bluuebunny/crossref_metadata_2025_split huggingface dataset:
MR colonography: How does air compare to water for colonic distention?
Authors: Ajaj Waleed , Lauenstein Thomas C. , Pelster Gregor , Goehde Susanne C. , Debatin Joerg F. , Ruehm Stefan G. 
Published: January 2004

AbstractPurposeTo prove the feasibility of air‐distended magnetic resonance colonography (MRC) and compare it with water‐based distention.Materials and MethodsIn five volunteers, the colon was imaged twice: once after distending the colon with air and a second time after distending the colon with water. A total of 50 patients, who had been referred to colonoscopy for a suspected colorectal pathology were randomized into water‐distention (N = 25) and air‐distention (N = 25) groups. A contrast‐enhanced T1‐weighted three‐dimensional volume interpolated breath‐hold (VIBE) sequence was collected. Comparative analysis was based on qualitative ratings of image quality and bowel distention, as well as contrast‐to‐noise ratio (CNR) measurements for the colonic wall with respect to the colonic lumen. In addition, patient acceptance was evaluated.ResultsInflammatory changes and colorectal masses were correctly identified on MRC in eight patients each. One 4‐mm polyp identified at colonoscopy was missed on water‐distended MRC. There were no false positive findings. No significant differences were found between air‐ and water‐distention regarding discomfort levels and image quality. The presence of air in the colonic lumen was not associated with susceptibility artifacts. CNR of the contrast‐enhanced colonic wall, as well as bowel distention, were superior on air‐distended three‐dimensional data sets.ConclusionMRC can be performed using either water or air for colonic distention. Both techniques permit assessment of the colonic wall and identification of colorectal masses. While discomfort levels are similar for both agents, MRC with air provides higher CNR and better colonic distention. J. Magn. Reson. Imaging 2004;19:216–221. © 2004 Wiley‐Liss, Inc.
Activation of neural pathways associated with sexual arousal in non‐human primates
Authors: Ferris Craig F. , Snowdon Charles T. , King Jean A. , Sullivan John M. , Ziegler Toni E. , Olson David P. , Schultz‐Darken Nancy J. , Tannenbaum Pamela L. , Ludwig Reinhold , Wu Ziji , Einspanier Almuth , Vaughan J. Thomas , Duong Timothy Q. 
Published: January 2004

AbstractPurposeTo evaluate brain activity associated with sexual arousal, fully conscious male marmoset monkeys were imaged during presentation of odors that naturally elicit high levels of sexual activity and sexual motivation.Material and MethodsMale monkeys were lightly anesthetized, secured in a head and body restrainer with a built‐in birdcage resonator and positioned in a 9.4‐Tesla spectrometer. When fully conscious, monkeys were presented with the odors of a novel receptive female or an ovariectomized monkey. Both odors were presented during an imaging trial and the presentation of odors was counterbalanced. Significant changes in both positive and negative BOLD signal were mapped and averaged.ResultsPeriovulatory odors significantly increased positive BOLD signal in several cortical areas: the striatum, hippocampus, septum, periaqueductal gray, and cerebellum, in comparison with odors from ovariectomized monkeys. Conversely, negative BOLD signal was significantly increased in the temporal cortex, cingulate cortex, putamen, hippocampus, substantia nigra, medial preoptic area, and cerebellum with presentation of odors from ovariectomized marmosets as compared to periovulatory odors. A common neural circuit comprising the temporal and cin‐gulate cortices, putamen, hippocampus, medial preoptic area, and cerebellum shared both the positive BOLD response to periovulatory odors and the negative BOLD response to odors of ovariectomized females.ConclusionThese data suggest the odor‐driven enhancement and suppression of sexual arousal affect neuronal activity in many of the same general brain areas. These areas included not only those associated with sexual activity, but also areas involved in emotional processing and reward. J. Magn. Reson. Imaging 2004;19:168–175. © 2004 Wiley‐Liss, Inc.
Mucosal arenavirus infection of primates can protect them from lethal hemorrhagic fever
Authors: Rodas Juan D. , Lukashevich Igor S. , Zapata Juan C. , Cairo Cristiana , Tikhonov Ilia , Djavani Mahmoud , Pauza C. David , Salvato Maria S. 
Published: January 2004

