bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in cannabinoid CB1 receptors in striatal and cortical regions of rats with experimental allergic encephalomyelitis, an animal model of multiple sclerosis
Authors: Berrendero Fernando , Sánchez Antonio , Cabranes Ana , Puerta Carmen , Ramos José A. , García‐Merino Antonio , Fernández‐Ruiz Javier 
Published: August 2002

AbstractData, initially anecdotal, but recently supported on more solid experimental evidence, suggest that cannabinoids might be beneficial in the treatment of some of the symptoms of multiple sclerosis (MS). Despite this evidence, there are no data on the possible changes in cannabinoid CB1 or CB2 receptors, the main molecular targets for the action of cannabinoids, either in the postmortem brain of patients with MS or in animal models of this disease. The present study addressed this question using the model of experimental allergic encephalomyelitis (EAE) in Lewis rats generated by inoculation of guinea pig myelin basic protein in Freund's adjuvant. After inoculation, animals were examined daily to detect the appearance of neurological signs. The first signs appeared around day 10 after inoculation, reaching the highest degree by day 13, when animals were sacrificed and their brains removed and used for analysis of CB1 receptor binding, mRNA levels, and activation of GTP‐binding proteins. CB1 receptor binding and mRNA levels were not affected in EAE rats in brain areas such as the hippocampus, limbic structures, and cerebellum. However, there was a marked decrease in both parameters in the caudate‐putamen, both in the lateral and medial parts, although this decrease did not correspond with decreases in binding in the nuclei recipient of striatal output neurons, which suggests that changes in CB1 receptors are exclusively located in the cell bodies of striatal neurons. In addition, CB1 receptor binding, but not mRNA levels, also decreased in the cerebral cortex, both in the deep and the superficial layers. The analysis of [35S]GTPγS binding after activation of CB1 receptors with WIN55,212‐2, a synthetic agonist, revealed that, despite the decrease in the number of CB1 receptors in EAE rats, these were more efficiently coupled to GTP‐binding protein‐mediated signaling mechanisms in both the caudate‐putamen and the cerebral cortex of these animals. In summary, these data suggest that the generation of EAE in Lewis rats would be associated with changes in CB1 receptors in striatal and cortical neurons, which might be related to the alleviation of some motor signs observed after the treatment with cannabinoid receptor agonists in similar models of MS in rodents. Synapse 41:195–202, 2001. © 2001 Wiley‐Liss, Inc.
Binding characteristics of selective serotonin reuptake inhibitors with relation to emission tomography studies
Authors: Elfving Betina , Bjørnholm Berith , Ebert Bjarke , Knudsen Gitte Moos 
Published: August 2002

AbstractWhen developing ligands for emission tomography studies, one of the major obstacles lies in the selection of ligand candidates. A previously unattended factor such as the influence of temperature on candidate ligand affinity is likely to play a role. By use of rat brain homogenates, the binding characteristics of [3H]‐(S)‐citalopram and [3H]‐(+)‐McN5652 and the receptor‐ligand interaction at the serotonin transporter of 17 selective serotonin reuptake inhibitors were compared at 21°C and 37°C, respectively. Ligand logP values were also calculated. The ratios for Ki at 37°C vs. 21°C varied between 0.2 and 2.2 for the selective serotonin reuptake inhibitors considered in this study, with most of the ligands displaying an inverse relationship between Ki and temperature. Ten of the 17 selective serotonin reuptake inhibitors were found to have pKi values statistically significantly different at 21°C compared to 37°C (P < 0.05). The logP values ranged between 3.6 and 4.8, except for DASB, 5‐iodo‐6‐nitroquipazine, and paroxetine where logP was 1.9, 2.2, and 5.0, respectively. Kd was 0.71 nM at 37°C and 0.31 nM at 21°C for [3H]‐(S)‐citalopram. For [3H]‐(+)‐McN5652 Kd was 0.11 nM at 37°C and 0.08 nM at 21°C. The association and dissociation was much faster for [3H]‐(S)‐citalopram as compared to [3H]‐(+)‐McN5652. It is concluded that temperature may affect Kd differently and that in vitro dissociation may help to predict whether a given ligand may be useful in PET studies. LogP values do not per se predict the potential of a given ligand as an emission tomography tracer. Synapse 41:203–211, 2001. © 2001 Wiley‐Liss, Inc.
Energy‐based damage assessment on structures during earthquakes
Authors: Wong Kevin K. F. , Wang Yumei 
Published: August 2002

