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Find video protocols related to scientific articles indexed in Pubmed.
Visualization of Latent Blood Stains Using Visible Reflectance Hyperspectral Imaging and Chemometrics.
J. Forensic Sci.
PUBLISHED: 11-11-2014
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The detection of latent traces is an important aspect of crime scene investigation. Blood stains on black backgrounds can be visualized using chemiluminescence, which is invasive and requires a darkened room, or near-infrared photography, for which investigators need to change filters manually to optimize contrast. We demonstrated the performance of visible reflectance hyperspectral imaging (400-720 nm) for this purpose. Several processing methods were evaluated: single wavelength bands, ratio images, principal component analysis (PCA), and "SIMPLe-to-use Interactive Self-modeling Mixture Analysis" (SIMPLISMA). Using these methods, we were able to enhance the contrast between blood stains and 12 different fabrics. On black cotton, blood dilutions were visible with a minimal concentration of 25% of whole blood. The hyperspectral camera system used in this study is portable and wireless, which makes it suitable for crime scene use. The described technique is noncontact and nondestructive, so all traces are preserved for further analysis.
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The Development and Implementation of a Competency-Based Curriculum for Training in Global Health Research.
Am. J. Trop. Med. Hyg.
PUBLISHED: 11-06-2014
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The Fogarty International Center (FIC) Global Health Fellows Program provides trainees with the opportunity to develop research skills through a mentored research experience, increase their content expertise, and better understand trends in global health research, funding organizations, and pathways to generate support. The Northern Pacific Global Health Fellows Research and Training Consortium, which hosts one of the FIC Global Health Programs, sought to enhance research training by developing, implementing, and evaluating a competency-based curriculum that uses a modular, asynchronous, web-based format. The curriculum has 8 core competencies, 36 learning objectives, and 58 assignments. Nineteen trainees completed their 11-month fellowship, engaged in the curriculum, and provided pre- and post-fellowship self-assessments. Self-assessed scores significantly improved for all competencies. Trainees identified the curriculum as one of the strengths of the program. This competency-based curriculum represents a first step toward creating a framework of global health research competencies on which further efforts could be based.
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The Value of Optical Coherence Tomography in Determining Surgical Margins in Squamous Cell Carcinoma of the Vulva: A Single-Center Prospective Study.
Int. J. Gynecol. Cancer
PUBLISHED: 11-04-2014
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Vulvar squamous cell carcinoma (VSCC) is treated with wide local excision. The challenge is to remove as much skin as necessary to prevent recurrence, but meanwhile preserve genital skin to diminish morbidity. Optical coherence tomography (OCT) is a noninvasive imaging tool that produces cross-sectional images. Optical coherence tomography could be helpful in determining appropriate surgical margins during excision of VSCC.
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Comparison of optical coherence tomography and histopathology in quantitative assessment of goat talus articular cartilage.
Acta Orthop
PUBLISHED: 10-29-2014
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Background and purpose - Optical coherence tomography (OCT) is a light-based imaging technique suitable for depiction of thin tissue layers such as articular cartilage. Quantification of results and direct comparison with a reference standard is needed to confirm the role of OCT in cartilage evaluation. Materials and methods - Goat talus articular cartilage repair was assessed quantitatively with OCT and compared with histopathology using semi-automated analysis software. Osteochondral defects were created centrally in goat tali with subsequent healing over 24 weeks. After sacrifice, the tali were analyzed using OCT and processed into histopathology slides. Cartilage thickness, repair tissue area, and surface roughness were measured. Also, light attenuation coefficient measurements were performed to assess differences in the properties of healthy tissue and repair tissue. Results - Intra-class correlation coefficients for resemblance between the 2 techniques were 0.95 (p < 0.001) for thickness, 0.73 (p = 0.002) for repair tissue area, and 0.63 (p = 0.015) for surface roughness. Light attenuation differed significantly between healthy cartilage (8.2 (SD 3.9) mm(-1)) and repair tissue (2.8 (SD 1.5) mm(-1)) (p < 0.001). Interpretation - Compared to histopathology as the standard reference method, OCT is a reproducible technique in quantitative analysis of goat talus articular cartilage, especially when assessing cartilage thickness and to a lesser extent when measuring repair tissue area and surface roughness. Moreover, differences in local light attenuation suggest measurable variation in tissue structure, enhancing the clinical applicability of quantitative measurements from cartilage OCT images.
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Platelets and fibrin in progression of liver disease: friends or foes?
J. Thromb. Haemost.
PUBLISHED: 10-24-2014
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Patients with chronic liver diseases may acquire substantial alterations in their hemostatic system when the disease progresses to fibrosis or cirrhosis[1]. Paradoxically, patients with cirrhosis show both hypo- and hypercoagulable features both from a clinical and laboratory perspective[2]. Clinically, the bleeding risk of patients with cirrhosis has long been recognized. Nevertheless, the hypocoagulable state of patients with cirrhosis has been overestimated since a frequent bleeding complication of patients with cirrhosis, variceal bleeding, is unrelated to deranged hemostasis[3]. This article is protected by copyright. All rights reserved.
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Optical Diagnostics for Upper Urinary Tract Urothelial Cancer: Technology, Thresholds, and Clinical Applications.
J. Endourol.
PUBLISHED: 10-16-2014
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Abstract Purpose: Developments in optical diagnostics have potential for less invasive diagnosis of upper urinary tract urothelial carcinoma (UUT-UC). This systematic review provides an overview of technology, applications, and limitations of recently developed optical diagnostics in the upper urinary tract and outlines their potential for future clinical applications. In addition, current evidence was evaluated. Literature Search: A PubMed literature search was performed and articles on narrow band imaging (NBI), photodynamic diagnosis (PDD), Storz professional imaging enhancement system (SPIES), optical coherence tomography (OCT), and confocal laser endomicroscopy (CLE) regarding UUT-UC were reviewed for data extraction. Study quality was reviewed according to Quality Assessment of Diagnostic Accuracy Studies and Innovation, Development, Exploration, Assessment, and Long-term follow-up (IDEAL) standards. Results: Four articles available for quality assessment, demonstrated high level of evidence, but low level of IDEAL stage. NBI and SPIES enhance contrast of mucosal surface and vascular structures, improving tumor detection rate. A first in vivo study showed promising results. PDD uses fluorescence to improve tumor detection rate. However, due to the acute angle of the ureterorenoscopes there is an increased risk of false positives. OCT produces cross-sectional high-resolution images, providing information on tumor grade and stage. A pilot study showed promising diagnostic accuracy. CLE allows ultrahigh-resolution microscopy of tissue resulting in images of the cellular structure. CLE cannot be applied in vivo in the upper urinary tract yet, due to technical limitations. Conclusions: NBI, SPIES, and PDD aim at improving visualization of UUT-UC through contrast enhancement. OCT and CLE aim at providing real-time predictions of histopathological diagnosis. For all techniques, more research has to be conducted before these techniques can be implemented in the routine management of UUT-UC. All techniques might be of value in specific clinical scenarios and allow for integration, for example, OCT with NBI, and could therefore improve tumor detection and staging and help in selecting the optimal treatment for the individual patient.
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Levels of angiogenic proteins in plasma and platelets are not different between patients with hepatitis B/C-related cirrhosis and patients with cirrhosis and hepatocellular carcinoma.
Platelets
PUBLISHED: 10-03-2014
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Abstract Increasing evidence suggests that levels of angiogenic proteins within blood platelets change at the earliest stages of cancer development and may thus provide a promising diagnostic and prognostic tool. Patients with cirrhosis have increased risk of developing hepatocellular carcinoma (HCC). We aimed to study whether development of HCC in hepatitis-related cirrhosis results in changes in platelet levels of angiogenic proteins. We studied the intraplatelet levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), hepatocyte growth factor (HGF), endostatin, platelet factor 4 (PF4) and thrombospondin type 1 (TSP-1) in 38 consecutive patients with hepatitis B- or C-related liver cirrhosis with or without HCC in addition to plasma levels of the same proteins. Twenty healthy volunteers were included to establish reference values for the various tests. Intraplatelet levels of VEGF, bFGF, HGF and endostatin were significantly higher in patients compared to controls. Intraplatelet levels of PDGF, PF4 and TSP-1 were comparable between patients and controls. Plasma levels of VEGF, bFGF and endostatin were comparable between patients and controls. Plasma levels of PDGF, PF4 and TSP-1 were decreased in patients, but this difference disappeared when levels were corrected for platelet count. Intraplatelet and plasma levels of all proteins assessed were comparable between patients with and without HCC. In conclusion, the intraplatelet levels of some angiogenic proteins are elevated in cirrhosis, but do not discriminate between patients with and without HCC. Thus, intraplatelet levels of angiogenic proteins do not seem useful as diagnostic or prognostic biomarker of HCC in cirrhotic patients.
