bluuebunny/crossref_metadata_2025 huggingface dataset:
Immortalization of human WI38 cells is associated with differential activation of the c‐myc origins
Authors: Tao Liang , Dong Zhifeng , Zannis‐Hadjopoulos Maria , Price Gerald B.
Published: August 2002

To study the possible relationships between origin activities and cellular processes leading to malignancy, we used an isogenic system of human embryo lung fibroblast cells WI38 and a SV40‐transformed variant, WI38 VA13 2RA (WI38(SV40)). We found that the activities of all initiation sites at the c‐myc locus were approximately two‐fold as high in WI38(SV40) cells as in WI38 cells. Thus, higher initiation frequency of origins at certain loci is induced with cell immortalization, one of the steps in the multi‐step process leading to malignancy. We measured the activities of the four c‐myc promoters P0, P1, P2, and P3 with nuclear runon assay in the two cell lines in order to detect potential individual promoter changes that may be also associated with immortalization by SV40 virus. The results show that the activities of the promoters P0, P1, and P3 did not significantly change, but the activity of the major promoter P2 in WI38(SV40) cells was about 7.5‐ to 8.0‐fold as high as that in WI38 cells. The increased activity of promoter P2, although ∼600 bp downstream of one of the major DNA replication initiation sites, had no preferential influence on the major sites of origin activity. Since the distribution of nascent strand abundance was not significantly altered, binding of transcription factors does not seem to facilitate the assembly of pre‐replication complex (pre‐RC) or otherwise preferentially alter the activities of the DNA replication proteins at this major initiation site. J. Cell. Biochem. 82:522–534, 2001. © 2001 Wiley‐Liss, Inc.
Low‐density caveolae‐like membrane from Xenopus laevis oocytes is enriched in Ras
Authors: Sadler Susan E.
Published: August 2002

Detergent‐free discontinuous sucrose density gradient centrifugation was used to resolve low‐ and high‐density membrane fractions from Xenopus laevis oocytes. Compared to high‐density membrane, low‐density oocyte membrane is enriched two‐fold in cholesterol and highly enriched in ganglioside GM1. Protein immunoblotting of membrane fractions from whole cells with polyclonal anti‐human caveolin antibody detected multiple bands, including a distinctive triad with apparent molecular weights of 21, 33, and 48 kDa. To more clearly determine which of these caveolin‐like protein(s) is associated with the oocyte plasma membrane, microdissection was used to separate external membrane (cortical preparations containing plasma membrane) from intracellular membrane. Cortical membrane preparations displayed a single 21‐kDa caveolin‐like protein in low‐density membrane. Internal oocyte membrane displayed the higher molecular weight bands of 33 and 48 kDa and a lesser amount of the 21‐kDa protein in low‐density membrane fractions. Monoclonal anti‐human Ras antibody detected a single 23‐kDa immunoblot band that is enriched an average of eight‐fold in low‐density membrane fractions prepared from whole cells. This is the first report of caveolin‐associated, low‐density membrane in amphibian oocytes, and is consistent with a role for caveolin and caveolae‐like microdomains in oocyte signal transduction. © 2001 Wiley‐Liss, Inc.
Molecular cloning and characterization of a RING‐H2 finger protein, ANAPC11, the human homolog of yeast Apc11p*
Authors: Chan Anna H. , Lee Simon M.Y. , Chim Stephen S. , Kok Louis D.S. , Waye Mary M.Y. , Lee Cheuk‐Yu , Fung Kwok‐Pui , Tsui Stephen K.W.
Published: August 2002

Yeast Apc11p together with Rbx1 and Roc2/SAG define a new class of RING‐H2 fingers in a superfamily of E3 ubiquitin ligases. The human homolog of Apc11p, ANAPC11 was identified during a large‐scale partial sequencing of a human liver cancer cDNA library and partial characterization was performed. This 514 bp full‐length cDNA has a predicted open reading frame (ORF) encoding 84 amino acids. The ORF codes for ANAPC11, the human anaphase promoting complex subunit 11 (yeast APC11 homolog), which possesses a RING‐H2 finger motif and exhibits sequence similarity to subunits of E3 ubiquitin ligase complexes. In Northern blot hybridization with poly(A) RNA of various human tissues using radio‐labelled ANAPC11 cDNA probe, we found strong signals detected in skeletal muscle and heart; moderate signals detected in brain, kidney, and liver; and detectable but low signals in colon, thymus, spleen, small intestine, placenta, lung, and peripheral blood leukocyte. The ANAPC11 gene is located at the human chromosome 17q25. ANAPC11 is distributed diffusely in the cytoplasm and nucleus with discrete accumulation in granular structures in all the cell lines (AML 12, HepG2, and C2C12) transfected. Expression level of ANAPC11 is found higher in certain types of cancer determined in the RNA dot blot experiment. J. Cell. Biochem. 83: 249–258, 2001. © 2001 Wiley‐Liss, Inc.
Putative basal lateral membrane receptors for 24,25‐dihydroxyvitamin D3 in carp and Atlantic cod enterocytes: Characterization of binding and effects on intracellular calcium regulation
Authors: Larsson Dennis , Nemere Ilka , Sundell Kristina
Published: August 2002

