bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐lasting synaptic modification in the rat hippocampus resulting from NMDA receptor blockade during development
Authors: Bellinger Frederick P. , Wilce Peter A. , Bedi Kuldip S. , Wilson Peter 
Published: August 2002

AbstractRecent reports have suggested that proper maturation of synapses in the hippocampus requires activation of NMDA receptors. We previously demonstrated that neonatal ethanol exposure results in a lasting reduction in synaptic strength in the hippocampus. To determine if this reduction was due to ethanol's effects on NMDA receptors, we investigated long‐term changes in synaptic properties resulting from administration of NMDA receptor antagonists to neonatal animals. Rats were injected daily from PND 4–9 with either the noncompetitive NMDA receptor antagonist MK‐801, the competitive NMDA receptor antagonist CPP, or the AMPA receptor antagonist NBQX. Control rats were either injected daily with physiological saline during the same period or left to develop normally. Hippocampal slices were prepared from nembutal‐anesthetized animals between PND 35 and PND 40. The maximum pEPSP and PS values were not significantly different between controls and NMDA antagonist‐treated animals. However, slices from animals injected with NMDA receptor antagonists required higher stimulus currents to attain comparable pEPSPs. The ratio of the slope of the pEPSP to the amplitude of the presynaptic volley was also reduced, as were pEPSP responses to specific stimulus currents. None of these effects were observed in slices prepared from animals treated with the AMPA receptor antagonist NBQX. Glutamate receptor antagonism did not produce lasting changes in long‐term potentiation or paired‐pulse facilitation. These results indicate activation of NMDA receptors during development is necessary for proper development of synapses. Synapse 43:95–101, 2002. © 2001 Wiley‐Liss, Inc.
Co‐localization of active caspase‐3 and DNA fragmentation (TUNEL) in normal and hyperthermia‐induced abnormal mouse development
Authors: Umpierre Carmen C. , Little Sally A. , Mirkes Philip E. 
Published: August 2002

AbstractBackgroundPrevious work has shown that caspase‐3 activation and DNA fragmentation, two hallmarks of apoptosis, are induced in day 9 mouse embryos exposed to hyperthermia (43°C); however, the methods used to assess caspase‐3 activation (Western blot) and DNA fragmentation (gel electrophoresis) did not allow these apoptotic events to be localized to specific cells within the embryo.MethodsTo co‐localize active caspase‐3 and DNA fragmentation to specific cells, we used paraffin sections of day 13 mouse limb buds, sections of control and hyperthermia‐treated day 9 mouse embryos, and sequential immunohistochemical staining for caspase‐3 and TUNEL staining for DNA fragmentation. We used a primary rabbit antibody specific for the active, p17 subunit of caspase‐3 and a goat anti‐rabbit secondary antibody conjugated to Alexa 594 fluorochrome (red fluorescence) to localize active caspase‐3. To co‐localize DNA fragmentation, we subsequently processed the same sections by the TUNEL method using fluorescein‐labeled dUTP (green fluorescence).ResultsUsing this dual labeling approach, we show that active caspase‐3 (caspase‐3 positive) and DNA fragmentation (TUNEL positive) occur in a sub‐population of interdigital mesenchyme cells of day 13 mouse limb buds. Using the same approach, we detected a small number of caspase‐3 positive and TUNEL‐positive cells in the central nervous system and in the mesenchyme of the first branchial arch of untreated day 9 mouse embryos. The number of caspase‐3 and TUNEL‐positive cells are greatly increased 5 hr after a brief exposure to hyperthermia (43°C, 13 min). Caspase‐3 and TUNEL‐positive cells were most abundant in the neuroepithelium of the developing central nervous system, mesenchyme of the first pharyngeal arch, and somitic mesoderm. In contrast, the heart, mesencephalic mesenchyme, and the visceral yolk sac contained few, if any, caspase‐3 and TUNEL‐positive cells.ConclusionsThis is the first demonstration that activation of caspase‐3 and DNA fragmentation co‐localize in cells programmed to die in the interdigital mesenchyme of day 13 limb buds and in the neuroepithelium and branchial arch mesenchyme of day 9 mouse embryos. Similarly, our results represent the first co‐localization of teratogen‐induced activation of caspase‐3 and DNA fragmentation in specific cells of early postimplantation mouse embryos, and confirm that cells of the developing central nervous system are acutely sensitive to the cell death‐inducing potential of hyperthermia, whereas cells of the heart are resistant. Finally, we show for the first time that, like cells of the heart, cells of the mesencephalic mesenchyme and the visceral yolk sac are also resistant to hyperthermia‐induced apoptosis. Teratology 63:134–143, 2001. © 2001 Wiley‐Liss, Inc.
Testing the toxicity of influents to activated sludge plants with the Vibrio fischeri bioassay utilising a sludge matrix
Authors: Hoffmann Caroline , Christofi Nick 
Published: August 2002

