bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro and in vivo characterization of [125I]iodomethyllycaconitine in the rat
Authors: Navarro H.A. , Xu H. , Zhong D. , Abraham P. , Carroll F.I. 
Published: August 2002

AbstractThe in vitro and in vivo binding characteristics of [125I]iodomethyllycaconitine ([125I]iodoMLA) were determined in the rat. [125I]iodoMLA binding to rat cerebral cortex membranes was saturable and reversible and its specific binding represented approximately 70–80% of the total binding. [125I]iodoMLA labeled a single site with Kd = 1.8 ± 0.4 nM and Bmax = 68 ± 3 fmol/mg protein. Kinetic analysis revealed a t1/2 for association and dissociation of 10.5 ± 3.1 and 10.3 ± 1.6 min, respectively. Pharmacological characterization of [125I]iodoMLA binding indicated that it was specific for the α7 nAChR. In vitro brain region binding studies revealed greater binding in regions known to contain high numbers of α7 nAChRs. The analysis of the biodistribution of intravenously administered [125I]iodoMLA indicated that it was rapidly cleared and exhibited poor brain penetration; nevertheless, the levels of [125I]iodoMLA in α7 nAChR‐rich target regions were significantly increased compared to the nontarget region (cerebellum) 60–120 min after administration. No metabolism of MLA by human liver S9 fraction was detected. Our results suggest that [125I]iodoMLA will be a useful radioligand to study the α7 nAChR in vitro and in vivo. Synapse 44:117–123, 2002. © 2002 Wiley‐Liss, Inc.
Influence of restraint stress on the expression and the serine/threonine phosphatase activity of calcineurin in the rat brain
Authors: Takahashi Jun , Tanaka Kazuhide , Morinobu Shigeru , Fujimaki Koichiro , Li Sheng‐Tian , Kato Kunio , Ohkawa Masako , Yamawaki Shigeto , Kato Nobumasa 
Published: August 2002

AbstractTo investigate the role of calcineurin (CaN) in the pathogenesis of stress‐related psychiatric disorders, we examined the expression of CaN A mRNA and the serine/threonine phosphatase activity of CaN in the rat brain following various restraint stress paradigms. Northern blot analysis revealed no significant changes in the levels of CaN A mRNA expression, in either the frontal cortex or the hippocampus, in response to a single restraint stress for either 15, 45, or 90 min. In addition, no significant change in the levels of CaN A mRNA was found 3 or 6 h after a single restraint stress for 90 min. In situ hybridization analysis revealed that a single restraint stress for 45 min had no influence on CaN A mRNA expression in the CA1 and CA3 pyramidal cell layers or in the dentate gyrus granule cell layer of the hippocampus. However, serine/threonine phosphatase activity was significantly increased in both regions in response to a single restraint stress for either 45 or 90 min. These results demonstrate that the single restraint stress paradigms used in this study increase the activity of CaN without any changes in the expression of CaN, suggesting that the activation of calmodulin and the increased levels of heat shock proteins in response to the restraint stress may upregulate the activity of CaN in the rat brain. Synapse 40:130–136, 2001. © 2001 Wiley‐Liss, Inc.
Genotoxic action of the sesquiterpene lactone centratherin on mammalian cells in vitro and in vivo
Authors: Burim Regislaine Valéria , Canalle Renata , Lopes João Luis Callegari , Vichnewski Walter , Takahashi Catarina Satie 
Published: August 2002

AbstractCentratherin is a sesquiterpene lactone known for its antimicrobial, anti‐inflammatory, and trypanocidal activities. The aim of this study was to determine the clastogenic and cytotoxic potential of centratherin in human lymphocytes and in mice. Human lymphocytes in culture were submitted to either continuous treatment or treatment during G2 phase of the cell cycle. After continuous treatment the 0.2 μg/ml concentration induced a significant increase in total of chromosomal aberrations (CA) and sister chromatid exchange compared to control, and it reduced the mitotic index (MI). In the treatment during G2 phase, centratherin induced a significant increase in the frequency of CA for all concentrations tested (0.1, 0.3, and 0.5 μg/ml). In the in vivo test system all three concentrations tested in mice (3.3, 6.7, and 13.3 mg/kg b.w.) induced a significant increase in CA compared to the negative control. On the basis of these results, centratherin showed clastogenic and cytotoxic activity on in vitro and in vivo mammalian systems. Teratogenesis Carcinog. Mutagen. 21:383–393, 2001. © 2001 Wiley‐Liss, Inc.
Green organic syntheses: Organic carbonates as methylating agents
Authors: Tundo Pietro , Perosa Alvise 
Published: August 2002

