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BACKGROUND - Injury to saphenous vein grafts during surgical preparation may contribute to the subsequent development of intimal hyperplasia, the primary cause of graft failure. Surgical skin markers currently used for vascular marking contain gentian violet and isopropanol, which damage tissue and impair physiologic functions. Brilliant blue FCF (FCF) is a nontoxic dye alternative that may also ameliorate preparation-induced injury.
METHODS - Porcine saphenous vein (PSV) was used to evaluate the effect of FCF on physiologic responses in a muscle bath. Cytotoxicity of FCF was measured using human umbilical venous smooth muscle cells. Effect of FCF on the development of intimal hyperplasia was evaluated in organ culture using PSV. Intracellular calcium fluxes and contractile responses were measured in response to agonists and inhibitors in rat aorta and human saphenous vein.
RESULTS - Marking with FCF did not impair smooth muscle contractile responses and restored stretch injury-induced loss in smooth muscle contractility of PSV. Gentian violet has cytotoxic effects on human umbilical venous smooth muscle cells, whereas FCF is nontoxic. FCF inhibited intimal thickening in PSV in organ culture. Contraction induced by 2'(3')-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate and intracellular calcium flux were inhibited by FCF, oxidized adenosine triphosphate, KN-62, and brilliant blue G, suggesting that FCF may inhibit the purinergic receptor P2X7.
CONCLUSIONS - Our studies indicated that FCF is a nontoxic marking dye for vein grafts that ameliorates vein graft injury and prevents intimal thickening, possibly due to P2X7 receptor inhibition. FCF represents a nontoxic alternative for vein graft marking and a potentially therapeutic approach to enhance outcome in autologous transplantation of human saphenous vein into the coronary and peripheral arterial circulation.
Copyright © 2016 Society for Vascular Surgery. All rights reserved.
IMPORTANCE - Surgical skin markers are used off-label to mark human saphenous veins (HSVs) to maintain orientation before implantation as aortocoronary or peripheral arterial bypass grafts. These surgical skin markers impair functional responses of the HSV tissue.
OBJECTIVES - To investigate the effect of brilliant blue dye 1 (brilliant blue FCF [for food coloring]; hereinafter, FCF) as a nontoxic alternative marking dye and to determine whether FCF has pharmacological properties.
DESIGN, SETTING, AND PARTICIPANTS - Segments of HSVs were collected in university hospitals from patients undergoing coronary artery bypass grafting procedures immediately after harvest (unmanipulated) or after typical intraoperative surgical graft preparation (after manipulation). Rat inferior venae cavae were used to determine the pharmacological properties and cellular targets of FCF. Endothelial and smooth muscle functional responses were determined in a muscle bath, and intimal thickening in HSVs was determined after 14 days in organ culture.
MAIN OUTCOMES AND MEASURES - Contractile responses were measured in force and converted to stress. Smooth muscle function was expressed as maximal responses to potassium chloride depolarization contractions. Endothelial function was defined as the percentage of relaxation of maximal agonist-induced contraction. Neointimal thickness was measured by histomorphometric analysis.
RESULTS - Human saphenous veins stored in the presence of FCF had no loss of endothelial or smooth muscle function. Unmanipulated HSVs preserved in the presence of FCF demonstrated a significant increase in endothelial-dependent relaxation (mean [SEM], 25.2% [6.4%] vs 30.2% [6.7%]; P = .02). Application of FCF to functionally nonviable tissue significantly enhanced the smooth muscle responses (mean [SEM], 0.018 [0.004] × 10⁵ N/m² vs 0.057 [0.016] × 10⁵ N/m²; P = .05). Treatment with FCF reduced intimal thickness in organ culture (mean [SEM], -17.5% [2.1%] for unmanipulated HSVs vs -27.9% [3.7%] for HSVs after manipulation; P < .001). In rat inferior venae cavae, FCF inhibited the contraction induced by the P2X7 receptor agonist 2'(3')-O-(4-benzoyl)benzoyl-adenosine-5'-triphosphate (mean [SEM], 14.8% [2.2%] vs 6.5% [1.8%]; P = .02) to an extent similar to the P2X7 receptor antagonist oxidized adenosine triphosphate (mean [SEM], 5.0% [0.9%]; P < .02 vs control) or the pannexin hemichannel inhibitor probenecid (mean [SEM], 7.3% [1.6%] and 4.7% [0.9%] for 0.5mM and 2mM, respectively; P < .05).