AbstractSeveral seismic damage indices have been developed using the energy concept in attempt to compensate for the inadequacy of ductility criteria. However, these indices are either based on implicitly defined energy as a cumulative effect on ductility or are unable to consider energy in a quantitative manner. In this paper, a method of assessing the structural performance during earthquakes based on both explicitly computed plastic rotation and plastic energy at every hinge of a moment‐resisting frame is proposed. This method uses the force analogy method to evaluate the structural response and energy in the inelastic domain. Inelastic deformation is expected to occur during major earthquakes, and active control based on an instantaneous optimal control algorithm is used to improve the structural performance. Comparisons are made between uncontrolled response and instantaneous optimal control response based on a single‐degree‐of‐freedom system to demonstrate the computation of plastic energy. Damage analysis of a six‐storey moment‐resisting steel frame is then presented to evaluate the performance and applicability of the proposed damage measure. Results show that the proposed damage assessment criteria are feasible and that active control can reduce plastic rotation and plastic energy, thereby reducing damage to a certain acceptable limit. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of chromosomal aberrations, micronuclei, and sister chromatid exchanges in hospital workers chronically exposed to ionizing radiation
Authors: Cardoso R.S. , Takahashi‐Hyodo S. , Peitl P. , Ghilardi‐Neto T. , Sakamoto‐Hojo E.T. 
Published: August 2002

AbstractCytogenetic analysis was performed in peripheral blood lymphocytes from hospital workers chronically exposed to ionizing radiation in comparison to matched non‐exposed individuals. The accumulated absorbed doses calculated for the radiation workers ranged from 9.5 to 209.4 mSv. The endpoints used were chromosomal aberrations (CA), micronuclei (MN), and sister chromatid exchanges (SCE). The frequencies of CA/100 cells observed for the exposed group were significantly (P=0.018) higher than in the control group: 3.2 and 2.6, respectively. Similarly, the mean numbers of SCE per cell were statistically higher (P=0.025) in the exposed group (6.2) in comparison with the control group (5.8). In the case of micronuclei analysis, no significant (P=0,06) difference between both groups was found, but these data should be cautiously interpreted since an increase in the frequencies of MN was found for radiation workers (3.0 MN/100 cells), compared to the control group (2.6 MN/100 cells) and this increase occur in parallel to CA and SCE frequencies. The difference between the results could be explained by the nature of CA and MN generation. The increased frequencies of CA and SCE in radiation workers indicate the cumulative effect of low‐level chronic exposure to ionizing radiation, and the relevance of conducting cytogenetic analysis in parallel to physical dosimetry in the working place. Teratogenesis Carcinog. Mutagen. 21:431–439, 2001. © 2001 Wiley‐Liss, Inc.
Learning and using science ideas when doing investigate‐and‐redesign tasks: A study of naive, novice, and expert designers doing constrained and scaffolded design work
Authors: Crismond David 
Published: August 2002

AbstractThis study reports on what naive, novice, and expert designers do and learn when investigating simple mechanical devices and then planning their redesign. Participating in the study were 32 high school and adult subjects who did two investigate‐and‐redesign (I&R) tasks. Same gender pairs of subjects with similar design experiences explored, analyzed, and evaluated different brands of a device, designed experiments to compare them, and then proposed their redesign. Each two‐hour session was videotaped, and portions were analyzed using methods adapted from protocol analysis techniques. Results suggest that when naive designers do I&R tasks, their learning is highly contextualized and device‐specific. Naive designers made few connections from their work to key science ideas, and instead used mechanical advantage preconceptions that they did not spontaneously redress during the I&R sequence. Experts made connections to concepts and cases, inferred key design decisions, and sought “critical design problems” for the devices studied. All groups used strategies involving analysis more than those involving synthesis or evaluation. Notably, during conceptual design, opportunities for using science, present especially when subjects analyze design ideas, went underutilized by nonexpert designers. Scaffolded questions are needed to focus the learning of science embedded in design‐oriented activities. All findings reported are tentative, given the limited number of cases included in this study. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 791–820, 2001
Aerodynamic analysis of HAWTs operating in unsteady conditions
Authors: Masson Christian , Smaïli Arezki , Leclerc Christophe 
Published: August 2002