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Refractive index determination of nanoparticles in suspension using nanoparticle tracking analysis.
Nano Lett.
PUBLISHED: 10-02-2014
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The refractive index (RI) dictates interaction between light and nanoparticles and therefore is important to health, environmental, and materials sciences. Using nanoparticle tracking analysis, we have determined the RI of heterogeneous particles <500 nm in suspension. We demonstrate feasibility of distinguishing silica and polystyrene beads based on their RI. The hitherto unknown RI of extracellular vesicles from human urine was determined at 1.37 (mean). This method enables differentiation of single nanoparticles based on their RI.
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Quantitative comparison of analysis methods for spectroscopic optical coherence tomography: reply to comment.
Biomed Opt Express
PUBLISHED: 09-01-2014
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We reply to the comment by Kraszewski et al on "Quantitative comparison of analysis methods for spectroscopic optical coherence tomography." We present additional simulations evaluating the proposed window function. We conclude that our simulations show good qualitative agreement with the results of Kraszewski, in support of their conclusion that SOCT optimization should include window shape, next to choice of window size and analysis algorithm.
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Treatment of coronary bifurcation lesions with the Absorb bioresorbable vascular scaffold in combination with the Tryton dedicated coronary bifurcation stent: evaluation using two- and three-dimensional optical coherence tomography.
EuroIntervention
PUBLISHED: 08-30-2014
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Aims: The Tryton bifurcation stent has been developed to improve clinical outcomes after treatment of bifurcation lesions. Limited data are available on the use of the Absorb bioresorbable vascular scaffold (BVS) in bifurcation lesions with side branches >2 mm. We present here the acute procedural results and midterm clinical follow-up of the first-in-man combined use of the Tryton stent and the Absorb scaffold for the treatment of complex bifurcation lesions. Methods and results: Ten patients treated with the Tryton stent in combination with Absorb BVS were included in the current report. Offline two- and three-dimensional optical coherence tomography (OCT) analyses were performed to gain more insights into this novel approach. Procedural success was 91%, whereas angiographic success was achieved in 82%. Two TLRs occurred (TLR rate 20%), whereas no deaths, myocardial infarctions or stent thromboses were observed up to six months of follow-up. Conclusions: We present a new treatment strategy in complex bifurcation lesions using the Tryton stent in combination with the Absorb BVS. This approach potentially offers an opportunity to treat complex bifurcation lesions with the Absorb BVS. Furthermore, three-dimensional OCT reconstructions give valuable insights into PCI of complex bifurcation lesions.
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Ultra-compact silicon photonic integrated interferometer for swept-source optical coherence tomography.
Opt Lett
PUBLISHED: 08-29-2014
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We demonstrate an ultra-compact silicon integrated photonic interferometer for swept-source optical coherence tomography (SS-OCT). The footprint of the integrated interferometer is only 0.75×5??mm2. The design consists of three 2×2 splitters, a 13 cm physical length (50.4 cm optical length) reference arm, and grating couplers. The photonic integrated circuit was used as the interferometer of an SS-OCT system. The sensitivity of the system was measured to be -62??dB with 115 ?W power delivered to the sample. Using the system, we demonstrate cross-sectional OCT imaging of a layered tissue phantom. We also discuss potential improvements in passive silicon photonic integrated circuit design and integration with active components.
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Novel Inhibitory Effects of Glycyrrhizic Acid on the Accumulation of Advanced Glycation End Product and Its Receptor Expression.
Nat Prod Bioprospect
PUBLISHED: 08-17-2014
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Beneficial effects of glycyrrhizic acid (GA), a bioactive extract of licorice root, in the prevention of metabolic syndrome have been consistently reported while advanced glycation end products (AGE) and receptor for advanced glycation end product (RAGE) are the leading factors in the development of diabetes mellitus. The aim of this study was to investigate the effects of GA on the AGE-RAGE axis using high-fat/high-sucrose (HF/HS) diet-induced metabolic syndrome rat models. Twenty four male Sprague-Dawley rats were randomly assigned into three groups for 4 weeks: (1) Group A, normal diet with standard rat chow; (2) Group B, HF/HS diet; (3) Group C, HF/HS diet and oral administration of 100 mg/kg GA per day. The results showed that HF/HS diet elevated the fasting blood glucose level and insulin resistance index which was prevented by GA supplementation. GA treatment significantly lowered the circulating AGE independent of its glucose-lowering effect. HF/HS diet also triggered RAGE upregulation in the abdominal muscles while GA administration downregulated RAGE expression in the abdominal muscles, aorta and subcutaneous adipose tissues. In conclusion, HF/HS diet could cause glucose intolerance, insulin resistance and upregulation of RAGE expression while GA ameliorated the metabolic dysregulation besides exhibiting inhibitory effects on the AGE-RAGE axis.
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Formulations of hormone therapy and risk of Parkinson's disease.
Mov. Disord.
PUBLISHED: 07-28-2014
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Hormone therapy (HT) is a class of medications widely prescribed to women in the Western world. Evidence from animal models and in vitro studies suggests that estrogen may protect against nigrostriatal system injury and increase dopamine synthesis, metabolism, and transport. Existing epidemiologic research indicates a possible reduced risk of Parkinson's disease (PD) associated with HT use. The objective of this study was to evaluate PD risk associated with specific HT formulations. Neurologist-confirmed cases and age-matched controls were identified from Group Health Cooperative (GHC) of Washington State. Final analysis included 137 female cases and 227 controls. Hormone therapy use was ascertained from the GHC pharmacy database, further classified as conjugated estrogens, esterified estrogens, and progestin. Ever use of HT formulation demonstrated a suggested elevated risk with esterified estrogen use (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.0-9.8), and no risk associated with conjugated estrogen use (OR, 0.6; 95% CI, 0.6-1.3). Restricting this analysis to prescriptions that included progestin further elevated the risk associated with esterified estrogen use (OR, 6.9; 95% CI, 2.1-22.9); again, no risk was associated with conjugated estrogen use (OR, 1.7; 95% CI, 0.6-5.0). The findings from this study suggest an increase in PD risk associated with esterified estrogen use combined with progestin, and no risk associated with conjugated estrogen with progestin. These findings could have important implications for choice of HT in clinical practice. © 2014 International Parkinson and Movement Disorder Society.
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Irreversible electroporation: Just another form of thermal therapy?
Prostate
PUBLISHED: 07-09-2014
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Irreversible electroporation (IRE) is (virtually) always called non-thermal despite many reports showing that significant Joule heating occurs. Our first aim is to validate with mathematical simulations that IRE as currently practiced has a non-negligible thermal response. Our second aim is to present a method that allows simple temperature estimation to aid IRE treatment planning.
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Management of coagulation abnormalities in liver disease.
Expert Rev Gastroenterol Hepatol
PUBLISHED: 06-28-2014
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Liver disease is characterized by changes in all phases of hemostasis. These hemostatic alterations were long considered to predispose patients with liver disease towards a bleeding tendency, as they are associated with prolonged conventional coagulation tests. However, these patients may also suffer from thrombotic complications, and we now know that the hemostatic system in patient with liver disease is, in fact, in a rebalanced state. In this review we discuss the concept of rebalanced hemostasis and its implications for clinical management of patients with liver disease. For instance, there is no evidence that the use of prophylactic blood product transfusion prior to invasive procedures reduces bleeding risk. Clinicians should also be aware of the possibility of thrombosis occurring in patients with a liver disease, and regular thrombosis prophylaxis should not be withheld in these patients.
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Immunolabeling and the compatibility with a variety of fingermark development techniques.
Sci. Justice
PUBLISHED: 06-11-2014
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Much information can be obtained from the chemical composition of a fingermark, which can be helpful in crime scene investigation. Immunolabeling can be used to extract information about the donor of the fingermark and it can also act as a fingermark development tool in sequence with the standard fingermark development techniques. However, before immunolabeling can be used in forensic practice more information on the possibilities and limitations of this technique is required. In this study, our aim was to investigate if immunolabeling is compatible with standard development protocols (indanedione-zinc, indanedione-zinc followed by ninhydrin spraying, physical developer, cyanoacrylate fuming, cyanoacrylate followed by basic yellow staining, lumicyanoacrylate fuming and polycyanoacrylate fuming). Immunolabeling was carried out successfully on all developed fingermarks, whereby dermcidin was selected as antigen of interest. We can conclude that immunolabeling is compatible with a wide variety of different fingermark developers. This finding in combination with previous findings, makes immunolabeling an interesting technique, which can be of great value in the forensic field.
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Glycyrrhizic Acid Can Attenuate Metabolic Deviations Caused by a High-Sucrose Diet without Causing Water Retention in Male Sprague-Dawley Rats.
