bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of gallbladder ejection fraction utilizing cholecystokinin‐stimulated magnetic resonance cholangiography and comparison with hepatobiliary scintigraphy
Authors: Vyas Pranav K. , Vesy Thomas L. , Konez Orhan , Ciavellara David P. , Hua Keidang , Gaisie Godfrey
Published: August 2002

Purpose

To evaluate the utility of magnetic resonance cholangiography (MRC) in estimation of gallbladder ejection fraction (GBEF) and to comparing this value to the conventional method, hepatobiliary scintigraphy (HBS).

Materials and Methods

Twenty‐one healthy volunteers were imaged on sequential weeks to determine GBEF using MRC and HBS. GBEF was calculated by HBS after infusion of 20 ng/kg of sincalide following injection of 111 Mbq of Tc 99m mebrofenin. For estimation by MRC, imaging of the gallbladder was performed before and after slow infusion of sincalide every 5 minutes, for a total of 60 minutes. Gallbladder imaging was performed using a heavily T2‐weighted 2D fast spin echo (FSE) sequence. Data was analyzed using a variance component analysis technique.

Results

Mean GBEF by HBS was 65.7%, with an SD of ±27.3%. Mean GBEF by MRC was 62.7%, with an SD of ± 20.4%. If minimum normal GBEF is set at 35%, two of the cases showed discordance, with HBS calculating an abnormally low average GBEF compared to MRC. Additionally, two cases showed abnormally low GBEF for both modalities. The coefficient of correlation between HBS and MRC was 0.72. Inter‐ and intraobserver variance is acceptable within the two modalities with <1.1% variation.

Conclusion

GBEF can be calculated with MRC, yielding similar values when a group of volunteers are considered. Further study with symptomatic patients is needed to determine the validity of this technique for clinical diagnosis. J. Magn. Reson. Imaging 2002;15:75–81. © 2002 Wiley–Liss, Inc.
Characterization of focal hepatic lesions with ferumoxides‐enhanced MR imaging: Utility of T1‐weighted spoiled gradient recalled echo images using different echo times
Authors: Kim Joo Hee , Kim Myeong‐Jin , Suh Sang Hyun , Chung Jae‐Joon , Yoo Hyung Sik , Lee Jong Tae
Published: August 2002

Purpose

To evaluate the different signal characteristics of focal hepatic lesions on ferumoxides‐enhanced MR imaging, including T1‐weighted spoiled gradient recalled echo (GRE) images using different echo times (TE) and T2‐ and T2*‐weighted images.

Materials and Methods

Ferumoxides‐enhanced MR imaging was performed using a 1.5‐T system in 46 patients who were referred for evaluation of known or suspected hepatic malignancies. One hundred and seven lesions (42 hepatocellular carcinomas [HCC], 40 metastases, 13 cysts, eight hemangiomas, three focal nodular hyperplasias [FNHs], and one cholangiocarcinoma) were evaluated. Postcontrast MR imaging included 1) T2‐weighted FSE; 2) T2*‐weighted GRE; 3) T1‐weighted spoiled GRE using moderate (TE = 4.2–4.4 msec) TE; and 4) minimum (TE = 1.8–2.1 msec) TE. Signal intensities of the focal lesions were rated by two radiologists in conference as follows: hypointense, isointense or invisible, hyperintense, and markedly hyperintense. Lesion‐to‐liver contrast‐to‐noise ratio (C/N) was measured by one radiologist for a quantitative assessment.

Results

On ferumoxides‐enhanced FSE images, 92% of cysts were “markedly hyperintense” and most of the other lesions were “hyperintense”, and the mean C/N of cysts was significantly higher than that of other focal lesions. T2*‐weighted GRE images showed most lesions with similar hyperintensities and the mean C/N was not significantly different between any two types of lesion. T1‐weighted GRE images using moderate TE showed all FNHsand hemangiomas, 29 (69%) HCCs and eight (20%) metastases as “hyperintense”. On T1‐weighted GRE images using minimum TE, however, all HCCs and metastasis except one were iso‐ or hypointense, while all of the FNHs and hemangiomas were hyperintense. Ring enhancement was highly suggestive of malignant lesions, and was more commonly seen on the minimum TE images than on the moderate TE images.

Conclusion

Addition of T1‐weighted GRE images using minimum and moderate TE is helpful for characterizing focal lesions in ferumoxides‐enhanced MR imaging. J. Magn. Reson. Imaging 2002;15:573–583. © 2002 Wiley‐Liss, Inc.
Improved multi‐station peripheral MR angiography with a dedicated vascular coil
Authors: Goyen Mathias , Ruehm Stefan G. , Barkhausen Jörg , Kröger Knut , Ladd Mark E. , Truemmler Karl‐Heinz , Bosk Silke , Requardt Martin , Reykowski Arne , Debatin Jörg F.
Published: August 2002

Delineation of small branch vessels can be crucial for assessing the peripheral arterial system of patients requiring surgical grafting. Thus signal‐to‐noise needs to be maximized. We evaluated the performance of a dedicated peripheral vascular coil in four subjects by comparing it to the body coil using DSA as the standard of reference. SNR and CNR values of the dedicated peripheral coil exceeded those obtained with the body coil by a mean of 398%, thus permitting improved delineation of the infrapopliteal arterial morphology. J. Magn. Reson. Imaging 2001;13:475–480. © 2001 Wiley‐Liss, Inc.
Analysis of contrast‐enhanced dynamic MR images of the lung
Authors: Torheim Geir , Amundsen Tore , Rinck Peter A. , Haraldseth Olav , Sebastiani Giovanni
Published: August 2002

