bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrically active axons degenerate when exposed to nitric oxide
Authors: Smith Kenneth J. , Kapoor Raju , Hall Susan M. , Davies Meirion 
Published: November 2004

AbstractAxonal degeneration is a major cause of permanent deficit in inflammatory neurological diseases such as multiple sclerosis. Axons undergo degeneration specifically at the site of the inflammatory lesions, suggesting that locally produced inflammatory factors mediate the phenomenon. One such factor is nitric oxide (NO), which we have previously reported can cause reversible conduction block in axons. Here we confirm these observations and extend them to show that axons exhibit the early stages of wallerian degeneration if they are conducting impulses at physiological frequencies while they are exposed to the low micromolar concentrations of NO that are likely to occur at sites of inflammation. Rat dorsal roots were concurrently exposed in vivo to both NO and sustained impulse activity at 1, 50, or 100 Hz. Although our in vivo observations necessarily focused on the more acute responses, morphological examination of exposed roots at the end of the recording period revealed nodal and paranodal changes consistent with acute wallerian degeneration in roots stimulated at 50 or 100 Hz. This interpretation was confirmed in a few experiments that were prolonged to permit more obvious indicators of degeneration to develop. In these experiments the formation of myelin ovoids and frank axonolysis occurred in more than 95% of fibers. Roots stimulated at only 1 Hz appeared normal. We propose that the combination of normal impulse traffic and NO at sites of inflammation may cause axonal degeneration and that electrical activity may therefore be an important factor in causing permanent disability in patients with neuroinflammatory disorders. Ann Neurol 2001;49:470–476
Characterization of lipids from human brain tissues by multinuclear magnetic resonance spectroscopy
Authors: Tugnoli V. , Tosi M. R. , Tinti A. , Trinchero A. , Bottura G. , Fini G. 
Published: November 2004

AbstractMultinuclear (1H, 13C, and 31P) magnetic resonance spectroscopy are applied to the biochemical characterization of the total lipid fraction of healthy and neoplastic human brain tissues. Lipid extracts from normal brains, glioblastomas, anaplastic oligodendrogliomas, oligodendrogliomas, and meningiomas are examined. Moreover, the unknown liquid content of a cyst adjacent to a meningioma is analyzed. Two biopsies from glioblastomas are directly studied by 1H‐NMR without any treatment (ex vivo NMR). The 1H‐ and 13C‐NMR analysis allows full characterization of the lipid component of the cerebral tissues. In particular, the presence of cholesteryl esters and triglycerides in the extracts of high grade tumors is correlated to the vascular proliferation degree, which is different from normal brain tissue and low grade neoplasms. The 31P spectra show that phosphatidylcholine is the prominent phospholipid and its relative amount, which is higher in gliomas, is correlated to the low grade of differentiation of tumor cells and an altered membrane turnover. The ex vivo 1H‐NMR data on the glioblastoma samples show the presence of mobile lipids that are correlated to cell necrotic phenomena. Our data allow a direct correlation between biochemical results obtained by NMR and the histopathological factors (vascular and cell proliferations, differentiation, and necrosis) that are prominent in determining brain tumor grading. © 2001 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 62: 297–306, 2001
Analysis of single‐chain antibody production in Pichia pastoris using on‐line methanol control in fed‐batch and mixed‐feed fermentations
Authors: Hellwig Stephan , Emde Frank , Raven Nicole P. G. , Henke Mario , van der Logt Paul , Fischer Rainer 
Published: November 2004

AbstractIn the last few years the Pichia pastoris expression system has been gaining more and more interest for the expression of recombinant proteins. Many groups have employed fermentation technology in their investigations because the system is fairly easy to scale up and suitable for the production in the milligram to gram range. A large number of heterologous proteins from different sources has been expressed, but the fermentation process technology has been investigated to a lesser extent. A large number of fermentations are carried out in standard bioreactors that may be insufficiently equipped to meet the demands of high‐cell‐density fermentations of methylotrophic yeasts. In particular, the lack of on‐line methanol analysis leads to fermentation protocols that may impair the optimal expression of the desired products. We have used a commercially available methanol sensor to investigate in detail the effects of supplementary glycerol feeding while maintaining a constant methanol concentration during the induction of a Mut+ strain of Pichia pastoris. Specific glycerol feed rates in the range of 38–4.2 mg · g−1 · h−1 (mg glycerol per gram fresh weight per hour) were investigated. Expression of the recombinant scFv antibody fragment was only observed at specific feed rates below 6 mg · g−1 · h−1. At low specific feed rates, growth was even lower than with methanol as the sole carbon source and the harvest expression level of the scFv was only half of that found in the control fermentation. These results show that glycerol inhibits expression driven by the AOX1 promoter even at extremely limited availability and demonstrate the benefits of on‐line methanol control in Pichia fermentation research. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 74: 344–352, 2001.
Mutations in the second C2 domain of synaptotagmin disrupt synaptic transmission at Drosophila neuromuscular junctions
Authors: Mackler Jennifer M. , Reist Noreen E. 
Published: November 2004