Nutrients
PUBLISHED: 06-04-2014
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Glycyrrhizic acid (GA) ameliorates many components of the metabolic syndrome, but its potential therapeutic use is marred by edema caused by inhibition of renal 11?-hydroxysteroid dehydrogenase 2 (11?-HSD2). We assessed whether 100 mg/kg per day GA administered orally could promote metabolic benefits without causing edema in rats fed on a high-sucrose diet. Groups of eight male rats were fed on one of three diets for 28 days: normal diet, a high-sucrose diet, or a high-sucrose diet supplemented with GA. Rats were then culled and renal 11?-HSD2 activity, as well as serum sodium, potassium, angiotensin II and leptin levels were determined. Histological analyses were performed to assess changes in adipocyte size in visceral and subcutaneous depots, as well as hepatic and renal tissue morphology. This dosing paradigm of GA attenuated the increases in serum leptin levels and visceral, but not subcutaneous adipocyte size caused by the high-sucrose diet. Although GA decreased renal 11?-HSD2 activity, it did not affect serum electrolyte or angiotensin II levels, indicating no onset of edema. Furthermore, there were no apparent morphological changes in the liver or kidney, indicating no toxicity. In conclusion, it is possible to reap metabolic benefits of GA without edema using the current dosage and treatment time.
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Side branch healing patterns of the Tryton dedicated bifurcation stent: a 1-year optical coherence tomography follow-up study.
Int J Cardiovasc Imaging
PUBLISHED: 03-27-2014
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The bare-metal Tryton Side Branch (SB) Stent™ (Tryton Medical, Durham, NC, USA) is used with a drug-eluting stent (DES) in the main branch (MB) to treat bifurcation lesions. It is argued that a drug-eluting Tryton-version is needed to improve clinical outcomes, although previous registries have shown good clinical results. More insights in neo-intimal hyperplasia (NIH) growth patterns of the Tryton treatment strategy are needed to decide if and where to drug-coat the stent. Ten patients returned for follow-up angiography (mean follow-up time 393 ± 103 days) and optical coherence tomography (OCT) pullbacks from the MB were obtained in all patients and from the SB in six patients. A per-strut analysis showed an uncovered strut rate of 0.7 % and an incompletely-apposed strut rate of 0.8 %. Most incompletely-apposed struts were found at the bifurcation region, in the luminal half facing towards the SB. Mean NIH thickness in the proximal MB, distal MB and SB were 0.14 ± 0.11, 0.19 ± 0.11, and 0.34 ± 0.19 mm, respectively, with a variety of growth patterns observed in the SB. We found good vascular healing of the DES in the MB, while healing was less favourably in the SB part. Furthermore, we observed a variety of NIH growth patterns in this SB part and more studies are needed to investigate the relation between growth patterns and clinical outcomes.
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Oxidation monitoring by fluorescence spectroscopy reveals the age of fingermarks.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 02-24-2014
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No forensic method exists that can reliably estimate the age of fingermarks found at a crime scene. Information on time passed since fingermark deposition is desired as it can be used to distinguish between crime related and unrelated fingermarks and to support or refute statements made by the fingermark donors. We introduce a non-contact method that can estimate the age of fingermarks. Fingermarks were approached as protein-lipid mixtures and an age-estimation model was build based on the expected protein and lipid oxidation reactions. Two measures of oxidation are required from the fingermark to estimate its age: 1) the relative amount of fluorescent oxidation products 2) the rate at which these products are formed. Fluorescence spectroscopy was used to obtain these measures. We tested the method on 44?fingermarks and were able to estimate the age of 55% of the male fingermarks, up to three weeks old with an uncertainty of 1.9?days.
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Duct-to-duct reconstruction in liver transplantation for primary sclerosing cholangitis is associated with fewer biliary complications in comparison with hepaticojejunostomy.
Liver Transpl.
PUBLISHED: 01-25-2014
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There is no consensus on the preferred type of biliary reconstruction for patients undergoing orthotopic liver transplantation (OLT) for primary sclerosing cholangitis (PSC). The aim of this study was to compare long-term outcomes after OLT for PSC using either duct-to-duct anastomosis or Roux-en-Y hepaticojejunostomy for biliary reconstruction. In a consecutive series of 98 adult patients undergoing OLT for PSC, 45 underwent duct-to-duct reconstruction, and 53 underwent Roux-en-Y biliary reconstruction. The median follow-up was 8.2 years (interquartile range?=?3.9-14.5 years). The outcomes of the 2 groups were compared. There were no significant differences in patient demographics or general surgical variables between the groups. The overall patient and graft survival rates were similar for the 2 groups. The incidence of biliary strictures and biliary leakage within the first year after transplantation did not differ between the 2 groups. However, significantly more patients in the Roux-en-Y group suffered at least 1 episode of cholangitis within the first year (9% in the duct-to-duct group versus 25% in the Roux-en-Y group, P?=?0.04). In addition, Roux-en-Y reconstruction was associated with a significantly higher rate of late-onset (>1 year after transplantation) nonanastomotic biliary strictures (NAS) in comparison with duct-to-duct reconstruction (24% versus 7% at 5 years and 30% versus 7% at 10 years, P?=?0.01). In conclusion, duct-to-duct biliary reconstruction in patients with PSC is associated with lower rates of posttransplant cholangitis and late-onset NAS in comparison with Roux-en-Y hepaticojejunostomy. If technically and anatomically feasible, duct-to-duct anastomosis can be performed safely in patients undergoing OLT for PSC.
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Hemostasis in liver disease: implications of new concepts for perioperative management.
Transfus Med Rev
PUBLISHED: 01-22-2014
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The hemostatic profile of patients with liver diseases is frequently profoundly different from that of healthy individuals. These complex alterations lead to abnormal results from routine laboratory tests, but because of the nature of these assays, they fail to accurately represent the patient's hemostatic state. Nevertheless, based on abnormal laboratory coagulation values, it has long been assumed that patients with liver disease have a natural bleeding tendency and are protected from thrombosis. This assumption is false; the average patient with liver disease is actually in a state of "rebalanced hemostasis" that can relatively easily be tipped toward both bleeding and thrombosis. The new paradigm of rebalanced hemostasis has strong implications for the clinic, which are presented in this review. There is no evidence that prophylactic transfusion of plasma helps to prevent procedure-related bleeding. In addition, the presence of independent risk factors such as poor kidney status or infections should be carefully assessed before invasive procedures. Furthermore, central venous pressure plays an important role in the risk of bleeding in patients with liver diseases, so during procedures, a restrictive infusion policy should be applied. Finally, thrombosis prophylaxis should not be withheld from patients with cirrhosis or acute liver failure, and clinicians should be alert to the possibility of thrombosis occurring in these patients.
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Injury to peribiliary glands and vascular plexus before liver transplantation predicts formation of non-anastomotic biliary strictures.
J. Hepatol.
PUBLISHED: 01-19-2014
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The peribiliary glands of large bile ducts have been identified as a niche of progenitor cells that contribute to regeneration of biliary epithelium after injury. We aimed to determine whether injury to the peribiliary glands of donor livers is a risk factor for development of non-anastomotic biliary strictures (NAS) after liver transplantation.
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Self-perception and quality of life in adolescents during treatment for a primary malignant bone tumour.
Eur J Oncol Nurs
PUBLISHED: 01-17-2014
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Adolescents experience physical and psychosocial changes as part of their normal development. It can be hypothesized that they have lower scores on Quality of Life (QoL) and self-perception when additional changes occur due to cancer treatment. The purpose of our study was to assess self-perception and QoL of adolescents during or up to three months after adjuvant treatment for a primary malignant bone tumour.
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Taurolidine lock is superior to heparin lock in the prevention of catheter related bloodstream infections and occlusions.
PLoS ONE
PUBLISHED: 01-01-2014
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Patients on home parenteral nutrition (HPN) are at risk for catheter-related complications; mainly infections and occlusions. We have previously shown in HPN patients presenting with catheter sepsis that catheter locking with taurolidine dramatically reduced re-infections when compared with heparin. Our HPN population therefore switched from heparin to taurolidine in 2008. The aim of the present study was to compare long-term effects of this catheter lock strategy on the occurrence of catheter-related bloodstream infections and occlusions in HPN patients.
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Criteria for Viability Assessment of Discarded Human Donor Livers during Ex Vivo Normothermic Machine Perfusion.