The vitamin D metabolite, 24R,25‐dihydroxyvitamin D3 (24R,25(OH)2D3), was tested for its ability to specifically bind to basal lateral membranes isolated from intestinal epithelium of Atlantic cod (a seawater fish), carp (a freshwater fish), and chicken. Specific saturable binding was demonstrated in membranes from all three species. Membranes from Atlantic cod, carp, and chicken revealed Kd's of 7.3 ± 0.9, 12.5 ± 0.9 and 7.8 ± 0.1 nM, and a Bmax for each species estimated to 57.9 ± 2.9, 195.1 ± 8.4 and 175 ± 0.8 fmol/mg protein, respectively. Scatchard analyses indicated a convex curvature and Hill analyses revealed apparent Hill coefficients of 1.84 ± 0.28, 1.80 ± 0.29, and 1.78 ± 0.27 for Atlantic cod, carp and chicken, suggesting a positive cooperative binding in all three species. Basal lateral membranes from Atlantic cod and carp were used to further characterize the binding moiety. In competition studies, basal lateral membranes from Atlantic cod or carp did not discriminate between 24R,25(OH)2D3 and the 24S,25(OH)2D3 isomer, whereas, 1,25(OH)2D3 and 25(OH)D3, were less effective in competing with [3H]24R,25(OH)2D3 for binding to basal lateral membranes in Atlantic cod and carp. In both the Atlantic cod and carp enterocyte basal lateral membranes, the binding activity could be extracted equally well with high salt as with detergent, indicating a peripheral membrane protein rather than an integral membrane binding protein. Finally, isolated Atlantic cod and carp enterocytes were chosen for analyses of signal transduction events mediated by the putative receptor. In both species, 24R,25(OH)2D3 but not 24S,25(OH)2D3, suppressed Ca2+‐uptake by enterocytes in a dose‐dependent manner. Enterocytes from Atlantic cod and carp, acclimated to Ca2+‐free media, responded by an intracellular Ca2+‐release within seconds after addition of 24R,25(OH)2D3 or 24S,25(OH)2D3. The effects on intracellular Ca2+‐release were dose‐dependent for both metabolites. 24S,25(OH)2D3 was effective at lower concentrations and triggered a higher response compared to 24R,25(OH)2D3. These results suggest that the binding molecule(s) for 24R,25(OH)2D3 and 24S,25(OH)2D3 is/are capable of acting as a receptor, mediating rapid, non‐genomic responses in intestinal cells. © 2001 Wiley‐Liss, Inc. J. Cell. Biochem. 83: 171–186, 2001. © 2001 Wiley‐Liss, Inc.
Retinoblastoma protein complexes with C/EBP proteins and activates C/EBP‐mediated transcription*
Authors: Charles Amos , Tang Xiaoren , Crouch Erika , Brody Jerome S. , Xiao Zhi‐Xiong Jim
Published: August 2002

The retinoblastoma protein (RB) recruits histone deacetylase (HDAC) to repress E2F‐mediated transactivation that plays a critical role in cell cycle regulation. RB is also involved in activation of expression of a number of tissue specific‐ and differentiation‐related genes. In this study, we examined the mechanism by which RB stimulated the expression of a differentiation‐related gene, the surfactant protein D (SP‐D), which plays important roles in innate host defense and the regulation of surfactant homeostasis. We demonstrated that RB specifically stimulated the activity of human SP‐D gene promoter. The RB family member, p107 but not p130, also increased SP‐D promoter activity. Activation by RB was mediated through a NF‐IL6 (C/EBPβ) binding motif in the human SP‐D promoter, and this sequence specifically bound to C/EBPα, C/EBPβ, and C/EBPδ. RB formed stable complexes with all three C/EBP family members. RB small pocket (amino acid residues 379–792), but not the C‐pocket (amino acid residues 792–928), was necessary and sufficient for its interaction with C/EBP proteins. Furthermore, we demonstrated that the complexes containing RB and C/EBP proteins directly interacted with C‐EBP binding site on DNA. These findings indicate that RB plays a positive, selective, and direct role in the C/EBP‐dependent transcriptional regulation of human SP‐D expression. J. Cell. Biochem. 83: 414–425, 2001. © 2001 Wiley‐Liss, Inc.
Differences in the uptake and nuclear localization of anti‐proliferative heparan sulfate between human lung fibroblasts and human lung carcinoma cells
Authors: Cheng Fang , Petersson Per , Arroyo‐Yanguas Yolanda , Westergren‐Thorsson Gunilla
Published: August 2002

Heparan sulfate inhibits the proliferation of normal human lung fibroblasts (HFL‐1) but not of a human lung carcinoma cell‐line (A549). In this study we investigated possible mechanisms and structural requirements by which antiproliferative heparan sulfates exerts its effects on binding, uptake and subcellular localisation. Both HFL‐1 and A549 cells were incubated with 125I‐ or rhodamine‐labeled L‐iduronate–rich antiproliferative heparan sulfate species as well as L‐iduronate‐poor inactive ones. The antiproliferative heparan sulfate was bound to the cell surface on both HFL‐1 and A549 cells, but to a lesser extent and with less affinity to A549 cells. Both cell types bound the antiproliferative heparan sulfate with one high‐ and with one low affinity site. The L‐iduronate–poor heparan sulfate bound to a lesser extent and with less affinity to both cell types compared to the antiproliferative heparan sulfate. The antiproliferative heparan sulfate accumulated in the cytoplasm of HFL‐1 cells after 24 h incubation, but after 72 h it was found evenly distributed in the nucleus. The time‐scale for antiproliferative activity correlated with nuclear localization. In contrast, in A549 cells it was only found near the nuclear membrane. The inactive heparan sulfate was taken up in considerably smaller amounts compared to the antiproliferative heparan sulfate and could not be detected in the nucleus of either HFL‐1 or A549 cells. Our data suggest that the antiproliferative activity of L‐iduronate–rich heparan sulfate on normal fibroblasts may be due to direct effects on nuclear processes, such as gene transcription. J. Cell. Biochem. 83: 597–606, 2001. © 2001 Wiley‐Liss, Inc.
Cognitive–behavioral therapy with gay, lesbian, and bisexual clients
Authors: Safren Steven A. , Rogers Tracey
Published: August 2002

