bluuebunny/crossref_metadata_2025_split huggingface dataset:
Policy analysis matrices: beyond simple sensitivity analysis
Authors: Morrison Jamie , Balcombe Kelvin 
Published: August 2002

AbstractAs an analytical methodology, the Policy Analysis Matrix (PAM) can be used to provide indicators of the incentives faced by producers in a given policy and institutional environment. However, the methodology suffers from the limitation that the analyst is unable to attach any level of confidence to the results, other than that generated through sensitivity analysis. In this paper the technique of bootstrapping is introduced as a general method for assessing the degree of uncertainty surrounding indicators derived from PAMs. The example of wheat production in Slovakia is used to demonstrate the usefulness of the additional information generated by this approach. Copyright © 2002 John Wiley & Sons, Ltd.
Testing for the law of one price: rice market integration in Bangladesh
Authors: Dawson P. J. , Dey P. K. 
Published: August 2002

AbstractRecent studies of spatial market integration have adopted error correction models to test for its existence and for market dominance. An integrated empirical framework is proposed here which tests for long‐run spatial market integration between price pairs using a dynamic vector autoregressive model and cointegration. Hypotheses tests of market integration, perfect market integration, and causality are conducted sequentially. The approach is illustrated using monthly prices from rice markets in Bangladesh since trade liberalisation in 1992. Results show that rice markets are perfectly integrated and that Dhaka dominates near markets but is dominated by more distant markets. Copyright © 2002 John Wiley & Sons, Ltd.
Localization of the large subunit of replication factor C near the 5′ end of DNA primers
Authors: Kolpashchikov Dmitry M. , Hughes Patrick , Favre Alain , Baldacci Giuseppe , Lavrik Olga I. 
Published: August 2002

AbstractReplication factor C (RFC) is a heteropentameric sliding clamp loader protein essential for processive synthesis of DNA by eukaryotic DNA polymerases δ and ϵ. To study the interaction of RFC with 3′ and 5′ ends of the DNA primer, we have developed chemical photocrosslinking assay using a synthetic DNA gap and DNA primer‐template structures. We have found that the radioactively labeled primers containing a photoreactive group at their 5′ end could crosslink with the largest RFC subunit (RFC140) on primer‐templates and DNA gap structures, but that 3′ end photoreactive primers could only crosslink with RFC140 within the DNA gap structure. Addition of replication protein A (RPA) to the reaction mixture resulted in the crosslinking of RPA subunits and inhibited crosslinking of RFC140 using 3′ but not 5′ photoreactive primers present at the gap. The results suggest specific contacts between RFC140 and the 5′ end of the DNA primer. Together with previous data, these experiments allow us to propose a model for the DNA polymerase switch during eukaryotic DNA replication. Copyright © 2001 John Wiley & Sons, Ltd.
Applications of novel affinity cassette methods: use of peptide fusion handles for the purification of recombinant proteins
Authors: Hearn Milton T W , Acosta Danilo 
Published: August 2002

AbstractIn this article, recent progress related to the use of different types of polypeptide fusion handles or ‘tags’ for the purification of recombinant proteins are critically discussed. In addition, novel aspects of the molecular cassette concept are elaborated, together with areas of potential application of these fundamental principles in molecular recognition. As evident from this review, the use of these concepts provides a powerful strategy for the high throughput isolation and purification of recombinant proteins and their derived domains, generated from functional genomic or zeomic studies, as part of the bioprocess technology leading to their commercial development, and in the study of molecular recognition phenomena per se. In addition, similar concepts can be exploited for high sensitivity analysis and detection, for the characterisation of protein bait/prey interactions at the molecular level, and for the immobilisation and directed orientation of proteins for use as biocatalysts/biosensors. Copyright © 2001 John Wiley & Sons, Ltd.
Magnetic resonance imaging of inflammatory bowel disease: Evaluation in a rabbit model
Authors: Knollmann Friedrich D. , Dietrich Thore , Bleckmann Tim , Böck Johannes , Mäurer Jürgen , Radtke Cornelia , Felix Roland 
Published: August 2002