PLoS ONE
PUBLISHED: 01-01-2014
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Although normothermic machine perfusion of donor livers may allow assessment of graft viability prior to transplantation, there are currently no data on what would be a good parameter of graft viability. To determine whether bile production is a suitable biomarker that can be used to discriminate viable from non-viable livers we have studied functional performance as well as biochemical and histological evidence of hepatobiliary injury during ex vivo normothermic machine perfusion of human donor livers. After a median duration of cold storage of 6.5 h, twelve extended criteria human donor livers that were declined for transplantation were ex vivo perfused for 6 h at 37°C with an oxygenated solution based on red blood cells and plasma, using pressure controlled pulsatile perfusion of the hepatic artery and continuous portal perfusion. During perfusion, two patterns of bile flow were identified: (1) steadily increasing bile production, resulting in a cumulative output of ?30 g after 6 h (high bile output group), and (2) a cumulative bile production <20 g in 6 h (low bile output group). Concentrations of transaminases and potassium in the perfusion fluid were significantly higher in the low bile output group, compared to the high bile output group. Biliary concentrations of bilirubin and bicarbonate were respectively 4 times and 2 times higher in the high bile output group. Livers in the low bile output group displayed more signs of hepatic necrosis and venous congestion, compared to the high bile output group. In conclusion, bile production could be an easily assessable biomarker of hepatic viability during ex vivo machine perfusion of human donor livers. It could potentially be used to identify extended criteria livers that are suitable for transplantation. These ex vivo findings need to be confirmed in a transplant experiment or a clinical trial.
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Abnormal hemostatic function one year after orthotopic liver transplantation can be fully attributed to endothelial cell activation.
F1000Res
PUBLISHED: 01-01-2014
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The long-term risk of thrombotic and vascular complications is elevated in liver transplant recipients compared to the general population. Patients with cirrhosis are in a hypercoagulable status during and directly after orthotopic liver transplantation, but it is unclear whether this hypercoagulability persists over time.
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Early elevated serum gamma glutamyl transpeptidase after liver transplantation is associated with better survival.
F1000Res
PUBLISHED: 01-01-2014
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Gamma glutamyl transpeptidase (GGT) is a membrane bound enzyme that plays a key role in the synthesis of the antioxidant glutathione. Epidemiological studies have linked high GGT with an increased risk of morbidity and cardiovascular mortality. In contrast, GGT is usually elevated in liver transplant recipients that experience good outcomes.
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Hypothermic oxygenated machine perfusion prevents arteriolonecrosis of the peribiliary plexus in pig livers donated after circulatory death.
PLoS ONE
PUBLISHED: 01-01-2014
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Livers derived from donation after circulatory death (DCD) are increasingly accepted for transplantation. However, DCD livers suffer additional donor warm ischemia, leading to biliary injury and more biliary complications after transplantation. It is unknown whether oxygenated machine perfusion results in better preservation of biliary epithelium and the peribiliary vasculature. We compared oxygenated hypothermic machine perfusion (HMP) with static cold storage (SCS) in a porcine DCD model.
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Differential in vitro inhibition of thrombin generation by anticoagulant drugs in plasma from patients with cirrhosis.
PLoS ONE
PUBLISHED: 01-01-2014
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Treatment and prevention of thrombotic complications is frequently required in patients with cirrhosis. However anticoagulant therapy is often withheld from these patients, because of the perceived bleeding diathesis. As a result of the limited clinical experience, the anticoagulant of choice for the various indications is still not known.
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Quantitative comparison of analysis methods for spectroscopic optical coherence tomography.
Biomed Opt Express
PUBLISHED: 11-01-2013
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Spectroscopic optical coherence tomography (sOCT) enables the mapping of chromophore concentrations and image contrast enhancement in tissue. Acquisition of depth resolved spectra by sOCT requires analysis methods with optimal spectral/spatial resolution and spectral recovery. In this article, we quantitatively compare the available methods, i.e. the short time Fourier transform (STFT), wavelet transforms, the Wigner-Ville distribution and the dual window method through simulations in tissue-like media. We conclude that all methods suffer from the trade-off in spectral/spatial resolution, and that the STFT is the optimal method for the specific application of the localized quantification of hemoglobin concentration and oxygen saturation.
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Design and evaluation of a laboratory prototype system for 3D photoacoustic full breast tomography.
Biomed Opt Express
PUBLISHED: 11-01-2013
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Photoacoustic imaging can visualize vascularization-driven optical absorption contrast with great potential for breast cancer detection and diagnosis. State-of-the-art photoacoustic breast imaging systems are promising but are limited either by only a 2D imaging capability or by an insufficient imaging field-of-view (FOV). We present a laboratory prototype system designed for 3D photoacoustic full breast tomography, and comprehensively characterize it and evaluate its performance in imaging phantoms. The heart of the system is an ultrasound detector array specifically developed for breast imaging and optimized for high sensitivity. Each detector element has an acoustic lens to enlarge the acceptance angle of the large surface area detector elements to ensure a wide system FOV. We characterized the ultrasound detector array performance in terms of frequency response, directional sensitivity, minimum detectable pressure and inter-element electrical and mechanical cross-talk. Further we evaluated the system performance of the laboratory prototype imager using well-defined breast mimicking phantoms. The system possesses a 2 mm XY plane resolution and a 6 mm vertical resolution. A vasculature mimicking object was successfully visualized down to a depth of 40 mm in the breast phantom. Further, tumor mimicking spherical objects with 5 and 10 mm diameter at 20 mm and 40 mm depths are recovered, indicating high system sensitivity. The system has a 170 × 170 × 170 mm(3) FOV, which is well suited for full breast imaging. Various recommendations are provided for performance improvement and to guide this laboratory prototype to a clinical version in future.
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Quantitative laser speckle flowmetry of the in vivo microcirculation using sidestream dark field microscopy.
Biomed Opt Express
PUBLISHED: 11-01-2013
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We present integrated Laser Speckle Contrast Imaging (LSCI) and Sidestream Dark Field (SDF) flowmetry to provide real-time, non-invasive and quantitative measurements of speckle decorrelation times related to microcirculatory flow. Using a multi exposure acquisition scheme, precise speckle decorrelation times were obtained. Applying SDF-LSCI in vitro and in vivo allows direct comparison between speckle contrast decorrelation and flow velocities, while imaging the phantom and microcirculation architecture. This resulted in a novel analysis approach that distinguishes decorrelation due to flow from other additive decorrelation sources.
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Optimized endoscopic autofluorescence spectroscopy for the identification of premalignant lesions in Barretts oesophagus.
Eur J Gastroenterol Hepatol
PUBLISHED: 09-26-2013
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Fluorescence spectroscopy has the potential to detect early cellular changes in Barretts oesophagus before these become visible. As the technique is based on varying concentrations of intrinsic fluorophores, each with its own optimal excitation wavelength, it is important to assess the optimal excitation wavelength(s) for identification of premalignant lesions in patients with Barretts oesophagus.
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Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering.
J Biomed Opt
PUBLISHED: 08-30-2013
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Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to the radiative transfer equation, implying that it is limited to tissues where the reduced scattering coefficient dominates over the absorption coefficient. Nevertheless, up to absorption coefficients of 20??mm-1 at reduced scattering coefficients of 1 and 11.5??mm-1, we observed excellent agreement (r2=0.994) between reflectance measurements of phantoms and the diffuse reflectance equation proposed by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], derived as an approximation to one of the diffusion dipole equations of Farrell et al. [Med. Phys.19, 879-888 (1992)]. However, two parameters were fitted to all phantom experiments, including strongly absorbing samples, implying that the reflectance equation differs from diffusion theory. Yet, the exact diffusion dipole approximation at high reduced scattering and absorption also showed agreement with the phantom measurements. The mathematical structure of the diffuse reflectance relation used, derived by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], explains this observation. In conclusion, diffuse reflectance relations derived as an approximation to the diffusion dipole theory of Farrell et al. can analyze reflectance ratios accurately, even for much larger absorption than reduced scattering coefficients. This allows calibration of fiber-probe set-ups so that the objects diffuse reflectance can be related to its absorption even when large. These findings will greatly expand the application of diffuse reflection spectroscopy. In medicine, it may allow the use of blue/green wavelengths and measurements on whole blood, and in forensic science, it may allow inclusion of objects such as blood stains and cloth at crime scenes.
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Infrared imaging of the crime scene: possibilities and pitfalls.
J. Forensic Sci.
PUBLISHED: 08-06-2013
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All objects radiate infrared energy invisible to the human eye, which can be imaged by infrared cameras, visualizing differences in temperature and/or emissivity of objects. Infrared imaging is an emerging technique for forensic investigators. The rapid, nondestructive, and noncontact features of infrared imaging indicate its suitability for many forensic applications, ranging from the estimation of time of death to the detection of blood stains on dark backgrounds. This paper provides an overview of the principles and instrumentation involved in infrared imaging. Difficulties concerning the image interpretation due to different radiation sources and different emissivity values within a scene are addressed. Finally, reported forensic applications are reviewed and supported by practical illustrations. When introduced in forensic casework, infrared imaging can help investigators to detect, to visualize, and to identify useful evidence nondestructively.
