bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absence of simian virus 40 in human brain tumors from northern India
Authors: Engels Eric A. , Sarkar Chitra , Daniel Richard W. , Gravitt Patti E. , Verma Kusum , Quezado Martha , Shah Keerti V. 
Published: October 2002

AbstractSimian virus 40 (SV40), a monkey polyomavirus, was a contaminant of early poliovirus vaccines administered to millions of individuals in the 1950s and early 1960s. SV40 causes brain tumors in laboratory animals, and SV40 DNA sequences have been variably identified in human choroid plexus tumors and ependymomas. We studied the possible association between SV40 and human brain tumors in northern India, where humans have frequent contact with SV40‐infected rhesus macaques. DNA from pathologic specimens from 33 ependymomas, 14 choroid plexus tumors and 18 control brain tissues (contused brain, brain metastases) was extracted and analyzed under masked conditions. We used real‐time PCR to detect and quantify SV40 (T antigen) and human (GAPDH) DNA sequences. The SV40 PCR assay detected as few as 10 copies of SV40 DNA and had a linear range from 1 × 102 to 1 × 106 copies. SV40 DNA was detected in 1 specimen (an ependymoma). However, few SV40 DNA copies were detected in this sample (<10 copies, equivalent to <1 copy/350 cells, based on simultaneous GAPDH quantification), and SV40 was not detected when this sample was retested. Our findings do not support a role for SV40 in choroid plexus tumors or ependymomas from northern India. © 2002 Wiley‐Liss, Inc.
Circadian efferent input to Limulus eyes: Anatomy, circuitry, and impact
Authors: Battelle Barbara‐Anne 
Published: October 2002

AbstractMuch is known about the anatomy of Limulus retinal efferent neurons and the structural and functional consequences of their activation. Retinal efferent axons arise from cell bodies located in the cheliceral ganglia of the brain, and they project out all of the optic nerves. Their unique neurosecretory‐like terminals contact all cell types in lateral eye ommatidia, the retinular cells of the median eye, and the internal rhabdom of ventral photoreceptors. Lateral and median rudimentary photoreceptors are also innervated. The activity of the efferents is circadian. They are active during the subjective night and inactive during the subjective day. Activation of the efferents drives dramatic and diverse changes in the structure and function of Limulus eyes and causes the sensitivity and responsiveness of the eyes to light to increase at night. Relatively little is known about the molecular mechanisms that produce these structural and functional changes, but one efferent‐activated biochemical cascade has been identified. The biogenic amine octopamine is released from efferent terminals, and an octopamine‐stimulated rise in cAMP in photoreceptors, with a subsequent activation of cAMP‐dependent protein kinase, mediates many of the known effects of efferent input. A photoreceptor‐specific protein, myosin III, is phosphorylated in response to efferent input; this protein may play a role in the efferent stimulated changes in photoreceptor structure and function. Anatomical, biophysical, biochemical, and molecular approaches are now being effectively combined in studies of Limulus eyes; thus, this preparation should be particularly useful for further detailed investigations of mechanisms underlying the modulation of primary sensory cells by efferent input. Microsc. Res. Tech. 58:345–355, 2002. © 2002 Wiley‐Liss, Inc.
High prevalence of GB virus C/hepatitis G virus genotype 3 among autochthonous Venezuelan populations
Authors: Loureiro Carmen L. , Alonso Roberto , Pacheco Belkis A. , Uzcátegui María G. , Villegas L. , León Graciela , de Saéz Arlette , Liprandi Ferdinando , López José L. , Pujol Flor H. 
Published: October 2002

