bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dental Health Status of Liver Transplant Candidates
Authors: Guggenheimer James , Eghtesad Bijan , Close John M. , Shay Christine , Fung John J. 
Published: January 2007

Abstract

A prerequisite dental evaluation is usually recommended for potential organ transplant candidates. This is based on the premise that untreated dental disease may pose a risk for infection and sepsis, although there is no evidence that this has occurred in organ transplant candidates or recipients. The purpose of this study was to assess the prevalence of dental disease and oral health behaviors in a sample of liver transplant candidates (LTCs). Oral examinations were conducted on 300 LTCs for the presence of gingivitis, dental plaque, dental caries, periodontal disease, edentulism, and xerostomia. The prevalence of these conditions was compared with oral health data from national health surveys and examined for possible associations with most recent dental visit, smoking, and type of liver disease. Significant risk factors for plaque-related gingivitis included intervals of more than 1 yr since the last dental visit (P = 0.004), smoking (P = 0.03), and diuretic therapy (P = 0.005). Dental caries and periodontal disease were also significantly associated with intervals of more than 1 yr since the last dental visit (P = 0.004). LTCs with viral hepatitis or alcoholic cirrhosis had the highest smoking rate (78.8%). Higher rates of edentulism occurred among older LTCs who were less likely to have had a recent dental evaluation (mean 88 months). In conclusion, intervals of more than 1 yr since the last dental visit, smoking, and diuretic therapy appear to be the most significant determinants of dental disease and the need for a pretransplantation dental screening evaluation in LTCs. Edentulous patients should have periodic examinations for oral cancer. Liver Transpl 13:280–286, 2007. © 2007 AASLD.
Primary Graft Nonfunction and Kupffer Cell Activation After Liver Transplantation From Non-Heart-Beating Donors in Pigs
Authors: Monbaliu Diethard , van Pelt Jos , De Vos Rita , Greenwood Joanne , Parkkinen Jaakko , Crabbé Tina , Zeegers Marcel , Vekemans Katrien , Pincemail Joël , Defraigne Jean-Olivier , Fevery Johan , Pirenne Jacques 
Published: January 2007

Abstract

More extensive use of non-heart-beating donors (NHBD) could reduce mortality on liver transplantation waiting lists, but this is associated with more primary nonfunction (PNF). We assessed which parameters are involved in the development of PNF in livers from NHBD in a previously validated pig liver transplantation model, in which livers were transplanted after exposure to incremental periods of warm ischemia. The risk of PNF was unacceptably high (>50%) when livers were exposed to >30 minutes' warm ischemia before a short cold ischemic period. This study examined how PNF is affected by Kupffer cell activation (β-galactosidase), the generation of cytokines tumor necrosis factor alpha and interleukin 6, antioxidant mechanisms (ascorbic acid, α-tocopherol, reduced glutathione), circulating redox-active iron, and sinusoidal endothelial cell function (hyaluronic acid clearance). Kupffer cells were more activated in PNF recipients, as suggested by higher β-galactosidase levels (15 minutes after reperfusion), and secondarily, by higher production of tumor necrosis factor alpha and interleukin 6 (180 minutes after reperfusion). In addition, α-tocopherol and reduced glutathione were lower, and ascorbic acid and redox-active iron higher in PNF recipients. Finally, PNF grafts displayed progressively decreasing hyaluronic acid clearance (suggesting sinusoidal endothelial cell dysfunction) and parenchymal edema. Consequently, a reduced-flow phenomenon was documented. In grafts from NHBD that are destined to fail, β-galactosidase activity (a surrogate of Kupffer cell activation) is higher, proinflammatory cytokines are overproduced, some antioxidant mechanisms fail, and circulating redox-active iron is more rapidly released. A no-flow phenomenon is eventually observed in these failing grafts. Liver Transpl 13:239–247, 2007. © 2007 AASLD.
Cytotoxic T-Cell-Mediated Defense Against Infections in Human Liver Transplant Recipients
Authors: Tanaka Koichi , Uemoto Shinji , Egawa Hiroto , Takada Yasutsugu , Ozawa Kazue , Teramukai Satoshi , Kasahara Mureo , Ogawa Kohei , Ono Masako , Sato Hiroshi , Takai Kenji , Fukushima Masanori , Inaba Kayo 
Published: January 2007