AbstractPurposeTo correlate intestinal contrast enhancement and wall thickening with the degree of inflammation in an experimental model of inflammatory bowel disease.Materials and MethodsInflammatory bowel disease was elicited in 39 New Zealand White rabbits by rectal instillation of 2,4,6‐trinitrobenzene sulphonic acid (TNBA). Magnetic resonance imaging (MRI) was used to determine bowel wall thickness and intestinal contrast enhancement after the administration of 0.1 mmol/kg of gadodiamide intravenously. MR measurements were compared with the complete histopathologic analysis.ResultsMR measurements of bowel wall thickness correlated well with histopathologic measurements in vitro (r = 0.85, P < 0.0001) and with histopathologic evidence of chronic inflammatory bowel disease (P < 0.02). Chronic inflammation was characterized by increased intestinal contrast enhancement (137 ± 25%) when compared to normal bowel (86 ± 7%, P = 0.04).ConclusionContrast‐enhanced MRI accurately reflects inflammatory bowel disease in the rabbit model. J. Magn. Reson. Imaging 2002;15:165–173. © 2002 Wiley‐Liss, Inc.
Implications of bulk motion for diffusion‐weighted imaging experiments: Effects, mechanisms, and solutions
Authors: Norris David G. 
Published: August 2002

AbstractThis review article describes the effect of bulk motion on diffusion‐weighted imaging experiments, and examines methods for correcting the resulting artifacts. The emphasis throughout the article is on two‐dimensional imaging of the brain. The effects of translational and rotational motion on the MR signal are described, and the literature concerning pulsatile brain motion is examined. Methods for ameliorating motion effects are divided into three generic categories. The first is methods that should be intrinsically insensitive to macroscopic motion. These include motion‐compensated diffusion‐weighting schemes, single‐shot EPI, projection reconstruction, and line scanning. Of these, only single‐shot EPI and projection reconstruction methods can obtain high‐quality images without compromising on sensitivity. The second category of methods is those that can be made insensitive to bulk motion. The methods examined here are FLASH and RARE. It is shown that for both sequences motion insensitivity is in general attained only at the cost of a 50% reduction in sensitivity. The final set of methods examined are those that correct for motion, primarily navigator echoes. The properties and limitations of the navigator echo approach are presented, as are those of methods which attempt to correct the acquired data by minimizing image artifacts. The review concludes with a short summary in which the current status of diffusion imaging in the presence of bulk motion is examined. J. Magn. Reson. Imaging 2001;13:486–495. © 2001 Wiley‐Liss, Inc.
Uterine fibroid embolization: Assessment of treatment response using perfusion‐weighted extraslice spin tagging (EST) magnetic resonance imaging
Authors: Hagspiel Klaus D. , Matsumoto Alan H. , Berr Stuart S. 
Published: August 2002

AbstractIn this pilot study, we demonstrate the feasibility of using an arterial spin tagging technique, Extraslice Spin Tagging (EST), to assess tumor perfusion before and after uterine fibroid embolization (UFE) and correlate the changes in perfusion with fibroid size reduction. We followed two patient volunteers over a six‐month period. The perfusion‐weighted image intensity decreased immediately after UFE. The size of the tumor decreased by 14% immediately after UFE and continued to decrease over a six‐month period to 84%. The imaging methods presented allow for rapid measurement of tumor volume and the evaluation of perfusion of the tumor without the need for intravenous administration of gadolinium compounds. J. Magn. Reson. Imaging 2001;13:982–986. © 2001 Wiley‐Liss, Inc.
Functional evaluation with intravoxel incoherent motion echo‐planar MRI in irradiated salivary glands: A correlative study with salivary gland scintigraphy
Authors: Zhang Lin , Murata Yuji , Ishida Ryuji , Ohashi Isamu , Yoshimura Ryoich , Shibuya Hitoshi 
Published: August 2002

AbstractThe purpose of this study was to determine the relationship between the apparent diffusion coefficient (ADC) measured on intravoxel incoherent motion (IVIM) echo‐planar magnetic resonance imaging (MRI) and salivary gland function. Twenty‐one patients with head and neck malignancies underwent MRI and salivary gland scintigraphy before and after radiotherapy. Based on the scintigraphic results, each major salivary gland was classified into two groups (dysfunctional and functional) and ADCs measured on IVIM MRI were compared between the two groups. Furthermore, the relationship of ADC to scintigraphic parameters, maximum accumulation (MA), and the uptake ratio (UR), were analyzed. ADCs of the dysfunctional group decreased significantly after radiotherapy (P < .01), whereas those of the functional group showed no significant change. Furthermore, positive correlations were found between the ADC ratio and both MA (P < .005) and UR (P < .001). ADC measurement on IVIM echo‐planar MRI is a potentially useful means of evaluating salivary gland function. J. Magn. Reson. Imaging 2001;14: 223–229. © 2001 Wiley‐Liss, Inc.
Temporal dynamics of blood flow effects in half‐Fourier fast spin echo 1H magnetic resonance imaging of the human lungs
Authors: Knight‐Scott Jack , Keilholz‐George Shella D. , Mai Vu M. , Christopher John M. 
Published: August 2002

