induced cell apoptosis.

CONCLUSIONα-Toxin-induced apoptosis is partially mediated by the extrinsic cell death pathway of TNF-α and caspase-8 and plays an important role in the vertical infection of S. aureus L-form to affect fetal growth and development.

Apoptosis ; Bacterial Toxins ; toxicity ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; L Forms ; Staphylococcal Infections ; Staphylococcus aureus ; Tumor Necrosis Factor-alpha ; metabolism

Objective:To evaluate a surgical approach for partial resection of the tenth rib through a retroperitoneal approach for the exposure of Crawford type IV thoracoabdominal aortic aneurysm and complex abdominal aortic aneurysm from 2014 to 2019.Methods:A retrospective analysis was conducted on clinical data and follow-up results of 7 patients who underwent treatment for Crawford type IV thoracoabdominal aortic aneurysm and complex abdominal aortic aneurysm through partial resection of the tenth rib via a retroperitoneal approach.Results:One case (14.3%) had associated Marfan syndrome, and 5 cases (71.4%) underwent left renal artery reconstruction. None of the patients experienced severe complications such as cardiopulmonary complications or renal failure postoperatively, and there was no statistically significant difference in serum creatinine levels between preoperative and postoperative stages during hospitalization ( P=0.205). Follow-up examinations showed no long-term vascular stenosis. Conclusions:Partial resection of the tenth rib through a retroperitoneal approach can avoid incisions of the pleura and diaphragm. It allows for the exposure of the aorta below the diaphragm and has the ability to treat aortic diseases below the diaphragm with smaller incisions and lower complication risks.