Abstract

Previous studies have shown that postoperative infection is highest in transplant recipients with preexisting high levels of cytotoxic T lymphocytes (CTLs). To study this phenomenon, 106 adult liver transplant recipients were divided into 3 groups, based on hierarchical clustering of the CD3+CD8+CD45 isoform fractions prior to living donor liver transplantation (LDLT). Group I had the highest naive T-cell levels (subset CD45RO−CCR7+), Group II had the highest effector/memory (EM) T-cell levels (subset CD45RO+CCR7−), and Group III had the highest effector T-cell levels (subset CD45RO−CCR7−). In Group I, CTLs upregulated in response to invading pathogens much earlier and more rapidly than the other groups; this response was associated with CD4+ T-cell help, downregulation of CD27+CD28+ subsets, and upregulation of interferon-gamma and perforin expression. In contrast, in Groups II and III, CTLs upregulated slowly following persistent viral infection and did not respond efficiently to acute infection. In addition, Group II's cytolytic responses were due mainly to upregulation of the CD8+ EM T-cell fraction, whereas Group III's cytolytic responses were attributable to upregulation of effector T cells. The prevalence of EM or effector T cells was dependent on differentiation of the CD8+ phenotype before LDLT. In conclusion, in most infected transplant recipients who died, generation of CD8+ CTLs had been suppressed without associated CD4+ T-cell help. Liver Transpl 13:287–293, 2007. © 2007 AASLD.
Protein–protein recognition and interaction hot spots in an antigen–antibody complex: Free energy decomposition identifies “efficient amino acids”
Authors: Lafont Virginie , Schaefer Michael , Stote Roland H. , Altschuh Danièle , Dejaegere Annick 
Published: January 2007

AbstractThe molecular mechanics Poisson–Boltzmann surface area (MM/PBSA) method was applied to the study of the protein–protein complex between a camelid single chain variable domain (cAb‐Lys3) and hen egg white lysozyme (HEL), and between cAb‐Lys3 and turkey egg white lysozyme (TEL). The electrostatic energy was estimated by solving the linear Poisson–Boltzmann equation. A free energy decomposition scheme was developed to determine binding energy hot spots of each complex. The calculations identified amino acids of the antibody that make important contributions to the interaction with lysozyme. They further showed the influence of small structural variations on the energetics of binding and they showed that the antibody amino acids that make up the hot spots are organized in such a way as to mimic the lysozyme substrate. Through further analysis of the results, we define the concept of “efficient amino acids,” which can provide an assessment of the binding potential of a particular hot spot interaction. This information, in turn, can be useful in the rational design of small molecules that mimic the antibody. The implications of using free energy decomposition to identify regions of a protein–protein complex that could be targeted by small molecules inhibitors are discussed. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Solution structure of ApaG from Xanthomonas axonopodis pv. citri reveals a fibronectin‐3 fold
Authors: Cicero Daniel O. , Contessa Gian M. , Pertinhez Thelma A. , Gallo Mariana , Katsuyama Angela M. , Paci Maurizio , Farah Chuck S. , Spisni Alberto 
Published: January 2007

AbstractApaG proteins are found in a wide variety of bacterial genomes but their function is as yet unknown. Some eukaryotic proteins involved in protein‐protein interactions, such as the human polymerase δ‐interacting protein (PDIP38) and the F Box A (FBA) proteins, contain ApaG homology domains. We have used NMR to determine the solution structure of ApaG protein from the plant pathogen Xanthomonas axonopodis pv. citri (ApaGXac) with the aim to shed some light on its molecular function. ApaGXac is characterized by seven antiparallel β strands forming two β sheets, one containing three strands (ABE) and the other four strands (GFCC′). Relaxation measurements indicate that the protein has a quite rigid structure. In spite of the presence of a putative GXGXXG pyrophosphate binding motif ApaGXac does not bind ATP or GTP, in vitro. On the other hand, ApaGXac adopts a fibronectin type III (Fn3) fold, which is consistent with the hypothesis that it is involved in mediating protein‐protein interactions. The fact that the proteins of ApaG family do not display significant sequence similarity with the Fn3 domains found in other eukaryotic or bacterial proteins suggests that Fn3 domain may have arisen earlier in evolution than previously estimated. Proteins 2007 © 2007 Wiley‐Liss, Inc.
Identification of FAKTS as a novel 14‐3‐3‐associated nuclear protein
Authors: Luhn Patricia , Wang Haining , Marcus Adam I. , Fu Haian 
Published: January 2007

