Imaging of intrahepatic and hilar cholangiocarcinoma.
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Bile Duct Neoplasms↗
Biomedical subjects
J M Lee
Publications and source records attributed to J M Lee.
Intrahepatic intraductal cholangiocarcinoma.
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Adenocarcinoma, Mucinous↗
Comparison of the immunogenicity of recombinant VP2 and VP3 of infectious pancreatic necrosis virus and marine birnavirus.
Recombinant proteins of truncated viral protein-2 (VP2) (aa 79-359) and VP3 of infectious pancreatic necrosis virus (IPNV) and marine birnavirus (MABV) were expressed in E. coli and their immunogenicities in fish were investigated. The recombinant proteins from IPNV were used to immunize rainbow trout and those from MABV to immunize flounder. The sera from the immunized fishes were assayed for antibody by ELISA and a neutralization test. Both the recombinant VP2 and VP3 produced antibodies in fish but the VP3 antibody titers were higher than that of the VP2 of IPNV and MABV. These results indicate that the recombinant VP3 is more immunogenic than the recombinant VP2.
Animals↗
Modulation of collagen proteolysis by chemical modification of amino acid side-chains in acellularized arteries.
In this study, we have examined the effects of specific chemical modifications of amino acid side-chains on the in vitro degradation of "native" collagen obtained from acellular matrix (ACM)-processed arteries. Two monofunctional epoxides of different size and chemistry were used to modify lysine, with or without methylglyoxal modification of arginine. Biochemical, thermomechanical, tensile mechanical, and multi-enzymatic (collagenase, cathepsin B, acetyltrypsin, and trypsin) degradation analyses were used to determine the effects of modifications.Collagen solubilization by enzymes was found to depend upon the size and chemistry of epoxides used to modify lysine residues. In general, the solubilization of native ACM collagen by collagenase, cathepsin B, trypsin, and acetyltrypsin was either unaltered or decreased after modification with glycidol. In contrast, n-butylglycidylether (n-B) treatment increased solubilization by all enzymes. Subsequent arginine modification significantly reduced collagen solubilization by acetyltrypsin for glycidol-treated ACM arteries, whereas increased collagen solubilization was observed for n-B-treated ACM arteries with all enzymes. Gel chromatographic analyses of collagen fragments solubilized by trypsin revealed that both the amount and sites of cleavage were altered after lysine and arginine modification. The ability to modulate the enzymatic degradation of tissue-derived materials as demonstrated in this study may facilitate the design of novel engineering scaffolds for tissue regeneration or collagen-based drug delivery systems.
Amino Acid Sequence↗
An analysis using DNA microarray of the time course of gene expression during syncytialization of a human placental cell line (BeWo).
Placental trophoblast syncytialization is a unique biological process. We have studied the time course of this process using DNA microarray in a cell model of syncytialization (the cytotrophoblast cell line BeWo following increased intracellular cAMP by forskolin). Total RNA was extracted from BeWo cells and labelled-cRNA target was then hybridized to a specific oligonucleotide probe set containing probes to over 12?000 human transcripts. Detectable levels of signal were found on average for 44 per cent of the total number of genes assayed. The correlation coefficient for the level of expression of independent replicates was #10878;0.99. The mRNA expression profile of specific genes analysed by microarray correlated quantitatively well with that analysed by reverse transcription-polymerase chain reaction and with protein secretion. In the absence of forskolin there are relatively few changes in gene expression (reaching a threshold of two fold); in the presence of forskolin there are a substantial number of changes. By clustering the patterns of altered gene expression at least ten groups could be extracted. Seven of these clusters involved increased gene expression and three decreased expression. Each cluster has been categorized by gene ontology (confining the analysis to genes with 'known' function). Among the genes with increased expression following forskolin treatment were many required for cellular communication (such as placental specific peptide hormones) and metabolism (such as cholesterol side chain cleavage enzyme). Several genes known to be involved in cell adhesion and fusion have markedly changed expression levels very early following forskolin exposure, thus preceding morphological fusion of BeWo cells. Further analysis of this data and expression profiling in general will be able to contribute to understanding the functional basis for the formation of the placental syncytiotrophoblast.
Amino Acid Transport Systems↗
Modulation of thyroidal radioiodine uptake by theophylline.