AbstractArenaviruses are transmitted from rodents to human beings by blood or mucosal exposure. The most devastating arenavirus in terms of human disease is Lassa fever virus, causing up to 300,000 annual infections in West Africa. We used a model for Lassa fever in which Rhesus macaques were infected with a related virus, lymphocytic choriomeningitis virus (LCMV). Our goals were to determine the outcome of infection after mucosal inoculation and later lethal challenge, to characterize protective immune responses, and to test cross‐protection between a virulent (LCMV‐WE) and an avirulent (LCMV‐ARM) strain of virus. Although intravenous infections in the monkey model were uniformly lethal, intragastric infections recapitulated the spectrum of clinical outcomes seen in human exposure to Lassa fever virus: death, recovery from disease, and most often, subclinical infection. Plaque neutralization, ELISA, lymphocyte proliferation, and chromium‐release assays were used to monitor humoral and cellular immune responses. Cross protection between the two strains was observed. The three out of seven monkeys that experienced protection were also the three with the strongest cell‐mediated immunity. J. Med. Virol. 72:424–435, 2004. © 2004 Wiley‐Liss, Inc.
Mechanisms of beta cell death during restricted and unrestricted enterovirus infection
Authors: Rasilainen Suvi , Ylipaasto Petri , Roivainen Merja , Bouwens Luc , Lapatto Risto , Hovi Tapani , Otonkoski Timo 
Published: January 2004

AbstractCoxsackie B virus (CVB‐5) infections potentially trigger and accelerate pancreatic beta cell damage leading to type 1 diabetes. In vivo, all viruses face natural resistance mediated by various host factors which restrict the progression of infection. Thus, the aims of this study were to generate a tissue culture model of restricted coxsackie B virus infection in primary islet cells by preventing the production of viral progeny with a selective inhibitor of viral RNA replication and to investigate the mechanisms of virus‐induced islet cell death during productive and restricted infective conditions. Cultured foetal porcine islet cells were infected effectively with the prototype strain of coxsackievirus B5 (CVB‐5). Nuclear viability stainings and electron microscopy showed productive infection to result in dominantly necrotic cell death with additional slight induction of apoptosis during the 7 days of follow‐up. The restricted conditions were created by addition of guanidine–hydrochloride (G–HCl) into culture medium. At 1 mM concentration, it significantly protected the infected cells from necrosis and thus maintained high viability. This was associated with increased significantly apoptosis. In perifusion analysis, the cellular ability to release insulin was reduced, although the metabolic integrity was preserved as shown by MTT‐analysis and cellular ATP levels. These data show that restriction of CVB‐5 replication with G–HCl protects islet cells against virus‐induced necrosis. However, restriction of viral replication shifts the mechanism of cell death from necrosis toward apoptosis. A slowly progressing subclinical infection of islets could thus lead to increased beta‐cell apoptosis. J. Med. Virol. 72:451–461, 2004. © 2004 Wiley‐Liss, Inc.
Apoptosis in dengue virus infected liver cell lines HepG2 and Hep3B
Authors: Thongtan Thananya , Panyim Sakol , Smith Duncan R. 
Published: January 2004

AbstractWhile both in vivo and in vitro evidence has suggested that liver cells undergo apoptosis in response to dengue virus infection, little is known about the mechanism of induction. Given that the p53 tumour suppressor gene is a key mediator of apoptosis, we sought to define the role of this gene in response to dengue virus infection. After infection, a p53 wild type liver cell line (HepG2) showed changes consistent with apoptosis including alterations of cell morphology, cellular detachment and DNA laddering. However, p53 was neither up‐regulated, nor showed any evidence of complexing with dengue virus proteins as determined by immunoprecipitation. Infection of a p53 null liver cell line (Hep3B) also produced changes consistent with the induction of apoptosis. While the profile of the cells undergoing apoptosis in each cell line was similar as determined by flow cytometry, the absolute levels were markedly different with up to 90% of Hep3B cells undergoing apoptosis compared to only 20% of HepG2 cells at day 5 post infection. By day 7, all Hep3B infected cells were dead. In contrast, it proved possible to culture dengue virus infected HepG2 cells for 3 months. Viral progeny released from the p53 null cell line were nine‐fold higher per attached cell than from the p53 wild type cell line. These results suggest that, while induction of apoptosis in liver cells is mediated by a non‐p53 regulated pathway, p53 may play a role in restricting the level of viral progeny to below a critical level at which apoptosis is triggered. J. Med. Virol. 72:436–444, 2004. © 2004 Wiley‐Liss, Inc.
Simultaneous detection of fourteen respiratory viruses in clinical specimens by two multiplex reverse transcription nested‐PCR assays
Authors: Coiras M.T. , Aguilar J.C. , García M.L. , Casas I. , Pérez‐Breña P. 
Published: January 2004