AbstractThis article presents a numerical method for predicting unsteady aerodynamics of horizontal axis wind turbines (HAWTs). In this method the flow field is described by the unsteady incompressible Navier–Stokes equations. The rotor and tower are idealized respectively as actuator disc and flat plate permeable surfaces on which external normal surficial forces are balanced by fluid pressure discontinuities. The external forces exerted by the rotor and tower on the flow are prescribed according to blade element theory. Dynamic behaviour of the rotor aerodynamic characteristics is simulated using either the Gormont or the Beddoes–Leishman model. The resulting mathematical formulation is solved using a control volume finite element method. The fully implicit scheme is used for time discretization. In general, the proposed method has demonstrated its capability to adequately represent the field data. It has been demonstrated that the accuracy of the predicted results depends primarily on the dynamic stall model as well as on the turbulence model employed. Copyright © 2001 John Wiley & Sons, Ltd.
Quantitative determination of metals in radish using x‐ray fluorescence spectrometry
Authors: Anjos M. J. , Lopes R. T. , Jesus E. F. O. , Simabuco S. M. , Cesareo R. 
Published: August 2002

AbstractUsing energy‐dispersive X‐ray fluorescence analysis with a Ti‐filtered x‐ray tube it was possible to determine the concentrations of several elements, such as K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr, Zr and Pb, at ppm levels in radish plants (root and foliage) cultivated in soils treated with concentrations of 10, 20 and 30 t ha−1 of organic compost from urban garbage. A significant increase was observed in the concentrations of K, Ca, Mn, Fe, Zn, Rb and Pb in radish plants cultivated in the treated soils in comparison with a control soil. The results suggest that radish plants can be used as bioindicator of contamination of agricultural soils. Copyright © 2002 John Wiley & Sons, Ltd.
Intraoperative Parathyroid Aspiration and Parathyroid Hormone Assay as an Alternative to Frozen Section for Tissue Identification
Authors: Perrier Nancy D. , Ituarte Philip , Kikuchi Shoichi , Siperstein Allan E. , Duh Quan Yang , Clark Orlo H. , Gielow Robert , Hamill Timothy 
Published: August 2002

AbstractMost people would agree that successful parathyroidectomy depends on two important variables: the surgeon's recognition and excision of the abnormal parathyroid gland(s) and the pathologist's confirmation that the removed tissue is parathyroid tissue. Frozen section is usually employed to confirm the identity of parathyroid tissue, but occasionally confirmation cannot be made without a permanent section, as with intrathyroidal glands. This study proposes a new method of expeditious and easy confirmation of parathyroid tissue utilizing the immunoassay for quick measurement of intraoperative parathyroid hormone (IOPTH). By directly aspirating the suspected adenoma, the assay becomes a rapid diagnostic tool that can be used as an alternative to frozen section. In cases where the surgeon is already planning to employ the assay, the elimination of frozen section is cost‐effective. Intraoperative aspiration of histologically confirmed parathyroid adenomas was performed on 12 consecutive patients undergoing parathyroid surgery. Parathyroid glands were aspirated with a 22‐gauge syringe after gland excision. Aspirates were placed in 1 to 3 ml of buffered saline. A similar process was performed on 12 thyroid controls. Specimens were centrifuged, aliquotted, and stored at −70°C. The parathyroid hormone value was analyzed electively by rapid assay and the values recorded. For all parathyroid aspirates, the rapid assay value was > 1500 pg/ml, exceeding the uppermost limit of the diagnostic chart. Values for thyroid aspirates ranged from 58 to 85 pg/ml (mean 75.7 pg/ml). In all cases tissue confirmation was achieved with permanent section. Values were 100% sensitive and specific. Measurement of PTH from intraoperative aspiration of suspected parathyroid adenomas is clinically useful in patients for whom frozen section would routinely be employed. Values > 1500 pg/ml secure the tissue diagnosis. There is no additional cost in cases where IOPTH monitoring is already being utilized to confirm cure. The elimination of frozen section could be cost‐effective and, for some institutions, actually decrease the operating time as the IOPTH assay takes only 15 minutes. PTH assay is an accurate diagnostic technique and to date is 100% sensitive and specific for differentiating between parathyroid tumors and thyroid nodules.
Laparoscopic versus Open Appendectomy: Prospective Randomized Trial
Authors: Hansen John Brendan , Smithers Bernard Mark , Schache David , Wall Daryl Robert , Miller Brian John , Menzies Betty Lynette 
Published: August 2002

