bluuebunny/crossref_metadata_2025 huggingface dataset:
The muscle standardized femur: A step forward in the replication of numerical studies in biomechanics
Authors: Viceconti M , Ansaloni M , Baleani M , Toni A
Published: March 2003

The standardized femur is the computer aided design (CAD) solid model of a synthetic human femur, commonly used in experiments in vitro, available in the public domain through the International Society of Biomechanics Finite Element Mesh Repository. Currently used by hundreds of researchers, it was made available to simplify the experimental cross-validation of numerical studies as well as their replication by other researchers. One aspect that the standardized femur left uncovered is the definition of muscles and ligaments. In particular, for a variety of simulations it would be extremely useful to map on to the femoral surface the insertion of the principal muscles. The aim of the present study was to create a new solid model, called the muscle standardized femur, where the femoral insertion of each muscle is mapped on to the surface of the femur. Published data on muscle insertion morphometry were registered to the model by applying an affine scaling defined on bone landmarks. Good agreement was found with another similar study in which only the insertion centres were defined. The new model will be made available in the public domain for no-profit uses. When combined with published data on the direction and intensity of muscular forces this model is expected to make a useful contribution to the steadily growing library of models and data sets made available to the biomechanical community.
Hydroformylation of 1-Hexene over Rhodium Supported on Active Carbon Catalyst
Authors: Li Baitao , Li Xiaohong , Asami Kenji , Fujimoto Kaoru
Published: March 2003

Hydroformylation of 1-hexene on rhodium catalyst was studied under mild reaction conditions (P=3.0 MPa, CO/H2 = 1/1, T=403 K). Its hydroformylation performances were investigated in a variety of solvent. It was found that the excellent activity for the heterogeneous catalyst was showed in the n-octane solvent, while poor activity in the alcoholic and H2O solvent.
Prospective Study of Alcohol Consumption and Risk of Dementia in Older Adults
Authors: Mukamal Kenneth J. , Kuller Lewis H. , Fitzpatrick Annette L. , Longstreth W. T. , Mittleman Murray A. , Siscovick David S.
Published: March 2003

Context

Alcohol consumption has been associated with complex changes in cerebral vasculature and structure in older adults. How alcohol consumption affects the incidence of dementia is less clear.

Objective

To determine the prospective relationship of alcohol consumption and risk of dementia among older adults.

Design, Setting, and Participants

Nested case-control study of 373 cases with incident dementia and 373 controls who were among 5888 adults aged 65 years and older who participated in the Cardiovascular Health Study, a prospective, population-based cohort study in 4 US communities. The controls were frequency-matched on age, death before 1999, and their attendance of a 1998-1999 clinic. Participants in this study underwent magnetic resonance imaging (MRI) of the brain and cognitive testing between 1992 and 1994 and were followed up until 1999.

Main Outcome Measures

Odds of incident dementia, ascertained by detailed neurological and neuropsychological examinations according to average alcohol consumption, assessed by self-reported intake of beer, wine, and liquor at 2 visits prior to the date of the MRI.

Results

Compared with abstention, the adjusted odds for dementia among those whose weekly alcohol consumption was less than 1 drink were 0.65 (95% confidence interval [CI], 0.41-1.02); 1 to 6 drinks, 0.46 (95% CI, 0.27-0.77); 7 to 13 drinks, 0.69 (95% CI, 0.37-1.31); and 14 or more drinks, 1.22 (95% CI, 0.60-2.49; P for quadratic term = .001). A trend toward greater odds of dementia associated with heavier alcohol consumption was most apparent among men and participants with an apolipoprotein E ϵ4 allele. We found generally similar relationships of alcohol use with Alzheimer disease and vascular dementia.

Conclusions

Compared with abstention, consumption of 1 to 6 drinks weekly is associated with a lower risk of incident dementia among older adults.
Issues in the design of switched linear control systems: A benchmark study
Authors: Leith D.J. , Shorten R.N. , Leithead W.E. , Mason O. , Curran P.
Published: March 2003

In this paper we present a tutorial overview of some of the issues that arise in the design of switched linear control systems. A benchmark regulation problem is then presented. Copyright © 2003 John Wiley & Sons, Ltd.
Neutropenia and agranulocytosis in England and Wales: Incidence and risk factors
Authors: van Staa T.P. , Boulton F. , Cooper C. , Hagenbeek A. , Inskip H. , Leufkens H.G.M.
Published: March 2003