AbstractThere is a need for rapid, sensitive, and accurate diagnosis of lower respiratory tract infections in children, elderly, and immunocompromised patients, who are susceptible to serious complications. The multiplex RT‐nested PCR assay has been used widely for simultaneous detection of non‐related viruses involved in infectious diseases because of its high specificity and sensitivity. A new multiplex RT‐PCR assay is described in this report. This approach includes nested primer sets targeted to conserve regions of human parainfluenza virus haemagglutinin, human coronavirus spike protein, and human enterovirus and rhinovirus polyprotein genes. It permits rapid, sensitive, and simultaneous detection and typing of the four types of parainfluenza viruses (1, 2, 3, 4AB), human coronavirus 229E and OC43, and the generic detection of enteroviruses and rhinoviruses. The testing of 201 clinical specimens with this multiplex assay along with other one formerly described by our group to simultaneously detect and type the influenza viruses, respiratory syncytial viruses, and a generic detection of all serotypes of adenovirus, covers the detection of most viruses causing respiratory infectious disease in humans. The results obtained were compared with conventional viral culture, immunofluorescence assay, and a third multiplex RT‐PCR assay for all human parainfluenza viruses types described previously. In conclusion, both multiplex RT‐PCR assays provide a system capable of detecting and identifying simultaneously 14 different respiratory viruses in clinical specimens with high sensitivity and specificity, being useful for routine diagnosis and survey of these viruses within the population. J. Med. Virol. 72:484–495, 2004. © 2004 Wiley‐Liss, Inc.
Infection with human papillomavirus alters expression of the small proline rich proteins 2 and 3
Authors: Lehr Elizabeth , Hohl Daniel , Huber Marcel , Brown Darron 
Published: January 2004

AbstractHuman papillomavirus (HPV) does not induce lysis of infected keratinocytes, and the exact mechanisms of viral escape are not known. As keratinocytes differentiate, the cornified cell envelope (CCE) develops, providing a protective barrier to the host. Our prior studies have identified abnormalities in CCEs isolated from genital epithelium infected with HPV 11 (a low‐risk HPV type) and HPV 59 (a high‐risk HPV type). These abnormalities included reduced thickness and increased fragility compared to CCEs in healthy epithelium. Transcription of loricrin is also reduced in HPV 11‐ and 59‐infected epithelium. In this study, uninfected and HPV 11‐ or 59‐infected human genital epithelium were examined for expression of the small proline rich proteins (SPRs), which serve as cross‐linking proteins within the CCE. Limiting cycle RT‐PCR was performed to detect the various SPR transcripts in HPV 11‐ and 59‐infected, or uninfected epithelium. Immunohistochemical analysis and immunoblot assays were performed to analyze the distribution and quantity of SPR2A, SPR2B, and SPR3. SPR2B transcripts were moderately increased in the HPV 11‐ and 59‐infected tissues and SPR3 transcripts were significantly increased in HPV 11‐infected tissues and minimally increased in HPV 59‐infected tissues. SPR2B protein quantities were moderately increased while SPR2A was not significantly changed. SPR3 protein, while not present in uninfected epithelium, was detected in abundance in HPV 11‐infected tissue. We conclude that low‐risk and high‐risk HPVs share the ability to alter expression of CCE proteins, although the exact mechanisms may differ. Expression of individual SPRs differed between these types and these alterations may play a role in fragility of CCEs in HPV infection. J. Med. Virol. 72:478–483, 2004. © 2004 Wiley‐Liss, Inc.
Latent human papillomavirus infection is comparable in the larynx and trachea
Authors: Abramson Allan L. , Nouri May , Mullooly Virginia , Fisch Gene , Steinberg Bettie M. 
Published: January 2004