AbstractTo protect the bioceonosis within activated sludge, a method of predicting the toxic effect of influents to the biological treatment stage of waste water treatment plants, based on DIN method 38412 L 34, has been developed. A population of the luminescent marine bacterium Vibrio fischeri was incorporated into a sludge testing matrix derived from a model laboratory and real activated sludge plants. The sludge was challenged with different concentrations of pure toxicants and complex aqueous samples, and light output by V. fischeri monitored. The results were compared to toxicant testing in the absence of sludge (standard test). The modified method was found to be less sensitive for some toxicants tested than the standard DIN and other bioluminescent tests, but considered more realistic as it provides buffering and takes into account sorption which can affect the sensitivity of the test towards some compounds. The method is comparable in terms of ease of use, speed, reproducibility and cost effectiveness to standard V. fischeri luminescence methods. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 422–427, 2001
Relative potencies of individual polycyclic aromatic hydrocarbons to induce dioxinlike and estrogenic responses in three cell lines
Authors: Villeneuve D. L. , Khim J. S. , Kannan K. , Giesy J. P. 
Published: August 2002

AbstractThe dioxinlike and estrogenic relative potencies (REPs) of 16 priority polycyclic aromatic hydrocarbons (PAHs), seven methylated PAHs, and two hydroxylated PAHs were examined using threein vitrocell bioassays. Anin vitro ethoxyresorufin‐O‐deethylase assay with PLHC‐1 fish hepatoma cells andin vitroluciferase assay with H4IIE‐luc recombinant rat hepatoma cells were used to evaluate dioxinlike potency. Anin vitroluciferase assay with MVLN, recombinant human breast carcinoma cells, was used to evaluate estrogenic potency. Seven of the 16 priority PAHs tested induced significant dioxinlike responses. Excluding outliers with large ranges of uncertainty, the dioxinlike REPs for the PAHs ranged from 10−6to 10−3. This is similar to the REPs reported for other xenobiotics of concern including polychlorinated naphthalenes (PCNs) and some polychlorinated biphenyls (PCBs). In general, REP estimates generated in this study were similar to those reported previously. However, a comparison of the estimates of total 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin equivalents derived using assay‐specific REPs with REPs reported in other studies indicated that the use of nonspecific REPs could lead to significant error in mass‐balance (potency‐balance) analyses. A 10‐h acid treatment completely destroyed the dioxinlike activity of a PAH mixture. Among the compounds tested, only benzo[a]anthracene and dibenz[a,h]anthracene induced significant responses in the MVLN bioassay. Relative estrogenic potencies were estimated to be approximately 10−7. Overall, this research contributes to the growing consensus regarding the dioxinlike potency of priority PAHs and PAH derivatives and provides some additional evidence about potentially estrogenic PAHs. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 128–137, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10041
A touch‐enabled system for multi‐resolution modeling and 3D painting‡
Authors: Ehmann Stephen A. , Gregory Arthur D. , Lin Ming C. 
Published: August 2002

AbstractWe present an intuitive system,inTouch, for interactively editing and painting a polygonal mesh using a force‐feedback device. An artist or a designer can use this system to create and refine a three‐dimensional multi‐resolution polygonal mesh. The appearance can be further enhanced by directly painting onto its surface. The system allows users to naturally create complex forms and patterns aided not only by visual feedback but also by their sense of touch. Copyright © 2001 John Wiley & Sons, Ltd.
Mobility culling: an efficient rendering algorithm using temporal coherence
Authors: Oh Kyoung‐Su , Shin Byeong‐Seok , Gil Shin Yeong 
Published: August 2002

