A call to action in thoracic transplant surgical training.

Thoracic organ recovery and implantation is increasing in complexity. Simultaneously the logistic burden and associated cost is rising. An electronic survey distributed to the surgical directors of thoracic transplant programs in the United States indicated dissatisfaction amongst 72% of respondents with current procurement training and 85% of respondents favored a process for certification in thoracic organ transplantation. These responses highlight concerns for the current paradigm of training in thoracic transplantation. We discuss the implications of advancements in organ retrieval and implant for surgical training and propose that the thoracic transplant community might address the need through formalized training in procurement and certification in thoracic transplantation.

Activated 4E-BP1 represses tumourigenesis and IGF-I-mediated activation of the eIF4F complex in mesothelioma.

BACKGROUND: Insulin-like growth factor (IGF)-I signalling stimulates proliferation, survival, and invasion in malignant mesothelioma and other tumour types. Studies have found that tumourigenesis is linked to dysregulation of cap-dependent protein translation. METHODS: The effect of IGF stimulation on cap-mediated translation activation in mesothelioma cell lines was studied using binding assays to a synthetic 7-methyl GTP-cap analogue. In addition, cap-mediated translation was genetically repressed in these cells with a dominant active motive of 4E-BP1. RESULTS: In most mesothelioma cell lines, IGF-I stimulation resulted in a hyperphosphorylation-mediated inactivation of 4E-BP1 compared with that in normal mesothelial cells. An inhibitor of Akt diminished IGF-I-mediated phosphorylation of 4E-BP1, whereas inhibiting MAPK signalling had no such effect. IGF-I stimulation resulted in the activation of the cap-mediated translation complex as indicated by an increased eIF4G/eIF4E ratio in cap-affinity assays. Akt inhibition reversed the eIF4G/eIF4E ratio. Mesothelioma cells transfected with an activated 4E-BP1 protein (4E-BP1(A37/A46)) were resistant to IGF-I-mediated growth, motility, and colony formation. In a murine xenograft model, mesothelioma cells expressing the dominant active 4E-BP1(A37/A46) repressor protein showed abrogated tumourigenicity compared with control tumours. CONCLUSION: IGF-I signalling in mesothelioma cells drives cell proliferation, motility, and tumourigenesis through its ability to activate cap-mediated protein translation complex through PI3K/Akt/mTOR signalling.

Spontaneous posterior rectus sheath hernia: a new clinical entity?

Hernias are often associated with congenital defects or incisional breakdown. We present a rare case of a spontaneous posterior rectus sheath herniation with associated incarcerated small bowel in a woman with no previous abdominal surgery. This is accompanied with a review of the literature and the suggestion that spontaneous posterior rectus sheath herniation is possibly a separate clinical entity.

Minimally invasive cancer surgery improves patient survival rates through less perioperative immunosuppression.

The import of the immune system to cancer survival is paramount. Immune effector cells are intimately involved in the patient's response to cancer. People with decreased immune function develop cancer more frequently. In the early stages of solid organ malignancies, surgery can potentially be curative. Surgical intervention, in and of itself, is immunosuppressive. Surgical resections are traditionally performed through large incisions. Technologic advances have allowed minimally invasive surgery (MIS) to evolve to the point it is now being used for cancer treatment. Recent minimally invasive series have reported improved survival and recurrence rates, as compared with historical data. We hypothesized that outcome differences for cancer patients undergoing open surgery vs. MIS are due to differential inhibition of immune effector cell function, in response to the different surgical stimulus. This increased immunosuppression after open surgery could potentially inhibit immune effector cell tumor surveillance as well as inhibit scavenging of any residual or micrometastatic disease or of tumor cells shed at the time of the operation. The less immunosuppressive MIS may leave immune function above a threshold level where remaining tumor is cleared. This difference would lead to less recurrence and to survival advantages. A deeper understanding of the integral components of the immune response to surgery would open the door for immunomodulation strategies and be of great clinical utility in guiding neoadjuvant, surgical, or adjuvant therapeutic decisions.

Multilaminate resorbable biomedical device under biaxial loading.

The design and test of a multilaminate sheet developed for a hernia repair application is presented. As biomaterial applications become more complex, characterization of uniaxial properties becomes insufficient and biaxial testing becomes necessary. A measure of the in-plane biaxial strength of the device is inferred from a ball burst test. The results of this test for different thicknesses of the device are correlated with the uniaxial strength of the material. A biaxial test such as the ball burst test is more indicative of the properties of a planar material than would be a uniaxial test. The interactions in the biaxial mode of failure are of value and can be related back to a classical uniaxial tensile test from the ball burst test. The material used in this study to fabricate the device was a resorbable biomaterial called small intestinal submucosa (SIS). The effects of rehydration on the stiffness and associated ball burst properties of the SIS device were also measured. It is shown that at a rehydration time of 5 min from a reference dry state, steady-state mechanical properties are reached.