AbstractDimethylcarbonate (DMC) is a valuable methylating reagent that can replace methyl halides and dimethylsulfate in the methylation of a variety of nucleophiles. It couples tunable reactivity and unprecedented selectivity towards mono‐C‐ and mono‐N‐methylation. In addition, it is a prototype example of a green reagent, because it is nontoxic, is made by a clean process, is biodegradable, and reacts in the presence of a catalytic amount of base, thereby avoiding the formation of undesirable inorganic salts as by‐products. Depending on the reaction conditions, DMC can be reacted under plug‐flow, CSTR, or batch conditions. Other remarkable reactions are those where DMC behaves as an oxidant. The reactivity of other carbonates is reported as well. © 2002 The Japan Chemical Journal Forum and John Wiley & Sons, Inc. Chem Rec 2: 13–23, 2002
Toxicity tests to assess pollutants removal during wastewater treatment and the quality of receiving waters in Argentina
Authors: Gómez Carlos E. , Contento Liliana , Carsen Andrés E. 
Published: August 2002

AbstractIn Argentina, legislation to control adverse impacts of effluent discharges and the quality of receiving waters is scant and relies mainly on the physicochemical characteristics of the effluents and receiving waters. Objectives of this study were to use standardized acute toxicity tests to assess treatment of petrochemical industry effluents and the toxicity of various treated industrial effluents in the Buenos Aires metropolitan area and their receiving waters. Tests for the first objective used Daphnia magna and Ceriodaphnia dubia; those for the second used D. magna, Spirillum volutans, and Scenedesmus spinosus. Chemical analyses demonstrated that the removal of aromatic hydrocarbon compounds (benzene, toluene, ethylbenzene, xylene, styrene, and naphthalene) from the petrochemical effluents ranged between 77 and 93%, but toxicity removal was significantly lower: untreated effluents were very toxic and treated effluents were very toxic to toxic [acute toxicity units (TUa)>3]. Physicochemical parameters measured according to current Argentinian regulations indicated that industrial effluents (e.g., from textile and paper industries) were within established guidelines, but 25% of the samples were moderately to highly toxic (TUa>1.33). However, for the receiving waters, toxicity tests were moderate to very toxic. The results show the need of including tests for toxicity of discharged effluents, and their effects on receiving waters of Argentina, especially for regulatory purposes. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 217–224, 2001
Heat shock protein 70 levels in rainbow trout primary epidermal cultures in response to 2,4‐dichloroaniline exposure: A novel in vitro aquatic toxicity marker
Authors: Kilemade Michael , Mothersill Carmel 
Published: August 2002

AbstractThe aim of this work was to investigate the use of the heat shock protein, HSP 70, as a sublethal measurement of ecotoxicity and to identify if the amount of HSP 70 synthesized is proportional to the chemical stress applied. This was achieved by quantifying the HSP 70 levels in primary cultured rainbow trout, Oncorhynchus mykiss (R.), skin epidermal cells in response to 2,4‐dichloroaniline (2,4‐DCA) exposure. The cellular stress response protects organisms from damage resulting from exposure to a wide variety of stressors including xenobiotics. The use of a HSP 70 polyclonal antibody on rainbow trout primary epidermal skin cultures exposed to 2,4‐DCA was investigated as a possible biomarker for environmental stress using an immunocytochemical approach. The epidermis is highly susceptible, as it is the interface between the fish and its aquatic environment. In this study we have developed a simple in vitro system for aquatic‐toxicity risk assessment. A method for the quantification of heat shock (stress) protein levels by immunocytochemistry is described. The antibody dilution range enabled the detection and quantification of only the inducible HSP 70 fraction. A 1:2000 dilution was decided upon. This assay was effective in detecting and quantifying the induced HSP 70. There was a direct toxicant concentration‐dependent increase in the levels of the cellular stress protein in the primary epidermal cultures. Enhanced localization of HSP 70 in the nuclei of the epidermal cells was observed following exposure to 2,4‐DCA. This work indicated the possibility of using heat shock protein induction and subsequent quantification as a sensitive system for aquatic toxicity risk assessment. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 253–259, 2001
Reduced‐trellis equalization using the M‐BCJR algorithm
Authors: Fragouli Christina , Seshadri Nambirajan , Turin William 
Published: August 2002