AbstractInteractive display of complex scenes is a challenging problem in computer graphics. Such current approaches as z‐buffer, level of detail and visibility culling have not fully used the temporal coherence between consecutive frames. When the viewing condition is fixed, the color and depth values of static polygons can be obtained from the result of the previous frame and only the remaining dynamic polygons require rendering. We present a method that enhances the speed of the conventional z‐buffer algorithm by exploiting the above temporal coherence. This algorithm is simple to combine with existing graphics hardware that supports the conventional z‐buffer algorithm. It can manipulate any scene suitable for the z‐buffer algorithm without preprocessing or human intervention. The rendering time is proportional to the number of dynamic polygons in each frame. Experimental results show that our method is faster than the conventional z‐buffer algorithm and the performance enhancement becomes higher as the fraction of static polygons increases. Copyright © 2001 John Wiley & Sons, Ltd.
Smart cell sectorization for third generation CDMA systems
Authors: Giuliano Romeo , Mazzenga Franco , Vatalaro Francesco 
Published: August 2002

AbstractSmart antennas are a powerful means to provide the increased bandwidth efficiency needed to deliver advanced third generation (3G) interactive multimedia services anywhere and anytime. In this paper we focus on the development of smart antennas located at the base stations of a code division multiple access (CDMA) cellular system. First, we review the main characteristics of antenna array systems and highlight some issues related to the inclusion of smart antennas in a 3G CDMA system. A classification of the proposed beamforming techniques and a discussion on the advantages and drawbacks of smart antennas are provided. Then, we introduce an original smart antenna technique based on rotation and resizing of the available sectors much simpler than common smart antennas based on beamforming techniques addressing a specific user. We discuss on the impact of the proposed technique in the base station architecture. Finally, we provide simulation results in order to show the effectiveness of the proposed approach and to relate transmission performance to system parameters. It turns out that the smart sectorization technique provides significant capacity improvements under statistically uniform user distribution (up to about 80 per cent for data traffic). Copyright © 2002 John Wiley & Sons, Ltd.
Channel modeling for satellite and HAPS system design
Authors: Vázquez‐Castro M. , Pérez‐Fontán F. , Arbesser‐Rastburg B. 
Published: August 2002

AbstractThis paper reviews the state of the art and current trends towards 3G and 3G+ mobile satellite systems that are being planned in parallel or within the International Mobile Telecommunications (IMT‐2000) framework. The subject is firstly approached by introducing the key and enabling technologies both for satellites and high altitude platform stations. After having introduced an overall picture, another review is presented on physical layer research activities including propagation and channel modeling. Finally, the use of the reviewed channel models for Code Division Multiple Access system level analysis is introduced and some current efforts towards system design are presented. Copyright © 2002 John Wiley & Sons, Ltd.
Flap/lead–lag aeroelastic stability of wind turbine blades
Authors: Chaviaropoulos P. K. 
Published: August 2002

AbstractA numerical tool for investigating the aeroelastic stability of a single wind turbine blade subjected to combined flap/lead–lag motion is presented. Its development is motivated by recent concern about destructive edgewise vibrations of modern stall‐controlled blades. The stability tool employs a finite element formulation to discretize in space the structural and aerodynamic governing equations. Unsteady aerodynamics is considered by means of the extended ONERA lift and drag models. The mathematical form of these models allows for a combined treatment of dynamics and aerodynamics through the introduction of a so‐called ‘aeroelastic beam element’. This is an extended two‐node beam element having both deformation and aerodynamic degrees of freedom. Several linear and non‐linear versions of the stability tool are available, differing in the way that instantaneous lift and/or drag is treated. In the linear case, stability is investigated through eigenvalue analysis. Time domain integration is employed for non‐linear stability analysis. Results are presented and discussed for a 17 m stall‐controlled blade. Copyright © 2001 John Wiley & Sons, Ltd.
Endoscopy, assisted percutaneous repair of the Achilles tendon ruptures: a cadaveric and clinical study
Authors: Turgut Akın , Günal İzge , Maralcan Gökhan , Köse Nusret , Göktürk Erol 
Published: August 2002