Diagnostic and therapeutic use of radioiodine in the management of thyroid disorders depends on the ability of thyroid cells to concentrate radioiodine, a process regulated by thyrotropin and dependent on the intracellular increase in cAMP. We tested the ability of theophylline, a drug known to increase intracellular cAMP via inhibition of phosphodiesterase, to modulate the thyroidal radioiodine uptake in FRTL-5 cells, in mice and in humans. In FRTL-5 cells, theophylline increased the uptake of radioactive iodine and intracellular cAMP only at low concentrations (1 microM). In mice, theophylline increased slightly the radioiodine uptake, although this increase varied from 1.5- to 6.6-fold. In humans, theophylline decreased slightly the radioiodine uptake, a decrease that became more pronounced with time after radioiodine administration. These studies suggest that theophylline modulates the radioiodine uptake in a dose-dependent fashion, although the modulation is mild and probably not applicable to the clinical setting.
Adult↗
TGF-beta1 polymorphism determines the progression of joint damage in rheumatoid arthritis.
OBJECTIVE: To determine whether transforming growth factor-beta1 (TGF-beta1) polymorphisms are associated with susceptibility to rheumatoid arthritis (RA) and to analyse whether they can affect the progression of radiographic severity. METHODS: A total of 143 RA patients and 148 healthy unrelated controls were tested for the TGF-beta1 polymorphisms using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). RESULTS: The TGF-beta1 polymorphisms were not associated with susceptibility to RA, although there was a trend that -509C/T and the 869T/C polymorphisms were associated with RA in the male population. The progression of radiographic severity, which was defined by a modified Sharp score plotted against disease duration, was significantly faster in the carrier of T allele at the -509 (p=0.048). CONCLUSION: Our data support the hypothesis that TGF-beta1 polymorphism may determine the progression of joint destruction in RA.
Adult↗
Hepatic bipolar radiofrequency ablation using perfused-cooled electrodes: a comparative study in the ex vivo bovine liver.
The purpose of this paper was to demonstrate the efficacy of the dual probe bipolar radiofrequency (RF) system with the perfused-cooled electrodes inducing coagulation necrosis in the ex vivo bovine liver. The perfused-cooled electrode that allows simultaneous internal cooling and interstitial hypertonic saline perfusion has been developed for RF ablation (RFA). RF was applied to excised bovine liver in a bipolar mode at 150 W using a 200 W generator with two perfused-cooled electrodes for 10 min. After placing the electrodes at 3 cm spacing in the explanted liver, 45 ablation zones were created with three different regimens: Group A, using both intraelectrode cooling and interstitial perfusion; group B, using only the intraelectrode cooling; and group C, using only interstitial perfusion. In groups A and C, RFA was performed with the infusion of 6% hypertonic saline at the rate of 2 ml min(-1). During RFA, we measured the tissue temperature at the midpoint between the two electrodes. The dimensions of the ablation zones and the changes in impedance, currents and liver temperature during RFA were compared in these three groups. The mean tissue impedance during RFA in group A (56.7+/-21.7 Omega) and group C (56.9+/-20.6 Omega) was significantly lower than group B (112+/-19.7 Omega) (p<0.001). The mean current was higher in group A (1765+/-128 mA) than groups B (760+/-321 mA) and C (1298+/-349 mA) (p<0.05). In addition, the shortest vertical diameter of coagulation necrosis was greater in groups A (4.9+/-0.5 cm) and C (4.6+/-0.7 cm) than in group B (3.5+/-0.4 cm) (p<0.05). The temperature at the mid-point between the two probes was higher in group A than other groups: 99 degrees C in group A, 88.9 degrees C in group B, and 94.3 degrees C in group C (p>0.05). The ratios of the diameter of the long-axis to the diameter of the vertical-axis of groups A, B and C were 1.1+/-0.1, 1.2+/-0.1, and 1.1+/-0.2, respectively (p<0.05). Bipolar RFA using intraelectrode cooling and the interstitial saline perfusion simultaneously produced ablation zones significantly larger than the area produced by only one measure.
Animals↗
Dynamic monitoring system for full-scale wastewater treatment plants.