Recent studies have demonstrated the potential of dynamic contrast‐enhanced magnetic resonance imaging (MRI) describing pulmonary perfusion. However, breathing motion, susceptibility artifacts, and a low signal‐to‐noise ratio (SNR) make automatic pixel‐by‐pixel analysis difficult. In the present work, we propose a novel method to compensate for breathing motion. In order to test the feasibility of this method, we enrolled 53 patients with pulmonary embolism (N = 24), chronic obstructive pulmonary disease (COPD) (N = 14), and acute pneumonia (N = 15). A crucial part of the method, an automatic diaphragm detection algorithm, was evaluated in all 53 patients by two independent observers. The accuracy of the method to detect the diaphragm showed a success rate of 92%. Furthermore, a Bayesian noise reduction technique was implemented and tested. This technique significantly reduced the noise level without removing important clinical information. In conclusion, the combination of a motion correction method and a Bayesian noise reduction method offered a rapid, semiautomatic pixel‐by‐pixel analysis of the lungs with great potential for research and clinical use. J. Magn. Reson. Imaging 2001;13:577–587. © 2001 Wiley‐Liss, Inc.
MR‐guided biopsy of musculoskeletal lesions in a low‐field system
Authors: Koenig Claudius W. , Duda Stephan H. , Truebenbach Jochen , Schott Ulrich G. , Maurer Franz , Claussen Claus D. , Pereira Philippe L.
Published: August 2002

Thirty magnetic resonance (MR)‐guided biopsies were obtained from 20 skeletal and 10 soft‐tissue lesions in 31 patients using an open 0.2 T MR system equipped with interventional accessories. The results from aspiration (N = 3), core biopsy (N = 15), and transcortical trephine biopsy (N = 12) were evaluated for accuracy and clinical efficacy. Specimens were successfully obtained from 29 patients. Results were clinically effective in 23 patients, rated definitive in 16, nonconclusive in 9, and unspecific in 2 patients. A false diagnosis due to sampling error occurred in 2 patients, and biopsy sampling was impossible in one case. The best diagnostic yield was achieved from nontranscortical biopsies of osteolytic or soft‐tissue masses. Results from transcortical biopsies were less specific due to the predominance of benign lesions. MR fluoroscopy for needle guidance was applied in 13 patients. Complete needle placement inside the magnet could be performed in 16 patients. MR‐guided biopsy using an open low‐field MR imager is feasible and clinically effective and will become a valuable tool in the management of musculoskeletal lesions. J. Magn. Reson. Imaging 2001;13:761–768. © 2001 Wiley‐Liss, Inc.
MRI: A role in clinical trials
Authors: Julian Thomas B.
Published: August 2002

The diagnosis and treatment of breast cancer has evolved significantly over the last 20 years. Breast‐conserving therapy is replacing the Halstedian concept of “en bloc” resection. Difficulties in detection, pre‐ and postoperative planning and follow up continue to challenge the clinician. Women at high risk present a significant clinical dilemma. MRI technology in many of these areas is providing more information about detection, tumor size, extent, and response to treatment. The careful and thoughtful inclusion of MRI in clinical trials may help continue the advancement of breast cancer care. J. Magn. Reson. Imaging 2001;13:837–841. © 2001 Wiley‐Liss, Inc.
Anatomy and physiology of the female pelvis: MR imaging revisited
Authors: Togashi Kaori , Nakai Asako , Sugimura Kazuro
Published: August 2002

This article reviews the normal anatomy of the female pelvis and focuses on uterine physiology, presenting the kinematics of the uterus that can be identified on ultra‐fast MR imaging. It also discusses the many facets of the junctional zone on MR imaging. Ultra‐fast MR imaging seems to be a powerful tool for evaluating normal anatomy, physiology, and pathology of the uterus. J. Magn. Reson. Imaging 2001;13:842–849. © 2001 Wiley‐Liss, Inc.
Improving the detectability of focal liver lesions on T2‐weighted MR images: Ultrafast breath‐hold or respiratory‐triggered thin‐section MRI?
Authors: Pauleit Dirk , Textor Jochen , Bachmann Reinald , Conrad Rudolf , Flacke Sebastian , Kreft Burkhard , Schild Hans
Published: August 2002

The purpose of this study was to determine whether a respiratory‐triggered (RT) T2‐weighted turbo spin‐echo (TSE) sequence with thin section can improve the detectability of focal liver lesions compared to a breath‐hold (BH) T2‐weighted TSE sequence. In 25 patients an RT TSE with 8‐mm sections (8‐TSE RT) and 5‐mm sections (5‐TSE RT) and a BH TSE sequence with 8‐mm sections (8‐TSE BH) were performed. Forty‐one focal liver lesions (mean: 1.8 ± 1.2 cm; 14 lesions ≤1 cm; 27 lesions >1 cm) were evaluated. The 5‐TSE RT was significantly better in lesion detection compared to the 8‐TSE BH sequence for all sizes of lesions (40/41 vs. 33/41; P = 0.014). For lesions >1 cm no relevant differences in the detection rate of the sequences were found (8‐TSE RT, 26/27; 5‐TSE RT, 26/27; 8‐TSE BH, 25/27), for lesions ≤1 cm the 5‐TSE RT provided significantly better sensitivity than the 8‐TSE BH (14/14 vs. 8/14, P = 0.015). The results of this study suggest that lesion detection could be significantly improved by using an RT TSE sequence with thin sections compared with a BH TSE sequence. J. Magn. Reson. Imaging 2001;14:128–133. © 2001 Wiley‐Liss, Inc.
Capsaicin as a source for painful stimulation in functional MRI
Authors: Malisza Krisztina L. , Docherty John C.
Published: August 2002