The objectives of this study were to estimate the incidence of idiosyncratic neutropenia and agranulocytosis in England and Wales and to evaluate their risk factors and outcomes. The study was conducted using data from the General Practice Research Database. All cases of idiosyncratic neutropenia or agranulocytosis were identified and the incidence was estimated. This was followed by a nested case‐control study, estimating odds ratios with drug exposure from conditional logistic regression. From 1987 to 1999, 3,224 patients with idiosyncratic neutropenia (50 with agranulocytosis) were identified. The incidences of neutropenia and agranulocytosis were estimated to be 120 and 7 cases per million people per year, respectively. The adjusted odds ratios for neutropenia were 34.7 (95% confidence interval 12.0–99.7) for current users of thyroid inhibitors, 9.5 (4.4–20.8) for users of disease‐modifying antirheumatic drugs, and 7.6 (4.9–11.9) for users of aminosalicylates. Other drugs with statistically significantly increased risks of neutropenia included antibacterial drugs, non‐opioid analgesics, NSAIDs, antidepressants, ulcer‐healing drugs, and anti‐epileptics. The increase in risk of neutropenia predominantly occurred during the first months of treatment. For most drugs investigated in this study, there was no relationship to daily dose. The excess 1‐year mortality was low among neutropenia and agranulocytosis cases and mostly explained by the underlying disease state. In conclusion, the highest risks of neutropenia were generally found in patients starting treatment. The excess 1‐year mortality was low among neutropenia and agranulocytosis cases and can be mostly explained by the underlying disease state. Am. J. Hematol. 72:248–254, 2003. © 2003 Wiley‐Liss, Inc.
Subcutaneous plasmacytomas with tropism to sites of previous trauma in a multiple myeloma patient treated with an autologous bone marrow transplant
Authors: Rosenblum Michael D. , Bredeson Christopher N. , Chang Chung‐Che , Rizzo J. Douglas
Published: March 2003

We report the case of a 59‐year‐old woman with Durie–Salmon stage IIIB IgGκ multiple myeloma (MM), who presented 83 days after autologous hematopoietic stem cell transplant (HSCT) with multiple subcutaneous plasmacytomas. These lesions were confined exclusively to sites where the patient had sustained local trauma. The patient had no pre‐transplant history of extramedullary disease and no evidence of plasma cells in the peripheral blood at any time throughout the course of her disease. This case represents the first report of refractory MM presenting as multiple subcutaneous plasmacytomas with specific tropism to sites of previous trauma. Selection of tumor cell subclones with unique chemokine receptor expression profiles that may explain this clinical observation is discussed. Am. J. Hematol. 72:274–277, 2003. © 2003 Wiley‐Liss, Inc.
Inhibition of cell surface mediated plasminogen activation by a monoclonal antibody against α‐Enolase
Authors: López‐Alemany Roser , Longstaff Colin , Hawley Stephen , Mirshahi Massoud , Fábregas Pere , Jardí Merce , Merton Elizabeth , Miles Lindsey A. , Félez Jordi
Published: March 2003

Localization of plasmin activity on leukocyte surfaces plays a critical role in fibrinolysis as well as in pathological and physiological processes in which cells must degrade the extracellular matrix in order to migrate. The binding of plasminogen to leukocytic cell lines induces a 30‐ to 80‐fold increase in the rate of plasminogen activation by tissue‐type (tPA) and urokinase‐type (uPA) plasminogen activators. In the present study we have examined the role of α‐enolase in plasminogen activation on the cell surface. We produced and characterized a monoclonal antibody (MAb) 11G1 against purified α‐enolase, which abrogated about 90% of cell‐dependent plasminogen activation by either uPA or tPA on leukocytoid cell lines of different lineages: B‐lymphocytic, T‐lymphocytic, granulocytic, and monocytic cells. In addition, MAb 11G1 also blocked enhancement of plasmin formation by peripheral blood neutrophils and monocytes. In contrast, MAb 11G1 did not affect plasmin generation in the presence of fibrin, indicating that this antibody did not interact with fibrinolytic components in the absence of cells. These data suggest that, although leukocytic cells display several molecules that bind plasminogen, α‐enolase is responsible for the majority of the promotion of plasminogen activation on the surfaces of leukocytic cells. Am. J. Hematol. 72:234–242, 2003. © 2003 Wiley‐Liss, Inc.
Partially successful treatment of a patient with chronic lymphocytic leukemia and Hodgkin's disease: Case report and literature review
Authors: Adiga Giridhar U. , Abebe Lool , Wiernik Peter H.
Published: March 2003