Cognitive–behavioral therapy (CBT) can be adapted to a wide range of clinical difficulties and presenting problems that face lesbians, gay men, and bisexual persons. The following article presents general guidelines for and two case examples of the use of CBT. The first case is a gay male struggling with social phobia. This case is an example of how to adapt a structured, empirically supported cognitive–behavioral treatment focusing on social phobia to situations that are associated with his sexual orientation. The second is a woman struggling with multiple issues including coming out. This case provides an example of how to add specific cognitive–behavioral techniques to coming‐out issues within the context of a more eclectic, longer‐term therapy. © 2001 John Wiley & Sons, Inc. J Clin Psychol/In Session 57: 629–643, 2001.
Inhibition of gap junction intercellular communication by extremely low‐frequency electromagnetic fields in osteoblast‐like models is dependent on cell differentiation
Authors: Yamaguchi Dean T. , Huang Jason , Ma Defang , Wang Paul K.C.
Published: August 2002

Electromagnetic fields have been used to augment the healing of fractures because of its ability to increase new bone formation. The mechanism of how electromagnetic fields can promote new bone formation is unknown, although the interaction of electromagnetic fields with components of the plasma membrane of cells has been hypothesized to occur in bone cells. Gap junctions occur among bone forming cells, the osteoblasts, and have been hypothesized to play a role in new bone formation. Thus it was investigated whether extremely low‐frequency (ELF) magnetic fields alter gap junction intercellular communication in the pre‐osteoblastic model, MC3T3‐E1, and the well‐differentiated osteoblastic model, ROS 17/2.8. ELF magnetic field exposure systems were designed to be used for an inverted microscope stage and for a tissue culture incubator. Using these systems, it was found that magnetic fields over a frequency range from 30 to 120 Hz and field intensities up to 12.5 G dose dependently decreased gap junction intercellular communication in MC3T3‐E1 cells during their proliferative phase of development. The total amount of connexin 43 protein and the distribution of connexin 43 gap junction protein between cytoplasmic and plasma membrane pools were unaltered by treatment with ELF magnetic fields. Cytosolic calcium ([Ca2+]i) which can inhibit gap junction communication, was not altered by magnetic field exposure. Identical exposure conditions did not affect gap junction communication in the ROS 17/2.8 cell line and when MC3T3‐E1 cells were more differentiated. Thus ELF magnetic fields may affect only less differentiated or pre‐osteoblasts and not fully differentiated osteoblasts. Consequently, electromagnetic fields may aid in the repair of bone by effects exerted only on osteoprogenitor or pre‐osteoblasts. J. Cell. Physiol. 190: 180–188, 2002. © 2002 Wiley‐Liss, Inc.
Phosphorylation of pRb is required for HGF‐induced muscle cell proliferation and is p27kip1‐dependent
Authors: Leshem Yael , Halevy Orna
Published: August 2002

Hepatocyte growth factor (HGF) plays a crucial role in the differentiation of skeletal muscle cells, where a process in which the retinoblastoma protein (pRb) has been implicated. We addressed the role of pRb in HGF‐mediated effects on the proliferation and differentiation of adult skeletal muscle myoblasts. HGF shifted pRb to its hyperphosphorylation forms and increased the transactivation of E2F1, a transcription factor required for S phase entry. A constitutively active pRb mutant blocked HGF‐dependent pRb phosphorylation and transactivation of E2F1 and increased cell proliferation. Accordingly, this mutant reversed the inhibitory effects of HGF on the expression of the cyclin‐dependent kinase (CDK) inhibitor p27 and myogenic differentiation markers. HGF‐mediated pRb phosphorylation was reversed by ectopic expression of p27, but neither the myogenic regulatory factor, MEF2, nor the myogenic inhibitory protein Twist had that effect. These results suggest that in response to HGF signaling, there is a decrease in p27 expression that results in an accumulation of hyperphosphorylated Rb protein, and subsequent progression of myoblasts into the G1 phase of the cell cycle. J. Cell. Physiol. 191: 173–182, 2002. © 2002 Wiley‐Liss, Inc.
Carbonic anhydrase II is an AP‐1 target gene in osteoclasts
Authors: David J.‐P. , Rincon M. , Neff L. , Horne W.C. , Baron R.
Published: August 2002

c‐Fos, a member of the AP‐1 family of transcription factors, is necessary for osteoclast differentiation but to date, none of the osteoclast‐phenotypic markers have been identified as AP‐1 target genes. Here, we demonstrate that carbonic anhydrase II (CA II), an enzyme necessary for osteoclast activity, is transcriptionally upregulated by c‐Fos/AP‐1. A functional AP‐1 binding site is present in the CA II promoter and is necessary for this regulation. Furthermore, we show that AP‐1 binding activity, mainly composed of Fra‐2 and JunD, is induced by treatment of bone marrow cultures with the osteoclastogenic hormone 1,25 dihydroxyvitamin D3. Fra‐2 and JunD are found in mature osteoclasts as well. Thus, our data demonstrate that cFos/AP‐1 can directly regulate the expression of this osteoclast marker and that AP‐1 activity is upregulated in osteoclast progenitors in response to osteoclastogenic signals. © 2001 Wiley‐Liss, Inc.
Role of transcription factor Ets‐1 in the apoptosis of human vascular endothelial cells
Authors: Teruyama Kazuhide , Abe Mayumi , Nakano Toru , Iwasaka‐Yagi Chika , Takahashi Shoki , Yamada Shogo , Sato Yasufumi
Published: August 2002