This paper proposes a new process monitoring method using dynamic independent component analysis (ICA), ICA is a recently developed technique to extract the hidden factors that underlie sets of measurements, whereas principal component analysis (PCA) is a dimensionality reduction technique in terms of capturing the variance of the data. Its goal is to find a linear representation of non-Gaussian data so that the components are statistically independent. PCA aims at finding PCs that are uncorrelated and are linear combinations of the observed variables, while ICA is designed to separate the ICs that are independent and constitute the observed variables. The dynamic ICA monitoring method is applying ICA to the augmenting matrix with time-lagged variables. The dynamic monitoring method was applied to detect and monitor disturbances in a full-scale biological wastewater treatment (WWTP), which is characterized by a variety of dynamic and non-Gaussian characteristics. The dynamic ICA method showed more powerful monitoring performance on a WWTP application than the dynamic PCA method since it can extract source signals which are independent of time and cross-correlation of variables.
Algorithms↗
Characterization and molecular genetic mapping of microsatellite loci in pepper.
Microsatellites or simple sequence repeats are highly variable DNA sequences that can be used as informative markers for the genetic analysis of plants and animals. For the development of microsatellite markers in Capsicum, microsatellites were isolated from two small-insert genomic libraries and the GenBank database. Using five types of oligonucleotides, (AT)(15), (GA)(15), (GT)(15), (ATT)(10) and (TTG)(10), as probes, positive clones were isolated from the genomic libraries, and sequenced. Out of 130 positive clones, 77 clones showed microsatellite motifs, out of which 40 reliable microsatellite markers were developed. (GA)(n) and (GT)(n) sequences were found to occur most frequently in the pepper genome, followed by (TTG)(n) and (AT)(n). Additional 36 microsatellite primers were also developed from GenBank and other published data. To measure the information content of these markers, the polymorphism information contents (PICs) were calculated. Capsicum microsatellite markers from the genomic libraries have shown a high level of PIC value, 0.76, twice the value for markers from GenBank data. Forty six microsatellite loci were placed on the SNU-RFLP linkage map, which had been derived from the interspecific cross between Capsicum annuum "TF68" and Capsicum chinense "Habanero". The current "SNU2" pepper map with 333 markers in 15 linkage groups contains 46 SSR and 287 RFLP markers covering 1,761.5 cM with an average distance of 5.3 cM between markers.
Capsicum↗
SEPT5_v2 is a parkin-binding protein.
Mutations in parkin are associated with various inherited forms of Parkinson's disease (PD). Parkin is a ubiquitin ligase enzyme that catalyzes the covalent attachment of ubiquitin moieties onto substrate proteins destined for proteasomal degradation. The substrates of parkin-mediated ubiquitination have yet to be completely identified. Using a yeast two-hybrid screen, we isolated the septin, human SEPT5_v2 (also known as cell division control-related protein 2), as a putative parkin-binding protein. SEPT5_v2 is highly homologous to another septin, SEPT5, which was recently identified as a target for parkin-mediated ubiquitination. SEPT5_v2 binds to parkin at the amino terminus and in the ring finger domains. Several lines of evidence have validated the putative link between parkin and SEPT5_v2. Parkin co-precipitates with SEPT5_v2 from human substantia nigra lysates. Parkin ubiquitinates SEPT5_v2 in vitro, and both SEPT5_v1 and SEPT5_v2 accumulate in brains of patients with ARJP, suggesting that parkin is essential for the normal metabolism of these proteins. These findings suggest that an important relationship exists between parkin and septins.
Aged↗
Non-linear registration for brain images by maximising feature and intensity similarities with a Bayesian framework.
The objective of this work was to provide a new, precise registration of the cortical mantle with a non-linear transformation. Image registration is broadly classified into two types, using intensity similarity and feature similarity. Whereas the former approach has merit in global brain matching, the latter provides a fast registration centred on a region of interest. The hybrid registration proposed in this paper was achieved using a Bayesian framework, which consisted of a likelihood model including intensity similarity and a prior model including feature information and a smoothing constraint. In this approach, each voxel was spatially transformed, so that the distance between corresponding features was shortened and also so that the intensity correlation was maximised. The result of the hybrid method clearly showed a good match of global brain (r = 0.930) by including intensity similarity. Moreover, this method compensated for the approximated sulcus of the feature-based method with intensity information, so that the geometric shape and thickness of the sulcus at the feature-defined region was likely to be registered. The accuracy in the feature-defined area was improved by 33.4% and 7.5% compared with feature-based and intensity-based methods, respectively.
Bayes Theorem↗
Attenuation of human-to-pig xenogenic cellular proliferation and Th1 response by expressing the human MHC II DQ exogenes on porcine cells.
