bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of tricyclic antidepressant drugs in plasma by means of solid‐phase microextraction‐liquid chromatography‐mass spectrometry
Authors: Alves Claudete , Santos‐Neto Alvaro J. , Fernandes Christian , Rodrigues José C. , Lanças Fernando M. 
Published: September 2007

AbstractSolid‐phase microextraction coupled to liquid chromatography and mass spectrometry (SPME‐LC‐MS) was used to analyze tricyclic antidepressant drugs desipramine, imipramine, nortriptyline, amitriptyline, and clomipramine (internal standard) in plasma samples. SPME was performed by direct extraction on a PDMS/DVB (60 µm) coated fiber, employing a stirring rate of 1200 rpm for 30 min, pH 11.0, and temperature of 30 °C. Drug desorption was carried out by exposing the fiber to the liquid chromatography mobile phase for 20 min, using a labmade SPME‐LC interface at 50 °C. The main variables experimentally influencing LC‐MS response were evaluated and mathematically modeled. A rational optimization with fewer experiments was achieved using a factorial design approach. The constructed empirical models were adjusted with 96–98% of explained deviation allowing an adequate data set comprehension. The chromatographic separation was realized using an RP‐18 column (150 mm × 2.1 mm, 5 µm particles) and ammonium acetate buffer (0.01 mol/l, pH 5.50) : acetonitrile (50 : 50 v/v) as mobile phase. Low detection levels were achieved with electrospray interface (0.1 ng/ml). The developed method showed specificity, linearity, precision, and limit of quantification adequate to assay tricyclic antidepressant drugs in plasma. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of a putative Xylella fastidiosa diffusible signal factor by HRGC‐EI‐MS
Authors: Colnaghi Simionato Ana Valéria , da Silva Denise Santos , Lambais Marcio Rodrigues , Carrilho Emanuel 
Published: September 2007

AbstractXylella fastidiosa (X.f.) is a plant pathogen with high levels of genomic similarity to Xanthomonas campestris pv. campestris (X.c.c.). It has been shown that X. fastidiosa synthesizes a putative diffusible signal factor (X.f.‐DSF) that activates regulation of pathogenicity factor (rpf) genes in a X.c.c. reporter system, which might be involved in the regulation of pathogenesis associated genes as in X.c.c., as well as in quorum‐sensing. The nature of the X.f.‐DSF is not known, whereas the X.c.c.‐DSF has been identified as cis‐11‐methyl‐2‐dodecenoic acid. In this work, the chemical nature of a putative X.f.‐DSF molecule, able to restore endoglucanase activity in a X.c.c. rpfF mutant, was investigated as if it was a fatty acid derivative. Bioassays with X.c.c. reporter bacterium and X.f. culture extracts, based on endoglucanase restoration activity, were also carried out in order to confirm the DSFs molecules similarities. For this reason, a gas chromatography–mass spectrometry method was developed with standard fatty acids methyl esters mixtures. The retention time, as well as the fragmentation patterns, of each standard was used to identify the DSF molecule synthesized by X.f. in the culture medium. Typical ester fragmentation patterns (the derivatized analyte) were observed, such as: McLafferty rearrangement and migration of the Hδ followed by 1,4‐hydrogen shift and cleavage of the bond CβCγ, confirming the nature of this molecule. This confirmation was corroborated by the common peaks in both spectra. Besides, the observed retention time reinforces our conclusion since it corresponds to a methyl ester with 15 carbons. Since the X.f.‐DSF molecule was tentatively identified as 12‐methyl‐tetradecanoic acid (by mass spectra library comparison), this standard compound was also analyzed, strongly suggesting that this is the identification of such a molecule. To our knowledge, this is the first time a DSF produced by X.f. has been characterized. Copyright © 2007 John Wiley & Sons, Ltd.
Statins enhance toll‐like receptor 4‐mediated cytokine gene expression in astrocytes: Implication of Rho proteins in negative feedback regulation
Authors: Konat Gregory W. , Krasowska‐Zoladek Alicja , Kraszpulski Michal 
Published: September 2007