Transcription factor Ets‐1 is induced in endothelial cells (ECs) by angiogenic factors, and promotes angiogenesis by inducing angiogenesis‐related genes such as MMPs and integrin β3. Here, we examined the effect of Ets‐1 on apoptosis in ECs. Overexpression of Ets‐1 in human umbilical vein endothelial cells (HUVECs) induced apoptosis under the serum‐deprived condition. VEGF inhibited apoptosis and augmented the DNA binding of Ets‐1 in HUVECs. The inhibition of transcriptional activity of endogenous Ets‐1 by a dominant negative molecule intensified the anti‐apoptotic effect of VEGF. Caspase inhibitors blocked apoptosis of HUVECs induced by Ets‐1. DNA array analysis showed that Ets‐1 up‐regulated pro‐apoptotic genes such as Bid, cytochrome p450, caspase‐4, p27, and p21 more than 2 fold, and down‐regualted anti‐apoptotic genes such as DAD‐1, AXL, Cox‐2, IAP‐2, and MDM‐2 less than 0.5 fold in HUVECs. These results indicate that Ets‐1 itself is pro‐apoptotic to ECs by modulating the expression of apoptosis‐related genes. © 2001 Wiley‐Liss, Inc.
Effect of a chemical synthesis‐based pharmaceutical wastewater on performance, acetoclastic methanogenic activity and microbial population in an upflow anaerobic filter
Authors: Ince B Kasapgil , Selcuk A , Ince O
Published: August 2002

The performance of an upflow anaerobic filter (UAF) treating a chemical synthesis‐based pharmaceutical wastewater was evaluated under various operating conditions. During start‐up, the UAF was initially fed by glucose till an organic loading rate (OLR) of approximately 7.5 kg COD m−3 day−1 with a hydraulic retention time of 2.3 days. A soluble COD removal efficiency of 98% was achieved before the addition of the wastewater. Initially, the filter inertia was acclimatized to the wastewater by sequential feeding of 10% (w/v), 30% (w/v) and 70% (w/v) of the pre‐aerated wastewater mixed with glucose followed by a 100% (w/v) pre‐aerated wastewater. During the operation, the COD removal efficiency and methane yield decreased to 75% and 0.30 m3 CH4 kg−1 CODremoved respectively. As the UAF became accustomed to the pre‐aerated wastewater, raw wastewater was fed in increasing ratios of 20% (w/v), 60% (w/v) and 80% (w/v) with the pre‐aerated wastewater as the remaining part. During this stage of the operation, a COD removal efficiency in a range of 77–86% was achieved and the methane yield decreased to 0.24 m3 CH4 kg−1 CODremoved. Finally, 100% (w/v) raw wastewater was fed and a COD removal efficiency of 65% was achieved with a methane yield of 0.20 m3 CH4 kg−1 CODremoved. At the end of the operation, acetoclastic methanogenic activity was only measured in the bottom section of the UAF, this showed a 90% reduction in comparison with activity of inoculation sludge. Microscopic examinations revealed that rod‐shaped methanogens remained as the dominant species whereas Methanosarcina‐like species and filaments were present only in insignificant numbers along the UAF.

© 2002 Society of Chemical Industry
Power Doppler imaging and resistance index measurement in the evaluation of acute renal transplant rejection
Authors: Chow Lawrence , Sommer F. Graham , Huang Jing , Li King C.P.
Published: August 2002

Purpose

This study was designed to test the hypotheses that power Doppler imaging has a predictive value in the assessment of acute renal allograft rejection and that the information garnered from the combination of resistance index (RI) determination and power Doppler imaging has an even greater predictive value in this assessment.

Methods

Power Doppler images obtained prior to 96 sequential renal allograft biopsies in 92 patients with suspected renal transplant rejection were retrospectively graded for parenchymal vascularity on a scale of 1 to 4: 1, normal, uniform cortical flow; 2, mild peripheral cortical hypoperfusion; 3, vascular pruning in cortex and medulla; and 4, no visible parenchymal flow, with flow seen only in central vessels. Power Doppler grades and RIs for these cases were compared to graft biopsy results.

Results

No statistically significant association was observed between parenchymal vascularity as graded by power Doppler imaging, RI, and the presence of acute transplant rejection.

Conclusions

Neither grading of vascularity on power Doppler images, RI measurement, nor the combination of these methods is an accurate means of detecting renal allograft rejection. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:483–490, 2001.
Even‐hole‐free graphs part I: Decomposition theorem
Authors: Conforti Michele , Cornuéjols Gérard , Kapoor Ajai , Vušković Kristina
Published: August 2002

We prove a decomposition theorem for even‐hole‐free graphs. The decompositions used are 2‐joins and star, double‐star and triple‐star cutsets. This theorem is used in the second part of this paper to obtain a polytime recognition algorithm for even‐hole‐free graphs. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 6–49, 2002
The morphological basis of hallucal orientation in extant birds
Authors: Middleton Kevin M.
Published: August 2002

The perching foot of living birds is commonly characterized by a reversed or opposable digit I (hallux). Primitively, the hallux of nonavian theropod dinosaurs was unreversed and lay parallel to digits II–IV. Among basal birds, a unique digital innovation evolved in which the hallux opposes digits II–IV. This digital configuration is critical for grasping and perching. I studied skeletons of modern birds with a range of hallucal designs, from unreversed (anteromedially directed) to fully reversed (posteriorly directed). Two primary correlates of hallucal orientation were revealed. First, the fossa into which metatarsal I articulates is oriented slightly more posteriorly on the tarsometatarsus, rotating the digit as a unit. Second, metatarsal I exhibits a distinctive torsion of its distal shaft relative to its proximal articulation with the tarsometatarsus, reorienting the distal condyles and phalanges of digit I. Herein, I present a method that facilitates the re‐evaluation of hallucal orientation in fossil avians based on morphology alone. This method also avoids potential misinterpretations of hallucal orientation in fossil birds that could result from preserved appearance alone. J. Morphol. 250:51–60, 2001. © 2001 Wiley‐Liss, Inc.
Morphology, histochemistry, and function of epaxial cervical musculature in the horse (Equus caballus)
Authors: Gellman K.S. , Bertram J.E.A. , Hermanson J.W.
Published: August 2002