AbstractGB virus C or hepatitis G virus (GBV‐C/HGV) is highly prevalent among population groups at risk of parenterally transmitted viral agents, but it has also a worldwide distribution in other non‐risk population groups. GBV‐C/HGV RNA and antibodies against its envelope protein (anti‐E2 Abs) were found in 3/86 (3%) and 7/89 (8%) of biomedical science personnel (BSP), in 31/453 (7%) and 37/200 (19%) of blood donors (BD), and in 6/64 (9%) and 26/59 (44%) of hemodialysis patients (HD) from Caracas, Venezuela. A significant gradient of GBV‐C/HGV exposure (anti‐E2 Abs and/or GBV‐C/HGV RNA) was found between BSP (lowest prevalence), BD, and HD (P < 0.001). GBV‐C/HGV RNA and anti‐E2 Abs were also found in 2/69 (2.9%) and 2/44 (4.5%) of individuals from a rural community, in 9/162 (5.5%) and 2/40 (5%) of West Amerindians, and in 14/56 (25%) and 4/53 (7.5%) of South Amerindians. Socioeconomic and cultural factors may have contributed to the relatively high risk of exposure to GBV‐C/HGV in BD and Amerindians. Whereas GBV‐C/HGV genotypes 1 (n = 1), 2 (n = 6), and 3 (n = 22) were present in Venezuela, only the Asiatic genotype 3 was found infecting Amerindians and rural populations (n = 16). Genotype assignment based on the 5′ noncoding region of the GBV‐ C/HGV genome was corroborated in some isolates by genetic analysis of the E2 region. This report confirms the circulation of the Asiatic genotype of GBV‐C/HGV among Amerindians, suggesting an old origin of GBV‐C/HGV. This might be associated with the apparently low pathogenesis of this virus. J. Med. Virol. 68:357–362, 2002. © 2002 Wiley‐Liss, Inc.
Epstein‐Barr virus‐associated gastric carcinoma in southern India: A comparison with a large‐scale Japanese series
Authors: Kattoor Jayasree , Koriyama Chihaya , Akiba Suminori , Itoh Tetsuhiko , Ding Shan , Eizuru Yoshito , Abraham Elizabeth K. , Chandralekha B. , Amma N.S. , Nair M. Krishnan 
Published: October 2002

AbstractEpidemiological and clinicopathological features of Epstein‐Barr virus (EBV) associated gastric carcinoma was compared in India and Japan, two countries differing markedly in gastric cancer incidence. Using in situ hybridization assay, the presence of EBV‐encoded small RNA (EBER) was examined in 215, and 2,011 gastric cancer cases in Kerala, India, and Japan, respectively. Ten cases (5%), all males, in the Indian series were EBER‐positive. This frequency was similar to that in the Japanese series (6.2%). As was the case with Japanese series, the EBV‐associated gastric carcinoma in the Indian series was observed most frequently in the middle part of the stomach (1 in antrum, 4 in middle part, 2 in cardia, and 3 unknown), and, histologically, the diffuse type Lauren's classification (8 cases) was more common than the intestinal type (2 cases). Virus subtyping by PCR‐RFLP revealed that all of the 10 EBV strains isolated from the EBER‐positive Indian cases were subtype A, and wild‐type F for Bam HI F region. In Bam HI I region, 8 cases were type C and the remaining 2 cases were type D. In either series, there was no significant difference in the frequency of tumors with p53 overexpression between EBER‐positive and ‐negative cases. However, the proportion of cells with p53 overexpression in EBER‐negative tumors was significantly higher than that in EBER‐positive tumors regardless of histological type in both series. In conclusion, the frequency and major clinicopathological features of EBV‐associated gastric carcinoma in south India were similar to those observed in Japanese series although gastric cancer incidence in these two countries differs markedly. J. Med. Virol. 68:384–389, 2002. © 2002 Wiley‐Liss, Inc.
Genetic analysis of measles viruses isolated in Morocco
Authors: Alla Amal , Liffick Stephanie L. , Newton Bruce R. , Elaouad Rajae , Rota Paul A. , Bellini William J. 
Published: October 2002

AbstractSequence analysis was conducted on the hemagglutinin (H) and nucleoprotein (N) genes from nine wild‐type measles viruses (MV) isolated during an outbreak that occurred in Morocco during 1998 and 1999. The sequence data showed that all the viruses were closely related to each other and were members of genotype C2. Genotype C2 has been shown to be circulating in Europe, and the sequences of the Moroccan isolates were most closely related to the sequences of recent viral isolates from western Europe. This report presents the first molecular epidemiological study of circulating wild‐type measles viruses in Morocco. Knowledge of the indigenous strain of measles virus circulating in Morocco will help to describe viral transmission pathways and should contribute to efforts to evaluate the effectiveness of future vaccination campaigns. J. Med. Virol. 68:441–444, 2002. © 2002 Wiley‐Liss, Inc.
Curing kinetics of boron‐containing phenol–formaldehyde resin formed from paraformaldehyde
Authors: Liu Yanfang , Gao Jungang 
Published: October 2002

AbstractA boron‐containing phenol–formaldehyde resin (BPFR) was synthesized from boric acid, phenol, and paraformaldehyde. The curing reaction of BPFR was studied by Fourier‐transform infrared spectrometry and differential scanning calorimetry. According to the heat evolution behavior during the curing process, several influencing factors on isothermal curing reaction were evaluated. The results show that the isothermal kinetic reaction of BPFR follows autocatalytic kinetics mechanism, and kinetic parameters m, n, k1, and k2, were derived, respectively. In the latter reaction stage, the curing reaction becomes controlled mainly by diffusion. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 638–644, 2002
Nd:YAG laser therapy for palliation of recurrent squamous cell carcinomas in the oral cavity
Authors: Paiva Marcos B. , Blackwell Keith E. , Saxton Romaine E. , Bublik Michael , Liu Carson D. , Paolini Ana Amélia P. Paiva , Calcaterra Thomas C. , Castro Dan J. 
Published: October 2002