AbstractEndoscopy‐assisted percutaneous repair of Achilles tendon ruptures were investigated in a cadaveric and clinical study. Sixteen above‐knee fresh amputation specimens in which different types of Achilles tendon ruptures were created were repaired percutaneously with the visualization of the tendon ends by endoscopy. Neither malalignment nor damage to the neurovascular structures was observed. Eleven patients were treated in this way. No reruptures, wound problems, or neurovascular injury were observed. All patients returned to daily activities 10–11 weeks after the repair. This technique seems to overcome certain problems of conservative, surgical, or percutaneous repair of the Achilles tendon ruptures.
Preoperative Evaluation of Pancreatic Masses with Positron Emission Tomography Using 18F‐fluorodeoxyglucose: Diagnostic Limitations
Authors: Sendler Andreas , Avril Norbert , Helmberger Hermann , Stollfuß Jens , Weber Wolfgang , Bengel Frank , Schwaiger Markus , Roder Jürgen D. , Siewert J. Rüdiger 
Published: August 2002

AbstractIdentification of pancreatic cancer in patients presenting with an enlarged pancreatic mass is a major diagnostic problem. Positron emission tomography (PET) using the radiolabeled glucose analogue 18F‐fluorodeoxyglucose (FDG) has been suggested to provide excellent accuracy for noninvasive determination of suspicious pancreatic masses. We conducted a prospective study to verify these results. Forty‐two patients admitted for pancreatic surgery underwent PET scanning. Image analysis was based on visual film evaluation and quantification of regional tracer uptake. PET imaging was visually analyzed by three observers blinded for the results of other diagnostic tests; they qualitatively graded the scans using a five‐point scale (I = low to V = high) for the presence and intensity of focal FDG uptake. Diagnosis was proven by histology (n= 38) or follow‐up (n= 4). Furthermore, the results of PET were compared with helical computed tomography (CT) and conventional ultrasonography (US), done during the routine diagnostic workup before pancreatic cancer surgery. Regarding only the results with scores of IV and V as positive for representing definite malignancy yielded a sensitivity of 71% and a specificity of 64% for film reading. Quantification of regional tracer uptake contributed no significant diagnostic advantage for differentiation between benign and malignant tumors. Helical CT revealed a sensitivity of 74% and a specificity of 45.5% and abdominal US 56% and 50%, respectively. We concluded that PET imaging provides only fair diagnostic accuracy (69%) for characterizing enlarged pancreatic masses. PET does not allow exclusion of malignant tumors. In doubtful cases, the method must be combined with other imaging modalities, such as helical CT. The results indicate that the number of invasive procedures is not significantly reduced by PET imaging.
Improvement of Operative Mortality after Curative Resection for Gastric Cancer: Population‐based Study
Authors: Msika Simon , Benhamiche Anne‐Marie , Tazi Mohamed A. , Rat Patrick , Faivre Jean 
Published: August 2002

AbstractIt is not well known if the improvement in operative mortality after surgery for gastric cancer reported in hospital series can be extrapolated to the whole population. The aim of this study was to determine trends in operative mortality over a 20‐year period in a nonselected community‐based series of patients. A database of 648 patients with gastric cancer resected with curative intent between 1976 and 1995 in a region with a half‐million population was divided into two periods: 1976–1983 and 1984–1995. Nonconditional logistic regression was performed to estimate the independent effects of the studied factors. Operative mortality was higher during the 1976–1983 period than during the 1984–1995 period (17.1% vs. 7.1%; p < 0.0001). When comparing the two study periods, operative mortality decreased dramatically from 26.2% to 10.0% in patients over age 70, from 31.8% to 7.9% after total gastrectomy, and from 30.7% to 6.3% after proximal esophagogastrectomy. Operative mortality after total gastrectomy was nearly the same as that after distal gastrectomy (7.9% vs 5.9%) during the second study period. During the first study period, operative mortality was independently associated with age at diagnosis, type of gastrectomy, and to a lesser degree stage at diagnosis; during the second study period, only age and stage at diagnosis were associated with the risk of operative mortality. This study indicates that in this well defined population operative mortality after curative resection for gastric cancer has decreased during the last 20 years. The results should encourage aggressive management of patients with gastric cancer, even in patients over 70 years of age.
Evaluation of S‐100b as a Specific Marker for Neuronal Damage Due to Minor Head Trauma
Authors: Biberthaler Peter , Mussack Thomas , Wiedemann Ernst , Kanz Karl‐Georg , Koelsch Martin , Gippner‐Steppert Cornelia , Jochum Marianne 
Published: August 2002