AbstractA prospective randomized trial comparing laparoscopic appendectomy with open appendectomy in patients with a diagnosis of acute appendicitis was conducted between October 1992 and April 1994. Of the 158 patients randomized, 7 patients were excluded because of protocol violations (conversion to laparotomy in 4, appendix not removed in 3). The 151 patients randomized to either a laparoscopic (n= 79) or an open appendectomy (n= 72) showed no difference in sex, age, American Society of Anesthesiology (ASA) rating, or previous abdominal surgery. The histologic classification of normal, catarrhal, inflamed, suppurative, and gangrenous appendicitis was not different between the two groups. Conversion from laparoscopic to open appendectomy was necessary in seven patients (9%) who had advanced forms of appendiceal inflammation. When compared to open appendectomy the laparoscopic group had a longer median operating time (63 minutes versus 40 minutes), fewer wound infections (2% versus 11%), less requirement for narcotic analgesia, and an earlier return to normal activity (median 7 days versus 14 days). There was no difference in morbidity, and both groups had a median time to discharge of 3 days. Laparoscopic appendectomy is as safe as open appendectomy; and despite the longer operating time, the advantages such as fewer wound infections and earlier return to normal activity make it a worthwhile alternative for patients with a clinical diagnosis of acute appendicitis.
Laparoscopic Cholecystectomy for Acute Cholecystitis: Is It Really Safe?
Authors: Kum Cheng‐Kiong , Eypasch Ernst , Lefering Rolf , Paul Andreas , Neugebauer Edmund , Troidl Hans 
Published: August 2002

AbstractThe prospectively collected data from 530 cholecystectomies performed in a university clinic from October 1989 to March 1991 were analyzed after 1 to 3 years of follow‐up. The aim of this study was to compare the results of laparoscopic cholecystectomy (LC) for acute cholecystitis with that for routine symptomatic gallbladders. The preoperative, intraoperative, and postoperative parameters of 424 routine (noninflamed) LCs and 54 LCs for acutely inflamed gallbladders were compared under the “intention to treat” principle. Operating time was longer in the inflamed group (median 97 minutes versus 75 minutes; p< 0.0001). Significantly more adhesions (20% versus 8%), more blood loss (48% versus 19%), a higher incidence of bile spillage (28% versus 12%), and lost stones (19% versus 8%) were encountered in patients with acute cholecystitis. Common bile duct (CBD) injuries were also more frequent in that group (5.5% versus 0.2%;p= 0.005). The rate of conversion to open surgery was higher than with routine LCs (13% versus 4%). There were two deaths in the routine LC group and none in the acutely inflamed group. There was no difference in postoperative pain intensity or postoperative fatigue according to visual analog scale measurements. Patients with acute cholecystitis stayed only 1 day longer (median 4 days versus 3 days) in hospital. The quality of life scores indicate return to almost normal values by the 14th postoperative day. Long‐term follow‐up (1–3 years) did not reveal any delayed clinical adverse effects. In summary, LC for inflamed gallbladders has a higher conversion rate than LC for routine symptomatic gallbladders. If successfully performed, it has definite benefit for the patient in terms of better postoperative recovery. The trade‐off is that the risk of CBD injury is significantly higher.
Carcinoid Tumors: Imaging Procedures and Interventional Radiology
Authors: Wallace Sidney , Ajani Jaffer A. , Charnsangavej Chusilp , DuBrow Ronelle , Yang David J. , Chuang Vincent P. , Carrasco C. Humberto , Dodd Gerald D. 
Published: August 2002