AbstractA cardiac‐triggered half‐Fourier single‐shot turbo spin echo (HASTE) technique is currently the method of choice for MR imaging of the lung parenchyma without the use of exogenous contrast agents. In this study, we specifically examined the effects of the cardiac cycle on the HASTE signal intensity of the lungs. Images were obtained from six healthy human volunteers at an end expiration breath‐hold using a HASTE sequence and a variable cardiac‐triggered delay time. Analysis of the data sets showed a 30% decrease in the lung signal intensity during systole, and a 15% decrease during mid‐diastole. These decreases correlate with phases of the cardiac cycle when the blood flow in the lungs is expected to be greatest. Misregistration artifacts, particularly from the pulmonary arteries and aorta, are worse during these periods of signal decrease. To minimize cardiac dependent signal losses, HASTE lung imaging should be performed after systole but before rapid filling of the ventricles.J. Magn. Reson. Imaging 2001;14:411–418. © 2001 Wiley‐Liss, Inc.
MRI of the foot and ankle: Prevalence and distribution of occult and palpable ganglia
Authors: Weishaupt Dominik , Schweitzer Mark E. , Morrison William B. , Haims Andrew H. , Wapner Keith , Kahn Mitchell 
Published: August 2002

AbstractThe purpose of this study was to evaluate the prevalence and anatomic distribution of occult and palpable ganglia of the foot and ankle as seen by MRI. Within a 7‐year period MRI of the ankle was performed on 2813 patients, and MRI of the foot on 2277 patients using a 1.5T magnet. In all, 167 ganglia in 155 patients were detected. MR images of these patients were reviewed retrospectively by two observers with regard to prevalence, imaging characteristics, and exact anatomic location of ganglia. Clinical findings and (when available) surgical reports were also reviewed. One hundred fifty‐seven ganglia in 145 patients were present on MR images of the ankle, and 10 ganglia in 10 patients on MR images of the foot, resulting in a prevalence of 5.6% (157/2813) in the ankle, and a prevalence of 0.4% (10/2277) in the foot. The most common location was the tarsal sinus or tarsal canal (57/167 ganglia [34.1%]). However, only four of these (7%) were palpable as a soft‐tissue mass. The second most common location was around the Lisfranc joint (23/167 [13.8%]), of which 11/23 [47.8%] were clinically palpable. Palpable ganglia were statistically larger in size than occult ganglia measured in any of three diameters (P = 0.01–0.002). In addition, ganglia of the foot and ankle represented 42% of all clinically suspected soft‐tissue masses. Ganglia in the foot and ankle are an infrequent finding on routine MRI of the foot and ankle. When they occur, these ganglia are most frequently located in the tarsal sinus and tarsal canal, where they are occult to clinical palpation. If ganglia are clinically palpable, they are most commonly located around the Lisfranc joint. In addition, palpable ganglia are larger than occult ganglia. J. Magn. Reson. Imaging 2001;14:464–471. © 2001 Wiley‐Liss, Inc.
Detectability of pulmonary perfusion defect and influence of breath holding on contrast‐enhanced thick‐slice 2D and on 3D MR pulmonary perfusion images
Authors: Matsuoka Shin , Uchiyama Katsuhiro , Shima Hideki , Terakoshi Hiroaki , Nojiri Yoko , Oishi Sonomi , Ogata Hitoshi 
Published: August 2002

AbstractThe present study assesses the detectability of perfusion defect and the influence of breathhold on pulmonary magnetic resonance (MR) perfusion imaging using contrast‐enhanced thick‐slice two‐dimensional (2D) fast gradient‐echo sequence compared with three‐dimensional (3D) fast spoiled gradient‐recalled sequence. Dynamic studies were performed in 16 patients. MR perfusion images were interpreted by two independent observers using perfusion scintigraphy as the reference standard. The patients were divided into two groups according to the duration of holding the breath measured during MR imaging. The sensitivity and specificity of 2D MR perfusion imaging in detecting perfusion defects were 93% and 94%, respectively, while those of 3D MR perfusion imaging were 89% and 85%, respectively. The diagnostic accuracy of 2D MR perfusion imaging was significantly higher than that of 3D MR perfusion imaging (P < 0.05) among those who could not hold their breath. Therefore, 2D MR perfusion imaging offers promise for evaluating pulmonary perfusion even among patients who cannot hold their breath. J. Magn. Reson. Imaging 2001;14:580–585. © 2001 Wiley‐Liss, Inc.
Hepatitis B virus DNA in serum of healthy black African adults positive for hepatitis B surface antibody alone: possible association with recombination between genotypes A and D
Authors: Owiredu William K.B.A , Kramvis Anna , Kew Michael C. 
Published: August 2002