AbstractBackground and ObjectivesThe objective of this study was to evaluate the outcome of laser photo‐thermoablation for palliation of recurrent squamous cell tumors of the oral cavity.Study Design/Patients and MethodsSeventeen patients were treated with the Nd:YAG laser (power output was 50 W) delivered through a curved oral handpiece.ResultsTen patients are alive, 7 with tumor remission, and 3 with persistent disease with an average follow‐up of 16 months (range = 2–36). A total of 29 tumor sites received laser treatment with 17 (58%) completely ablated. Stratified by tumor site Nd:YAG treatment led to complete local response in 8/10 buccal mucosa, 2/5 retromolar trigone, 2/2 tongue, 2/5 gingiva, 1/2 floor of mouth, 2/4 hard palate.ConclusionsNd:YAG laser treatment of recurrent oral cavity squamous cell carcinoma can be performed safely and repeated as needed to achieve tumor palliation. However, extended follow‐up may be needed before convincing evidence of long‐term therapeutic benefits is obtained. Lasers Surg. Med. 31:64–69, 2002. © 2002 Wiley‐Liss, Inc.
Effect of branching and molecular weight on the viscoelastic properties of poly(butyl acrylate)
Authors: Former Carsten , Castro Jeffrey , Fellows Christopher M. , Tanner Roger I. , Gilbert Robert G. 
Published: October 2002

AbstractA series of poly(butyl acrylate) samples were prepared by emulsion polymerization with a range of molecular weights and degrees of chain branching. Characterization was performed with NMR (giving the fraction of branching, ranging from approximately 0 to 7%), gel permeation chromatography, viscometry, and determination of the gel fraction. The dynamic mechanical response, that is, the frequency dependence of the storage and loss moduli G′(ω) and G″(ω) was measured from 0.02 to 200 Hz. The occurrence of a significant insoluble fraction in the sample meant that full characterization of the molecular weight distribution was not possible, and so an unambiguous separation of the dependencies of the mechanical response on the degree of long‐chain branching (LCB) and short‐chain branching (SCB) and the molecular weight could not be made; however, trends dependent on the molecular weight alone were insufficient to model the results. At high frequencies, all trends in G′(ω) and G″(ω) could be ascribed to molecular weight dependencies; at low frequencies, the effects of both the molecular weight and total degree of branching could be inferred, with more highly branched samples showing lower storage and loss moduli. Although the relative amounts of SCB and LCB could not be determined, no dynamic features attributable to LCB were observed. The low‐frequency trends could be semiquantitatively fitted with reptation and retraction theory if it was assumed that an increased degree of SCB led to an increased tube size. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3335–3349, 2002
Synthesis of new amphiphilic diblock copolymers containing poly(ethylene oxide) and poly(α‐olefin)
Authors: Lu Yingying , Hu Youliang , Wang Z. M. , Manias E. , Chung T. C. 
Published: October 2002

AbstractThis article discusses an effective route to prepare amphiphilic diblock copolymers containing a poly(ethylene oxide) block and a polyolefin block that includes semicrystalline thermoplastics, such as polyethylene and syndiotactic polystyrene (s‐PS), and elastomers, such as poly(ethylene‐co‐1‐octene) and poly(ethylene‐co‐styrene) random copolymers. The broad choice of polyolefin blocks provides the amphiphilic copolymers with a wide range of thermal properties from high melting temperature ∼270 °C to low glass‐transition temperature ∼−60 °C. The chemistry involves two reaction steps, including the preparation of a borane group‐terminated polyolefin by the combination of a metallocene catalyst and a borane chain‐transfer agent as well as the interconversion of a borane terminal group to an anionic (O−K+) terminal group for the subsequent ring‐opening polymerization of ethylene oxide. The overall reaction process resembles a transformation from the metallocene polymerization of α‐olefins to the ring‐opening polymerization of ethylene oxide. The well‐defined reaction mechanisms in both steps provide the diblock copolymer with controlled molecular structure in terms of composition, molecular weight, moderate molecular weight distribution (Mw/Mn < 2.5), and absence of homopolymer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3416–3425, 2002
Electron capture negative ion mass spectra of some typical matrix‐assisted laser desorption/ionization matrices
Authors: Asfandiarov N. L. , Pshenichnyuk S. A. , Fokin A. I. , Lukin V. G. , Fal'ko V. S. 
Published: October 2002

