The neurocognitive enhancement of surgeons: an ethical perspective

Neurocognitive enhancement is a rapidly expanding scientific field. The vast ethical implications of this developing field for surgical practice have yet to be considered within the literature. This article outlines the reasons surgeons may, in the near future, consider using neurocognitive enhancement and addresses the resulting significant ethical implications of this. We do not seek to support or denounce the potential role of neurocognitive enhancement in surgeons, but to stimulate a debate, which, with ever-increasing levels of stimulant use in schools and colleges, and with a pharmaceutical industry driving the creation of new neuroactive products, has now become a necessity.     

Does Re-operation have an Effect on Outcome Following Heart Transplantation?

OBJECTIVE: Previous cardiac operation has traditionally been considered as a potential risk factor for patients undergoing heart transplantation. This study aimed to evaluate the outcome of patients undergoing heart transplantation as a second cardiac procedure and compare it with primary heart transplantation, using meta-analytical methodology. METHODS: A literature search was undertaken to identify relevant comparative studies. Outcomes of interest were classified into four categories: (a) intra-operative times; (b) post-operative outcomes; (c) resources; (d) actuarial outcomes. RESULTS: Seven studies matched the selection criteria, reporting on 1004 patients. Six hundred and twenty-three had transplantation as primary operation and 381 as re-operation. The 1-year, 2-year, and 5-year mortality were similar for the two groups (HR=0.85, p=0.54; HR=0.97, p=0.88; and HR=1.04, p=0.92, respectively). Total operative, cold-ischaemic, by-pass, and cross-clamp times were significantly longer for the re-operation group by 59.44 (p<0.001), 14.62 (p=0.05), 25.24 (p<0.001), and 7.93 (p<0.001)min, respectively. Both ICU and hospital stay were longer for the re-operation group but only the former was statistically significant (WMD=1.37; p=0.02). Post-operative complications were similar, except re-exploration rate and blood transfusion requirement, which were higher in the re-operation group (OR=3.51; p<0.001 and WMD=2.21; p<0.001, respectively). CONCLUSIONS: Heart transplantation following previous cardiac operation is technically demanding requiring longer operative times compared to primary heart transplantation. It does not, however, add a significant risk to the survival of the patient, and associated morbidity is not significantly compromised.     

The 2005 Italian Quality Control Study for the evaluation of CD4 cells in centers involved in the treatment of HIV type 1 patients

We report the results of an external quality control program, including 17 Italian centers involved in the care of patients infected by HIV, to evaluate CD4 T cell count proficiency and reproducibility. The centers received two commercial stabilized blood preparations, one with "normal" and one with "low" CD4 T cell content. The centers were asked to process the samples two times, 1 week apart, with the same procedure used for samples from HIV patients. Most centers showed a good performance of CD4 frequency and absolute count determinations. In particular, the "low" sample was correctly analyzed by all centers; only two underestimated the "normal" sample CD4 frequency, and only one underestimated the CD4 absolute count by >100 CD4 cells/microl. Overall, our data suggest that most Italian laboratories provide reliable and reproducible results in evaluating CD4 T cells in HIV(+) samples.     

Multi-detector computed tomography in coronary artery bypass graft assessment: a meta-analysis

Multi-detector computed tomography (MDCT) has become an alternative to coronary angiography in diagnosis of graft occlusion and stenosis after coronary artery bypass. A literature search was performed for studies comparing angiography to 8-slice, 16-slice, and 64-slice MDCT in the assessment of coronary grafts. In assessing occlusion, 14 studies produced pooled sensitivity of 97.6%, specificity of 98.5%, diagnostic odds ratio of 934.2, area under the curve of 0.996, and Q* of 0.977. Ninety-six percent of all grafts were visualized for occlusion assessment. Beta blockers, symptomatic status, and postoperative period did not significantly affect diagnostic performance. Stenosis assessment produced sensitivity of 88.7% and specificity of 97.4%. Eighty-eight percent of patent grafts could be assessed for stenosis. The diagnostic accuracy of MDCT approaches angiography for diagnosing graft occlusion and stenosis in patients with venous and arterial coronary bypass grafts. Our findings show that cardiac surgeons will need to interpret MDCT images of both native and grafted vessels soon in preparation for primary or re-do coronary bypass grafting procedures.     

Studies of genomic copy number changes in human cancers reveal signatures of DNA replication stress

Human cancers are characterized by the presence of genomic instability. Recently, two studies have catalogued the presence of a specific class of genomic aberrations, large deletions and insertions, in a few thousand human cancers and reported that most of the prevalent recurrent focal deletions targeted common fragile sites and large genes. In various experimental systems, deletions in common fragile sites and large genes have been linked to the presence of DNA replication stress. Thus, taken together, these results suggest the presence of DNA replication stress in human cancers, consistent with the recently proposed oncogene-induced DNA damage model for cancer development.     

Receptor interacting protein kinases mediate retinal detachment-induced photoreceptor necrosis and compensate for inhibition of apoptosis

Apoptosis has been shown to be a significant form of cell loss in many diseases. Detachment of photoreceptors from the retinal pigment epithelium, as seen in various retinal disorders, causes photoreceptor loss and subsequent vision decline. Although caspase-dependent apoptotic pathways are activated after retinal detachment, caspase inhibition by the pan-caspase inhibitor Z-VAD fails to prevent photoreceptor death; thus, we investigated other pathways leading to cell loss. Here, we show that receptor interacting protein (RIP) kinase-mediated necrosis is a significant mode of photoreceptor cell loss in an experimental model of retinal detachment and when caspases are inhibited, RIP-mediated necrosis becomes the predominant form of death. RIP3 expression, a key activator of RIP1 kinase, increased more than 10-fold after retinal detachment. Morphological assessment of detached retinas treated with Z-VAD showed decreased apoptosis but significantly increased necrotic photoreceptor death. RIP1 kinase inhibitor necrostatin-1 or Rip3 deficiency substantially prevented those necrotic changes and reduced oxidative stress and mitochondrial release of apoptosis-inducing factor. Thus, RIP kinase-mediated programmed necrosis is a redundant mechanism of photoreceptor death in addition to apoptosis, and simultaneous inhibition of RIP kinases and caspases is essential for effective neuroprotection and may be a novel therapeutic strategy for treatment of retinal disorders.