Morphological evaluation of experimental autologous rectus fascia sheath vascular grafts used for arterial replacement in a dog model

Although experimental autologous patch or tubular conduit vascular grafts made from the internal rectus fascia sheath (IRFS) have been reported in the literature, thorough morphological evaluation and verification of the histological arterialisation of such grafts are lacking. Four purpose-bred Beagle dogs were utilised to create eight arterial internal rectus fascia sheath (ARFS) grafts implanted between bisected ends of the external iliac arteries. Four out of the eight ARFS grafts were patent after three months. Haematoxylin-eosin and Azan staining verified that the grafts gained a vessel-like layered structure with the presence of large amounts of collagen fibres. Although the inner surface of the intact IRFS was originally covered with claudin-5-negative and pancytokeratin-positive mesothelial cells in control samples, the internal cells of the ARFS grafts became claudin-5 positive and pancytokeratin negative like in intact arteries. Spindle-shaped cells of the wall of ARFS grafts were α-smooth muscle actin (α-SMA) positive just like the smooth muscle cells of intact arteries, but α-SMA immunoreactivity was negative in the intact IRFS. According to these findings, the fibroblast cells of the ARFS graft have changed into myofibroblast cells. The study has proved that ARFS grafts may be used as an alternative in arterial replacement, since the graft becomes morphologically and functionally similar to the host vessel via arterialisation

Antagonism of LPS and IFN-gamma induced iNOS expression in human atrial endothelia by morphine, anandamide, and estrogen

AIM: To determine whether inducible nitric oxide synthase (iNOS) stimulation of human atrial fragments can be diminished by the naturally occurring signal molecules, such as morphine, anandamide, and estrogen. The use of iNOS as an indicator is justified since it has been associated with initiation of various types of cellular damage either directly or indirectly. METHODS: Western blots were performed on control and drug-exposed atrial tissue before and after lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) exposure. RESULTS: Preincubation of the tissue with morphine, anandamide or estrogen prior to, but not after, the addition of LPS + IFN-gamma, blocked iNOS expression. The nitric oxide donor SNAP also blocked iNOS induction while preincubation of atrial fragments with an inhibitor of NOS, L-NAME, prior to morphine or anandamide exposure, restored LPS + IFN-gamma induction of iNOS. CONCLUSION: These data suggest a direct regulatory link at the transcriptional level between constitutive (c) NOS and iNOS in human atrial tissue

μ3 Opiate receptor expression in lung and lung carcinoma: ligand binding and coupling to nitric oxide release

The mu 3 opiate receptor subtype is expressed in human surgical specimens of both normal lung and non-small-cell lung carcinoma. Nitric oxide (NO) release is mediated through the mu 3 receptor, and in lung carcinoma, morphine-stimulated NO release is significantly higher and prolonged than in normal lung. Using reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis we show that specific mu opioid receptor transcripts are present in lung carcinoma and other cells with the mu 3 profile. Our findings identify a unique role for the mu 3 opiate receptor in opiate-mediated NO release and suggest that endogenous opiates, through their release of NO, may play a role in cancer progression

Morphine and anandamide stimulate intracellular calcium transients in human arterial endothelial cells: coupling to nitric oxide release

Both morphine and anandamide significantly stimulated cultured endothelial intracellular calcium level increases in a concentration-dependent manner in cells pre-loaded with fura 2/AM. Morphine is more potent than anandamide (approximately 275 vs. 135 nM [Ca]i), and the [Ca]i for both ligands was blocked by prior exposure of the cells to their respective receptor antagonist, i.e., naloxone and SR 171416A. Various opioid peptides did not exhibit this ability, indicating a morphine-mu3-mediated process. In comparing the sequence of events concerning morphine's and anandamide's action in stimulating both [Ca]i and nitric oxide production in endothelial cells, we found that the first event precedes the second by 40+/-8 sec. The opiate and cannabinoid stimulation of [Ca]i was attenuated in cells leeched of calcium, strongly suggesting that intracellular calcium levels regulate cNOS activity

Fiber-optic monitoring of spinal cord hemodynamics in experimental aortic occlusion