Functional magnetic resonance imaging (fMRI) was used to examine the brain processing of capsaicin‐induced painful stimulation in the α‐chloralose anesthetized rat. Experiments were performed on a 9.4‐T magnet (Magnex, UK) with Avance console (Bruker, Germany) using a surface coil tuned to 400.5 MHz centred over the rat forebrain. Gradient‐echo images of two slices, with an echo time of 25 msec, repetition time of 70 msec, and 50 repetitions, were acquired per experiment. These images were analyzed using a fuzzy cluster analysis technique (EvIdent™). Activation of areas of the brain known to be associated with the processing of pain, namely the anterior cingulate (bilateral), frontal cortex (bilateral), and sensory motor cortex (contralateral), was found in all animals (N = 6) following injection of 25μL of capsaicin (128μg/mL in 7.5% dimethylsulfoxide [DMSO]) into the dorsal forepaw. It is possible to reproduce the pain response in a given animal several times throughout the course of an experiment, provided that sufficient time is allowed between capsaicin injections. This acute phase of capsaicin‐induced pain involving stimulation of C polymodal nociceptors was examined by functional imaging. There was a substantial initial increase in activation in regions of the brain associated with pain and there was a trend towards increasing activation with repeated stimulations. Treatment with morphine (3 mg/kg, intravenously) was found to substantially reduce, if not completely eliminate, the areas of functional activation associated with physiologic pain (anterior cingulate and frontal cortex) after C‐nociceptor stimulation with capsaicin (N = 6). FMRI involving capsaicin‐induced painful stimulation could prove to be an effective tool for the study of novel analgesics and the central nervous system processing of pain. J. Magn. Reson. Imaging 2001;14:341–347. © 2001 Wiley‐Liss, Inc.
Adaptive vessel tracking: Automated computation of vessel trajectories for improved efficiency in 2D coronary MR angiography
Authors: Saranathan Manojkumar , Ho Vincent B. , Hood Maureen N. , Foo Thomas K. F. , Hardy Christopher J.
Published: August 2002

A new method was investigated for improving the efficiency of ECG‐gated coronary magnetic resonance angiography (CMRA) by accurate, automated tracking of the vessel motion over the cardiac cycle. Vessel tracking was implemented on a spiral gradient‐echo pulse sequence with sub‐millimeter in‐plane spatial resolution as well as high image signal to noise ratio. Breath hold 2D CMRA was performed in 18 healthy adult subjects (mean age 46 ± 14 years). Imaging efficiency, defined as the percentage of the slices where more than 30 mm of the vessel is visualized, was computed in multi‐slice spiral scans with and without vessel tracking. There was a significant improvement in the efficiency of the vessel tracking sequence compared to the multi‐slice sequence (56% vs. 32%, P < 0.001). The imaging efficiency increased further when the true motion of the coronary arteries (determined using a cross correlation algorithm) was used for vessel tracking as opposed to a linear model for motion (71% vs. 57%, P < 0.05). The motion of the coronary arteries was generally found to be linear during the systolic phase and nonlinear during the diastolic phase. The use of subject‐tailored, automated tracking of vessel positions resulted in improved efficiency of coronary artery illustration on breath held 2D CMRA. J. Magn. Reson. Imaging 2001;14:368–373. Published 2001 Wiley‐Liss, Inc.
Proton transfer via strained transition states in the elimination of alcohols from MH+ ions of stereoisomeric diethers and hydroxy esters upon chemical ionization and collision‐induced dissociation
Authors: Denekamp Chagit , Mandelbaum Asher
Published: August 2002

The isobutane chemical ionization (CI) mass spectra of cis‐ and trans‐1,4‐di(alkoxymethyl)cyclohexanes, with a tertiary alkoxy group ROH and a primary group R′OH, are identical, and they exhibit exclusive elimination of the alcohol ROH originating from the tertiary alkoxyl. The high abundance of the [MH − ROH]+ ion and the absence of [MH − R′OH]+ and MH+ ions is unexpected in the case of trans‐diethers, and it suggests proton transfer from the primary alkoxyl OR′ to the tertiary OR group prior to the elimination of ROH, despite the large distance between them in the trans configuration. Various isomerization pathways were explored in order to account for the similar behavior of the cis‐ and trans‐isomers upon chemical ionization. The results show that the hydrogens at positions 1 and 4 are not involved in the elimination of ROH. Methyl substitution at positions 1 and 4 leads to the competitive elimination of ROH and R′OH, indicating suppression of the proton transfer. Methyl substitution at position 1 adjacent to the primary alkoxy group has a minor effect on the chemical ionization behavior of the diethers. On the other hand, methyl substitution at position 4, adjacent to the tertiary alkoxy group, suppresses the proton transfer, (i.e. both [MH − ROH]+ and [MH − R′OH]+ are abundant in the CI mass spectra of the trans‐isomers), indicating an effect of steric hindrance. The results suggest that direct proton transfer via a strained proton‐bound transition‐state occurs, and methyl substitution at positions 1 and 4 can affect the relative stability of the transition‐state structures involved. Similar behavior has been observed in the CI and collision‐induced dissociation spectra of 1,4‐hydroxy ester cyclohexanes. Copyright © 2001 John Wiley & Sons, Ltd.
Reaction monitoring of platinum(II) complex–5′‐guanosine monophosphate adduct formation by ion exchange liquid chromatography/electrospray ionization mass spectrometry
Authors: Zöllner Peter , Zenker Andrea , Galanski Mathea Sophia , Keppler Bernhard K. , Lindner Wolfgang
Published: August 2002

Cisplatin and four structurally related platinum(II) complexes were incubated with guanosine 5′‐monophosphate (5′‐GMP) in water at 37 °C. The adduct formation reactions were monitored with cation‐ and anion‐exchange liquid chromatography/electrospray ionization mass spectrometry. In addition to mono‐ and bis‐adducts of guanosine 5′‐monophosphate with the platinum(II) complexes, other molecular species, presumably with a binuclear structure (two platinum(II) centres), were detected in the reaction mixtures, which have not been reported previously, indicating an unexpected complexity of adduct formation. Anion‐exchange chromatography revealed the presence of isomers of two complexes which presumably result from the restricted rotation at the platinum— N‐7 (5′‐GMP) bonds. All reaction products were characterized in both the positive and negative ion modes. Furthermore, preliminary kinetics and half‐times of complex formation were investigated for cisplatin and two other platinum(II) complexes, monitoring the relative concentrations of free 5′‐GMP and of mono‐ and bis‐GMP adducts as a function of time (250 h) using an internal standard protocol with thymidine 5′‐monophosphate. Copyright © 2001 John Wiley & Sons, Ltd.
A fast atom bombardment and matrix‐assisted laser desorption/ionization mass spectrometry study of doubly charged porphyrins
Authors: Schäfer M. , Budzikiewicz H.
Published: August 2002