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Animals↗
Lung transplantation-the surgical experience.
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Cause of Death↗
Germline transformation of the sawfly, Athalia rosae (Hymenoptera: Symphyta), mediated by a piggyBac-derived vector.
A piggyBac construct carrying two green fluorescent protein (GFP)-coding sequences one driven by Bombyx mori actin gene promoter and the other by Drosophila melanogaster heat-shock protein 70 (hsp70) promoter were injected together with a nonautonomous helper plasmid containing an active piggyBac transposase gene into the posterior end of mature unfertilized eggs dissected from the ovaries of Athalia rosae (Hymenoptera: Symphyta). These injected eggs, which developed as haploid male embryos upon artificial activation, were cultured to adulthood. Of 278 injected eggs, 61 grew to G(0) haploid adult males. These G(0) haploid males were individually mated to diploid females. The progeny embryos (G(1) generation) were examined for GFP expression. Four GFP-positive embryos (from three independent G(0) matings) were obtained. Two eclosed as diploid adult G(1) females. Mature unfertilized eggs dissected from the GFP-positive G(1) diploid females were activated artificially, and the resultant embryos were examined for GFP expression, separated and cultured to adulthood (G(2) generation). The G(2) haploid embryos segregated to GFP-positive and -negative individuals. By mating the G(2) adult haploid males individually to diploid females, stocks were established in which the piggyBac construct was stably integrated into the genome, as evidenced by GFP expression and Southern blot hybridization. The piggyBac transposition occurred at its canonical target TTAA sequence. These results, which demonstrate the first successful stable transposon-mediated germline transformation in Hymenoptera, will expand the usefulness of the piggyBac vector.
Animals↗
New monitoring technique with an ICA algorithm in the wastewater treatment process.
A new monitoring method using independent component analysis (ICA) is suggested for the wastewater treatment process (WWTP). ICA is an extension of PCA (Principal Component Analysis). While PCA can only impose independence up to the second order (mean and variance) with constraint on the direction vectors to be orthogonal, ICA imposes statistical independence up to more than second order on the individual component and has no orthogonal condition. When the variables have the Gaussian distribution, PCA itself provides a satisfactory result in monitoring performance. However, the measured variables are not often normally distributed. In this case, ICA can provide better monitoring results than PCA since ICA is based on the assumption that the latent variables are not normally distributed. In this paper, the ICA monitoring algorithm with kernel density estimation was applied to fault detection and diagnosis of the wastewater simulation benchmark. ICA with kernel density estimation gives better results than PCA in disturbance detection in spite of severe periodic features of the wastewater plant.
Algorithms↗
Development of a virtual speaking simulator using Image Based Rendering.
The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology has enabled the use of virtual reality (VR) for the treatment of the fear of public speaking. There are two techniques for building virtual environments for the treatment of this fear: a model-based and a movie-based method. Both methods have the weakness that they are unrealistic and not controllable individually. To understand these disadvantages, this paper presents a virtual environment produced with Image Based Rendering (IBR) and a chroma-key simultaneously. IBR enables the creation of realistic virtual environments where the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma-keys puts virtual audience members under individual control in the environment. In addition, real time capture technique is used in constructing the virtual environments enabling spoken interaction between the subject and a therapist or another subject.
Computer Simulation↗
Role of conformational changes in the heme-dependent regulation of human soluble guanylate cyclase.
Soluble guanylate cyclase (sGC) is a receptor for endogenous and exogenous nitric oxide (NO) and is activated many fold upon its binding, making it a core enzyme in the nitric oxide signal transduction pathway. Much effort has been made to understand the link between binding of NO at the sGC heme and activation of the cyclase activity. We report here the first direct evidence for the role of conformational changes in transmitting the signal between the heme and cyclase domains. Using both circular dichroism (CD) and fluorescence spectroscopies, we have probed the effect that the sGC activators NO and 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl-indazole (YC-1) and the inhibitor 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one (ODQ) have on the structure of the protein. Surprisingly, binding of either ODQ or YC-1 to NO-bound sGC cause virtually identical changes in the far-UV CD spectra of sGC, reflecting a perturbation in the secondary structure of the enzyme. This change is absent upon binding of NO, YC-1 or ODQ alone. Using this and previous data, we propose a working model for the mechanism of activation of sGC by NO and YC-1 and inhibition by ODQ.
Acrylamide↗