AbstractToll‐like receptors (TLRs) are sentinels of innate immunity that recognize pathogenic molecules and trigger inflammatory response. Because inflammatory mediators are detrimental to the host, the TLR response is regulated by feedback inhibition. Statins, the inhibitors of isoprenoid biosynthesis, have been shown to be potent modulators of TLR activity, and this modulation may provide insight regarding mechanisms of the feedback inhibition. In the present study, we examined feedback mechanisms that regulate TLR4 activity in astrocytes using statins to perturb postligational signaling. Astrocytic cultures established from newborn rat brains were exposed to lipopolysaccharide (LPS), the ligand for TLR4. The up‐regulation of expression of genes encoding interleukin (IL)‐1β, IL‐6, and tumor necrosis factor‐α (TNFα) was determined by real‐time RT‐PCR. Pretreatment of the cells with either atorvastatin or simvastatin enhanced the LPS‐induced up‐regulation of cytokine gene expression. The most profound enhancement of approximately 17‐fold was observed for theIl‐6gene. The enhancements for theTnfaandIl‐1bgenes were approximately 5‐ and 3.5‐fold, respectively. Mevalonate fully reversed the effects of statins, indicating that these drugs act through the inhibition of isoprenoid synthesis. The inhibition of protein geranylgeranylation, but not protein farnesylation, mimicked the effects of statins, strongly indicating that the enhancement is mediated by the Rho proteins. In support of this notion, pretreatment of cells with toxin B, a specific inhibitor of the Rho proteins, also enhanced LPS‐triggered up‐regulation of the cytokine genes. These results indicate that the Rho proteins are involved in the activation of negative feedback inhibition of TLR4 signaling in astrocytes. © 2007 Wiley‐Liss, Inc.
Forecasting precipitation for hydroelectric power management: how to exploit GCM's seasonal ensemble forecasts
Authors: García‐Morales Marta Benito , Dubus Laurent 
Published: September 2007

AbstractThe EDF group is the biggest French electric power producer and distributor. Its activities are greatly related to weather and climate. In particular, optimal management of the hydroelectric power production system requires a good forecast of water resources, from several days to several months in advance. Currently, only climatology at the seasonal timescale is used for operational production management. Seasonal probabilistic forecasts would improve watershed management at some months' lead‐time if they are skilful enough. For this, two main problems have to be addressed: first, direct precipitation forecasts at this timescale have little, but positive, skill over Europe; second, the spatial scales of seasonal forecasting models are not adequate to predict local precipitation at the river basin scale. This study aims to evaluate the quality of seasonal forecasts of precipitation for 48 catchments in southern France. These are obtained by spatially downscaling global scale seasonal forecasts of geopotential height at 850 hPa. The method used is based on singular value decomposition and multiple linear regression. The statistical downscaling model is calculated from 45 years of observed local precipitation in the watersheds and geopotential fields from ERA40 re‐analysis data. The statistical model is then applied to the seasonal hindcasts from the DEMETER project. Two main results arise from this work. First, we show that it is possible to obtain useful and valuable information for EDF at the local scale from global seasonal averaged information. Second, we find that only a probabilistic multi‐model ensemble forecast approach provides useful information for EDF catchments, even with quite low skill, and that a deterministic approach, using only the ensemble mean of the forecasts, is not better than a forecast based on climatology. It has, nevertheless, to be pointed out that for operational purposes, being able to know that a forecast for a given location or date is not reliable is, in itself, valuable information. Copyright © 2007 Royal Meteorological Society
Gene expression in endoprosthesis loosening: Chitinase activity for early diagnosis?
Authors: Morawietz L. , Weimann A. , Schroeder J. H. , Kuban R. J. , Ungethuem U. , Kaps C. , Slevogt H. , Gehrke T. , Krukemeyer M. G. , Krenn V. 
Published: September 2007