Chronic lymphocytic leukemia (CLL) is rarely associated with Hodgkin's disease (HD). We report a case of nodular sclerosis HD in a patient previously diagnosed with CLL. Reed‐Sternberg cells were CD15+ and CD30+. He was treated with dose‐escalated CHOP and at relapse, mitoxantrone, vinblastine, and CCNU (MVC) with partial response to the former and complete response to the latter, although the patient died 15 months later. Data from 88 other similar cases published in the English language were analyzed. Based on the histological and clinical features at the time of transformation, these patients were divided into distinct categories for analysis. Prognosis was found to be poorer in patients with continued active CLL when compared with those with CLL in remission at the time of transformation to HD. It is suggested that these two presentations may derive from different pathogenic mechanisms. Am. J. Hematol. 72:267–273, 2003. © 2003 Wiley‐Liss, Inc.
Pure red cell aplasia in a Sjögren's syndrome/lupus erythematosus overlap patient
Authors: Mavragani Clio P. , Vlachaki Eythymia , Voulgarelis Michalis
Published: March 2003

Hematological complications of systemic lupus erythematosus usually include anemia of chronic disease and peripheral destruction of blood cells. We describe the case of a young woman with Sjögren's syndrome'lupus erythematosus overlap, mother of infant with congenital heart block, complicated by pure red cell aplasia. The patient was asymptomatic until the onset of severe anemia. A serum inhibitor of erythropoiesis was detected before the onset of immunosuppression. Bone marrow examination showed a low CD4:CD8 ratio, an immune defect possibly linked with the unrestrained production of antibodies against erythroid progenitor cells. Am. J. Hematol. 72:259–262, 2003. © 2003 Wiley‐Liss, Inc.
Pallidal neuronal activity: Implications for models of dystonia
Authors: Hutchison William D. , Lang Anthony E. , Dostrovsky Jonathan O. , Lozano Andres M.
Published: March 2003

Dystonia is a neurological syndrome involving sustained contractions of opposing muscles leading to abnormal movements and postures. Recent studies report abnormally low pallidal neuronal activity in patients with generalized dystonia, suggesting hyperkinetic disorders result from underactive basal ganglia output. We examined this hypothesis in 11 patients with segmental and generalized dystonia undergoing microelectrode exploration of the internal globus pallidus (GPi) before pallidotomy or deep brain stimulation (DBS) implantation. The mean firing rates and firing patterns were compared with those in six patients with Parkinson's disease (PD). In seven patients who underwent surgery under local anesthesia, the mean GPi firing rate was 77Hz, similar to the 74Hz observed in the PD patients. However, in three dystonic patients under propofol anesthesia, GPi mean firing rate was much reduced (31Hz), and the firing pattern was distinguished by long pauses in activity, as reported by others. Low‐dose propofol in one other dystonia patient also seemed to suppress GPi firing. These results indicate that an abnormally low basal ganglia output is not the sine qua non of dystonia. The widely accepted pathophysiological models of dystonia that propose global decreases in basal ganglia output need to be viewed with caution in light of these findings. Ann Neurol 2003
Epilepsy after early‐life seizures can be independent of hippocampal injury
Authors: Raol Yogendra Sinh H. , Budreck Elaine C. , Brooks‐Kayal Amy R.
Published: March 2003

Prolonged early‐life seizures are considered potential risk factors for later epilepsy development, but mediators of this process remain largely unknown. Seizure‐induced structural damage in hippocampus, including cell loss and mossy fiber sprouting, is thought to contribute to the hyperexcitability characterizing epilepsy, but a causative role has not been established. To determine whether early‐life insults that lead to epilepsy result in similar structural changes, we subjected rat pups to lithium‐pilocarpine–induced status epilepticus during postnatal development (day 20) and examined them as adults for the occurrence of spontaneous seizures and alterations in hippocampal morphology. Sixty‐seven percent of rats developed spontaneous seizures after status epilepticus, yet only one third of these epileptic animals exhibited visible hippocampal cell loss or mossy fiber spouting in dentate gyrus. Most epileptic rats had no apparent structural alterations in the hippocampus detectable using standard light microscopy methods (profile counts and Timm's staining). These results suggest that hippocampal cell loss and mossy fiber sprouting can occur after early‐life status epilepticus but may not be necessary prerequisites for epileptogenesis in the developing brain. Ann Neurol 2003
An attention modulated response to disgust in human ventral anterior insula
Authors: Krolak‐Salmon Pierre , Hénaff Marie‐Anna , Isnard Jean , Tallon‐Baudry Catherine , Guénot Marc , Vighetto Alain , Bertrand Olivier , Mauguière François
Published: March 2003