AbstractIn some patients with chronic liver disease induced by hepatitis B virus, viral DNA is known to persist in low concentration in serum after seroconversion to hepatitis B surface antibody‐positivity. This phenomenon has, however, not been documented in asymptomatic black African carriers of hepatitis B virus. Using nested amplification by the polymerase chain reaction, we detected low concentrations of hepatitis B virus DNA in the serum of 6 of 23 (26%) healthy black African adults with normal liver function and with hepatitis B virus surface antibody as the only serological marker of the virus. This finding offers one explanation for the earlier observation of integrated hepatitis B virus DNA in hepatocellular carcinomas in black Africans whose serum was positive for surface antibody alone. A number of genetic changes were found in the six isolates that might be responsible for evasion of the immune response and persistence of the virus. Isolated mutations were detected in the “a” determinant of the surface gene and in the encapsidation signal. In all five isolates sequenced in the core promoter, mutations were present in the upstream regulatory region. Recombination between genotypes A and D was present in three of the isolates, including both of those in which the entire genome was sequenced. This change in genotype also overlapped the amino end of the polymerase domain and may result in sufficiently low levels of replication to allow viral persistence. Topoisomerase 1 specific trinucleotides were concentrated in the vicinity of the recombination breakpoints. J. Med. Virol. 64:441–454, 2001. © 2001 Wiley‐Liss, Inc.
Recovery of adult oligodendrocytes is preceded by a “lag period” accompanied by upregulation of transcription factors expressed in developing young cells
Authors: Afshari Fatemah S. , Chu Annie K. , Sato‐Bigbee Carmen 
Published: August 2002

AbstractCell cultures prepared from oligodendrocytes directly obtained from adult rat brain are composed of mature cells that lose their cell processes and myelin membrane during their isolation and therefore represent a very useful model to investigate the factors that could stimulate their recovery. We have observed that mature oligodendrocytes isolated from adult animals remain as round cells that lack processes for the first 3–4 days in culture. At the end of this lag period, however, the majority of the adult oligodendrocytes show a remarkable recovery, rapidly growing complex and extensive cell processes. Interestingly, the end of this lag period is accompanied by a dramatic upregulation in the expression of thyroid hormone (T3) receptor (TR). The functional importance of this increase in TR levels is supported by the observation that the majority of the cells cultured in the presence of T3 show significantly more extensive and complex process outgrowth than the control cells in cultures lacking this hormone. In addition, this reactivation of the adult cells was also preceded by an increased expression of glucocorticoid receptor (GR) and cyclic AMP‐response element binding protein (CREB), two transcription factors that together with TR appear to play important roles in the control of neonatal oligodendrocyte development. Thus, it is possible to hypothesize that upregulation of these proteins may be part of the metabolic changes that occur during the lag period required for recovery of the adult oligodendrocytes. These observations raise the question of whether these transcription factors may play any significant role during remyelination after demyelinating lesions of adult CNS. © 2002 Wiley‐Liss, Inc.
Regulation of kynurenic acid synthesis in C6 glioma cells
Authors: Kocki Tomasz , Dolińska Monika , Dybel Anna , Urbańska Ewa M. , Turski Waldemar A. , Albrecht Jan 
Published: August 2002