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Volumetric in vivo visualization of upper urinary tract tumors using optical coherence tomography: a pilot study.
J. Urol.
PUBLISHED: 08-02-2013
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Knowledge of tumor stage and grade is paramount for treatment decision making in cases of upper urinary tract urothelial carcinoma but this condition cannot be accurately assessed by current techniques. Optical coherence tomography can hypothetically provide the urologist with real-time intraoperative information on tumor grade and stage. In this pilot study we report what are to our knowledge the first results of optical coherence tomography for grading and staging upper urinary tract urothelial carcinoma.
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Enhancing case ascertainment of Parkinsons disease using Medicare claims data in a population-based cohort: the Cardiovascular Health Study.
Pharmacoepidemiol Drug Saf
PUBLISHED: 07-24-2013
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We sought to improve a previous algorithm to ascertain Parkinsons disease (PD) in the Cardiovascular Health Study by incorporating additional data from Medicare outpatient claims. We compared our results to the previous algorithm in terms of baseline prevalence and incidence of PD, as well as associations with baseline smoking characteristics.
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Localized measurement of longitudinal and transverse flow velocities in colloidal suspensions using optical coherence tomography.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 07-09-2013
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We report on localized measurement of the longitudinal and transverse flow velocities in a colloidal suspension using optical coherence tomography. We present a model for the path-length resolved autocorrelation function including diffusion and flow, which we experimentally verify. For flow that is not perpendicular to the incident beam, the longitudinal velocity gradient over the coherence gate causes additional decorrelation, which is described by our model. We demonstrate simultaneous imaging of sample morphology and longitudinal and transverse flow at micrometer scale in a single measurement.
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Routine coagulation assays underestimate levels of antithrombin-dependent drugs but not of direct anticoagulant drugs in plasma from patients with cirrhosis.
Br. J. Haematol.
PUBLISHED: 06-25-2013
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There is increasing recognition that thrombotic complications may occur in patients with cirrhosis, and literature on antithrombotic treatment in these patients is rapidly emerging. Due to extensive haemostatic changes in patients with cirrhosis, careful monitoring of anticoagulant therapy may be required. Recent data suggest that plasma levels of low molecular weight heparin (LMWH) are substantially underestimated by the anti-activated factor X (anti-Xa) assay in patients with cirrhosis. We studied the in vitro recovery of antithrombin (AT)-dependent and -independent anticoagulant drugs in plasma from 26 patients with cirrhosis and 30 healthy controls and found substantially reduced anti-Xa levels when AT-dependent anticoagulant drugs were added to the plasma of patients with cirrhosis. LMWH (0·2 U/ml) had the poorest recovery in plasma from patients with cirrhosis (0·13 ± 0·06 U/ml, compared to 0·23 ± 0·03 U/ml in controls, P < 0·0001), followed by unfractionated heparin and fondaparinux. In contrast, the recovery of rivaroxaban and dabigatran was identical between patients and controls. These data suggest that the anti-Xa assay cannot be used to monitor AT-dependent anticoagulant drugs in patients with cirrhosis, as it substantially underestimates drug levels. The direct factor Xa and IIa inhibitors, however, may be monitored through the respective anti-Xa and anti-IIa assays in patients with cirrhosis.
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Prothrombin complex concentrate in the reduction of blood loss during orthotopic liver transplantation: PROTON-trial.
BMC Surg
PUBLISHED: 06-17-2013
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In patients with cirrhosis, the synthesis of coagulation factors can fall short, reflected by a prolonged prothrombin time. Although anticoagulants factors are decreased as well, blood loss during orthotopic liver transplantation can still be excessive. Blood loss during orthotopic liver transplantation is currently managed by transfusion of red blood cell concentrates, platelet concentrates, fresh frozen plasma, and fibrinogen concentrate. Transfusion of these products may paradoxically result in an increased bleeding tendency due to aggravated portal hypertension. The hemostatic effect of these products may therefore be overshadowed by bleeding complications due to volume overload.In contrast to these transfusion products, prothrombin complex concentrate is a low-volume highly purified concentrate, containing the four vitamin K dependent coagulation factors. Previous studies have suggested that administration of prothrombin complex concentrate is an effective method to normalize a prolonged prothrombin time in patients with liver cirrhosis. We aim to investigate whether the pre-operative administration of prothrombin complex concentrate in patients undergoing liver transplantation for end-stage liver cirrhosis, is a safe and effective method to reduce perioperative blood loss and transfusion requirements.
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Senile retinoschisis versus retinal detachment, the additional value of peripheral retinal OCT scans (SL SCAN-1, Topcon).
Acta Ophthalmol
PUBLISHED: 06-15-2013
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Purpose:? A peripheral senile retinoschisis is sometimes difficult to distinguish from a retinal detachment by biomicroscopy alone. This study evaluated spectral domain OCT (SD-OCT) scans of the far peripheral retina to improve the differentiation between these diseases. Methods:? Patients were included in whom the distinction between retinal detachment and senile retinoschisis was not clear based on biomicroscopy alone, or who had a presumed clinical diagnosis of senile retinoschisis. OCT scans were made with the SLSCAN-1, through a hand-held lens and a 3-mirror contact lens, while the area of interest was simultaneously observed with the slit lamp. The SLSCAN-1 is a SD-OCT integrated into a slit lamp, superluminescent diode light source with a central wavelength of 830?nm, bandwidth 30?nm, scan resolution 8-9??m in tissue, scan depth 2?mm, scan speed 5000?A-scans per second. Results:? In the 11 patients with an uncertain diagnosis, OCT scans showed a senile retinoschisis in four and a retinal detachment in seven patients. Fifteen of the 18 patients with a presumed diagnosis of retinoschisis showed a retinoschisis on OCT. In five of them, the OCT scans revealed a schisis detachment. Interestingly, three of the 18 patients had a retinal detachment. Conclusion:? Senile retinoschisis may mimic a peripheral retinal detachment and vice versa. Differentiation is important with respect to therapeutic decisions. OCT scans of the far peripheral retina, which can be made with the SLSCAN-1 through a 3-mirror contact lens, can contribute significantly to this differentiation. The obtained scans of the far peripheral retina clearly visualize the anatomic differences between both diseases.
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The compatibility of fingerprint visualization techniques with immunolabeling.
J. Forensic Sci.
PUBLISHED: 05-17-2013
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The chemical composition of a fingermark potentially holds a wealth of information about the fingermark donor, which can be extracted by immunolabeling. Immunolabeling can be used to detect specific components in fingermarks; however, to be applicable in the forensic field, it should be compatible with commonly used fingerprint visualization techniques. In this study, the compatibility of immunolabeling with two different fingerprint visualization techniques, magnetic powdering and ninhydrin staining, was investigated on fingermarks deposited on glass and on nitrocellulose membranes. With dermcidin as antigen of interest, immunolabeling was performed successfully on all developed fingermarks. We can conclude that immunolabeling is compatible with magnetic powdering and ninhydrin staining, which can be of great forensic value.
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The nanobig rod class of gold nanorods: optimized dimensions for improved in vivo therapeutic and imaging efficacy.
Nanotechnology
PUBLISHED: 04-25-2013
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Currently, gold nanorods can be synthesized in a wide range of sizes. However, for the intended biological applications gold nanorods with approximate dimensions 50 nm × 15 nm are used. We investigate by computer simulation the effect of particle dimensions on the optical and thermal properties in the context of the specific applications of photoacoustic imaging. In addition we discuss the influence of particle size in overcoming the following biophysical barriers when administrated in vivo: extravasation, avoidance of uptake by organs of the reticuloendothelial system, penetration through the interstitium, binding capability and uptake by the target cells. Although more complex biological influences can be introduced in future analysis, the present work illustrates that larger gold nanorods, designated by us as nanobig rods, may perform better at meeting the requirements for successful in vivo applications compared to their smaller counterparts, which are conventionally used.
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Decreased tissue factor pathway inhibitor (TFPI)-dependent anticoagulant capacity in patients with cirrhosis who have decreased protein S but normal TFPI plasma levels.
Br. J. Haematol.