AbstractThe complexity of channel equalization using the BCJR algorithm [Bahl LR et al. IEEE Transactions on Info. Theory 1974; 20: 284–287] grows exponentially with the channel memory. The M‐BCJR algorithm [Franz V, Anderson J. IEEE J. Selected Areas Comm. 1998; 16(2): 186–195] provides a method for reduced‐trellis channel equalization, but its performance varies significantly with the distribution of a channel energy to its taps. This paper proposes a variation of the M‐algorithm, based on the implementation of the BCJR algorithm in the logarithmic domain, which can offer robust performance. Designer choices such as the decision delay, maximum and minimum phase transformation, and selection of states are discussed. Simulation results demonstrate the effect of different parameters on the proposed algorithm's performance. Copyright © 2001 John Wiley & Sons, Ltd.
Optimization of parameters in electron probe microanalysis
Authors: Bonetto Rita , Castellano Gustavo , Trincavelli Jorge 
Published: August 2002

AbstractA method for the refinement of atomic and experimental parameters applicable to several spectroscopic techniques is presented. This kind of procedure, previously used in x‐ray diffraction, is shown to be a powerful tool in electron probe microanalysis (EPMA). This method consists of minimizing the differences between an experimental x‐ray spectrum and a function proposed to account for the bremsstrahlung and characteristic peaks from the corresponding sample, and also for detection artifacts. This complicated function involves several parameters related to different sources (x‐ray production, x‐ray attenuation, sample composition, x‐ray detection, etc.). Initial values must be supplied for them, and after a numerical iterative procedure is performed, improved values are achieved. Depending on the particular situation, certain parameters may be known a priori, so that they can be fixed, allowing the others to vary. In this way, the method can be used for different purposes: determination of atomic parameters such as fluorescence yields, transition rates or photoelectric cross‐sections, quantitative standardless analysis, determination of detector characteristics, etc. This work is intended to present the general aspects of the method for refining EPMA parameters, and to give some examples of its application to the aforementioned issues. Even when only EPMA spectra are included in this work, the method can be applied to different spectroscopic techniques, such as x‐ray fluorescence, particle‐induced x‐ray emission, etc. Copyright © 2001 John Wiley & Sons, Ltd.
Meiotic crossing‐over in the regions of homology between homeologous chromosomes V
Authors: Shubochkina Elena A. , Nielsen Trine L. , Nilsson‐Tillgren Torsten 
Published: August 2002

AbstractHomeologous chromosomes V of Saccharomyces cerevisiae and S. carlsbergensis virtually do not recombine in meiosis. Artificially created short regions of homology were found toinduce meiotic crossing‐over if they contained sequences located upstream of the S. carlsbergensis ILVI gene. Heterozygous restriction site markers were introduced withinthe 1.1 kb region of homology to monitor conversion events associated with the crossovers. In the presence of five heterozygosities, 85% of crossovers showed associated conversion. Crossovers with no detected conversion were found in the two largest (0.34 and 0.29 kb) intervals, into which the 1.1 kb region was divided by the introduction of the five markers, whereas the shortest conversion tracts observed did not exceed 0.26 kb. Several lines of evidence suggest that each crossover required a formation of heteroduplex DNA with the considerable minimal length of ∼200–260 bp. Copyright © 2001 John Wiley & Sons, Ltd.
Increasing sulphite formation in Saccharomyces cerevisiae by overexpression of MET14 and SSU1
Authors: Donalies Ute E. B. , Stahl Ulf 
Published: August 2002

AbstractSaccharomyces cerevisiae produces sulphite as an intermediate product during the assimilatory reduction of sulphate to sulphide. Three genes, MET3, MET14 and MET16, are essential for this reduction. We investigated the level of transcription of these genes in strains of S. cerevisiae with high, medium and low sulphite formation. The level of MET14‐ and MET16‐mRNA varied with sulphite production, whereas the level of MET3‐mRNA was very weak in almost all strains. We also analysed the effect of overexpression of MET14 and MET16 on sulphite formation. Two strains with low sulphite production were transformed with high‐copy plasmids containing either or both MET14 and MET16. The overexpression of these two genes leads to a two‐ to three‐fold sulphite formation. In addition, inactivation of MET10, encoding a subunit of the sulphite reductase, also leads to a distinct increase in sulphite formation; however, the cells became methionine auxotroph. The overexpression of SSU1, a gene encoding a putative sulphite pump, yields a slight increase in sulphite accumulation, whereas overexpression of SSU1, together with MET14, increases sulphite formation up to 10‐fold. Furthermore, sulphite formation strongly depends on growth conditions, e.g. yeast transformants growing in wort produce much higher amounts of sulphite when compared to growth in minimal media. The addition of glucose can also increase the sulphite formation in strains overexpressing MET14 and/or SSU1 under oxygen‐limiting conditions, while the addition of glucose has no significant effect under aerobic conditions. Copyright © 2002 John Wiley & Sons, Ltd.
Assessment of testicular endocrine function in captive African elephants by measurement of urinary and fecal androgens
Authors: Ganswindt Andre , Heistermann Michael , Borragan Santiago , Hodges J. Keith 
Published: August 2002