In this mass spectrometry (MS) study of doubly charged porphyrin salts, fast atom bombardment (FAB) and matrix‐assisted laser desorption/ionization (MALDI) MS techniques are utilized to examine several unique ionic species. The predominant transformation of preformed doubly charged ions in the desorption/ionization mechanism of FAB and MALDI is the result of deprotonation reactions to form singly charged ions of the type [M2+ − H+]+ and of one‐electron reductions to form radical cations [M2+ + e−]+·. The dependence of this phenomenon and the formation of a number of additional ionic species on the different matrices and the FAB‐matrix additive benzoquinone is examined. The significant analogous behavior of doubly charged porphyrins in FAB‐ and MALDI‐MS leads to the conclusion that one‐electron reductions are of distinct relevance in the desorption/ionization mechanism of MALDI. Copyright © 2001 John Wiley & Sons, Ltd.
In‐gel deglycosylation of sodiumdodecyl sulfate polyacrylamide gel electrophoresis‐separated glycoproteins for carbohydrate estimation by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Kilz S. , Budzikiewicz H. , Waffenschmidt S.
Published: August 2002

Mass determination by mass spectrometric methods (electrospray ionization mass spectrometry (ESI‐MS), matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS)) of sodiumdodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE)‐separated proteins is a well known procedure and reliable protocols are available. In our efforts to use the established methods to determine the molecular mass of the disulfide brigded, heterodimeric glycoprotein GP3 and to determine the carbohydrate content of each protein subunit we developed an in‐gel chemical deglycosylation method. For this purpose we established experimental conditions that allow maximum extraction of the high molecular mass protein subunits and developed a routine method to apply the HF–pyridine deglycosylation protocol to proteins isolated from polyacrylamide gel pieces. The novel protocol and extraction procedure described can be used to analyze O‐glycosylated proteins up to 150 kDa after SDS‐PAGE separation. Copyright © 2002 John Wiley & Sons, Ltd.
Quantitative gas chromatographic/mass spectrometric analysis of morphine glucuronides in human plasma by negative ion chemical ionization mass spectrometry
Authors: Leis Hans Jörg , Fauler Günter , Raspotnig Günther , Windischhofer Werner
Published: August 2002

A sensitive and specific method for the determination of morphine glucuronides in human plasma is presented. Morphine glucuronides, namely morphine‐6‐glucuronide (M6G) and morphine‐3‐glucuronide (M3G), were extracted from plasma by solid‐phase extraction on C18 cartridges at pH 9.3 and derivatized to their pentafluorobenzyl ester trimethylsilyl ether derivatives. The compounds were measured by gas chromatography/negative ion chemical ionization mass spectrometry without any further purification. Using this detection mode, a diagnostic useful fragment ion at m/z 748 was obtained at high relative abundance for both target compounds. [2H3]‐labeled morphine glucuronides were used as internal standards. Calibration graphs were calculated by polynomial fit within a range of 10–1280 and 15–1920 nmol l−1 for the 6‐ and 3‐glucuronide, respectively. At the limit of quantitation (LOQ), the inter‐assay precision was 2.21% (M3G) and 2.23% (M6G) and the GC/MS assay variability was 1.8% (M3G) and 0.9% (M6G). The accuracy at the LOQ showed deviations of +4.92% (M3G) and +1.5% (M6G). The sample recovery after solid‐phase extraction was 84.7% for both M3G and M6G. The method is rugged, rapid and robust and has been applied to the batch analysis of morphine glucuronides during pharmacokinetic profiling of the drugs. Copyright © 2002 John Wiley & Sons, Ltd.
Structure, energetics and reactivity of ternary complexes of amino acids with Cu(II) and 2,2′‐bipyridine by density functional theory. A combination of radical‐induced and spin‐remote fragmentations
Authors: Seymour Jennifer L. , Tureček František
Published: August 2002

The structures, electron distributions and dissociation energies of gas‐phase ternary complexes of Cu(II) with 2,2′‐bipyridine and leucine, isoleucine and lysine were addressed by density functional theory using the hybrid B3LYP functional, effective core potentials and the 6–31 + G(d) and LANL2DZ basis sets. The calculations confirm the previously suggested structures, in which amino acid carboxylates coordinate to the Cu atom by the carboxylate and α‐amino groups in square‐planar complexes. The dissociation energies for consecutive eliminations of CO2 and alkyl radicals from isomeric singly charged complexes of leucine and isoleucine correlate with the ion relative abundances observed in collisionally activated dissociation mass spectra. Doubly charged lysine complexes show extremely low dissociation energies that are consistent with the <1 eV center‐of‐mass collision energies that were used in previous CAD studies. The calculated charge and spin densities point to radical‐induced dissociations of singly charged complexes with an open‐electron shell. In contrast, the unpaired electron is virtually inert in doubly charged, open‐shell complexes that undergo charge‐induced, spin‐remote dissociations in the amino acid residues. Copyright © 2002 John Wiley & Sons, Ltd.
Mosquito cells bind and replicate hepatitis C virus
Authors: Germi Raphaële , Crance Jean‐Marc , Garin Daniel , Guimet Josette , Thelu Marie‐Ange , Jouan Alain , Zarski Jean‐Pierre , Drouet Emmanuel
Published: August 2002