PUBLISHED: 04-10-2013
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Protein S acts as a cofactor for tissue factor pathway inhibitor (TFPI) in the down regulation of thrombin generation, and acquired and congenital protein S deficiencies are associated with a concomitant TFPI deficiency. In contrast, in patients with liver diseases, decreased protein S, but normal or increased levels of TFPI have been reported. We compared TFPI and protein S plasma levels between 26 patients with cirrhosis and 20 healthy controls and found that TFPI levels were comparable between patients (111 ± 38%) and controls (108 ± 27%), despite reduced protein S levels (74 ± 23% in patients vs. 98 ± 10% in controls). Subsequently, we quantified the activity of the TFPI-protein S system by measuring thrombin generation in the absence and presence of neutralizing antibodies to protein S or TFPI. Ratios of peak thrombin generation in the absence and presence of these antibodies were calculated. Both the protein S and the TFPI ratios were increased in patients with cirrhosis compared to controls. Protein S ratios were (0·62 [0·08-0·93] in patients vs. 0·32 [0·20-0·54] in controls; TFPI ratios were 0·50 [0·05-0·90] in patients vs. 0·18 [0·11-0·49] in controls). Thus, although the acquired protein S deficiency in patients with cirrhosis is not associated with decreased TFPI levels, the TFPI/protein S anticoagulant system is functionally impaired.
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Evaluation of superparamagnetic iron oxide nanoparticles (Endorem®) as a photoacoustic contrast agent for intra-operative nodal staging.
Contrast Media Mol Imaging
PUBLISHED: 04-04-2013
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Detection of tumor metastases in the lymphatic system is essential for accurate staging of malignancies. Commercially available superparagmagnetic nanoparticles (SPIOs) accumulate in normal lymph tissue after injection at a tumor site, whereas less or no accumulation takes place in metastatic nodes, thus enabling lymphatic staging using MRI. We verify for the first time the potential of SPIOs, such as Endorem(®) as a novel photoacoustic (PA) contrast agent in biological tissue. We injected five Wistar rats subcutaneously with variable amounts of Endorem(®) and scanned the resected lymph nodes using a tomographic PA setup. Findings were compared using histology, vibrating sample magnetometry (VSM) and 14 T MR-imaging. Our PA setup was able to detect the iron oxide accumulations in all the nodes containing the nanoparticles. The distribution inside the nodes corresponded with both MRI and histological findings. VSM revealed that iron quantities inside the nodes varied between 51 ± 4 and 11 ± 1 µg. Nodes without SPIO enhancement did not show up in any of the PA scans. Iron oxide nanoparticles (Endorem(®)) can be used as a PA contrast agent for lymph node analysis and a distinction can be made between nodes with and nodes without the agent. This opens up possibilities for intra-operative nodal staging for patients undergoing nodal resections for metastatic malignancies.
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An optimized ultrasound detector for photoacoustic breast tomography.
Med Phys
PUBLISHED: 03-08-2013
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Photoacoustic imaging has proven to be able to detect vascularization-driven optical absorption contrast associated with tumors. In order to detect breast tumors located a few centimeter deep in tissue, a sensitive ultrasound detector is of crucial importance for photoacoustic mammography. Further, because the expected photoacoustic frequency bandwidth (a few MHz to tens of kHz) is inversely proportional to the dimensions of light absorbing structures (0.5-10+ mm), proper choices of materials and their geometries and proper considerations in design have to be made to implement optimal photoacoustic detectors. In this study, we design and evaluate a specialized ultrasound detector for photoacoustic mammography.
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Hypercoagulability as a contributor to thrombotic complications in the liver transplant recipient.
Liver Int.
PUBLISHED: 02-04-2013
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Traditionally, perioperative bleeding complications were a major concern during orthotopic liver transplantation, but a tremendous decline in transfusion requirements has been reported over the last decade. In recent years, there has been an increasing awareness towards perioperative thrombotic complications, including liver vessel thrombosis, and systemic venous and arterial thromboembolic events. Whereas a number of these thrombotic complications were previously categorized as surgical complications, increasing clinical and laboratory evidence suggest a role for the haemostatic system in thrombotic complications occurring during and after transplantation. High levels of the platelet adhesive protein von Willebrand factor with low levels of its regulator ADAMTS13, an increased potential to generate thrombin, and temporary hypofibrinolysis are all indicative of increased haemostatic potential after transplantation. Clinical evidence for a role of the haemostatic system in post-operative thromboses includes a higher thrombotic risk in patients with various acquired thrombotic risk factors. Although data on efficacy of anticoagulant therapy after liver transplantation are scarce, one study has shown a significant decrease in the risk for late hepatic artery thrombosis by antithrombotic therapy with aspirin. These findings suggest that antihaemostatic therapy in prevention or treatment of thromboembolic complications after liver transplantation may be relevant. Studies on efficacy and safety of these interventions are required as many of the thrombotic complications have a pronounced negative impact on graft and patient survival.
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An unbalance between von Willebrand factor and ADAMTS13 in acute liver failure: implications for hemostasis and clinical outcome.
Hepatology
PUBLISHED: 02-04-2013
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Emerging evidence supports the concept of a rebalanced hemostatic state in liver disease as a result of a commensurate decline in prohemostatic and antihemostatic drivers. In the present study, we assessed levels and functionality of the platelet-adhesive protein von Willebrand factor (VWF) and its cleaving protease ADAMTS13 in the plasma of patients with acute liver injury and acute liver failure (ALI/ALF). Furthermore, we explored possible associations between VWF, ADAMTS13, and disease outcome. We analyzed the plasma of 50 patients taken on the day of admission for ALI/ALF. The plasma of 40 healthy volunteers served as controls. VWF antigen levels were highly elevated in patients with ALI/ALF. In contrast, the collagen-binding activity and the ratio of the VWF ristocetin cofactor activity and VWF antigen was significantly decreased when compared with healthy controls. Also, the proportion of high molecular weight VWF multimers was reduced, despite severely decreased ADAMTS13 levels. In spite of these functional defects, platelet adhesion and aggregation were better supported by plasma of patients with ALI/ALF when compared with control plasma. Low ADAMTS13 activity, but not high VWF antigen, was associated with poor outcome in patients with ALI/ALF as evidenced by higher grades of encephalopathy, higher transplantation rates, and lower survival. VWF or ADAMTS13 levels were not associated with bleeding or thrombotic complications. Conclusion: Highly elevated levels of VWF in plasma of patients with ALI/ALF support platelet adhesion, despite a relative loss of function of the molecule. Furthermore, low ADAMTS13 activity is associated with progressive liver failure in the patient cohort, which might be attributed to platelet-induced microthrombus formation in the diseased liver resulting from a substantially unbalanced VWF/ADAMTS13 ratio.
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Stress and Its Effects on Glucose Metabolism and 11?-HSD Activities in Rats Fed on a Combination of High-Fat and High-Sucrose Diet with Glycyrrhizic Acid.
J Diabetes Res
PUBLISHED: 01-29-2013
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Chronic stress has been shown to have a strong link towards metabolic syndrome (MetS). Glycyrrhizic acid (GA) meanwhile has been shown to improve MetS symptoms caused by an unhealthy diet by inhibiting 11 ? -HSD 1. This experiment aimed to determine the effects of continuous, moderate-intensity stress on rats with and without GA intake on systolic blood pressure (SBP) across a 28-day period, as well as glucose metabolism, and 11 ? -HSD 1 and 2 activities at the end of the 28-day period. Adaptation to the stressor (as shown by SBP) resulted in no significant defects in glucose metabolism by the end of the experimental duration. However, a weakly significant increase in renal 11 ? -HSD 1 and a significant increase in subcutaneous adipose tissue 11 ? -HSD 1 activities were observed. GA intake did not elicit any significant benefit in glucose metabolism, indicating that the stress response may block its effects. However, GA-induced improvements in 11 ? -HSD activities in certain tissues were observed, although it is uncertain if these effects are manifested after adaptation due to the withdrawal of the stress response. Hence the ability of GA to improve stress-induced disturbances in the absence of adaptation needs to be investigated further.
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Predictors of functional outcome among stroke patients in Lima, Peru.
J Stroke Cerebrovasc Dis
PUBLISHED: 01-22-2013
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Because of the aging population in low- and middle-income countries, cerebrovascular disease is expected to remain a leading cause of death. Little has been published about stroke in Peru. We conducted a retrospective cohort study of hospitalized stroke patients at a referral center hospital in Lima, Peru to explore factors associated with functional outcome among stroke patients.
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Prophylactic anticoagulation for venous thromboembolism in hospitalized cirrhosis patients is not associated with high rates of gastrointestinal bleeding.
Liver Int.
PUBLISHED: 01-18-2013
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Hospitalized patients with cirrhosis are at risk to develop venous thromboembolism. Although current guidelines support the routine administration of thromboprophylaxis to hospitalized patients, there is limited data regarding the safety or efficacy of this practice in hospitalized cirrhosis patients.
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Simultaneous labeling of multiple components in a single fingermark.
Forensic Sci. Int.