AbstractThe aim of the study was to identify markers for the early diagnosis of endoprosthesis loosening, for the differentiation between wear particle–induced and septic loosening and to gather new insights into the pathogenesis of endoprosthesis loosening. Gene expression profiles were generated from five periprosthetic membranes of wear particle–induced and five of infectious (septic) type using Affymetrix HG U133A oligonucleotide microarrays. The results of selected differentially expressed genes were validated by RT‐PCR (n = 30). The enzyme activity and the genotype of chitinase‐1 were assessed in serum samples from 313 consecutive patients hospitalized for endoprosthesis loosening (n = 54) or for other reasons, serving as control subjects (n = 259). Eight hundred twenty‐four genes were differentially expressed with a fold change greater than 2 (data sets on http://www.ncbi.nlm.nih.gov/geo/ GSE 7103). Among these were chitinase 1, CD52, calpain 3, apolipoprotein, CD18, lysyl oxidase, cathepsin D, E‐cadherin, VE‐cadherin, nidogen, angiopoietin 1, and thrombospondin 2. Their differential expression levels were validated by RT‐PCR. The chitinase activity was significantly higher in the blood from patients with wear particle–induced prosthesis loosening (p = 0.001). However, chitinase activity as a marker for early diagnosis has a specificity of 83% and a sensitivity of 52%, due to a high variability both in the disease and in the control group. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:394–403, 2008
Ischemia/reperfusion‐induced necrosis and apoptosis in the cells isolated from rat skeletal muscle
Authors: Wang Wei Z. , Fang Xin‐Hua , Stephenson Linda L. , Khiabani Kayvan T. , Zamboni William A. 
Published: September 2007

AbstractNecrosis was considered to be the solo mechanism for ischemia/reperfusion (I/R)‐induced cell death. Recent evidence from I/R models of the heart, liver, kidney, and brain indicates that apoptosis is a major contributor to I/R‐induced cell death. However, evidence of I/R‐induced apoptosis in skeletal muscle is sparse and divided. The purpose for the present study was to investigate I/R‐induced necrosis and apoptosis in the cells isolated from rat skeletal muscle. A rat gracilis muscle model was used. After surgical preparation, clamps were applied on the vascular pedicle to create 4 h of ischemia and released for 24 h of reperfusion (I/R, n = 10). Clamping was omitted in sham I/R rats (sham I/R, n = 10). The muscle samples were harvested after 24 h of reperfusion for the process of cell isolation. Cells were stained by Propidium Iodide (PI) or Annexin V‐FITC or both. Twenty thousand cells from each muscle sample were scanned and analyzed by flow cytometry. The average percentage of live cells was 45 ± 2% in the I/R group versus 65 ± 3% in the sham I/R group (p < 0.01). The average percentage of necrotic cells was 18 ± 1% in I/R versus 12 ± 1% in sham I/R (p < 0.01). The average percentage of apoptotic cells was 40 ± 3% in I/R versus 27 ± 3% in sham I/R (p < 0.01). Our results clearly demonstrated that I/R not only causes necrosis, but also accelerates apoptosis in the cells isolated from rat skeletal muscle. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:351–356, 2008
Matrix‐induced autologous chondrocyte implantation in sheep: objective assessments including confocal arthroscopy
Authors: Jones C. W. , Willers C. , Keogh A. , Smolinski D. , Fick D. , Yates P. J. , Kirk T. B. , Zheng M. H. 
Published: September 2007

AbstractThe assessment of cartilage repair has largely been limited to macroscopic observation, magnetic resonance imaging (MRI), or destructive biopsy. The aims of this study were to establish an ovine model of articular cartilage injury repair and to examine the efficacy of nondestructive techniques for assessing cartilage regeneration by matrix‐induced autologous chondrocyte implantation (MACI). The development of nondestructive assessment techniques facilitates the monitoring of repair treatments in both experimental animal models and human clinical subjects. Defects (Ø 6 mm) were created on the trochlea and medial femoral condyle of 21 sheep randomized into untreated controls or one of two treatment arms: MACI or collagen‐only membrane. Each group was divided into 8‐, 10‐, and 12‐week time points. Repair outcomes were examined using laser scanning confocal arthroscopy (LSCA), MRI, histology, macroscopic ICRS grading, and biomechanical compression analysis. Interobserver analysis of the randomized blinded scoring of LSCA images validated our scoring protocol. Pearson correlation analysis demonstrated the correlation between LSCA, MRI, and ICRS grading. Testing of overall treatment effect independent of time point revealed significant differences between MACI and control groups for all sites and assessment modalities (Asym Sig < 0.05), except condyle histology. Biomechanical analysis suggests that while MACI tissue may resemble native tissue histologically in the early stages of remodeling, the biomechanical properties remain inferior at least in the short term. This study demonstrates the potential of a multisite sheep model of articular cartilage defect repair and its assessment via nondestructive methods. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:292–303, 2008
Liver Transplantation in Patients Over 60 and 65 Years
Authors: Cross Timothy J.S. , Antoniades Charalambos G. , Muiesan Paolo , Al-Chalabi Thawab , Aluvihare Varuna , Agarwal Kosh , Portmann Bernard C. , Rela Mohammed , Heaton Nigel D. , O'Grady John G. , Heneghan Michael A. 
Published: September 2007