Several studies have demonstrated some hepatitis C virus (HCV) replication in lymphocyte and hepatocyte cell lines such as in African green monkey Vero cells. The aim of the present study was to select other cell lines able to bind and replicate HCV. Human hepatoma PLC/PRF/5 cells, human lymphoma Namalwa cells, Vero and mosquito AP61 cells were inoculated with HCV‐positive plasma, washed six times and examined for the presence of the viral genome at different times post infection, using an RT‐PCR method. Binding of HCV to cells was estimated by HCV RNA detection in cells 2 hr after inoculation and in the last wash of these cells. Successive virus passages in cells were carried out. All the cells studied were able to bind HCV but only AP61 and Vero cells provided evidence of replication and production of infectious virus: virus RNA was detected during 28 days post‐infection in four successive virus passages. CD81 molecules, a putative HCV receptor, were detected by cytofluorometric analysis. Vero cells express CD81 molecules whereas these molecules were not detected on AP61 cells. It is suggested that other receptors are involved in HCV binding to Vero and AP61 cells. J. Med. Virol. 64:6–12, 2001. © 2001 Wiley‐Liss, Inc.
Evaluation of hepatitis C antibody testing in saliva specimens collected by two different systems in comparison with HCV antibody and HCV rna in serum*
Authors: van Doornum G.J.J. , Lodder A. , Buimer M. , van Ameijden E.J.C. , Bruisten S.
Published: August 2002

Two different ELISA assays, the Ortho HCV 3.0 ELISA (Ortho Diagnostics Systems) and the Mono‐Lisa anti‐HCV Plus (Sanofi Diagnostics Pasteur) were evaluated for the detection of hepatitis C virus (HCV) antibody in saliva samples. Specimens were collected from 152 individuals who participated in a longitudinal cohort study on HIV infection, and who used illicit drugs. Saliva specimens were collected using two different systems: Salivette (Sarstedt) and Omni‐Sal (Saliva Diagnostic Systems). Saliva specimens were tested following modified protocols by both ELISAs, and the results were compared with serum specimens that were tested according to the instructions of the manufacturer. Serum samples of 102 (67%) participants were positive by both assays, and 50 persons were negative for HCV antibody. A total of 99 of the 102 serum specimens were confirmed as positive using Ortho Riba HCV 3.0 (Ortho Diagnostics System) and Deciscan HCV (Sanofi Diagnostics Pasteur), and 3 yielded discrepant results. As no cut‐off level is known for testing saliva samples by ELISA, 3 different levels were chosen: mean (M) + 1 standard deviation (SD), M + 2 SD, and M + 3 SD of the optical densities of saliva tests of the 50 HCV serum antibody negative persons. At a level of M + 1 SD and M + 2 SD the Salivette/Mono‐Lisa combination gave the greatest proportion of HCV antibody positive saliva specimens obtained from the 102 HCV serum antibody positive participants, 88% and 79%, respectively. Differences between the various collection systems and assay combinations were not significant statistically. In 76 of the 102 persons with HCV antibodies in serum, HCV RNA was detected in serum. Salivary presence of HCV RNA, however, could not be demonstrated. The results show that the assays compared are unsuitable for diagnostic use, but the sensitivities of the assays are acceptable for use in epidemiological studies. J. Med. Virol. 64:13–20, 2001. © 2001 Wiley‐Liss, Inc.
Antibodies raised to short synthetic peptides with sequences derived from HIV‐1 SF2 gp120 can both neutralize and enhance HIV‐1 SF13: A later variant isolated from the same host
Authors: Davis David , Trischmann Heike , Stephens D. Michael , Lachmann Peter J.
Published: August 2002

HIV‐1 SF13 emerged in a patient with immunity to HIV‐1 SF2. This study determined the effect of antibodies raised to HIV‐1 SF2 on the replication of the later variant. Antisera in rats were raised previously to a complete set of overlapping, synthetic 15mer peptides following the sequence of HIV‐1 SF2 gp120. These sera have now been used in neutralization and enhancement assays against viruses derived from molecular clones of both variants. The sets of peptides inducing neutralizing antibodies to the two variants overlap. Antibodies to the third variable region of HIV‐1 SF2 only neutralize the homologous virus whereas those to the second and fourth variable regions neutralize both variants. In contrast, the sets of major epitopes involved in enhancement do not overlap. Epitopes for both variants form two clusters when superimposed on the conformation of the conserved regions. To determine if antibodies with the potential to enhance or neutralize HIV‐1 SF2 change over time in infected individuals sera from chimpanzees were used because no material was still available from the original patient. Antibodies to HIV‐1 SF2 neutralizing epitopes and HIV‐1 SF13 enhancing epitopes were present in the circulation of chimpanzees infected with HIV‐1 SF2. Once antibodies to the neutralizing epitopes were induced they persisted whereas antibodies to the enhancing epitopes varied with time after infection. Conditions may therefore exist within individual hosts where not only neutralizing but also enhancing antibodies have the potential to contribute to the selection pressure operating on the circulating population of polymorphic variants. J. Med. Virol. 64:207–216, 2001. © 2001 Wiley‐Liss, Inc.
Differences between the quantitative antigenemia assay and the cobas amplicor monitor quantitative PCR assay for detecting CMV viraemia in bone marrow and solid organ transplant patients
Authors: Flexman James , Kay Ian , Fonte Rebecca , Herrmann Richard , Gabbay Eli , Palladino Silvano
Published: August 2002