AbstractRecurrent respiratory papillomas are benign airway tumors caused by Human Papillomaviruses (HPVs) types 6 and 11. The disease is characterized by multiple recurrences of papillomas following surgical removal, caused by activation of latent HPV DNA. Most patients have laryngeal disease, while only a small subset has tracheal involvement. We have asked whether the lower frequency of tracheal papillomas was due to reduced prevalence of latent/subclinical tracheal HPV infection or reduced likelihood of activation to clinically apparent disease. A total of 121 biopsies of clinically normal laryngeal and tracheal tissues from 61 patients with laryngeal papillomas were analyzed for HPV DNA by polymerase chain reaction, confirmed by Southern blot hybridization. Patients were followed for 3–18 years (mean = 5.5 ± 4.4), with only one developing subsequent tracheal disease. There was no significant difference in prevalence of latent HPV DNA between larynx and trachea, analyzing either those patients with a single biopsy or those with more than one biopsy of larynx, trachea, or both. There was also no significant difference between tracheal latency with HPV 6 and HPV 11. We conclude that HPV infects tracheal mucosa and is maintained as a latent infection in the trachea as efficiently as in the larynx. Therefore, we propose that the low frequency of tracheal disease reflects a lower frequency of HPV activation, and postulate that cellular factors that differ between the stratified squamous epithelium of the larynx and the ciliated pseudo‐stratified columnar epithelium of the trachea contribute to this difference. J. Med. Virol. 72:473–477, 2004. © 2004 Wiley‐Liss, Inc.
Clade analysis and surface antigen polymorphism of hepatitis B virus American genotypes
Authors: Devesa Marisol , Rodríguez Carmen , León Graciela , Liprandi Ferdinando , Pujol Flor Helene 
Published: January 2004

AbstractEight genotypes (A–H) of hepatitis B virus (HBV) have been described, HBV genotypes F and H being autochthonous to America. HBV genotype F has been classified in four clusters. The objective of this study was to gain insight into the molecular epidemiology of HBV American genotypes, as well as to analyze the genotype‐related polymorphism in some functional domains of the surface proteins. The sequences of the S region of 106 isolates genotype F and H were analyzed, out of which 47 isolates genotype F circulated in different Venezuelan populations. Most of the Venezuelan isolates genotype F were grouped in cluster III (n = 39) and 7 in cluster II. One isolate obtained from a blood donor could not be classified in any clade and harbored amino acid substitutions characteristic of a vaccine escape mutant (G145R) and a stop codon in the surface antigen. Amino acid analysis of the PreS and S gene products showed unique genetic characteristics in genotype F and H sequences in some important domains involved in the early steps of infection. Out of 30 available sequences, two complete genome sequences of HBV genotype F from Venezuela were obtained. Phylogenetic analysis of these complete genomes confirmed the presence of four clusters inside genotype F, differing in more than 4% nucleotide divergence. Our extended analysis showed that genotype F clades Ia, III, and IV exhibit a restricted geographic distribution (Central America, the North and the South of South America, respectively) while clades Ib and II are found in all the Americas except in the Northern South America and North America respectively. J. Med. Virol. 72:377–384, 2004. © 2004 Wiley‐Liss, Inc.
Direct evidence that naturally occurring mutations within hepatitis B core epitope alter CD4+ T‐cell reactivity
Authors: Torre Francesco , Cramp Matthew , Owsianka Ania , Dornan Ed , Marsden Howard , Carman William , Williams Roger , Naoumov Nikolai V. 
Published: January 2004