AbstractA series of seven typical matrix‐assisted laser desorption/ionization (MALDI) matrices has been investigated by means of electron capture negative ion mass spectrometry (ECNI‐MS). It has been shown that the most effective matrices form deprotonated negative ions predominantly in the low‐energy region. Relative dissociative cross sections have been measured for all molecules under investigation. The relative integrated abundance of [M − H]− ion formation in the series changes by four orders of magnitude. It has been shown that 2,5‐DHB (gentisic acid), one of the most effective MALDI matrices, has maximal relative intensity of [M − H]− formation at the energy ∼0.8 eV. This result is in accordance with a finding of Frankevich and Zenobi [Book of Abstracts, Workshop‐school “Mass spectrometry in chemical physics, bio‐physics and environmental sciences”, Zvenigorod, Russia, April, 25–26, 2002, p. 40] that a probable origin of negative ions in MALDI is the process of low‐energy (0.5–1 eV) dissociative electron capture by matrix molecules. Copyright © 2002 John Wiley & Sons, Ltd.
Varicella‐zoster virus latency in human ganglia
Authors: Kennedy Peter G.E. 
Published: October 2002

AbstractVaricella‐zoster virus (VZV) is a human herpesvirus which causes varicella (chickenpox) as a primary infection, and, following a variable period during which it remains in latent form in trigeminal and dorsal root ganglia, reactivates in later life to cause herpes zoster (shingles). VZV is a significant cause of neurological disease including post‐herpetic neuralgia which may be persistent and highly resistant to treatment, and small and large vessel encephalitis. VZV infections are more frequent with advancing age and in immunocompromised individuals. An understanding of the mechanisms of latency is crucial in developing effective therapies for VZV infections of the nervous system. Such studies have been hampered by the difficulties in working with the virus and also the lack of a good animal model of VZV latency. It is known that the ganglionic VZV burden during latency is low. Two of the key questions that have been addressed are the cellular site of latent VZV and the identity of the viral genes which are transcribed during latency. There is now a consensus that latent VZV resides predominantly in ganglionic neurons with less frequent infection of non‐neuronal satellite cells. There is considerable evidence to show that at least five viral genes are transcribed during latency. Unlike herpes simplex virus‐1 latency, viral protein expression has been demonstrated during VZV latency. A precise knowledge of which viral genes are expressed is crucial in devising novel antiviral therapy using expressed genes as therapeutic targets. Whether gene expression at both the transcriptional and translational levels is more extensive than currently reported will require much more work and probably new molecular technology. Copyright © 2002 John Wiley & Sons, Ltd.
PSAMS: a communication protocol specification assessment and measurement system
Authors: Huang Sun‐Jen , Lai Richard 
Published: October 2002

AbstractAn obstacle to the uses of software metrics and size models, which we have developed for measuring the complexity and maintainability of a communication protocol specified in Estelle and for estimating the size of its specification and implementation, is the time‐consuming effort in collecting the metrics. To address this problem, a software system called PSAMS (protocol specification assessment and measurement system) for automatically calculating the metrics and sizes of specification and implementation has been developed. This paper describes the design of PSAMS, which provides five functionalities for a communication protocol Estelle specification: exploring its specification, measuring its complexity, assessing its maintainability, estimating its specification size and estimating its implementation size. To demonstrate the usefulness of PSAMS, we have applied it to measure the complexity and maintainability of 10 communication protocol Estelle specifications; the measurement results and decision support information provided by each functionality are presented in this paper. With PSAMS, communication protocol designers and developers are able to assess the complexity of a communication protocol early in the specification stage and have information which helps them manage a communication software project better. Copyright © 2002 John Wiley & Sons, Ltd.
Food restriction modulates amphetamine‐conditioned place preference and nucleus accumbens dopamine release in the rat
Authors: Stuber Garret D. , Evans Scott B. , Higgins Michael S. , Pu Yanping , Figlewicz Dianne P. 
Published: October 2002