The relationship between quantitative PCR (COBAS Amplicor CMV Monitor, Roche Diagnostics) and quantitative antigenemia (Monofluor pp65, Sanofi Diagnostics) was examined for monitoring CMV viraemia. A total of 469 specimens from immunocompromised haematology and solid organ transplant patients were tested by quantitative antigenemia and qualitative PCR. Quantitative PCR (QPCR) was performed on the 245 specimens in which CMV DNA was detected by qualitative PCR. To exclude any effect due to specific anti‐CMV treatment, analysis of antigenemia and QPCR results was only performed on the 164 of 245 specimens collected from patients not on ganciclovir or foscarnet treatment. Forty seven specimens had <400 CMV copies/mL and a negative antigen result, four specimens were antigen positive (all between 1 to 10 positive CMV cells/2 × 105 leucocytes) and had <400 CMV copies/mL. Fifty‐one specimens had a CMV viral load ≥400 copies/mL and a negative antigen result and 62 specimens had a CMV viral load ≥400 copies/mL and a positive antigen. The viral load was shown to be as high as 43,000 copies/mL in some patients with a negative antigen and occurred in non‐neutropenic patients. The correlation coefficient for antigen and QPCR results for specimens from bone marrow transplant patients, was 0.69 with an average CMV viral load of 3,200 copies/mL (SEM = 800) and an average antigen of nine positive CMV cells/2 × 105 leucocytes (SEM = 3). In the corresponding solid organ transplant group, the correlation coefficient for antigen and QPCR results was 0.71 with an average CMV viral load of 9,900 copies/mL (SEM = 2,100) and an average antigen of 26 positive CMV cells/2 × 105 leucocytes (SEM = 6). Both the average viral load and the average antigen result in specimens from solid organ transplant patients, were significantly higher than the average viral load and antigen result in the corresponding group of bone marrow transplant patients (Two‐Sample‐for‐Means z‐Test, P = 0.001 and P = 0.003, respectively). The differences in the kinetics of the two assays in monitoring CMV and their ability to predict CMV disease was also assessed in a sub‐group of patients. In conclusion, the two assays used in this study do not always show parallel changes in CMV viral load, but may be complementary for the diagnosis and management of CMV disease. The observation that non‐neutropenic patients can have a high viral load in plasma and a negative antigenemia has implications for laboratories using antigenemia alone to monitor patients for CMV disease. J. Med. Virol. 64:275–282, 2001. © 2001 Wiley‐Liss, Inc.
Genetic characterization of hypervariable region 1 in patients chronically infected with hepatitis C virus genotype 2
Authors: Fan Xiaofeng , Di Bisceglie Adrian M.
Published: August 2002

The hypervariable region 1 (HVR1) has been most reliably identified in the genome of HCV genotype 1 isolates and thought to possibly play a role in immune evasion and development of chronic infection. There are few studies, however, of other HCV genotypes to determine if they also have such a hypervariable region present, and it is unclear whether or not there is any genotype‐dependent difference in the genetic characteristics of HVR1. We determined the nucleotide sequence of 5′ end of E2/NS1 region of the HCV genome spanning HVR1 of multiple genotype 1 and 2 HCV isolates and carried out a detailed genetic analysis. Similarity plots identified two hypervariable regions within the genotype 2 sequences, a larger one corresponding to HVR1 as well as a smaller 27‐nucleotide region of hypervariability. The synonymous substitutions per synonymous site (ds) was greater than nonsynonymous substitutions per nonsynonymous site (dn) within genotype 1 group whereas dn and ds were similar in the genotype 2 group. Analysis of amino acid sequences revealed several conserved sites across genotype 1 and 2 (amino acid numbers 2,6, 20 and 26) and overall similar hydropathic profiles were found within two genotypes. Still, despite the hypervariability, the HVR1 showed a genotype‐specific phylogenetic clustering. Thus, HVR1 appears to be conserved between genotypes in keeping with it having an important survival function. Genotype 2 appears to have a greater rate of nonsynonymous substitutions within HVR1, suggesting a greater positive evolutionary pressure. J. Med. Virol. 64:325–333, 2001. © 2001 Wiley‐Liss, Inc.
Identification of a DNA encapsidation sequence for human polyomavirus pseudovirion formation
Authors: Ou Wei‐Chih , Hseu Tzong‐Hsiung , Wang Meilin , Chang Han , Chang Deching
Published: August 2002

Human polyomavirus is a naked capsid virus containing a closed circular double‐stranded DNA genome. The mechanism of DNA encapsidation for the viral progeny formation is not fully understood. In this study, DNA encapsidation domain of the major capsid protein, VP1, of the human polyomavirus JCV was investigated. When the first 12 amino acids were deleted, the E. coli expressed VP1 (ΔN12VP1) failed to encapsidate the host DNA although the integrity of the capsid‐like structure was maintained. In addition, capsid‐like particles of ΔN12VP1 did not package exogenous DNA in vitro, which is in contrast to that of the full‐length VP1 protein. These findings suggest that the N‐terminal of the first 12 amino acids of VP1 were responsible for DNA encapsidation. The importance of amino acids in the DNA encapsidation domain was determined further using site‐directed mutagenesis. All of the positively charged amino acids at the N‐terminal region of VP1 were essential for DNA encapsidation. The results indicate that the N‐terminal region of the human polyomavirus major capsid protein VP1 may be involved in viral genome encapsidation during progeny maturation. J. Med. Virol. 64:366–373, 2001. © 2001 Wiley‐Liss, Inc.
Longitudinal study of serum neutralization of HIV‐1 in infected plasma donors
Authors: Abelian Arthur V. , Saurya Shreesh , Ash Stephen , Karpas Abraham
Published: August 2002