AbstractAndrogen measurements in urine and/or feces represent a potentially important tool for monitoring testicular endocrine function in the African elephant. To assess the feasibility of this approach, the aims of the present study were to: 1) examine the presence and relative abundance of immunoreactive testosterone (iT) and its 5α‐reduced 17‐oxometabolite epiandrosterone (iEA) in African elephant excreta, and 2) compare urine and fecal androgen profiles in animals of different ages and during the musth and non‐musth condition. Urine and fecal samples were collected over periods of up to 3 years from five bulls (ages 7–24 years) living in three mixed social groups. In parallel, indications of musth were recorded by keeper staff as an independent marker of male androgen status. Measurements of iT and iEA were carried out by enzymeimmunoassay (EIA) following methanolic extraction of hydrolyzed urine and lyophilized fecal powder. High‐pressure liquid chromatography (HPLC) of musth phase samples confirmed the presence of substantial quantities of testosterone (T) and epiandrosterone (EA) in both urine and feces. EA was predominant in feces, whereas T was more abundant in urine. In each male, the two androgen measures were significantly correlated (feces, r = 0.71–0.93, P < 0.0001; urine, r = 0.86–0.91, P < 0.0001), as were fecal and urinary concentrations of each of the two androgens measured (r = 0.35–0.77, P < 0.0001). Moreover, in the two oldest males that showed clear signs of musth, levels of iEA and iT were markedly elevated during musth compared to non‐musth periods (differences were significant for feces in both animals, but in urine only for one). Collectively, the data show that measurement of urinary and fecal androgens generates useful information on gonadal status in male African elephants, and as such should provide new opportunities to improve the management and welfare of bulls maintained in captivity, as well as to examine physiological correlates of reproductive function in free‐ranging animals. Zoo Biol 21:27–36, 2002. © 2002 Wiley‐Liss, Inc.
Postoperative Biliary Ascariasis: Presentation and Management—Experience
Authors: Wani Nazir A. , Shah Omar J. , Naqash Sameer H. 
Published: August 2002

AbstractSubsequent to preoperative and perioperative indications the common bile duct was explored in 705 patients over a 12‐year period, from January 1983 to December 1994. Consequent postoperative T‐tube cholangiography revealed the presence of worms in 22 patients. Expulsion of the worms followed T‐tube irrigation with 0.9% normal saline in 18 patients. Only one patient had to be reexplored to remove the ascaris. In two patients the worm was removed along with the T‐tube, and in one patient the worm came out through the T‐tube tract.
Impact of Initial Surgical Treatment on Survival of Patients with Differentiated Thyroid Cancer: Experience of an Endocrine Surgery Center in an Iodine‐deficient Region
Authors: Duren Mete , Yavuz Nihat , Bukey Yusuf , Ozyegin M. Ates , Gundogdu Sadi , Açbay Ozer , Hatemi Husrey , Uslu Ihami , Onsel Çetin , Aksoy Figen , Oz Feriha , Unal Gurcan , Duren Erol 
Published: August 2002