CONCLUSIONS AND RELEVANCE - Treatment with FCF did not impair endothelial or smooth muscle function in HSVs. Brilliant blue FCF enhanced endothelial-dependent relaxation, restored smooth muscle function, and prevented intimal hyperplasia in HSVs in organ culture. These pharmacological properties of FCF may be due to P2X7 receptor or pannexin channel inhibition. Brilliant blue FCF is an alternative, nontoxic marking dye that may improve HSV conduit function and decrease intimal hyperplasia.
OBJECTIVE - To elucidate the long-term effects of liver transplantation (LT) on familial amyloid polyneuropathy (FAP).
METHODS - We investigated clinicopathological and biochemical characteristics of systemic tissues in four autopsied cases of FAP patients surviving more than 10 years after LT and seven autopsied cases without LT. For analysing the truncated form of transthyretin (TTR) in amyloid, we also employed specimens from additional 18 FAP patients.
RESULTS - Several tissue sites such as the heart, tongue and spinal cord had moderate-to-severe amyloid deposits but other tissues showed no or mild amyloid deposition. Those findings seemed similar to those observed in senile systemic amyloidosis (SSA), a sporadic amyloidosis caused by wild-type (WT) TTR. Also, amyloid deposits in systemic tissue sites except for the spinal cord in patients after LT derived mostly from WT TTR secreted from the normal liver grafts. In addition, in non-transplantation patients, proportions of WT TTR seemed to be relatively high in those tissue sites in which patients after LT had severe amyloid deposition, which suggests that WT TTR tends to form amyloid in those tissue sites. Finally, although the truncation of TTR in amyloid deposits did not depend on undergoing LT, we elucidated the truncation of TTR occurred predominantly in patients from non-endemic areas of Japan, where FAP amyloidogenic TTR V30M patients are late onset and low penetrance, compared with patients from an endemic area of Japan.
CONCLUSIONS - FAP may shift to systemic WT TTR amyloid formation after LT, which seems to be similar to the process in SSA. The truncation of TTR in amyloid deposits may depend on some genetic or environmental factors other than undergoing LT.
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BACKGROUND - Activation of the P2X7 receptor on peripheral neurons causes the formation of pannexin pores, which allows the influx of calcium across the cell membrane. Polyethylene glycol (PEG) and methylene blue have previously been shown to delay Wallerian degeneration if applied during microsuture repair of the severed nerve. Our hypothesis is that by modulating calcium influx via the P2X7 receptor pathway, we could improve PEG-based axonal repair. The P2X7 receptor can be stimulated or inhibited using bz adenosine triphosphate (bzATP) or brilliant blue (FCF), respectively.
METHODS - A single incision rat sciatic nerve injury model was used. The defect was repaired using a previously described PEG methylene blue fusion protocol. Experimental animals were treated with 100 μL of 100 μM FCF solution (n = 8) or 100 μL of a 30 μM bzATP solution (n = 6). Control animals received no FCF, bzATP, or PEG. Compound action potentials were recorded prior to transection (baseline), immediately after repair, and 21 d postoperatively. Animals underwent behavioral testing 3, 7, 14, and 21 d postoperatively. After sacrifice, nerves were fixed, sectioned, and immunostained to allow for counting of total axons.
RESULTS - Rats treated with FCF showed an improvement compared with control at all time points (n = 8) (P = 0.047, 0.044, 0.014, and 0.0059, respectively). A statistical difference was also shown between FCF and bzATP at d 7 (P < 0.05), but not shown with d 3, 14, and 21 (P > 0.05).
CONCLUSIONS - Blocking the P2X7 receptor improves functional outcomes after PEG-mediated axonal fusion.
Copyright © 2013 Elsevier Inc. All rights reserved.
The polyphenol curcumin is the principal flavor and color component of the spice turmeric. Beyond its culinary uses, curcumin is believed to positively impact human health and displays antioxidant, anti-inflammatory, antibacterial, and chemopreventive properties. It also is in clinical trials as an anticancer agent. In aqueous solution at physiological pH, curcumin undergoes spontaneous autoxidation that is enhanced by oxidizing agents. The reaction proceeds through a series of quinone methide and other reactive intermediates to form a final dioxygenated bicyclopentadione product. Several naturally occurring polyphenols that can form quinones have been shown to act as topoisomerase II poisons (i.e., they increase levels of topoisomerase II-mediated DNA cleavage). Because several of these compounds have chemopreventive properties, we determined the effects of curcumin, its oxidative metabolites, and structurally related degradation products (vanillin, ferulic acid, and feruloylmethane) on the DNA cleavage activities of human topoisomerase IIα and IIβ. Intermediates in the curcumin oxidation pathway increased the level of DNA scission mediated by both enzymes ~4-5-fold. In contrast, curcumin and the bicyclopentadione, as well as vanillin, ferulic acid, and feruloylmethane, had no effect on DNA cleavage. As found for other quinone-based compounds, curcumin oxidation intermediates acted as redox-dependent (as opposed to interfacial) topoisomerase II poisons. Finally, under conditions that promote oxidation, the dietary spice turmeric enhanced topoisomerase II-mediated DNA cleavage. Thus, even within the more complex spice formulation, oxidized curcumin intermediates appear to function as topoisomerase II poisons.