AbstractThrough bioinformatics and experimental approaches, we have assigned the first biochemical property to a predicted protein product in the human genome as a new 14‐3‐3 binding protein. 14‐3‐3 client proteins represent a diverse group of regulatory molecules that often function as signaling integrators in response to various environmental cues and include proteins such as Bad and Foxo. Using 14‐3‐3 as a probe in a yeast two‐hybrid screen, we identified a novel 14‐3‐3 binding protein with unknown function, initially designated as clone 546. Confocal microscopy revealed that clone 546 localized to the nucleus of mammalian cells. Additional studies show that the gene encoding clone 546 is expressed in many human tissues, including the thymus, as well as a number of cancer cell lines. The interaction of clone 546 with 14‐3‐3 was confirmed in mammalian cells. Interestingly, this interaction was markedly enhanced by the expression of activated Akt/PKB, suggesting a phosphorylation dependent event. Mutational analysis was carried out to identify Ser479 as the predominant residue that mediates the clone 546/14‐3‐3 association. Phosphorylation of Ser479 by AKT/PKB further supports a critical role for Akt/PKB in regulation of the clone 546/14‐3‐3 interaction. On the basis of these findings, we named this undefined protein FAKTS: Fourteen‐three‐three associated AKT Substrate. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Probing nascent structures in peptides using natural abundance 13C NMR relaxation and reduced spectral density mapping
Authors: Slupsky Carolyn M. , Spyracopoulos Leo , Booth Valerie K. , Sykes Brian D. , Crump Matthew P. 
Published: January 2007

AbstractThe main chain motional properties for a series of peptides that appear to have preferred conformations in solution have been systematically studied using solution‐state nuclear magnetic resonance spectroscopy. The series of peptides were derived from the N‐termini of pro‐inflammatory chemokine proteins and HoxB1, a transcriptional regulator. As an unstructured control, a ten residue peptide was designed, synthesized, and found to be minimally structured from solution NMR data. The dynamic properties of the main chain for the peptides were assessed through longitudinal and transverse main chain 13Cα relaxation rates and the heteronuclear nuclear Overhauser effect. Motional parameters were interpreted using reduced spectral density mapping and compared with those derived from an extended Lipari–Szabo model in which the rotational correlation time was calculated for each main chain site of the peptide. Comparison of spectral density and Lipari–Szabo analyses for the peptides to those of the unstructured control peptide reveals significant differences in the dynamic behavior of the peptides. The amplitude of picosecond to nanosecond timescale motions for the main chain is observed to decrease for all of the chemokine peptides and HoxB1 over the regions that show partial structure at low temperatures. Comparatively, changes in picosecond to nanosecond timescale motions for the unstructured control peptide show no correlation with sequence position. These results indicate that there are distinguishable low temperature motional differences between an intrinsically unstructured peptide and peptides that have an inherent propensity to structure. Proteins 2007; © 2006 Wiley‐Liss, Inc.
Gender ratios in high school science departments: The effect of percent female faculty on multiple dimensions of students' science identities
Authors: Gilmartin Shannon , Denson Nida , Li Erika , Bryant Alyssa , Aschbacher Pamela 
Published: January 2007

AbstractTo examine how school characteristics are tied to science and engineering views and aspirations of students who are underrepresented in science and engineering fields, this mixed‐methods study explores relationships between aspects of students' science identities, and the representation of women among high school science teachers. Quantitative analyses tested the hypothesis that percent female faculty would have a positive effect on girls' science interests, and perceptions in particular, given the potentially greater availability of women role models. Findings indicate that percent female science faculty does not have an effect on a range of science measures for both male and female students, including the ways in which they understand scientific practice, their science self‐concept, and their interest in science‐related college majors. As qualitative data demonstrate, this could reflect practical constraints at schools where female faculty are concentrated and narrow perceptions of science teachers and “real” science. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 980–1009, 2007
Human insulin receptor juxtamembrane domain independent insulin signaling
Authors: Sattar Akm A. , Berhanu Chali , Gebreselassie Surafel , Berhanu Paulos 
Published: January 2007