AbstractFood restriction has been shown to increase self‐administration of psychostimulants, including cocaine and amphetamine (AMPH). Consistent with this, food‐restricted rats are more sensitized to the rewarding effects of cocaine as measured by conditioned place preference (CPP). This study investigated whether moderate food restriction in rats (15 g/day) results in an increased CPP, relative to ad libitum‐fed controls, to a second psychostimulant, AMPH. Conditioning trials consisted of six alternating injections of i.p. AMPH (0.425–6.8 mg/kg) and i.p. saline, paired with distinct environments. On Day 7, a drug‐free 20‐min choice test for environment was carried out to assess CPP. 0.85 mg/kg AMPH significantly increased CPP in food‐restricted vs. ad libitum‐fed rats. At 1.7 and 3.4 mg/kg AMPH, food‐restricted rats showed decreased CPP, but increased locomotor activity, relative to ad libitum fed controls. To evaluate whether an alteration in extracellular fluid DA levels in the nucleus accumbens (NAc) core could account for these behavioral alterations, DA release was measured by microdialysis. DA release to a single acute i.p. injection of either 0.85 or 1.7 mg/kg AMPH was comparable in food‐restricted and ad libitum fed rats. However, ad libitum fed rats demonstrated conditioned DA release after an AMPH conditioning paradigm analogous to the CPP paradigm, whereas food‐restricted rats demonstrated no conditioned DA release. In conclusion, altered DA release in the nucleus accumbens core is not a primary effect of moderate food restriction and cannot completely account for either the altered CPP behavior or enhanced locomotor activity observed in this study. Synapse 46:83–90, 2002. © 2002 Wiley‐Liss, Inc.
GBR‐12909 effect on dopamine outflow depends on phosphorylation in the caudate nucleus of the rat
Authors: Thümen A. , Qadri F. , Sarkar R. , Moser A. 
Published: October 2002

AbstractModulation of the dopamine (DA) transporter inhibitor GBR‐12909 effect on DA release by protein kinases and protein phosphatases was studied in slices of the rat caudate nucleus measuring DA outflow in the superfusate of static chambers. Activation of protein kinase A and C markedly enhanced the effect of GBR‐12909, whereas protein kinase inhibition by H7 reduced the GBR‐12909 effect. Inhibition of protein phosphatases (PPP) 1 and 2A by okadaic acid did not modify basal outflow of DA. However, after the addition of okadaic acid a dramatic and biphasic effect was found when DA outflow was enhanced by GBR‐12909. Inhibition of PPP 2A enhanced extracellular DA levels, while inhibition of PPP 1 and 2A completely abolished the effect of GBR‐12909. In contrast to tetrodotoxin, the voltage‐activated calcium channel blocker ω‐conotoxin MVIIC inhibited GBR‐12909 effects on DA outflow. Additionally, in aCSF devoid of calcium GBR‐12909 did not increase DA liberation. These results suggest a complex and strong influence of phosphorylation on GBR‐12909 effects on calcium channel‐dependent DA outflow at low‐affinity piperazine binding sites in slices of the rat caudate nucleus in vitro. Synapse 46:72–78, 2002. © 2002 Wiley‐Liss, Inc.
5‐HT1A receptor imaging in the human brain: Effect of tryptophan depletion and infusion on [18F]MPPF binding
Authors: De Haes Joanna I. Udo , Bosker Fokko J. , Van Waarde Aren , Pruim Jan , Willemsen Antoon T.M. , Vaalburg Willem , Den Boer Johan A. 
Published: October 2002

AbstractThe 5‐HT1A receptor has been implicated in a variety of physiological processes, psychiatric disorders, and neurodegenerative disorders. [18F]MPPF is a useful radioligand for quantitative imaging of 5‐HT1A receptors in human subjects. Previous studies have shown that the binding of some radioligands is sensitive to changes in neurotransmitter concentration, whereas in other cases, binding is not affected. In the present study we investigated if [18F]MPPF binding to the 5‐HT1A receptor is sensitive to changes in 5‐HT. Changes in 5‐HT levels were achieved by influencing its synthesis through tryptophan depletion, including a tryptophan‐free amino acid drink 4.5 h prior to the PET scan and tryptophan infusion (10 mg/ml, 50 mg/kg, 30 min, starting 60 min prior to the PET scan). Binding of [18F]MPPF in the brain of six healthy, male volunteers was compared in these two conditions. Mean binding potentials in the medial temporal cortex, cortical regions, and raphe nucleus did not significantly differ between the two conditions. The results of the study show that, under the experimental conditions used, [18F]MPPF binding was not affected. It is hypothesized that the increases in 5‐HT levels needed to produce a measurable effect on [18F]MPPF binding would be significantly greater than that possible with tryptophan manipulation. Therefore, in pathological conditions, where such large increases in 5‐HT levels are not expected, [18F]MPPF seems a useful ligand to measure 5‐HT1A receptor distribution without the interference of endogenous 5‐HT. Synapse 46:108–115, 2002. © 2002 Wiley‐Liss, Inc.