AbstractExacerbations of chronic hepatitis B have been associated with accumulation of mutations in the HBV core gene, with amino acid (aa) substitutions clustering between aa 50 and 69. This region of the nucleocapsid protein is known as an immunodominant epitope for CD4+ T‐lymphocytes, however the impact of these mutations on T‐cell reactivity has not been investigated. For this purpose, we undertook fine mapping of the reactivity of peripheral blood lymphocytes, isolated from patients with acute (n = 8) or chronic hepatitis B (n = 10), against a panel of branched synthetic peptides. The peptide aa sequences corresponded to the wild type HBV (aa 50–69), or contained 1–3 aa changes derived on the basis of naturally occurring mutations. In four of eight patients with acute hepatitis B the wild type peptide 50–69, which corresponded to the core gene sequence of HBV present in these patients, induced a strong T‐cell proliferative response. In the same cases, the T‐cell response to the mutant peptides was altered at various degrees, depending on the number and the position of aa changes. The most pronounced inhibition of CD4+ T‐cell response (between 44 and 92%) was caused by a peptide ligand with two aa substitutions at positions 64 and 67. These results demonstrate that mutations within immunodominant epitopes of the HBV nucleocapsid can affect the CD4+ T‐lymphocyte reactivity, which may have a role for the accumulation of certain HBV strains after hepatitis flares during the course of chronic HBV infection. J. Med. Virol. 72:370–376, 2004. © 2004 Wiley‐Liss, Inc.
Kinetics of viremia and acute liver injury in relation to outcome of neonatal woodchuck hepatitis virus infection
Authors: Wang Yun , Menne Stephan , Baldwin Betty H. , Tennant Bud C. , Gerin John L. , Cote Paul J. 
Published: January 2004

AbstractThe kinetics of serum viral responses and acute liver injury were studied during neonatal woodchuck hepatitis virus (WHV) infection in relation to the chronic or resolved outcome. The mean concentrations of serum WHV DNA and surface antigen were significantly higher by week 10 post infection in chronic infections compared to resolving infections, and diverged even further by the time of peak viral load development in serum (week 12). After week 12, these viral markers were detected less frequently with time and at lower concentrations in the resolved outcome. In both outcomes, mean serum activities of hepatic enzymes became increased significantly above baseline by weeks 10–12, peaked at week 14, and normalized by weeks 20–22, thus indicating transient acute liver injury. The increasing liver injury responses were comparable between outcomes at week 12, when serum viral load was markedly higher in the developing chronic infections. This suggested a deficiency in early non‐cytolytic control of infection in the chronic outcome. At week 14, liver injury was significantly greater in the resolved outcome and associated with higher mean Fas ligand (FasL) and perforin messenger RNAs (mRNAs) in liver compared to the chronic outcome. This indicated greater immune‐mediated killing of infected hepatocytes during resolution. Thus, chronicity as an outcome of neonatal WHV infection develops relatively early during the acute phase of infection due to reduced immune‐mediated clearance of infected hepatocytes by both cytolytic and non‐cytolytic processes. J. Med. Virol. 72:406–415, 2004. © 2004 Wiley‐Liss, Inc.
The El Niño–southern oscillation and Antarctica
Authors: Turner John 
Published: January 2004

AbstractThis paper reviews our understanding of how the effects of the El Niño–southern oscillation (ENSO) might be transmitted from the tropical Pacific Ocean to the Antarctic, and examines the evidence for such signals in the Antarctic meteorological, sea ice, ice core and biological records. Many scientific disciples concerned with the Antarctic require an understanding of how the climatic conditions in the tropical and mid‐latitude regions affect the Antarctic, and it is hoped that this review will aid their work.The most pronounced signals of ENSO are found over the southeast Pacific as a result of a climatological Rossby wave train that gives positive (negative) height anomalies over the Amundsen–Bellingshausen Sea during El Niño (La Niña) events. However, the extra‐tropical signature can sometimes show a high degree of variability between events in this area. In West Antarctica, links between ENSO and precipitation have shown variability on the decadal time scale. Across the continent itself, it is even more difficult to relate meteorological conditions to ENSO, yet analyses of the long meteorological records from the stations do indicate a distinct switch in sign of the pressure anomalies from positive to negative across the minimum in the southern oscillation index.The oceanic signals of ENSO around the Antarctic are less clear, but it has been suggested that the Antarctic circumpolar wave could be forced by the phenomenon.Ice‐core data offer the potential to help in understanding the long‐term relationship between ENSO and the climate of the Antarctic, but there are difficulties because of the need to smooth the ice‐core data to overcome the mixing of snow on the surface. Nevertheless, analysis of methylsulphonic acid in a South Pole core has shown high variability on ENSO time scales.It is clear that some evidence of ENSO can be found in the Antarctic meteorological and ice‐core records; however, many of the relationships tend not to be stable with time, and we currently have a poor understanding of the transfer functions by which such signals arrive at the Antarctic from the tropical Pacific. Copyright © 2004 Royal Meteorological Society