Abstract

With increased demand for liver transplantation (LT), outcomes of older recipients have been subjected to greater scrutiny, as previous studies have demonstrated poorer survival outcomes. Outcomes of 77 patients aged > 65 yr (group 1) who underwent transplantation between 1988 and 2003 at King's College Hospital, London, were compared with all recipients aged between 60 and 64 yr (group 2, n = 137) and 202 time-matched control patients with chronic liver disease aged between 18-59 yr (group 3). Patient survival at 30-days for groups 1, 2, and 3 were 99%, 94%, and 94%, respectively (P = not significant [NS]). At 1-yr, survival in the 3 groups was 82%, 86%, and 83%, respectively (P = NS), and at 5-yr patient survival was comparable (73%, 80%, and 78%, respectively) (P = NS). Episodes of acute cellular rejection (ACR) were fewer in the older cohorts (43% vs. 45% vs. 61%, P = 0.0016), although there was no significant difference identified in the numbers of patients in each group who experienced ACR (P = 0.16). A similar but nonsignificant trend was identified for rates of chronic rejection among the groups. In conclusion, these data suggest that survival of patients over 60 and 65 yr undergoing LT is satisfactory, at least in the first 5-yr posttransplantation. In addition, patients over 65 yr experience less rejection, with good graft survival. Thus, LT should not be denied to patients >65 yr on the basis of age alone, once a comprehensive screen for comorbidity has been undertaken. Liver Transpl 13:1382–1388. 2007. © 2007 AASLD.
Resistance to Combined Ganciclovir and Foscarnet Therapy in a Liver Transplant Recipient with Possible Dual-Strain Cytomegalovirus Coinfection
Authors: Rodriguez John , Casper Katherine , Smallwood Gregory , Stieber Andrei , Fasola Carlos , Lehneman Jennifer , Heffron Thomas 
Published: September 2007

Abstract

We present a case report of a cytomegalovirus (CMV)-seronegative, 58-year-old male who received a CMV-seropositive donor liver transplant without CMV prophylaxis. On postoperative day 30, the patient developed primary CMV disease that responded to ganciclovir. On postoperative day 114, however, he was diagnosed with recurrent CMV infection. Despite aggressive, combined antiviral treatment with ganciclovir and foscarnet and reduction of immunosuppression, viral clearance was never achieved. Serum samples were collected throughout the infectious process for viral DNA analysis. Portions of the UL97 and UL54 genes were amplified and compared to the AD169 wild-type strain. Sequencing studies revealed the presence of mutations in viral isolates obtained after clinical resistance was observed. These mutations were not present in samples obtained during the primary CMV infection. Our findings suggest the presence of coinfection with at least 2 different strains of CMV rather than induction of mutations after ganciclovir therapy. Liver Transpl 13:1396–1400. 2007. © 2007 AASLD.
Lessons Learned From Anatomic Variants of the Hepatic Artery in 1,081 Transplanted Livers
Authors: López-Andújar Rafael , Moya Angel , Montalvá Eva , Berenguer Marina , De Juan Manuel , San Juan Fernando , Pareja Eugenia , Vila Juan José , Orbis Francisco , Prieto Martín , Mir José 
Published: September 2007