AbstractThe exon 16‐encoded juxtamembrane (JM) domain of human insulin receptor (hIR) harbors the NPEY motif which couples the insulin‐activated hIR kinase to downstream signal transduction molecules. We sought to determine if signal transduction requires the entire exon 16‐encoded 22‐amino acid JM domain. Transfected CHO cells were generated stably expressing either the wild‐type hIR (hIR‐WT) or two mutant hIRs (hIRΔEx16 in which the JM domain was deleted, and hIRrosJM in which the deleted segment was replaced by the corresponding domain of v‐ros protein). The mutant hIRΔEx16 and hIRrosJM exhibited similar insulin‐binding as the hIRWT. Insulin internalization and insulin dose‐response experiments toward activation of downstream signal transduction molecules demonstrated that: i) the presence of intact hIR‐JM domain which harbors the NPEY motif is essential for Shc phosphorylation but not for IRS‐1 phosphorylation; ii) insulin signal transduction can occur independent of the JM domain of hIR and without participation of the NPEY motif; iii) engagement of this putative alternative downstream signal transduction is Shc independent and is dependent on insulin concentration; and iv) insulin internalization does not necessarily require the hIR specific aa sequence of the JM domain which can be partially substituted by the JM domain of the v‐ros tyrosine kinase.
Medical undergraduate students' beliefs and attitudes toward pain – How do they mature?
Authors: Niemi‐Murola Leila , Nieminen Juha T. , Kalso Eija , Pöyhiä Reino 
Published: January 2007

AbstractAt the University of Helsinki, pain‐related topics are taught throughout medical studies but without a formal pain curriculum. The purpose of this study was to assess medical students’ attitudes towards pain.A questionnaire using a 6‐point Likert scale was constructed to measure pain‐related attitudes and beliefs described in previous studies. After a pilot study, the questionnaire was developed to assess attitudes towards elderly patients’ pain, prescription of opioids, assessment of pain and anxiety concerning chronic pain and its treatment. An electronic questionnaire with seven demographic and 28 pain‐related items was sent via e‐mail to 680 medical students at the University of Helsinki, Finland. Three reminders were sent with a new letter of encouragement. The students had 3 weeks to answer the questionnaire.The questionnaire was returned by 63.4% of the students (N = 430). There were statistically significant differences between the students in different study years showing increasing empathy towards elderly patients’ pain (p < 0.001), willingness to prescribe opioids (p < 0.001) and anxiety about meeting patients suffering from chronic pain (p < 0.01). Final year students felt significantly more often anxious about seeing a chronic pain patient (p < 0.05) compared with the first year students. Female students were more anxious about seeing a patient suffering from chronic pain (p < 0.05) and they were less confident of their ability to treat chronic pain patients in primary care (p < 0.001) than the male students.The general attitudes of students mature as hoped for during medical studies. Attitudes towards treating the pain of cancer patients and elderly patients are positive. Attention should be paid to helping students to cope with their emotions and to reducing their anxiety about meeting patients with chronic pain.
New Culture Approaches for Yessotoxin Production from the Dinoflagellate Protoceratium reticulatum
Authors: José Gallardo Rodríguez Juan , del Carmen Cerón García María , Camacho Francisco García , Sánchez Mirón Asterio , Belarbi El Hassan , Grima Emilio Molina 
Published: January 2007