AbstractThis retrospective clinical study was designed to analyze the impact of the initial surgical procedure on the survival of 1000 patients with differentiated thyroid cancer of follicular cell origin who had a thyroid operation and were followed for the 30 years between 1968 and 1998 (median 14 years) in an iodine‐deficient region where goiter is endemic. There were 753 women and 247 men with a mean age of 42.8 ± 6.7 years (range 17–86 years). Patients were divided into three groups. All patients had undergone thyroxine treatment and thyroid‐stimulating hormone (TSH) suppression, and most had had iodine‐131 treatment postoperatively. Group A consisted of 336 patients with differentiated thyroid cancer (DTC) who were treated with bilateral subtotal thyroidectomy in our institution or elsewhere. Group B consisted of 158 patients with DTC who were treated initially with unilateral total lobectomy and contralateral subtotal lobectomy in our institution or elsewhere and underwent reoperation in our department. Group C consisted of 506 patients with DTC who were treated initially with total or near‐total thyroidectomy in our department. Kaplan‐Meyer survival analysis was used. Recurrence was seen in 23% and death in 8% of the patients. The 20‐year survival rates were 76%, 85%, and 92% for groups A, B, and C, respectively. The survival difference among the patients of group A and groups B and C was found to be statistically different (p < 0.001). Long‐term survival of patients with differentiated thyroid cancer living in endemic areas for goiter can be influenced by the initial surgical treatment. Patients treated initially with total or near‐total thyroidectomy appear to have a better prognosis.
Indicators of Fatigue and of Prolonged Weaning from Mechanical Ventilation in Surgical Patients
Authors: O'Keefe Grant E. , Hawkins Kenneth , Boynton Jackie , Burns Darren 
Published: August 2002

Abstract.Indicators of weaning success have been tested primarily in patients who have been ventilated for short periods of time, and they may not be as accurate in cases where support has been required for longer than a few days. In patients requiring longer periods of support it is difficult to estimate the likelihood of successful liberation. Therefore we evaluated established weaning indices for their accuracy in surgical patients who required ≥ 72 hours of mechanical ventilation. Surgical patients who required mechanical ventilation for ≥ 72 hours were prospectively followed (over 6 months). We obtained standard indices of ventilatory function daily once patients were ready to wean. These indices included the respiratory rate/tidal volume ratio (RSBI), the maximal inspiratory pressure, and the minute ventilation. The duration of weaning and explicitly defined episodes of fatigue were the outcomes of interest. Statistical analyses evaluated the multiple factors that might influence the duration of weaning. Ninety‐five patients (66% trauma; 34% surgery) survived to begin weaning, and 93% were liberated. The median duration of mechanical ventilation prior to weaning was 4 days (range 3–16 days), and the median duration of weaning was 3 days (range 0–56 days). Fatigue occurred in 36 patients and was not reliably predicted by any of the weaning measurements. However, a RSBI of >105 on the first day of weaning was associated with prolonged weaning. By multivariate analysis, an RSBI of >105 on the first day of weaning predicted prolonged weaning (hazard ratio 1.9; p= 0.03). After 72 hours of mechanical ventilation, clinical fatigue and successful liberation are not reliably predicted by standard indices of respiratory muscle strength and reserve. However, an RSBI of >105 observed once the patient is ready to wean is associated with prolonged weaning.
Pancreaticobiliary Maljunction‐Associated Pancreatitis: An Experimental Study on the Activation of Pancreatic Phospholipase A2
Authors: Nakamura Tetsuro , Okada Akira , Higaki Jun , Tojo Hiromasa , Okamoto Mitsuhiro 
Published: August 2002

AbstractCongenital dilatation of the bile duct (CDBD), or choledochal cyst, is often complicated by recurrent pancreatitis. Reflux of pancreatic juice into the bile duct through pancreaticobiliary maljunction (PBM), an anomaly commonly associated with CDBD, and ensuing activation of pancreatic enzymes could be involved in the pathophysiologic mechanism of recurrent pancreatitis. A study was undertaken to follow the time course of the activity of phospholipase A2 (PLA2) in animal models of PBM. The assay procedures for PLA2 were evaluated, as were the conditions for separating the active enzyme from its inactive proenzyme (pro‐PLA2) by immunoblotting. A rat model was designed according to Block's method with some modifications. The kinetics of prophospholipase A2 (proPLA2) activation in bile was examined by measuring PLA2 activity and by immunoblotting using anti‐rat pancreatic enzyme antibody after separating PLA2 from its zymogen under nonreducing conditions. Experimental animals were divided into three groups: group 1 (PBM group) in which bile and pancreatic juice were mixed with occlusion of the papilla; group 2, in which the papilla and hepatic hilus were occluded without mixing the two juices; and group 3, in which simple laparotomy was done. In group 1 animals, pro‐PLA2 in bile was activated to its active form. In group 2 animals, where proPLA2 was predominant, there was only slight elevation of PLA2 activity in bile. In group 1 an immunohistologic study demonstrated localization of PLA2 around necrotic foci in the pancreatic parenchyma. These results suggest the involvement of activated PLA2 in the pathogenesis of choledochal cyst‐associated pancreatitis.