PUBLISHED: 01-16-2013
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A fingermark contains important forensic information of the donor, not only in its ridge pattern, but also in the chemical composition of its secretion. Detection and identification of these secretions can be done by immunolabeling. In this study, we describe for the first time a reproducible immunolabeling method that allows the simultaneous detection of multiple components of interest. This method not only reduces the manipulation of fingermarks, but also different types of information can be obtained about the donor in one labeling session. To prove the concept of this technique, we selected two general components as antigens of interest, dermcidin and the human serum albumin. Conjugation of both antibodies to two different synthetic fluorophores, followed by simultaneous incubation of both conjugated antibodies, resulted in successful multiple immunolabeling of fingermarks left on a porous nitrocellulose membrane and on a non-porous glass slide surface. In order to minimize false positives to prevent non-specific binding of antibodies to fingermarks and surface carriers, careful blocking and washing steps were found crucial. With this reproducible protocol, high quality images could be obtained from the multiple labeled fingermarks. In conclusion, simultaneous multiple immunolabeling of antibodies in fingermarks can identify specific components in the secretion of the fingermark, including components related to hygiene, diet, time of day, contacts gender and drug use. Multiple immunolabeling therefore has the potential to make a major impact in the forensic field.
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Established and new-generation antithrombotic drugs in patients with cirrhosis - possibilities and caveats.
J. Hepatol.
PUBLISHED: 01-15-2013
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Until recently, it was widely accepted that patients with cirrhosis have a bleeding tendency related to the changes in the hemostatic system that occur as a consequence of the disease. However, it has now been well established that patients with cirrhosis are at risk for both bleeding and thrombotic complications. These thrombotic complications include portal vein thrombosis, deep vein thrombosis and pulmonary embolism, and coronary or cerebrovascular infarctions. Antithrombotic drugs to prevent or treat thrombotic complications in patients with cirrhosis have been used only minimally in the past due to the perceived bleeding risk. As the thrombotic complications and the necessity of antithrombotic treatment in these patients are increasingly recognized, the use of antithrombotic drugs in this population is likely increasing. Moreover, given the rising incidence of fatty liver disease and generally longer survival times of patients with chronic liver diseases, it would be reasonable to presume that some of these thrombotic complications may be increasing in incidence over time. In this review, we will outline the indications for antithrombotic treatment in patients with cirrhosis. Furthermore, we will discuss the available antithrombotic drugs and indicate possible applications, advantages, and caveats. Since for many of these drugs very little experience in patients with cirrhosis exists, these data are essential in the design of future clinical and laboratory studies on mechanisms, efficacy, and safety of the various antithrombotic strategies in these patients.
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The impact of hepatic steatosis on liver regeneration after partial hepatectomy.
Liver Int.
PUBLISHED: 01-14-2013
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Experimental studies in animals have suggested that liver regeneration is impaired in steatotic livers. However, few studies have focused on the impact of steatosis in patients undergoing partial hepatectomy (PH). This study aims to determine the role of steatosis on liver regeneration in humans following PH.
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Clot lysis time and the risk of myocardial infarction and ischaemic stroke in young women; results from the RATIO case-control study.
Br. J. Haematol.
PUBLISHED: 11-15-2011
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Reduced overall fibrinolytic capacity increases the risk of myocardial infarction (MI), as demonstrated in studies with predominantly male participants. We determined the influence of altered fibrinolysis on the risk of MI and ischaemic stroke (IS) in young women. The RATIO (Risk of Arterial Thrombosis In relation to Oral contraceptives) study is a population-based case-control study including young women with MI (n=203), IS (N=175) and 638 matched healthy controls. Fibrinolytic potential was determined with a tissue factor/tissue plasminogen activator induced clot-lysis assay. Odds ratios (OR) adjusted for cardiovascular risk factors were obtained with logistic regression. Clot-lysis time (CLT) was divided into tertiles based on the control group (T1-T3), with T2 as reference. Hypofibrinolysis (prolonged CLT) was associated with an increase in risk of MI (T3 vs. T2, OR 2·8; 95%confidence interval [CI] 1·7-4·7). Hyperfibrinolysis (decreased CLT) had no clear effect (T1 vs. T2, OR 1·6; 95% CI 0·9-2·9). Hypofibrinolysis did not affect the risk of IS (T3 vs. T2, OR 1·5; 95% CI 0·7-3·0), whereas hyperfibrinolysis increased this risk (T1 vs. T2, OR 4·1; 95% CI 2·1-8·0). Oral contraceptive use and smoking further increased these risks. Hypofibrinolysis increases the risk for MI in young women, a finding similar to previous studies. Counter-intuitively, hyperfibrinolysis increased the risk of IS four-fold, which suggests that MI and IS have different aetiologies.
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In vivo low-coherence spectroscopic measurements of local hemoglobin absorption spectra in human skin.
J Biomed Opt
PUBLISHED: 10-28-2011
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Localized spectroscopic measurements of optical properties are invaluable for diagnostic applications that involve layered tissue structures, but conventional spectroscopic techniques lack exact control over the size and depth of the probed tissue volume. We show that low-coherence spectroscopy (LCS) overcomes these limitations by measuring local attenuation and absorption coefficient spectra in layered phantoms. In addition, we demonstrate the first in vivo LCS measurements of the human epidermis and dermis only. From the measured absorption in two distinct regions of the dermal microcirculation, we determine total hemoglobin concentration (3.0±0.5 g?l and 7.8±1.2 g?l) and oxygen saturation.
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Gold nanorods as molecular contrast agents in photoacoustic imaging: the promises and the caveats.
Contrast Media Mol Imaging
PUBLISHED: 10-26-2011
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Rod-shaped gold nanoparticles exhibit intense and narrow absorption peaks for light in the far-red and near-infrared wavelength regions, owing to the excitation of longitudinal plasmons. Light absorption is followed predominantly by non radiative de-excitation, and the released heat and subsequent temperature rise cause strong photoacoustic (optoacoustic) signals to be produced. This feature combined with the relative inertness of gold, and its favorable surface chemistry, which permits affinity biomolecule coupling, has seen gold nanorods (AuNR) attracting much attention as contrast agents and molecular probes for photoacoustic imaging. In this article we provide an short overview of the current status of the use of AuNR in molecular imaging using photoacoustics. We further examine the state of the art in various chemical, physical and biochemical phenomena that have implications for the future photoacoustic applications of these particles. We cover the route through fine-tuning of AuNR synthetic procedures, toxicity reduction by appropriate coatings, in vitro cellular interactions of AuNRs, attachment of targeting antibodies, in vivo fate of the particles and the effects of certain light interactions with the AuNR.
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Optical properties of neonatal skin measured in vivo as a function of age and skin pigmentation.
J Biomed Opt
PUBLISHED: 09-29-2011
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Knowledge of the optical properties of neonatal skin is invaluable when developing new, or improving existing optical techniques for use at the neonatal intensive care. In this article, we present in vivo measurements of the absorption ?(a) and reduced scattering coefficient ?(s) () of neonatal skin between 450 and 600 nm and assess the influence of age and skin pigmentation on the optical properties. The optical properties were measured using a spatially resolved, steady state diffuse reflectance spectroscopy setup, combined with a modified spatially resolved diffusion model. The method was validated on phantoms with known values for the absorption and reduced scattering coefficient. Values of ?(a) and ?(s) () were obtained from the skin at four different body locations (forehead, sternum, hand, and foot) of 60 neonates with varying gestational age, postnatal age, and skin pigmentation. We found that ?(a) ranged from 0.02 to 1.25 mm(-1) and ?(s) () was in the range of 1 to 2.8 mm(-1) (5th to 95th percentile of the patient population), independent of body location. In contrast to previous studies, no to very weak correlation was observed between the optical properties and gestational maturity, but a strong dependency of the absorption coefficient on postnatal age was found for dark skinned patients.
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Initial results of imaging melanoma metastasis in resected human lymph nodes using photoacoustic computed tomography.
J Biomed Opt
PUBLISHED: 09-29-2011
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The pathological status of the sentinel lymph node is important for accurate melanoma staging, ascertaining prognosis and planning treatment. The standard procedure involves biopsy of the node and histopathological assessment of its status. Drawbacks of this examination include a finite sampling of the node with the likelihood of missing metastases, and a significant time-lag before histopathological results are available to the surgeon. We studied the applicability of photoacoustic computed tomographic imaging as an intraoperative modality for examining the status of resected human sentinel lymph nodes. We first applied the technique to image ex vivo pig lymph nodes carrying metastases-simulating melanoma cells using multiple wavelengths. The experience gained was applied to image a suspect human lymph node. We validated the photoacoustic imaging results by comparing a reconstructed slice with a histopathological section through the node. Our results suggest that photoacoustics has the potential to develop into an intraoperative imaging method to detect melanoma metastases in sentinel lymph nodes.
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Prothrombotic gene polymorphisms: possible contributors to hepatic artery thrombosis after orthotopic liver transplantation.