The semispinalis capitis and splenius muscles of the horse were analyzed for gross morphology, microarchitecture, fiber length, and fiber type. Although these two muscles are similar in size and anatomical position, they are very different from one another in structural design and histochemistry, implying diverse functional roles in the animal's behavior. The histochemical staining profile was limited to two fiber types: slow oxidative and fast glycolytic. The splenius muscle has simple architecture, long fibers, and a 60/40 ratio of SO to FG cross‐sectional area. The semispinalis capitis has complex architecture with short‐fibered, concentric compartments dorsal to its central tendon and longer‐fibered compartments ventrally. The entire dorsal region has an increasing gradient of slow oxidative fiber percentage from caudal to cranial (58–71% SO). In contrast, the ventral region has a decreasing gradient of slow oxidative fibers from caudal to cranial (48–67% FG). These patterns can be interpreted within the context of the cervical musculature during locomotion and posture to indicate the functional advantages of this organization. J. Morphol. 251:182–194, 2002. © 2002 Wiley‐Liss, Inc.
Estimation and visualization of regional and global pulmonary perfusion with 3D magnetic resonance angiography
Authors: Halliburton Sandra S. , Paschal Cynthia B. , Rothpletz John D. , Loyd James E.
Published: August 2002

The purposes of this work were to estimate regional and global pulmonary perfusion and display pulmonary vasculature in 10 postoperative lung transplant patients using breath‐hold, contrast‐enhanced (0.2 mmol/kg, Gd DTPA‐BMA, Omniscan, Nycomed, Inc., Princeton, NJ), three‐dimensional (3D) magnetic resonance angiography (MRA) with specially designed double‐variable‐angle uniform signal excitation (VUSE) radio frequency (RF) pulses. Double‐VUSE scans imaged both lungs simultaneously during contrast agent injection and provided both qualitative and quantitative information about pulmonary perfusion. Double‐VUSE pulses clearly displayed healthy and diseased vessels. There was a strong correlation between contrast‐enhanced double‐VUSE MRA flow estimates and those measured from nuclear scans for global or whole lung (R2 = 0.95; P = 0.000002) and upper, central, and lower thirds of the lung (R2 = 0.89, 0.92, and 0.86, respectively; P < 0.001 for each region). In conclusion, 3D MRA using VUSE pulses in combination with a contrast agent is a valuable tool for the assessment of pulmonary perfusion that simultaneously acquires data for both the qualitative display of pulmonary vessels and the quantification of regional and global differential pulmonary blood flow. J. Magn. Reson. Imaging 2001;14:734–740. © 2001 Wiley‐Liss, Inc.
In vivo quantitative proton MRSI study of brain development from childhood to adolescence
Authors: Horská Alena , Kaufmann Walter E. , Brant Larry J. , Naidu Sakkubai , Harris James C. , Barker Peter B.
Published: August 2002

Purpose

To quantify regional variations in metabolite levels in the developing brain using quantitative proton MR spectroscopic imaging (MRSI).

Materials and Methods

Fifteen healthy subjects three to 19 years old were examined by in vivo multislice proton MRSI. Concentrations of N‐acetyl aspartate (NAA), total choline (Cho), total creatine (Cr), and peak area ratios were determined in selected frontal and parietal gray and white matter regions, basal ganglia, and thalamus.

Results

In cortical gray matter regions, the ratio of NAA/Cho increased to a maximum at 10 years and decreased thereafter (P = 0.010). In contrast, in white matter, average ratios NAA/Cho increased linearly with age (P = 0.045). In individual brain regions, age‐related changes in NAA/Cho were found in the putamen (P = 0.044). No significant age‐related changes in NAA, Cho, Cr, or other metabolite ratios could be determined.

Conclusion

Consistent with recent studies using other structural and functional neuroimaging techniques, our data suggest that small but significant changes occur in regional cerebral metabolism during childhood and adolescence. Non‐linear age related changes of NAA/Cho in frontal and parietal areas, resembling previously reported age related changes in rates of glucose utilization and cortical volumes, may be associated with dendritic and synaptic development and regression. Linear age‐related changes of NAA/Cho in white matter are also in agreement with age‐related increases in white matter volumes, and may reflect progressive increases in axonal diameter and myelination. J. Magn. Reson. Imaging 2002;15:137–143. Published 2002 Wiley‐Liss, Inc.
0.5 M Gd chelate (Magnevist®) versus 1.0 M Gd chelate (Gadovist®): Dose‐independent effect on image quality of pelvic three‐dimensional MR‐angiography
Authors: Goyen Mathias , Lauenstein Thomas C. , Herborn Christoph U. , Debatin Jörg F. , Bosk Silke , Ruehm Stefan G.
Published: August 2002

To compare the effect on image quality of a 1.0 M gadolinium (Gd) chelate to that of a conventional 0.5 M Gd chelate, five healthy volunteers and seven patients with angiographically documented aorto‐iliac disease underwent a mono‐station three‐dimensional magnetic resonance angiography (MRA) exam (Siemens SONATA®, Erlangen, Germany) twice, once using Gadovist® 1.0 and the other time using Magnevist® as the contrast agent. All subjects received a fixed volume of Gadovist® 1.0, corresponding to a dose between 0.1 and 0.15 mmol/kg body weight followed by a saline flush. For the Magnevist® exam, the contrast agent volumes and flow rates were doubled. For both quantitative and qualitative analysis of the angiographic data sets, the arterial tree was divided into nine segments. 1 M Gadovist® 1.0‐enhanced three‐dimensional MRA data sets were characterized by significantly higher signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) values compared to 0.5 M Magnevist®‐enhanced images. The data revealed mean SNR/CNR increases exceeding 70% (P < 0.01). Although there was no statistically significant difference in the rating of image quality (P > 0.05), the Gadovist® 1.0 exam led to better delineation of the arterial morphology, especially of small vessels. J. Magn. Reson. Imaging 2001;14:602–607. © 2001 Wiley‐Liss, Inc.
Electrospray tandem mass spectrometric study of alkyl 1‐methylpyridinium ether derivatives of alcohols
Authors: Quirke J. Martin E. , Van Berkel Gary J.
Published: August 2002