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOBackground: Spinal cord ischemia occurs frequently during thoracic aneurysm repair. Current methods based on electrophysiology techniques to detect ischemia are indirect, non-specific, and temporally slow. In this article, the authors report the testing of a spinal cord blood flow and oxygenation monitor, based on diffuse correlation and optical spectroscopies, during aortic occlusion in a sheep model. Methods: Testing was carried out in 16 Dorset sheep. Sensitivity in detecting spinal cord blood flow and oxygenation changes during aortic occlusion, pharmacologically induced hypotension and hypertension, and physiologically induced hypoxia/hypercarbia was assessed. Accuracy of the diffuse correlation spectroscopy measurements was determined via comparison with microsphere blood flow measurements. Precision was assessed through repeated measurements in response to pharmacologic interventions. Results: The fiber-optic probe can be placed percutaneously and is capable of continuously measuring spinal cord blood flow and oxygenation preoperatively, intraoperatively, and postoperatively. The device is sensitive to spinal cord blood flow and oxygenation changes associated with aortic occlusion, immediately detecting a decrease in blood flow (-65 32%; n = 32) and blood oxygenation (-17 +/- 13%, n = 11) in 100% of trials. Comparison of spinal cord blood flow measurements by the device with microsphere measurements led to a correlation of R-2 = 0.49, P < 0.01, and the within-sheep coefficient of variation was 9.69%. Finally, diffuse correlation spectroscopy is temporally more sensitive to ischemic interventions than motor-evoked potentials. Conclusion: The first-generation spinal fiber-optic monitoring device offers a novel and potentially important step forward in the monitoring of spinal cord ischemia.Background: Spinal cord ischemia occurs frequently during thoracic aneurysm repair. Current methods based on electrophysiology techniques to detect ischemia are indirect, non-specific, and temporally slow. In this article, the authors report the testing of a spinal cord blood flow and oxygenation monitor, based on diffuse correlation and optical spectroscopies, during aortic occlusion in a sheep model. Methods: Testing was carried out in 16 Dorset sheep. Sensitivity in detecting spinal cord blood flow and oxygenation changes during aortic occlusion, pharmacologically induced hypotension and hypertension, and physiologically induced hypoxia/hypercarbia was assessed. Accuracy of the diffuse correlation spectroscopy measurements was determined via comparison with microsphere blood flow measurements. Precision was assessed through repeated measurements in response to pharmacologic interventions. Results: The fiber-optic probe can be placed percutaneously and is capable of continuously measuring spinal cord blood flow and oxygenation preoperatively, intraoperatively, and postoperatively. The device is sensitive to spinal cord blood flow and oxygenation changes associated with aortic occlusion, immediately detecting a decrease in blood flow (-65 32%n = 32) and blood oxygenation (-17 +/- 13%, n = 11) in 100% of trials. Comparison of spinal cord blood flow measurements by the device with microsphere measurements led to a correlation of R-2 = 0.49, P < 0.01, and the within-sheep coefficient of variation was 9.69%. Finally, diffuse correlation spectroscopy is temporally more sensitive to ischemic interventions than motor-evoked potentials. Conclusion: The first-generation spinal fiber-optic monitoring device offers a novel and potentially important step forward in the monitoring of spinal cord ischemia.123613621373FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP [2012/02500-8]2012/02500-8The authors thank the Biostatistical Consulting Core at Stony Brook University (Stony Brook, New York) for consulting with them on the statistical analysis. The authors also thank the veterinary technicians at the Division of Laboratory Animal Resources (DLAR) at Stony Brook University and Cecille Just, an electroencephalography (EEG) specialist, from the EEG Department at Stony Brook Hospital (Stony Brook, New York), for their assistance with their sheep experiments. This work has been supported by the Craig H. Neilsen Foundation (Encino, California)Stony Brook University Fusion Award (Stony Brook, New York)Stony Brook University’s Department of AnesthesiologyOffice of the Vice President for ResearchSchool of Medicine and University Hospital (Stony Brook, New Yorkto Drs. Floyd and Kogler)National Institutes of Health (Bethesda, Marylandgrant nos. R01-NS060653 and P41-EB015893 to Dr. Yodh)and the São Paulo Research Foundation through grant no. 2012/02500-8 (São Paulo, Brazilto Dr. Galler)