The dermal granular glands of the South African clawed frog, Xenopus laevis, contain antimicrobial peptides (AMPs) that are secreted following local nerve stimulation. These natural antibiotics are active against bacteria and fungi including Batrachochytrium dendrobatidis, a fungal pathogen that causes the skin disease chytridiomycosis. Granular gland secretion can be stimulated in the laboratory by norepinephrine injection. We found that two injections of 80nmol/g norepinephrine were necessary to fully deplete the AMP stores. One injection resulted in the secretion of most of the stored peptides. A second injection, 2 days later, released a small amount of additional AMPs that are not compositionally different from those released by the first injection. A third injection, 4 days after the first, did not result in further AMP release. Mass spectrometry and histology confirmed that glands are depleted after two injections. Periodic acid-Schiff staining indicated that mucus gland secretion was also induced by norepinephrine.
Copyright © 2011 Elsevier Ltd. All rights reserved.
Marking human saphenous vein graft (HSV) with a surgical skin marker to prevent twisting on implantation is a common practice in peripheral and coronary artery bypass procedures. This study is designed to examine the effects of surgical skin markers on the HSV smooth muscle and endothelial functional responses. De-identified HSV remnants were collected during peripheral and coronary artery bypass procedures. Physiologic responses of the HSV were measured using a muscle bath. Veins that were marked with surgical skin markers intraoperatively generated significantly less contractile force to depolarizing KCl (110 mM) and receptor-mediated contractile agonists than unmarked HSV, suggesting that surgical skin markers impaired HSV smooth muscle contractility. To directly access the effects of chemical components in the surgical skin markers, unmarked HSV was exposed to isopropyl alcohol (a solvent commonly used in surgical skin markers) or methylene blue (a dye). Smooth muscle contractility was significantly reduced by isopropyl alcohol and methylene blue. Endothelial-dependent relaxation to carbachol was significantly reduced after exposure to surgical skin markers. Our data demonstrated that marking HSV with surgical skin markers reduces smooth muscle and endothelial functional viability.
Clinical Histopathology is based on the analysis of immunohistochemistry (IHC) stained tissue images. Selection of antibodies for detecting the presence, type, and grade of cancerous tissue has a great influence on the diagnostic potential of IHC tests. Automated evaluation methods for tissue microarrays applied to many combinations of antibody and tissue type can speed development of new clinical assays. We present an automatic method that successfully quantifies stain intensity, fraction of cells stained and sub-cellular location of staining in tissue microarray images. The method combines an opponent color preprocessor and a novel statistical approach for identifying brown and blue staining, followed by multilevel morphological processing. We verify the capability of our method by comparing the results to manually annotated image databases. We also demonstrate cross-tissue robustness using two clinical case study data.
BACKGROUND - The presence of fat in the liver is considered a major risk for postoperative complication after liver surgery and transplantation. The current standard of quantification of hepatic steatosis is microscopic evaluation by pathologists, although consistency in such assessment remains unclear. Computerized image analysis is an alternative method for objective assessment of the degree of hepatic steatosis.
METHODS - High resolution images of hematoxylin and eosin stained liver sections from 46 consecutive patients, initially diagnosed with liver steatosis, were blindly assessed by 4 established expert pathologists from different institutions. Computerized analysis was carried out simultaneously on the same sections. Interobserver agreement and correlation between the pathologists' and computerized assessment were evaluated using intraclass correlation coefficients (ICC), Spearman rank correlation coefficients, or descriptive statistics.
RESULTS - Poor agreement among pathologists (ICC: 0.57) was found regarding the assessment of total steatosis, (ICC >0.7 indicates acceptable agreement). Pathologists' estimation of micro- and macrosteatosis disclosed also poor correlation (ICC: 0.22, 0.55, respectively). Inconsistent assessment of histological features of steatohepatitis (lobular inflammation, portal inflammation, hepatocyte ballooning, and Mallory hyaline) was documented. Poor conformity was also shown between the computerized quantification and ratings of 3 pathologists (Spearman rank correlation coefficients: 0.22, 0.82, 0.28, and 0.38).
CONCLUSION - Quantification of hepatic steatosis in histological sections is strongly observer-dependent, not reproducible, and does not correlate with the computerized estimation. Current standards of assessment, previously published data and the clinical relevance of hepatic steatosis for liver surgery and transplantation must be challenged.