The fragmentation of 15 alkyl 1‐methylpyridinium ether derivatives (D+) of primary and secondary alcohols, benzylic alcohols and phenyl‐substituted alcohols was investigated using energy‐resolved tandem mass spectrometry. Fragmentation pathways and mechanisms, including the influence of substituents, on the formation of the major product ions, which appear at m/z 110, [D − 109]+ and [D − 111]+, were postulated. Comparison of the abundances of these ions in the product ion spectra of isomeric alcohol derivatives, obtained at the same center‐of‐mass collision energy (2.0 eV), was found to provide the ability to differentiate among some isomers. Copyright © 2001 John Wiley & Sons, Ltd.
Suppression of proinflammatory cytokines and induction of IL‐10 in human monocytes after coxsackievirus B3 infection
Authors: Hofmann P. , Schmidtke M. , Stelzner A. , Gemsa D.
Published: August 2002

Coxsackievirus B3 (CVB3) causes acute and chronic myocarditis, which is accompanied by an intense mononuclear leukocyte infiltration. Because myocardial tissue damage may either result from viral infections or from a dysregulated immune response, the susceptibility of human monocytes and macrophages to CVB3 was examined in this study with regard to virus replication, virus persistence, and release of cytokines. Monocytes were infected by CVB3 as shown by the intracellular appearance of plus‐ and minus‐strand viral RNA, which was also capable of persisting for more than 10 days. Fresh monocytes were not permissive for full virus replication whereas monocyte‐derived macrophages yielded a low amount of new viruses, which led to cell death. Although CVB3 infection induced the mRNA for the proinflammatory cytokines tumor necrosis factor‐alpha (TNF‐α), interleukin (IL)‐1, and IL‐6, only little cytokine production occurred. When infected monocytes were stimulated in addition by lipopolysaccharides (LPS), cytokine production was partially suppressed. In striking contrast, IL‐10 expression was strongly and persistently induced by CVB3 on the mRNA and the protein level. These data show a dysregulated cytokine response in CVB3‐exposed human monocytes and macrophages, which is characterized by a suppression of proinflammatory cytokines and a dominance of IL‐10. This viral strategy may aid CVB3, causing chronic myocardiopathy. J. Med. Virol. 64:487–498, 2001. © 2001 Wiley‐Liss, Inc.
Increased levels of antiviral MxA protein in peripheral blood of patients with A chronic disease of unknown etiology*
Authors: Chieux Vincent , Chehadeh Wassim , Hautecoeur Patrick , Harvey Jeanne , Wattré Pierre , Hober Didier
Published: August 2002

Interferon alpha (IFN‐α) is synthesized in response to viral infections. MxA protein, induced specifically by IFN‐α and β, expressed in peripheral blood cells, is detected more consistently than circulating IFN‐α in serum of patients with viral infections. Thus, activation of the IFN‐α/MxA system can be used as additional marker of the presence of a virus in patients. Therefore MxA protein and IFN‐α levels were measured in patients with multiple sclerosis (MS), a chronic neurological disease of unknown etiology, in order to investigate the possible role of viruses in the expression of this disease. The means of MxA values obtained by using an immunochemiluminescent assay were significantly higher in blood of patients with remitting (n = 197) or relapsing (n = 39) multiple sclerosis (MS) patients and in patients with viral infections than in blood from healthy controls (n = 25) and from patients with bacterial infections (n = 12). Intra‐individual variance in MxA levels in seven clinically stable remitting patients with MS was observed in the course of a follow‐up, and high MxA levels were detected in three of them in blood samples collected consecutively over several months. By using an ultra sensitive assay, a higher MxA‐inducer activity was obtained with sera from MS patients (n = 39) than with those from healthy controls (n = 12). Experiments with neutralizing antibodies proved that this activity in serum from patients was due to IFN‐α, whereas IFN‐α could not be detected by other methods. Altogether these results demonstrate that there is an activation of the IFN‐α/MxA system in MS patients, which is consistent with the hypothesis that a viral infection may be associated with MS. J. Med. Virol. 65:301–308, 2001. © 2001 Wiley‐Liss, Inc.
Semiquantitative PCR analysis of Epstein‐Barr virus DNA in clinical samples of patients with EBV‐associated diseases
Authors: Meerbach Astrid , Gruhn Bernd , Egerer Renate , Reischl Udo , Zintl Felix , Wutzler Peter
Published: August 2002