Abstract.Management of patients with minor head trauma (MHT) continues to be debated in the literature. Measurement of S‐100b in serum has been introduced into the discussion as an additional screening tool for intracerebral injuries because routine cranial computed tomography (CCT) of a large number of patients causes logistic difficulties, and the neurologic examination is often impaired by a high frequency of coincidental intoxication. The aim of our study was to determine the diagnostic value of measuring S‐100b in the serum of MHT patients to identify risk groups. Additional validity should be aquired by a comparison with plasma levels of polymorphonuclear neutrophil (PMN) elastase an established general trauma marker. A series of 52 patients with MHT were included in the prospective study. At admission the patients underwent a routine CCT scan to detect intracerebral lesions, and blood samples were drawn to investigate circulating levels of S‐100b and PMN elastase. For comparison, data for a positive control group of 10 severe head trauma patients (initial Glasgow Coma Scale score < 8) and for a negative control group with 20 healthy volunteers were obtained. The interval between MHT and admission to our hospital was 73.4 ± 47.0 minutes. The initial S‐100b serum levels of MHT patients were 0.470 ± 0.099 ng/ml, those of the positive control group were 7.16 ± 3.77 ng/ml, and those of the negative control group were 0.05 ± 0.01 ng/ml. Relevant pathologic CCT scans were detected in 28.8% of MHT patients; one patient of that group was subjected to immediate surgical intervention (1.9%). At a cut‐off point of 0.1 ng/ml, the sensitivity of positive S‐100b levels reached 100% and the specificity 40.5%. Plasma levels of PMN elastase reached 60.52 ± 10.75 ng/ml in the MHT group, 66.4 ± 14.92 ng/ml in the severely head‐injured group, and 23.26 ± 1.53 ng/ml in the negative control group. Serum levels of S‐100b seem to be a highly sensitive but not very specific marker for isolated neurotrauma. Measurement of this parameter may be helpful as an additional screening tool to identify high risk groups in the cohort of MHT patients.
Prospective Randomized Comparison of Open versus Laparoscopic Appendectomy in Men
Authors: Cox Michael R. , McCall John L. , Toouli James , Padbury Robert T.A. , Wilson Thomas G. , Wattchow David A. , Langcake Mary 
Published: August 2002

AbstractA prospective, randomized trial was performed to compare open appendectomy with laparoscopic appendectomy in men with a clinical diagnosis of acute appendicitis. Sixty‐four patients with a median age of 25 years (range 18–84 years) were randomized to open appendectomy (n= 31) or laparoscopic (n= 33) appendectomy. Of the 64 men, 56 (87.5%) had appendicitis (27 open, 29 laparoscopic procedures). The mean operating times were 50.6 ± 3.7 minutes (± SEM) for open and 58.9 ± 4.0 minutes for laparoscopic appendectomy (p= 0.13). Five (15%) patients randomized to laparoscopic appendectomy had an open operation. The mean postoperative hospital stay was significantly longer for open appendectomy (3.8 ± 0.4 days) than for laparoscopic appendectomy (2.9 ± 0.3 days) (t= 2.05,df= 62,p= 0.045). The complication rate after open appendectomy (25.8%) was not significantly different from that after laparoscopic appendectomy (12.1%). There was a single postoperative death due to a pulmonary embolus in the laparoscopic group and a single death due to cardiac and renal failure in the open group. The mean time to return to normal activities was significantly longer following open appendectomy (19.7 ± 2.4 days) than after laparoscopic appendectomy (10.4 ± 0.9 days), (t= 3.75,df= 49,p= 0.001). In conclusion, laparoscopic appendectomy in men has significant advantages in terms of a more rapid recovery compared to open appendectomy. There were no significant disadvantages to laparoscopic appendectomy compared to open appendectomy.