Earlier studies provided suggestive evidence about the effectiveness of passive immunotherapy for AIDS patients using plasma donated by healthy HIV‐1 infected individuals and revealed beneficial effects of plasmapheresis for the immune system of the donors. In this study, anti‐HIV‐1 neutralizing activity in 31 healthy HIV‐1 infected donors of plasma participating in a passive immunotherapy study was investigated as a function of time. Average studied period was 33 months. Using the highly cytopathic HIV‐1 NDK strain and MOLT4 cells, it was shown by means of syncytia formation inhibition assay and polyclonal HIV‐1 antigen‐capture assay that viral neutralizing titers tend either to remain unchanged or increase over time. These findings support the notion that the immune system is not affected adversely in HIV‐1 infected plasma donors and lend further support to the feasibility of passive immunotherapy for AIDS patients. J. Med. Virol. 65:649–658, 2001. © 2001 Wiley‐Liss, Inc.
Detection of human group C rotaviruses in Nigeria and sequence analysis of their genes encoding VP4, VP6, and VP7 proteins
Authors: Adah Mohammed Ignatius , Wade Abel , Oseto Mitsuaki , Kuzuya Mitsutaka , Taniguchi Koki
Published: August 2002

In a survey on the etiology of acute gastroenteritis in infants and young children in Nigeria, group C human rotaviruses were detected in two of 112 rotavirus positive stool specimens collected between 1999 and 2000. The VP7, VP6, and VP4 genes of the two Nigerian human group C rotavirus strains (Jajeri and Moduganari) were sequenced in this study. Comparative sequence analysis with other published human group C rotaviruses showed that the genes encoding the three structural proteins were remarkably conserved in primary structure with few mutations. The VP4 and VP7 genes from the two Nigerian strains were related more closely to each other than to those of other published strains, and formed a separate cluster on the phylogenetic tree. In contrast, it was of note that VP6 gene of strain Moduganari was related more closely to the Brazilian strain Belem than to the other Nigerian strain Jajeri. This is the first report of identification of human group C rotavirus in Nigeria and constitutes the first sequence data of human group C rotaviruses in the African continent. J. Med. Virol. 66:269–275, 2002. © 2002 Wiley‐Liss, Inc.
Detection and identification of dengue‐1 virus in clinical samples by a nested‐PCR followed by restriction enzyme digestion of amplicons
Authors: De Paula Sérgio Oliveira , Lima Danielle Malta , da Fonseca Benedito Antônio Lopes
Published: August 2002

Dengue viruses cause a disease with clinical findings ranging from asymptomatic infections to severe manifestations, characterised by haemorrhage and shock and known as dengue haemorrhagic fever/dengue shock syndrome. Since this fever and syndrome usually results from sequential infections by distinct dengue serotypes, rapid detection and identification of dengue viruses circulating in endemic areas are important to implement control measures, and ultimately to avoid secondary infections that could result in dengue haemorrhagic fever/dengue shock syndrome. A nested‐PCR was developed followed by restriction enzyme (Kpn I) digestion of the amplicons to differentiate dengue‐1 from dengue‐2. Seventy‐five IgM‐containing samples collected from 2 to 17 days after the beginning of the symptoms were examined. These samples were submitted to nested‐PCR amplification, the amplicons were digested with Kpn I, and the results compared to virus isolation in C6/36 cells and to results obtained by the standard PCR. Out of 75 tested samples, virus was isolated from 2 (2.6%), 17 (22.7%) were positive by the regular PCR protocol, and 58 (77.3%) were positive by nested‐PCR. All of the amplicons digested by Kpn I identified dengue‐1 virus as the infecting strain. These results indicate that the nested‐PCR provided a high yield of dengue genome amplification even in the presence of IgM antibodies, and restriction enzyme digestion defined rapidly the circulating serotype. Therefore, the combination of these techniques may be useful to rapidly identify dengue viruses in countries where dengue‐1 and dengue‐2 circulates, and this approach can also be applied to the other two serotypes. J. Med. Virol. 66:529–534, 2002. © 2002 Wiley‐Liss, Inc.
Increased frequency of IFN‐γ‐producing peripheral CD8+ T cells with memory‐phenotype in patients with chronic hepatitis C
Authors: Murata Masayuki , Nabeshima Shigeki , Maeda Naoyasu , Nakashima Hisashi , Kashiwagi Seizaburo , Hayashi Jun
Published: August 2002

To identify the capacity for cytokine production and the phenotypic characteristics of peripheral CD8+ T cells in patients with chronic hepatitis C, 31 patients with chronic hepatitis C and 22 healthy controls were studied at the single cell level by three‐color flow cytometry. Whole blood was stained with surface CD8, intracellular interferon‐γ (IFN‐γ), and interleukin‐4 (IL‐4), surface CD8, CD28, and intracellular IFN‐γ after stimulation with PMA plus ionomycin, and then surface CD8, CD45RA, and CD28. IFN‐γ‐producing peripheral CD8+ T cells were found frequently in patients than in controls (P < 0.05), whereas IL‐4‐producing peripheral CD8+ T cells were not. Although the frequency of peripheral CD28+CD8+ and CD28−CD8+ T cells in patients was not different from that of controls, CD28+CD8+ T cells exceeded CD28−CD8+ T cells in the capacity for IFN‐γ‐production after mitogenic stimulation (P < 0.01). In a more detailed analysis of the CD28+CD8+ T cells, CD45RA−CD28+CD8+ T cells, defined phenotypically as memory cells, were found frequently in patients than in controls (P < 0.05). There were no significant correlations between the frequency of IFN‐γ‐producing peripheral CD8+ T cells and hepatitis C virus RNA level or serum alanine aminotransferase level in patients. These data suggest that functionally T cytotoxic type 1 and memory CD8+ T cells are predominant in the peripheral blood of chronic hepatitis C patients and that such activated CD8+ T cells are associated with liver damage. J. Med. Virol. 67:162–170, 2002. © 2002 Wiley‐Liss, Inc.
Expression and regulation of golli products of myelin basic protein gene during in vitro development of oligodendrocytes
Authors: Givogri Maria I. , Bongarzone Ernesto R. , Schonmann V. , Campagnoni Anthony T.
Published: August 2002