AbstractThe synaptic vesicle protein, synaptotagmin, has been hypothesized to mediate several functions in neurotransmitter release including calcium sensing, vesicle recycling, and synaptic vesicle docking. These hypotheses are based on evidence from in vitro binding assays, peptide and antibody injection experiments, and genetic knockout studies. Synaptotagmin contains two domains that are homologous to the calcium ion (Ca2+)‐binding C2 domain of protein kinase C. The two C2 domains of synaptotagmin have broadly differing ligand‐binding properties. We have focused on the second C2 domain (C2B) of synaptotagmin I, in particular, on a series of conserved lysine residues on β‐strand 4 of C2B. This polylysine motif binds clathrin‐adapter protein AP‐2, neuronal calcium channels, and inositol high polyphosphates. It also mediates Ca2+‐dependent oligomerization. To investigate the importance of these lysine residues in synaptic transmission, we have introduced synaptotagmin I (syt) transgenes harboring specific polylysine motif mutations into flies otherwise lacking the synaptotagmin I protein (sytnull). Electrophysiological analyses of these mutants revealed that evoked transmitter release is decreased by ≈36% and that spontaneous release is increased approximately twofold relative to sytnull flies that express a wild type syt transgene. Synaptotagmin expression in both the mutant and the wild type transgenic lines was equivalent, as measured by semiquantitative Western blot analysis. Thus, the alteration in synaptic transmission was due to the mutation and not to the level of synaptotagmin expression. We conclude that synaptotagmin interactions mediated by the C2B polylysine motif are required to attain full synaptotagmin function in vivo. J. Comp. Neurol. 436:4–16, 2001. © 2001 Wiley‐Liss, Inc.
Zona incerta: Substrate for contralateral interconnectivity in the thalamus of rats
Authors: Power Brian D. , Mitrofanis John 
Published: November 2004

AbstractWe have shown previously that the zona incerta (ZI), a small nucleus deriving from the ventral thalamus, has extensive ipsilateral connections with the higher order and intralaminar nuclei of the dorsal thalamus and that there are many ipsilateral interconnections between the different cytoarchitectonic sectors of the ZI. In this study, we explore the contralateral connections that the ZI has with its opposing nucleus as well as with the other nuclei of the thalamus. Injections of biotinylated dextran or cholera toxin subunit B were made into each of the different ZI sectors (rostral, dorsal, ventral, and caudal) and into intralaminar and higher order dorsal thalamic nuclei of Sprague‐Dawley rats by using stereotaxic coordinates. Brains were fixed in aldehyde and processed using standard methods. Our results show that, after injections limited to a given ZI sector, labelled terminal‐like elements and cells were seen across the other sectors of the ZI of the contralateral side. Furthermore, after each of these ZI injections, labelling was seen in the intralaminar (e.g., parafascicular, central lateral, and central medial) and higher order (e.g., posterior thalamic, lateral posterior, and lateral dorsal) nuclei of the contralateral side. These patterns of labelling were confirmed after tracer injections into intralaminar and higher order nuclei; after such injections, labelling was seen in the contralateral ZI. In all cases, there was labelling on the ipsilateral side as well, and this was generally heavier than on the contralateral side. Overall, our results indicate that there is a network of interconnections between the ZI of both sides of the thalamus and that the ZI has contralateral connections with the intralaminar and higher order nuclei. Hence, the ZI furnishes a substrate that spreads activity to both sides of the brain. J. Comp. Neurol. 436:52–63, 2001. © 2001 Wiley‐Liss, Inc.
Localization of neuropeptide Y mRNA and peptide in the chicken hypothalamus and their alterations after food deprivation, dehydration, and castration
Authors: Kameda Yoko , Miura Masaaki , Nishimaki Toshiyuki 
Published: November 2004