AbstractFed‐batch and perfusion cultures were carried out in a traditional glass 2‐L bioreactor with the toxic dinoflagellate Protoceratium reticulatum. The maximum cell concentration obtained was 2.3 × 105 cell·mL−1, which is almost 1 order of magnitude higher than the maximum previously referenced for this species. L1 medium was shown to be clearly deficient in nitrate and phosphate for this strain, and addition of highly concentrated aliquots of these nutrients allowed higher cell concentrations to be obtained. This species consumed high amounts of nitrate and phosphate, 2.1 × 10‐3 and 2.3 × 10‐4 μmol·h−1·cell−1, respectively. However, this consumption produced a very low number of cells compared to other classes of microalgae, indicating that this species is, like other dinoflagellates, a poor competitor in terms of utilization of inorganic nutrients. Higher production of toxins and pigments was strongly associated with cell number in the culture, with maximum values of 700 ng·mL−1 and 1321 μg·mL−1, respectively. Most yessotoxins remained within the cells and not in the cell‐free culture medium, and their production was not related to either the age of the culture or the cell growth phase.
Transient Gene Expression Levels from Multigene Expression Vectors
Authors: Underhill Michèle F. , Smales C. Mark , Naylor Louise H. , Birch John R. , James David C. 
Published: January 2007

AbstractMultigene expression vectors are commonly utilized whereby the (over)expression of two or more genes is desired simultaneously and often at supposedly equivalent levels. We have characterized dual‐gene and pEE14.4 RlucMFluc expression plasmids in which the second hCMV‐MIE promoter is replaced with a c‐myc IRES to enable one‐step coordinated expression of multiple genes in eukaryotic cells. The efficacy of these plasmids has been tested in Chinese hamster ovary (CHO) cells using renilla and firefly luciferase reporter genes, with the reporter gene in either position 1 or 2 from the 5′ to 3′ direction, respectively. The dual‐gene constructs gave enhanced second position gene expression levels compared to the first gene during transient transfection experiments (4‐ to 50‐fold increase 24 h post‐transfection). The pEE14.4 RlucMFluc plasmid gave enhanced first cistron expression compared to the second cistron (∼19‐fold increase 24 h post‐transfection). More equivalent transient expression levels were obtained by undertaking co‐transfection of the appropriate single gene plasmids. Reporter gene mRNA levels in the transfected cells were also evaluated by qRT‐PCR and compared to the observed protein expression levels. Analysis of the resulting data showed that transcriptional limitation of the first cistron in the dual‐gene expression system and not translational limitation was the major limiting factor. Taken together these data suggest that relative protein expression levels expected from heterologous gene products in a multigene vector cannot be predicted on copy number alone and it is important to characterize multigene or oligocistronic systems prior to use.
Effect of the Engineered Indole Pathway on Accumulation of Phenolic Compounds in Catharanthus roseus Hairy Roots
Authors: Chung Ill‐Min , Hong Seung‐Beom , Peebles Christie A. M. , Kim Jin‐Ae , San Ka Yiu 
Published: January 2007

AbstractCatharanthus roseus has been well‐known to contain indole alkaloids effective for treatment of diverse cancers. We examined the intracellular accumulation profiles of phenolic compounds in response to ectopic overexpression of tryptophan feedback‐resistant anthranilate synthase holoenzyme (ASαβ) in C. roseus hairy roots. Among 13 phenolic compounds measured, 6 phenolic compounds were detected in late exponential phase ASαβ hairy roots. Uninduced and induced ASαβ hairy roots accumulated up to 1.2 and 4.5 mg/g DW over a 72‐h period, respectively. Upon induction, in parallel with a rapid increase in tryptophan in the first 48 h, accumulation of phenolic compounds tended to increase to a maximum level (4.5 mg/g DW) at 48 h, after which phenolic levels decreased back to the uninduced level by 72 h. Naringin was a predominant form that comprised about 72% and 36% of the total content of phenolic compounds in the uninduced and induced lines, respectively. Upon induction, accumulation of catechin drastically increased with the highest level (3.6 mg/g) occurring at 48 h, whereas that of all others except for salicylic acid showed no statistical difference. Catechin is a final product of the flavonoid pathway, and thus metabolic flux into this pathway is transiently increased by overexpression of AS. Like catechin, salicylic acid is very sensitive to induction as it began to increase to 5‐fold within 4 h of induction, but unlike catechin, no significant accumulation of salicylic acid was noted after 4 h of induction. The results suggest differential regulation of this particular biosynthesis branch within the phenolic pathway.