Transplantation
PUBLISHED: 08-13-2011
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Gene polymorphisms involved in hemostasis have been associated with an increased risk of thromboembolic events. The aim of this study was to assess whether prothrombotic gene polymorphism is a risk factor for hepatic vascular thrombosis after orthotopic liver transplantation (OLT).
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Multiple passive element enriched photoacoustic computed tomography.
Opt Lett
PUBLISHED: 08-03-2011
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Recently, we presented a method using laser-induced ultrasound from an external absorber (passive element) to image the ultrasound transmission parameters of an object under photoacoustic tomographic investigation. The method suffers from long measurement times due to the requirement for a large number of views and consequently physical projections around the object. Here we propose and validate an approach that permits a multitude of views to be obtained within a limited projection scenario. The approach uses a plurality of spatially distributed external absorbers in the path of the light, that results in multiple laser-induced ultrasound sources to interrogate the object from a number of angles. This reduces the required number of rotation angles or physical projections around the object, permitting a considerable reduction in imaging time without significant degradation in image quality. The approach brings the concept of hybrid imaging of ultrasound transmission parameters together with photoacoustic imaging, into the realm of practical application.
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Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited.
J Biomed Opt
PUBLISHED: 08-03-2011
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A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where temperature distributions during F-T are relatively homogeneous. In this work, in breast-sized samples we observed substantial temperature differences between the shallow regions and the interior during the F-T procedure. We investigated whether spatial variations were also present in the acoustic and optical properties. The speed of sound, acoustic attenuation, and optical reduced scattering coefficients were measured on specimens sampled at various locations in a large phantom. In general, the properties matched values quoted for breast tissue. But while acoustic properties were relatively homogeneous, the reduced scattering was substantially different at the surface compared with the interior. We correlated these variations with gel microstructure inspected using scanning electron microscopy. Interestingly, the phantoms reduced scattering spatial distribution matches the optical properties of the standard two-layer breast model used in x ray dosimetry. We conclude that large PVA samples prepared using the standard recipe make excellent breast tissue phantoms.
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Protection of bile ducts in liver transplantation: looking beyond ischemia.
Transplantation
PUBLISHED: 06-02-2011
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Biliary complications, especially nonanastomotic biliary strictures (NAS), are a major cause of morbidity after orthotopic liver transplantation. Of all donor and recipient characteristics known to increase the risk of developing NAS, the role of prolonged ischemia times is most extensively described in the literature. However, there is increasing evidence that several other, non-ischemia-related factors play a critical role in the pathogenesis of NAS as well. The clinical presentation of NAS may vary considerably among liver transplant recipients, including large variations in time of occurrence, and in location and severity of the strictures. Additional underlying causes such as bile salt toxicity and immune-mediated injury are believed to explain the wide spectrum of biliary strictures after orthotopic liver transplantation. Current and emerging insight in the pathogenesis of NAS and potential targets to reduce biliary injury and preserve bile ducts are discussed in this overview.
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Endoscopic carbon dioxide laser diverticulostomy versus endoscopic staple-assisted diverticulostomy to treat Zenkers diverticulum.
Head Neck
PUBLISHED: 05-28-2011
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The 2 most frequently used endoscopic methods to treat Zenkers diverticulum are staple-assisted and CO(2) laser esophagodiverticulostomy.
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Markers of inflammation in prevalent and incident Parkinsons disease in the Cardiovascular Health Study.
Parkinsonism Relat. Disord.
PUBLISHED: 05-23-2011
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Studies demonstrate existence of inflammation in prevalent Parkinsons disease (PD). We assessed associations of baseline levels of inflammatory markers with prevalent PD at baseline (1989) and incident PD identified over 13 years of follow-up of the Cardiovascular Health Study.
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Amelioration of glucose homeostasis by glycyrrhizic acid through gluconeogenesis rate-limiting enzymes.
Eur. J. Pharmacol.
PUBLISHED: 05-11-2011
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The activities of phosphoenolpyruvate carboxykinase (PEPCK) are influenced by active glucocorticoids which are activated by 11-?-hydroxysteroid dehydrogenase 1 (11?-HSD1) while hexose-6-phosphate dehydrogenase (H6PDH) influences the activities of 11-?HSD1 in a cofactor manner. Dysregulation of PEPCK and H6PDH has been associated with the pathogenesis of metabolic syndrome. Sixteen male Sprague Dawley rats, fed ad libitum, were assigned to two groups, control and treated, with the treated group being given GA at 100mg/kg for one week. Blood and subcutaneous and visceral adipose tissue, abdominal and quadriceps femoris muscle, liver and kidney were examined. GA treatment led to an overall significant decrease in blood glucose while HOMA-IR. PEPCK activities decreased in the liver but increased in the visceral adipose tissue. H6PDH activities also decreased significantly in the liver while 11?-HSD1 activities decreased significantly in all studied tissues except for subcutaneous adipose tissue. Adipocytes in the subcutaneous and visceral depots showed a reduction in size. Though increased glycogen storage was seen in the liver, no changes were observed in the kidneys and muscles. Results from this study may imply that GA could counteract the development of type 2 diabetes mellitus by improving insulin sensitivity and probably by reduction of H6PDH, 11?-HSD1 and a selective decrease in PEPCK activities.
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Acousto-optic-assisted diffuse optical tomography.
Opt Lett
PUBLISHED: 05-05-2011
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We introduce and experimentally demonstrate acousto-optic-assisted diffuse optical tomography (DOT) using a holography-based acousto-optic setup. The method is based on probing a scattering medium with a localized acoustical modulation of the phase of the scattered light. The optical properties of the scattering medium are recovered with ultrasound-limited resolution by applying DOT reconstruction methods on a set of the measured intensities of light, modulated at different locations throughout the medium.
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Polymorphisms in CCR6 are associated with chronic graft-versus-host disease and invasive fungal disease in matched-related hematopoietic stem cell transplantation.
Biol. Blood Marrow Transplant.
PUBLISHED: 04-21-2011
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Graft-versus-host disease (GVHD) and fungal infections are frequent complications after allogeneic hematopoietic stem cell transplantation (HSCT). Single nucleotide polymorphisms (SNPs) in genes of the immune system can influence the inflammatory cascade and T cell-driven alloimmune reactions after HSCT, and thus increasing the incidence of GVHD and infectious complications. Here, we investigated the effect of SNPs in IL-23R and CCR6 on posttransplantation outcome in 161 recipients of partially T cell-depleted HSCT. Remarkably, IL-23R SNPs were not associated with clinical outcome, but we found that disparities in the CCR6 tagSNP rs2301436 and SNP rs3093023 are independently associated with the occurrence of chronic GVHD (cGVHD) and invasive fungal disease. In multivariate analysis, patients receiving a transplant from a homozygous rs2301436 G allele donor showed less cGVHD (odds ratio [OR]: 0.16; P = .002), as was the case for a homozygous donor rs3093023 G allele (OR: 0.24; P = .005). In parallel, the GG genotype at rs2301436 in donors was associated with a higher incidence of invasive fungal disease at day 100 after HSCT (OR: 3.59; P = .008). This study shows that CCR6 SNPs can be used to predict clinical outcome, and that polymorphisms in the CCR6 gene may influence T cell-mediated immune reactions after HSCT.
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Proteolytic and genetic variation of the alpha-2-antiplasmin C-terminus in myocardial infarction.
Blood
PUBLISHED: 04-19-2011
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Alpha-2-antiplasmin (?2AP) undergoes both N- and C-terminal cleavages, which significantly modify its activities. Compared with other Ser protease inhibitors (serpins), ?2AP contains an ~50-residue-extended C-terminus, which binds plasmin(ogen). We developed 2 new ELISAs to measure the antigen levels of free total ?2AP and free C-terminally intact ?2AP to investigate whether ?2AP antigen levels or ?2AP C-terminal cleavage were associated with myocardial infarction (MI) in 320 male MI survivors and 169 age-matched controls. Patients had 15.2% reduced total ?2AP antigen levels compared with controls (93.8 vs 110.6 U/dL, P < .001), with a 10.1-fold (95% confidence interval [CI]: 5.5-18.9) increased MI risk for levels in the 1st quartile compared with the 4th quartile. The percentage of C-terminal cleavage did not differ between patients and controls (38.7% and 38.1%, respectively, P = .44). In addition, all individuals were genotyped for the polymorphism Arg407Lys, which is located near the start of the extended C-terminus. Arg407Lys was not associated with ?2AP C-terminal cleavage, total ?2AP antigen levels, or MI risk (odds ratios compared with Arg/Arg: Arg/Lys 0.74, 95% CI: 0.50-1.10; Lys/Lys 0.77, 95% CI: 0.31-1.92). Our data show that levels of free full-length ?2AP were decreased in MI, that the percentage of C-terminally cleaved ?2AP was unaltered, and that Arg407Lys did not influence ?2AP levels or MI risk.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.