AbstractLocalization of neuropeptide Y (NPY) mRNA in the hypothalamus of chickens was studied by in situ hybridization with digoxigenin‐labeled chicken NPY cRNA probe. The largest number of perikarya‐expressing NPY mRNA was found within the mediobasal hypothalamus, including the infundibular nucleus, inferior hypothalamic nucleus, and median eminence. Many NPY perikarya were noted to surround the nucleus rotundus and to be present in the supraoptic nucleus. Moreover, some perikarya were detected in the nucleus of basal optic root, bed nucleus pallial commissure, and nucleus striae terminalis close to the lateral forebrain bundle. NPY‐immunoreactive nerve fibers were densely distributed in these regions containing the NPY mRNA‐expressing perikarya. Following food deprivation for four days, perikarya‐expressing NPY mRNA and peptide were markedly increased in the mediobasal hypothalamus and particularly so in the infundibular nucleus. No changes, however, were detected in other regions containing NPY‐positive perikarya. Water deprivation induced less increase in NPY‐positive perikarya in the mediobasal hypothalamus compared to food deprivation. After gonadectomy, the number of NPY‐positive perikarya in the mediobasal hypothalamus was unaltered. Northern blot analysis with 32P‐labeled chicken NPY cDNA probe demonstrated that a 2.7‐fold increase of NPY mRNA was induced by starvation and a 1.5‐fold increase was induced by dehydration, whereas the NPY mRNA band remained unchanged after gonadectomy. Thus, it seems that NPY neurons located in the mediobasal hypothalamus are involved in feeding behavior but not reproductive activity. J. Comp. Neurol. 436:376–388, 2001. © 2001 Wiley‐Liss, Inc.
Immunocytochemical analysis of basket cells in rat piriform cortex
Authors: Ekstrand Jeffrey J. , Domroese Mark E. , Feig Sherry L. , Illig Kurt R. , Haberly Lewis B. 
Published: November 2004

AbstractBasket cells, defined by axons that preferentially contact cell bodies, were studied in rat piriform (olfactory) cortex with antisera to γ‐aminobutyric acid (GABA)ergic markers (GABA, glutamate decarboxylase) and to peptides and calcium binding proteins that are expressed by basket cells. Detailed visualization of dendritic and axonal arbors was obtained by silver‐gold enhancement of staining for vasoactive intestinal peptide (VIP), cholecystokinin (CCK), parvalbumin, and calbindin. Neuronal features were placed into five categories: soma‐dendritic and axonal morphologies, laminar distributions of dendritic and axonal processes, and molecular phenotype. Although comparatively few forms were distinguished within each category, a highly varied co‐expression of features from different categories produced a “combinatorial explosion” in the characteristics of individual neurons. Findings of particular functional interest include: dendritic distributions suggesting that somatic inhibition is mediated by feedforward as well as feedback pathways, axonal variations suggesting a differential shaping of the temporal aspects of somatic inhibition from different basket cells, evidence that different principal cell populations receive input from different combinations of basket cells, and a close association between axonal morphology and molecular phenotype. A finding of practical importance is that light microscopic measurements of boutons were diagnostic for the molecular phenotype and certain morphological attributes of basket cells. It is argued that the diversity in basket cell form in the piriform cortex, as in other areas of the cerebral cortex, reflects requirements for large numbers of specifically tailored inhibitory processes for optimal operation that cannot be met by a small number of rigidly defined neuronal populations. J. Comp. Neurol. 434:308–328, 2001. © 2001 Wiley‐Liss, Inc.
Bi‐level image coding for digital printing using genetic algorithm
Authors: Tanaka Masaharu , Sakanashi Hidenori , Mizoguchi Masanobu , Higuchi Tetsuya 
Published: November 2004

AbstractWe propose a bi‐level image coding method for digital printing images, using Genetic Algorithms (GAs). These images have resolutions as high as those of photographs; therefore, the coding method is required to achieve high compression ratios. Our GA‐based method can obtain higher compression ratios by optimizing the coding algorithm according to the features of the printing images. We have confirmed that our method is 1014 times as fast as a full search, and that the compression ratio is 9.26% better than that of conventional methods. In addition, the compression ratio is 42% higher than that of the JBIG standard. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(9): 1–10, 2001
Applying mixed methods under the framework of theory‐driven evaluations
Authors: Chen Huey‐tsyh 
Published: November 2004