AbstractStudies with brain slices have provided evidence that synthesis of kynurenic acid (KYNA) from kynurenine (KYN), which occurs in astrocytes, is modulated by changes in the ionic composition of the medium and the presence of depolarizing agents or the excitatory amino acid glutamate (Glu). The present study analyzed the effects of changes in incubation medium on KYNA synthesis in cultured C6 glioma cells. The synthesis was not affected by omission of Na+ and raising K+ concentration to 50 mM, conditions that in brain slices stimulate or inhibit KYNA formation, respectively. KYNA synthesis in C6 cells was inhibited by the absence of Ca2+, which contrasts with its Ca2+ independence in brain slices. Also, lack of Mg2+ and addition of a chloride channel blocker, 4‐acetamido‐4′‐isothiocyanatostilbene‐2,2′‐disulfonate (SITS), did not affect the synthesis. KYNA synthesis in C6 cells was dose dependently inhibited by Glu. The inhibitory effect of Glu was not affected by GDPβS, an antagonist of metabotropic Glu receptors, the receptor class prevailing in C6 cells, suggesting that Glu acted intracellularly. NH4Cl and veratridine decreased KYNA production, mirroring the effects noted in brain slices. KYNA synthesis was strongly reduced in the presence of leucine (Leu), and the uptake of [14C]Leu was inhibited by the KYNA precursor KYN, which points to Leu as a potential endogenous modulator of KYNA formation in CNS cells. © 2002 Wiley‐Liss, Inc.
Differential in vitro degradation of particular Fos family members expressed by kainic acid in nuclear and cytosolic fractions of murine hippocampus
Authors: Manabe Takayuki , Ogita Kiyokazu , Nakamichi Noritaka , Yoneda Yukio 
Published: August 2002

AbstractMice were injected with kainic acid (KA) at a convulsive dose, followed by homogenization of the hippocampus in the presence of different protease and phosphatase inhibitors, and subsequent preparation of nuclear and cytosolic fractions. An intraperitoneal injection of KA resulted in marked expression of particular Fos family members, including c‐Fos, Fra‐2, and Fos‐B, but not Fra‐1 proteins, in both fractions 2 to 18 h after administration. These fractions were individually incubated at 30°C for 1 to 18 h for determination of in vitro degradation. Similarly rapid degradation was seen with c‐Fos protein between nuclear fractions obtained 2 and 18 h after administration, while no significant degradation was found for c‐Fos protein in cytosolic fractions obtained 2 h after administration during incubation. By contrast, in vitro incubation led to rapid degradation of c‐Fos protein in cytosolic fractions obtained 18 h after administration. Degradation profiles were peculiar to each member protein in nuclear and cytosolic fractions obtained 2 and 18 h after administration. Dialysis prevented degradation of c‐Fos protein in nuclear fractions without markedly affecting that in cytosolic fractions in a manner independent of the time after administration. The addition of inhibitors for phosphatases, but not for proteases, accelerated the degradation of c‐Fos protein in nuclear fractions previously dialyzed. These results suggest that in vivo KA signals may modulate heterologous machineries responsible for breakdown of each Fos family member in a unique manner in nuclear fractions, rather than cytosolic fractions, of murine hippocampus. J. Neurosci. Res. 64:34–42, 2001. © 2001 Wiley‐Liss, Inc.
TrkA induces differentiation but not apoptosis in C6‐2B glioma cells
Authors: Pflug Beth R. , Colangelo Anna Maria , Tornatore Carlo , Mocchetti Italo 
Published: August 2002

AbstractNerve growth factor (NGF) binds to the TrkA tyrosine kinase and the p75 neurotrophin receptors. Depending upon which receptor is activated, NGF can induce differentiation or apoptosis. C6‐2B glioma cells express the p75 receptor, but NGF decreases their growth only when TrkA is introduced (C6trk). It is unclear, however, whether TrkA reduces C6‐2B cell growth by apoptosis or differentiation. To examine which mechanisms account for the anti‐proliferative effect of NGF in these cells, we first analyzed whether NGF causes apoptosis by flow cytometry, two‐site immunoassay and in situ TUNEL. None of these methods indicated that C6trk undergo apoptosis. Additional apoptotic markers, such as Bcl‐2, Bax, Bad, p53, caspase 3, and NF‐κB were also used. C6trk cells exhibited lower levels of Bcl‐2 compared with the parental C6 mock cells, but no changes in the levels of other apoptotic proteins. Moreover, NGF increased AP‐1 binding activity in C6trk cells, suggesting that NGF may induce differentiation. We then examined whether TrkA changes the glioma phenotype. In C6trk cells, but not in C6mock cells, NGF enhanced the levels of neuron‐specific enolase as well as the levels of A2B5 and 2′, 3′‐cyclic nucleotide 3′‐phosphodiesterase, markers for oligodendrocytes, without affecting the expression of other neuronal markers. Our data suggest that the antiproliferative properties of TrkA may rely on its ability to induce differentiation of C6 cells from undifferentiated glioma to oligodendrocytes. J. Neurosci. Res. 64:636–645, 2001. © 2001 Wiley‐Liss, Inc.