The laboratory diagnosis of primary and reactivated Epstein‐Barr virus (EBV) infection is based on serologic methods in immunocompetent patients. However, in immunocompromised patients, serologic data are difficult to interpret and do not often correlate with clinical data. In order to find a useful and practical marker for diagnosis of EBV‐related diseases, a polymerase chain reaction (PCR) assay was established for semiquantitative detection of EBV sequences. The method was based on a nested PCR, using primers of the virus capsid antigen p23 region and an endpoint dilution. This method was carried out on 68 plasma samples, 68 samples of peripheral blood mononuclear cells and 5 cerebrospinal fluid samples of 39 patients with various diseases to evaluate the EBV‐genome copy number. Samples from patients suffering from infectious mononucleosis served as positive controls for active EBV infection. In 5 patients with infectious mononucleosis, high copy numbers of EBV genomes in peripheral blood mononuclear cells were detected within a range of 1,000–40,000 copies in 105 peripheral blood mononuclear cells. In contrast, samples from 19 latently infected persons either showed low copy numbers (10–100 in 105 peripheral blood mononuclear cells) or were EBV PCR negative. Comparable results were observed in seven renal transplant patients without any symptoms. The practical value of the semiquantitative detection of EBV DNA was demonstrated in three bone marrow transplant recipients. Two developed a lymphoproliferative disease associated with extremely high amounts of EBV DNA in plasma (16,000 and 50,000 copies/ml, respectively) and peripheral blood mononuclear cells (100,000 and 6.5 million copies in 105 peripheral blood mononuclear cells, respectively). The high EBV load in plasma and peripheral blood mononuclear cells was reduced dramatically after successful antiviral therapy in one case. The third bone marrow transplant recipient developed an EBV‐induced transverse myelitis with an increased number of EBV‐genome copies in peripheral blood mononuclear cells and EBV‐positive cerebrospinal fluid samples. After combined antiviral and immune therapy, the EBV‐genome copy numbers decreased and the patient recovered completely. These data demonstrate a good correlation between semiquantitative detection of EBV genomes and clinical findings. The method is recommended for the diagnosis of EBV‐associated diseases in patients after transplantation, as well as for monitoring the response to therapy. J. Med. Virol. 65:348–357, 2001. © 2001 Wiley‐Liss, Inc.
Host range studies of GB virus‐B hepatitis agent, the closest relative of hepatitis C virus, in New World monkeys and chimpanzees†
Authors: Bukh Jens , Apgar Carl L. , Govindarajan Sugantha , Purcell Robert H.
Published: August 2002

GB virus‐B (GBV‐B) is a member of the Flaviviridae family of viruses. This RNA virus causes acute resolving hepatitis in experimentally infected tamarins, but its natural host remains unknown. GBV‐B and a related virus, GBV‐A, were recovered from serum containing the “GB agent,” which was believed to have originated from a surgeon (initials: GB) with acute hepatitis. GBV‐B has special interest because it is the virus related most closely to hepatitis C virus, which is an important cause of acute and chronic liver disease in humans. In the present study, we found that the host range of GBV‐B includes owl monkeys. Tamarins and owl monkeys belong to two different families of New World monkeys. The natural history of GBV‐B in the two owl monkeys studied was similar to that previously found for tamarins and was characterized by early appearance of viremia and viral clearance. However, the peak viral titers of GBV‐B observed in owl monkeys (105 genome equivalents [GE] /ml) were lower than those observed in experimentally infected tamarins (107–108 GE/ml) and acute hepatitis was observed in only one animal. If GBV‐B were indeed a virus of humans, it would be expected to infect chimpanzees, a surrogate of humans, because all recognized human hepatitis viruses are transmissible to chimpanzees and cause hepatitis. However, in the present study, we failed to transmit GBV‐B to a naive chimpanzee. In addition, a second naive chimpanzee transfected intrahepatically with RNA transcripts from an infectious clone of GBV‐B did not become infected. Thus, chimpanzees are apparently not susceptible to GBV‐B. Finally, we failed to detect GBV‐B in acute‐phase serum from surgeon GB. Our data suggest that GBV‐B is not a human virus and that GBV‐B, like GBV‐A, is a virus of New World monkeys. J. Med. Virol. 65:694–697, 2001. © 2001 Wiley‐Liss, Inc.
Characterization of a human monoclonal antibody obtained after immunization with plasma vaccine and a booster with recombinant‐DNA hepatitis B vaccine
Authors: Heijtink R.A. , Kruining J. , van Bergen P. , de Rave S. , van Hattum J. , Schutten M. , Osterhaus A.D.M.E.
Published: August 2002

A human monoclonal antibody type IgG4, designated 1Ff4, was obtained by Epstein Barr virus transformation of peripheral blood lymphocytes from a hepatitis B vaccinee (HB‐VAX: plasma‐derived vaccine) after one boost of yeast recombinant DNA derived vaccine (Engerix‐B). 1Ff4 binds preferentially to HBsAg/adw2 and HBsAg/ayw1. In binding experiments, it competes with antibodies induced by vaccination with HB‐VAX‐DNA (yeast recombinant) and HB‐VAX (plasma‐derived vaccine). 1Ff4 competes in part with a monoclonal antibody for the w/r region. Partial inhibition of binding of HBsAg/adw2 to solid phase anti‐HBs was detected, resembling inhibition obtained using other human monoclonal specific for the “a”‐loop. 1Ff4 does not bind to linear peptides covering the two “a”‐loops or to an adw2/G145R mutant, its binding to wild type HBsAg strongly depends on the presence of disulphide bonds. In a large series of HBsAg‐positive samples from an endemic area, 1Ff4 antibodies were successfully used to discriminate between an adw2 and an adrq+ strain. The characterisation of 1Ff4 and other human monoclonal anti‐HBs antibodies may help to understand the fine specificity of protective antibodies elicited by immunization. J. Med. Virol. 66:304‐311, 2002. © 2002 Wiley‐Liss, Inc.
Promoting axonal regeneration in the central nervous system by enhancing the cell body response to axotomy
Authors: Plunet Ward , Kwon Brian K. , Tetzlaff Wolfram
Published: August 2002