AbstractThe hypervascular nature of carcinoid tumors and their metastases allows a more aggressive role by the radiologist in diagnosis and interventional management. Double‐contrast gastrointestinal studies still best define the primary neoplasms. Appendiceal tumors, the most frequent site of carcinoids, frequently escape radiologic detection until large enough to be discovered by computed tomography (CT). Superior mesenteric arteriography of the small bowel and cecum is useful when the scanning procedures are not revealing. The “spokewheel” configuration of the desmoplastic mesenteric masses and lymph node metastases are best seen by CT, whereas hepatic metastases can be demonstrated by CT, CT‐angioportography (CTAP), ultrasonography (US), magnetic resonance imaging (MRI), and octreotide scintigraphy. Percutaneous needle biopsy with radiologic guidance confirms the diagnosis of carcinoid tumors and their metastases. Hepatic arteriography is frequently performed in preparation for hepatic embolization or chemoembolization. Hepatic vascular occlusion therapy, the procedure of choice for the management of inoperable carcinoid liver metastases, results in a partial response in at least 50% of patients and a mortality rate of 5%. Chemoembolization with microencapsulated cytotoxic agents and direct percutaneous ethanol injection should also be considered for the treatment of liver metastases.
Gastric Carcinoids and Neuroendocrine Carcinomas: Pathogenesis, Pathology, and Behavior
Authors: Rindi Guido , Bordi Cesare , Rappel Sigrid , La Rosa Stefano , Stolte Manfred , Solcia Enrico 
Published: August 2002

AbstractThe goal of this study was to provide information of prognostic value for gastric endocrine tumors. A total of 205 gastric endocrine tumors have been studied: 193 well differentiated tumors [2 gastrin cell tumors, 191 enterochromaffin‐like (ECL) cell tumors] and 12 poorly differentiated carcinomas. Subtyping of ECL cell tumors (carcinoids) resulted in 152 associated with chronic atrophic gastritis (CAG) (type 1); 12 associated with hypertrophic gastropathy (HG) due to Zollinger‐Ellison syndrome with multiple endocrine neoplasia type I (type 2), and 27 with no specific association (type 3, sporadic). Type 1 cases occurred most often in female (108 of 152), elderly (mean 63 years) patients, with no tumor‐related death at an overall mean follow‐up of 53 months. The 12 type 2 cases were equally distributed between the sexes (six of each), with a mean age of 45 years; there was one tumor‐related death (49 months after diagnosis) and an overall mean survival of 84 months. Type 3 cases were mostly in men (20 of 27), with a mean age of 55 years; there were seven tumor‐related deaths at a mean follow‐up of 28 months. Poorly differentiated neuroendocrine carcinomas were observed in elderly patients (mean 63 years, range 41–76 years) of both sexes, with nine tumor‐related deaths and a mean survival of 7 months. It was concluded that correct clinicopathologic subtyping may predict the clinical behavior of gastric endocrine tumors.
Pattern of Organ Failure following Severe Trauma
Authors: Regel Gerd , Grotz Martin , Weltner Tobias , Sturm Johannes A. , Tscherne Harald 
Published: August 2002

AbstractMultiple organ failure (MOF) is considered to be the leading cause of death after severe trauma. Although there is extensive literature on MOF, little is known about the pattern, sequence, and onset of this clinical syndrome. The first goal of this clinical study was to define MOF; the second was to assess the typical onset, sequence, and pattern of MOF; and the third was to define certain risk factors for the development of MOF in 342 multiple trauma patients. Patients with an Injury Severity Score (ISS): > 20 (mean 35.7) were included. Three well established MOF scoring methods were used to give strict definitions of MOF: 11.4% of the total patient population developed MOF, and 88.6% did not. Respiratory failure was most frequent in patients developing MOF (74.4%), and these patients had the highest mortality rate (65.5%) compared to patients with failure of other organ systems (liver, cardiovascular system). Generally, the lung is the first organ to fail after injury (failure after 3.7 ± 2.8 days). Significant renal failure and the need for dialysis decreased to < 5%; other signs of organ dysfunction (gastric, central nervous system) are difficult to verify. Typical risk factors for the development of MOF after severe trauma are the severity, type, and distribution of injury as well as the indicators of prolonged hemorrhagic shock (elevated lactate levels). The main therapeutic efforts, therefore, should be the effective treatment of traumatic hemorrhagic shock during the initial phase, adequate resuscitation, optimal oxygenation, and early surgical treatment.