AbstractThe application of mixed methods under the framework of theory‐driven evaluations can minimize the potential tension and conflict of mixing qualitative and quantitative methods, as well as compensate for each method's weaknesses. Mixed methods should not be applied indiscriminantly, however, but rather contingently under particular conditions as described in this chapter.
Genetic imbalances in 26 cases of penile squamous cell carcinoma
Authors: Alves Gilda , Heller Anita , Fiedler Wolfgang , Campos Mércia Mendes , Claussen Uwe , Ornellas Antônio Augusto , Liehr Thomas 
Published: November 2004

AbstractTo obtain more information on chromosomal changes in the up‐to‐now poorly studied tumor class of penile squamous cell carcinoma (SCC), we performed a comparative genomic hybridization study of 26 cases of this rare tumor. DNA sequence copy number alterations (CNAs) very similar to those detected in other SCC types, such as oral and esophageal SCC, were noted. The most common copy number gains were found in 8q24, 16p11–12, 20q11–13, 22q, 19q13, and 5p15, and the most common deletions were detected in 13q21–22, 4q21–32, and along the X chromosome. Classifying the patients according to the number of CNAs showed a possible correlation with clinical outcome. © 2001 Wiley‐Liss, Inc.
The sedimentary records in Mediterranean rockshelters and caves: Archives of environmental change
Authors: Woodward Jamie C. , Goldberg Paul 
Published: November 2004

AbstractIt is important to develop rigorous methods and robust conceptual models for the interpretation of rockshelter and cave sediment records so that the cultural sequences they contain can be considered in their proper environmental context. Much of what we know about the prehistory of the Mediterranean region and adjacent areas has largely been pieced together from materials excavated from sedimentary sequences in these environments. The rockshelters and caves of the region form important environmental and sedimentary archives. Recent work has begun to consider if the remarkable climatic variability evident in the high resolution lacustrine and ice core records is manifest in the rockshelter and cave sediment records of the area. In this context, the two main characteristics of a rockshelter or cave site which control its usefulness as an archive of environmental change are the temporal resolution of the sedimentary record and the environmental sensitivity of the site. Many rockshelters and caves can be described as either Active Karst Settings (AKS) or Passive Karst Settings (PKS) and site type is an important influence on climatic sensitivity with a direct influence upon the usefulness of the sedimentary sequence as a proxy record of climate change. It is now clear that some sites may preserve detailed paleoclimatic records and the climatic signal may be represented by distinctive suites of micromorphological features, by variations in the input of allogenic sediment, or by fluctuations in the mineral magnetic properties of the fine sediment fraction. It can be argued that data derived from the analysis of bulk coarse‐grained samples often lacks the stratigraphic resolution and environmental sensitivity that can be obtained from other approaches. The most favorable sites for detailed paleoclimatic reconstruction appear to be in active karst settings such as Theopetra Cave (Greece) and Pigeon Cave (Morocco) where micromorphological analyses offer insights into the stratigraphic record that are not otherwise obtainable. The temporal resolution of a site can only be established through a rigorous stratigraphic analysis and a comprehensive dating program. These are fundamental considerations in the study of rockshelter sediment records, especially when attempting to correlate between sites and draw comparisons with other proxy records of environmental change derived from sedimentary environments with rather different characteristics. Rockshelters and caves are part of a wider sediment system, and their investigation must be accompanied by detailed geomorphological, sedimentological, paleoecological, and geochronological studies of the off‐site Quaternary record. © 2001 John Wiley & Sons, Inc.
Advanced hypopharyngeal carcinoma treatment results according to treatment modalities
Authors: Kim Suzy , Wu Hong‐Gyun , Heo Dae‐Seog , Kim Kwang Hyun , Sung Myung‐Whun , Park Charn Il 
Published: November 2004