Abstract

The aim of this study is to contribute our experience to the knowledge of the anatomic variations of the hepatic arterial supply. The surgical anatomy of the extrahepatic arterial vascularization was investigated prospectively in 1,081 donor cadaveric livers, transplanted at La Fe University Hospital from January 1991 to August 2004. The vascular anatomy of the hepatic grafts was classified according to Michels description (Am J Surg 1966;112:337-347) plus 2 variations. Anatomical variants of the classical pattern were detected in 30% of the livers (n = 320). The most common variant was a replaced left artery arising from the left gastric artery (9.7%) followed by a replaced right hepatic artery arising from the superior mesenteric artery (7.8%). In conclusion, the information about the different hepatic arterial patterns can help in reducing the risks of iatrogenic complications, which in turn may result in better outcomes not only following surgical interventions but also in the context of radiological treatments. Liver Transpl 13:1401–1404, 2007. © 2007 AASLD
Can Peripheral Venous Pressure Be An Alternative to Central Venous Pressure During Right Hepatectomy in Living Donors?
Authors: Choi Soo Joo , Gwak Mi Sook , Ko Justin Sang , Kim Gaab Soo , Kim Tae Hyeong , Ahn Hyun , Kim Jie Ae , Yang Mikyung , Lee Sang , Kim Myung 
Published: September 2007

Abstract

The safety of living donors is a matter of cardinal importance in addition to obtaining optimal liver grafts to be transplanted. Central venous pressure (CVP) is known to have significant correlation with the amount of bleeding during parenchymal transection and many centers have adopted CVP monitoring for right hepatectomy. However, central line cannulation can induce some serious complications. Peripheral venous pressure (PVP) has been suggested as a comparable alternative to CVP. The aim of this study was to determine whether a clinically acceptable agreement or a reliable correlation between CVP and PVP exist and if CVP can be replaced by PVP in living liver donors. A central venous catheter was placed through the right internal jugular vein and a peripheral venous catheter was inserted at antecubital fossa in the right arm. CVP and PVP were recorded in 15-minunte intervals in 50 adult living donors. The paired data were divided into 3 stages: preparenchymal transection, parenchymal transection, and postparenchymal transection. A total of 1,430 simultaneous measurements of CVP and PVP were recorded. Overall, the PVP, CVP, and bias were 7.0 ± 2.46, 5.9 ± 2.32, and 1.16 ± 1.12 mmHg, respectively. A total of 88.9% of all measurements were clinically within acceptable limits of bias (±2 mmHg). Regression analysis showed a high correlation coefficient between PVP and CVP (r = 0.893; P < 0.001) and the limits of agreement were −1.03 to 3.34 overall. In conclusion, frequencies of differences, bias, correlation coefficient, and limits of agreement between PVP and CVP remained relatively constant throughout the operation. Therefore, PVP measurement in the arm can be an alternative to predict CVP and further, obviate central venous catheter-related complications in living liver donors. Liver Transpl 13:1414–1421, 2007. © 2007 AASLD.
Human Leukocyte Antigen and Adult Living-Donor Liver Transplantation Outcomes
Authors: Jakab Simona S. , Navarro Victor J. , Colombe Beth W. , Daskalakis Constantine , Herrine Steven K. , Rossi Simona 
Published: September 2007

Abstract

Human leukocyte antigen (HLA) compatibility has no clinically significant impact in cadaveric liver transplantation. Less is known regarding living-donor liver transplantation (LDLT). Our prior analysis of the Organ Procurement and Transplantation Network (OPTN) database suggested a higher graft failure rate in patients who underwent LDLT from donors with close HLA match. We further investigated the effect of HLA-A, -B, and -DR matching on 5-yr graft survival in adult LDLT by analyzing OPTN data regarding adult LDLT performed between 1998 and 2005. We evaluated associations between 5-yr graft survival and total, locus-specific, and haplotype match levels. Separate analyses were conducted for recipients with autoimmune (fulminant autoimmune hepatitis, cirrhosis secondary to autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis) or nonautoimmune liver disease. Multivariable Cox proportional hazard models were used to evaluate interactions and adjust for potential confounders. Among 631 patients with available donor/recipient HLA data, the degree of HLA match had no significant effect on 5-yr graft survival, even when analyzed separately in recipients with autoimmune vs. nonautoimmune liver disease. To be able to include all 1,838 adult LDLTs, we considered a first-degree related donor as substitute for a close HLA match. We found no difference in graft survival in related vs. unrelated pairs. In conclusion, our results show no detrimental impact of close HLA matching on graft survival in adult LDLT, including in recipients with underlying autoimmune liver disease. Liver Transpl 13:1405–1413, 2007. © 2007 AASLD.