The myelin basic protein (MBP) gene produces two families of proteins, the classic MBPs, important for myelination of the CNS, and the golli proteins, whose biological role in oligodendrocytes (OLs) is still unknown. The goals of this work were to study the in vitro pattern of expression of the golli products during OL differentiation and to compare it with that of the classic MBP products of the gene. Mouse primary glial cultures were analyzed at the mRNA and protein levels with an array of techniques. We found that OLs express golli mRNA primarily during intermediate stages of differentiation, which was confirmed by immunocytochemical analysis. Golli expression was low in proliferating OL progenitors as well as in terminally mature OLs. Golli proteins were found associated with the OL cell soma and nuclei and, to a lesser extent, with the cellular processes. We also found that golli proteins are not targeted to myelin in vitro and in vivo, in contrast to the classic MBPs. Finally, we found that golli expression is regulated during OL development and can be manipulated by growth factors such as basic fibroblast growth factor, neurotrophin‐3, and retinoic acid. J. Neurosci. Res. 66:679–690, 2001. © 2001 Wiley‐Liss, Inc.
Potentiation of nuclear activator protein‐1 DNA binding following brief exposure to N‐methyl‐D‐aspartate in immature cultured rat hippocampal neurons
Authors: Hirai Takao , Kuramoto Nobuyuki , Maruyama Hiroko , Balcar Vladimir J. , Nakamura Yoichi , Yoneda Yukio
Published: August 2002

Similar potentiation was seen with the nuclear transcription factor activator preotein‐1 (AP1) binding in rat hippocampal neurons cultured for 3 and 9 DIV, when determined immediately after exposure to 500 μM N‐methyl‐D‐aspartate (NMDA) for 60–120 min. Growth‐associated protein‐43 was markedly expressed in hippocampal neurons cultured for 3–5 DIV, with a decline up to 9 DIV. In immature neurons cultured for 3 DIV, NMDA was effective in significantly potentiating AP1 binding even in the presence of Mg2+ with less potency than in the absence of Mg2+ when determined immediately after sustained exposure for 120 min. When determined 120 min after brief exposure for 5 min, by contrast, NMDA significantly potentiated AP1 binding at a range of 100–500 μM only in the absence of Mg2+ in immature neurons cultured for 3 DIV. At least 60 min was required for significant potentiation of AP1 binding as an interval between brief exposure and subsequent cell harvest. Dizocilpine abolished the potentiation determined 120 min after brief exposure to 500 μM NMDA, and both dantrolene and nifedipine were similarly effective in significantly preventing the potentiation at 10–50 μM. These results suggest that NMDA may potentiate AP1 binding following a sustained increase in intracellular free Ca2+ concentrations through influxes across NMDA‐operated and L‐type voltage‐sensitive Ca2+ channels, in addition to release from intracellular Ca2+ stores, in immature cultured rat hippocampal neurons. © 2002 Wiley‐Liss, Inc.
Detection of prolactin receptor mRNA in the corpus striatum and substantia nigra of the rat
Authors: Pi Xiujun , Voogt James L. , Grattan David R.
Published: August 2002

The observation of prolactin modulation of the nigrostriatal dopaminergic system suggests the expression of prolactin receptor in the corpus striatum or substantia nigra. The present study investigated expression of prolactin receptor mRNA in tissues microdissected from the corpus striatum and substantia nigra of the rat. By using reverse transcription PCR combined with Southern hybridization, the long form of prolactin receptor mRNA was detected in the substantia nigra, caudate putamen, globus pallidus, and ventral pallidum in ovariectomized rats, whereas the short form was not detectable in any of these areas. Estrogen had no effect on expression of the long‐form mRNA in the substantia nigra and corpus striatum. By using the RNase protection assay, the expression of both short and long forms of prolactin receptor mRNA was observed in the corpus striatum in ovariectomized rats. Again, levels of expression were not significantly altered by estrogen treatment. Both forms of prolactin receptor mRNA were clearly expressed in the choroid plexus and were up‐regulated by estrogen treatment. The expression of both forms of prolactin receptor mRNA in nigrostriatal areas may help to support the hypothesis that prolactin has direct actions on these brain regions. © 2002 Wiley‐Liss, Inc.
γ‐Aminobutyric acidA ρ receptor subunits in the developing rat hippocampus
Authors: Didelon Frédéric , Sciancalepore Marina , Savic' Natasa , Mladinic' Miranda , Bradbury Andrew , Cherubini Enrico
Published: August 2002

The RT‐PCR approach was used to estimate the expression of γ‐aminobutyric acid (GABA)A ρ receptor subunits in the hippocampus of neonatal and adult rats. All three ρ subunits were detected at postnatal day (P) 2, the ρ3 subunit being expressed at an extremely low level. The ρ1 and ρ2 products appeared to be developmentally regulated; they were found to be more pronounced in adulthood. In another set of experiments, to correlate gene expression with receptor function, GABAA ρ subunit mRNAs were detected with single‐cell RT‐PCR in CA3 pyramidal cells (from P3–P4 hippocampal slices), previously characterized with electrophysiological experiments for their bicuculline‐sensitive or ‐insensitive responses to GABA. In 6 of 19 cells (31%), pressure application of GABA evoked at –70 mV inward currents that persisted in the presence of 100 μM bicuculline (314 ± 129 pA). RT‐PCR performed in two of these neurons revealed the presence of ρ1 and ρ2 subunits, the latter being present with the α2 subunit. A ρ2 subunit was also found in 1 neuron (among 9) exhibiting a response to GABA, which was completely abolished by bicuculline. This might be due to the lack of putative accessory GABAA subunits that can coassemble with ρ2 to make functional receptors. Similar experiments from 10 P15 CA3 pyramidal cells failed to reveal any ρ1–3 transcripts. However, these neurons abundantly express α3 subunits. It is likely that in CA3 pyramidal cells of neonatal and adult hippocampus GABAA ρ subunits are present but at very low levels of expression. © 2002 Wiley‐Liss, Inc.