AbstractBackgroundThe purpose of this retrospective study is to compare the treatment results of locally advanced hypopharyngeal carcinoma according to treatment modalities.MethodsSeventy‐three patients with locally advanced hypopharyngeal carcinoma treated at the Department of Therapeutic Radiology, Seoul National University Hospital, between August 1979 and July 1997 were retrospectively analyzed. Twenty‐three patients were treated with radiotherapy (RT) alone, 18 patients were treated with surgery and postoperative RT, and 32 patients were treated with neoadjuvant chemotherapy (CTx) and RT. Median follow‐up period was 28 months.ResultsThe overall 5‐year survival rates were 15.7% for the RT alone group, 46.8% for surgery and postoperative RT group, and 43.0% for neoadjuvant CTx and RT group. The 5‐year disease‐free survival rates were 13.9%, 47.4%, and 30.7%, respectively. Surgery and postoperative RT or neoadjuvant CTx and RT showed superiority over RT alone in terms of both overall survival and disease‐free survival rates. No significant differences were found in overall and disease‐free survival rates between the surgery and postoperative RT group and neoadjuvant CTx and RT group (p= .15,p= .13). In the neoadjuvant CTx and RT group, 12 patients (38%) retained their larynx more than 5 years.ConclusionNeoadjuvant CTx and RT is an effective strategy to achieve organ preservation without compromising the survival of patients with locally advanced hypopharyngeal carcinoma. © 2001 John Wiley & Sons, Inc. Head Neck 23: 713–717, 2001.
Observer error in the assessment of nodal disease in head and neck cancer
Authors: Alderson David J. , Jones Terry M. , White Sarah J. , Roland Nicholas J. 
Published: November 2004

AbstractBackgroundThere is no previously published information on clinicians' abilities to accurately differentiate between different stages of node positive disease in head and neck cancer.MethodsForty‐two surgeons examined standardized nodes in a model neck and estimated nodal size. Each recorded their confidence in their ability to perform the task using a visual analogue scale. Reference nodes of known size were provided for comparison during a second examination of each node. The study was repeated after 1 month.ResultsAccuracy was poor and was not dependent on experience or confidence. There was a tendency to underestimate the size of smaller nodes. Estimates were strongly influenced by volume independent of largest diameter (p < .001). Reference nodes aided accuracy (p = .031). Subjects were not consistent on repeated testing (p < .001).ConclusionsBoth trainees and specialists are poor at accurately staging nodal disease using palpation alone. © 2001 John Wiley & Sons, Inc. Head Neck 23: 739–743, 2001.
Incidence of cervical node involvement in metastatic cutaneous malignancy involving the parotid gland
Authors: O'Brien Christopher J. , McNeil Edward B. , McMahon Jeremy D. , Pathak Irvin , Lauer Christopher S. 
Published: November 2004

AbstractBackgroundThe parotid lymph nodes represent an important group of nodes at risk for metastatic involvement from cutaneous malignancies of the head and neck. When treating patients with metastatic disease in the parotid gland it has been our custom to also remove the lymph nodes of the neck on the basis that these nodes represent other nodal groups at risk for metastatic involvement. The aim of this study is to determine the incidence of cervical node involvement among patients with clinical metastatic SCC or melanoma of the parotid to determine whether treatment of the clinically negative neck is warranted.MethodsThe study group consists of 123 prospectively accessioned patients with clinical metastatic cutaneous squamous cell carcinoma (SCC) (n = 73) or melanoma (n = 50) involving the parotid gland and a minimum of 2 years of follow up, irrespective of the clinical status of the neck.ResultsAmong 73 patients with metastatic SCC in the parotid, 19 (26%) had clinical neck involvement, and 16 of these were pathologically positive (84%). A total of 37 patients had elective neck dissections, and 13 were pathologically positive, which is an overall rate of 52% neck involvement among patients having neck dissection. Among 50 patients with metastatic melanoma in the parotid, 19 (38%) patients were initially seen with clinical neck disease, and all were pathologically positive. Among 31 patients with clinically negative necks, 26 had neck dissections and seven had positive nodes (27%). Overall, 58% of patients with melanoma who had a neck dissection had positive nodes.ConclusionPatients with metastatic cutaneous SCC and melanoma involving the parotid gland had a high incidence of clinical (26% and 38%, respectively) and occult neck disease (35% and 27%). Treatment of the clinically negative neck in the presence of clinical metastatic parotid cancer should be considered to reduce the likelihood of failure in cervical nodes, to define the extent of disease, and to assist with patient selection for adjuvant therapy. © 2001 John Wiley & Sons, Inc. Head Neck 23: 744–748, 2001.