Neurons projecting into the peripheral nervous system (PNS) regenerate their axons after injury, in contrast to those confined to the central nervous system (CNS). Both neuronal and nonneuronal factors contribute to the lack of CNS regeneration. In this review we concentrate on the differential gene expression response to axotomy in PNS vs. CNS neurons. In general CNS neurons fail to up‐regulate or sustain the expression of regeneration‐associated proteins (RAGs), including trophic factors and their receptors. The presumed lack of trophic support of axotomized CNS neurons provided the rationale for the exogenous application of trophic factors, either to the lesion site or to the cell bodies. Here, we review our data on the application of trophic factors to rubrospinal and corticospinal neurons. Cell body treatment of axotomized rubrospinal neurons with brain‐derived neurotrophic factor (BDNF) reversed atrophy, increased GAP‐43 and Tα‐1 tubulin mRNA expression, and promoted axonal regeneration into peripheral nerve grafts. Importantly, BDNF cell body treatment was still effective in the chronic setting, i.e., when initiated 1 year after injury, but BDNF had no effect when applied to the chronic spinal cord injury site. The ability to promote regeneration in chronically injured neurons will hopefully contribute to the development of treatment strategies for chronic spinal injuries. © 2002 Wiley‐Liss, Inc.
Synucleins in ocular tissues
Authors: Surguchov Andrei , McMahan Belinda , Masliah Eleizer , Surgucheva Irina
Published: August 2002

Synucleins are small proteins associated with neurodegenerative diseases and some forms of cancer. Most studies of this group of proteins have been directed to the elucidation of their role in the brain and their connection to the formation of depositions in brain tissues. Here we describe the localization of different types of synucleins in ocular tissues. By Western blot analysis, all members of the synuclein family are found in the retina and optic nerve, where their relative ratio varies. The data on immunohistochemical staining show that different members of the synuclein family have different localizations in ocular tissues. α‐Synucleins and β‐synucleins are present predominantly in the inner plexiform layer, whereas γ‐synuclein is in the nerve fiber layer. In transgenic mice overexpressing α‐synuclein, a different pattern of localization depending on the promoter used for the expression was observed. In Alzheimer's disease patients, immunohistochemical staining for γ‐synuclein revealed the loss of immunoreactivity in the nerve fiber layer and the nerve fiber layer and the appearance of immunopositive cells in or near the outer nuclear layer. We conclude that, in mature eyes, synucleins are present predominantly in the retina and optic nerve, and the immunoreactivity of γ‐synuclein changes specifically in the retina of Alzheimer's disease patients. In transgenic mice overexpressing α‐synuclein, immunopositive deposits in the optic nerve and accumulation of immunoreactivity in specific retinal cells were found. J. Neurosci. Res. 65:68–77, 2001. © 2001 Wiley‐Liss, Inc.
T‐cell responses to oligodendrocyte‐specific protein in multiple sclerosis
Authors: Vu T. , Myers L.W. , Ellison G.W. , Mendoza F. , Bronstein J.M.
Published: August 2002

Oligodendrocyte‐specific protein (OSP) is concentrated in CNS myelin and is a potential autoantigen in the development of multiple sclerosis (MS). We performed proliferation assays with lymphocytes from MS patients and normal controls. OSP peptide‐induced proliferation was common in relapsing‐remitting MS and controls samples but was less pronounced in samples from secondary progressive MS subjects. These data demonstrate that OSP‐reactive T cells are part of the normal immune repertoire and therefore have the potential to contribute to the pathogenesis of MS. Given the lack of specificity to MS, OSP‐reactive T‐cells are unlikely to be solely responsible for the disease process. J. Neurosci. Res. 66:506–509, 2001. © 2001 Wiley‐Liss, Inc.
Wintertime temperature anomalies in Alaska correlated with ENSO and PDO
Authors: Papineau John M.
Published: August 2002

Wintertime (November–March) surface air temperatures at 14 stations throughout the state of Alaska are correlated with the Southern Oscillation Index and the Pacific Decadal Oscillation index, for the years 1954–2000. On the seasonal and monthly timescales, the principal results are: (i) During El Niño winters, temperatures are near normal in western Alaska but significantly warmer than normal for the eastern two‐thirds of the state. (ii) La Niña winters produce significant below normal temperatures statewide. (iii) Temperature patterns produced during El Niño, La Niña, and neutral winters are modified by the concurrent state of the North Pacific sea‐surface temperature anomalies, as indicated by the Pacific Decadal Oscillation index.

On the sub‐monthly timescale, temperatures across Alaska are to the first order correlated with the alternating zonal to meridional Pacific/North American pattern. Analysis of daily winter temperatures at Fairbanks indicates that cold anomalies are more frequent and are longer in duration than warm anomalies, primarily due to radiational cooling of the boundary layer and the subsequent formation of deep temperature inversions. The development of strong inversions over the interior of Alaska limits the response of temperatures to changes in the synoptic‐scale flow pattern. Warm anomalies in contrast to cold anomalies, are primarily a function of warm air advection, therefore temperatures during warm anomalies fluctuate in phase with changes in the synoptic‐scale flow. Ultimately, air temperatures across Alaska are a function of: synoptic‐scale forcings, radiative cooling of the boundary layer as well as local and regional effects such as downslope and drainage winds. Copyright © 2001 Royal Meteorological Society
Force constant calculation from Raman and IR spectra in the three non‐cubic phases of BaCeO3
Authors: Gupta H. C. , Simon P. , Pagnier T. , Lucazeau G.
Published: August 2002

Raman spectroscopic data for BaCeO3 were modeled with the use of a small set of force constants in its three phases (Pnma, Imma and R3c) using experimental IR and Raman data. An IR reflectance spectrum of BaCeO3 in its Pnma phase is provided for the first time. Raman band symmetry assignments in the Pnma phase were re‐examined and the assignments of Genet et al. were confirmed. The distribution of the Raman bands of the Pnma phase between the zone center and X point in Imma is provided and band assignments were extended to the Imma and R3c phases. Calculated values for both Raman‐ and IR‐active modes are provided in the three phases. The variations in force constants throughout the phase transitions are briefly discussed. Copyright © 2001 John Wiley & Sons, Ltd.