The human brain is expert in analyzing rapidly and precisely facial features, especially emotional expressions representing a powerful communication vector. The involvement of insula in disgust recognition has been reported in behavioral and functional imaging studies. However, we do not know whether specific insular fields are involved in disgust processing nor what the processing time course is. Using depth electrodes implanted during presurgical evaluation of patients with drug‐refractory temporal lobe epilepsy, we recorded intracerebral event‐related potentials to human facial emotional expressions, that is, fear, disgust, happiness, surprise, and neutral expression. We studied evoked responses in 13 patients with insular contacts to specify the insular fields involved in disgust processing and assess the timing of their activation. We showed that specific potentials to disgust beginning 300 milliseconds after stimulus onset and lasting 200 milliseconds were evoked in the ventral anterior insula in four patients. The occurrence and latency of event‐related potentials to disgust in the ventral anterior insula were affected by selective attention. The analysis of spatial and temporal characteristics of insular responses to disgust facial expression lead us to underline the crucial role of ventral anterior insula in the categorization of facial emotional expressions, particularly the disgust. Ann Neurol 2003
Synthesis of novel C2‐symmetrical chiral sulfides and their utility in asymmetric epoxidation of aldehydes
Authors: Ishizaki Miyuki , Hoshino Osamu
Published: March 2003

Novel C2‐symmetrical chiral sulfides were synthesized from (R,R)‐tartaric acid and their utility in the asymmetric epoxidation of aldehydes with benzyl bromide was examined. Among the sulfides used, silyl ether‐type sulfides were found to be superior to diol‐ and benzyl ether‐type sulfides. Also, the presence of an aromatic group on the sulfide was proven to be an important factor for increasing enantioselectivity. Chirality 15:300–305, 2003. © 2003 Wiley‐Liss, Inc.
A Facile Synthesis of a Push‐Pull Mixed‐Ligand Pd‐Dithiolene Complex Containing the Et2timdt Ligand (Et2timdt = Monoreduced Diethylimidazolidine‐2,4,5‐trithione)
Authors: Aragoni M. Carla , Arca Massimiliano , Denotti Carla , Devillanova Francesco A. , Grigiotti Emanuela , Isaia Francesco , Laschi Franco , Lippolis Vito , Pala Luca , Slawin Alexandra M. Z. , Zanello Piero , Woollins J. Derek
Published: March 2003

The reaction of the dithiolene [Pd(Et2timdt)2] (Et2timdt = formally monoreduced diethylimidazolidine‐2,4,5‐trithione) with Br2 or IBr yields the complex [Pd(Et2timdt)Br2], a good starting material for the synthesis of novel push‐pull mixed‐ligand Pd‐dithiolenes. The synthesis and characterisation of the unsymmetrical dithiolene [Pd(Et2timdt)(mnt)] (mnt = maleonitriledithiolato dianion) is also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structures, and Properties of a Series of [Cd8Se(SePh)12Cl4]2− Cluster Compounds with Different Counterions
Authors: Eichhöfer Andreas , Hampe Oliver , Blom Martine
Published: March 2003

A series of seven single‐crystalline ionic CdSe cluster compounds, all possessing the cluster anion [Cd8Se(SePh)12Cl4]2−, but with different counterions, has been synthesized. The compounds were characterized in the solid state, solution, and gas phases using single‐crystal XRD, powder XRD, UV/Vis spectroscopy, and FT mass spectrometry. The results of the crystal structure determination show that the increasing size of the different counterions does not simply lead to an increase in the shortest inter‐cluster distance, but rather to changes in the crystal structure. Room‐temperature UV/Vis absorption and reflectance spectra of the crystalline powders are virtually identical, proving that the electronic transitions in the energy range probed can be attributed to the cluster anion [Cd8Se(SePh)12Cl4]2−. The band of the first transition in the solid‐state UV/Vis spectra are broadened relative to that in the solution spectra, as it is possibly affected by the collective interactions between the nanoclusters in the three‐dimensional crystal lattice. Interestingly, in solution, the position and feature of the lowest‐energy transition band changes as the solvent is varied. As FT mass spectrometry gives clear evidence for the existence of the intact [Cd8Se(SePh)12Cl4]2− cluster anion in all these solutions, these shifts can be interpreted in terms of solvatochromic effects. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Lanthanide Chelates Based on Diethylenetriamine Fitted with O‐Benzoic Acid Pendant Arms
Authors: Imbert Daniel , Fatin‐Rouge Nicolas , Bünzli Jean‐Claude G.
Published: March 2003

A new polycarboxylate ligand H5L has been synthesized by the attachment of five benzoate subunits onto a diethylenetriamine framework. Seven pKa values have been determined by potentiometry, spectrophotometry and NMR spectroscopy as 1.9(2), 2.8(2), 3.87(5), 4.58(6), 4.87(6), 9.19(6) and 11.68(5), the first four corresponding to the carboxylic functions and the last three to amine sites. The interaction between H5L and LnIII ions in dilute aqueous solution has been examined by UV/Vis absorption and emission spectrometries, and has been found to result in monometallic complexes that are moderately stable in the pH range 3.7−7.5. Conditional stability constants at pH 5.3 are logK11 = 5.3(2), 6.6(1), 6.5(1) and 7.2(3) for La, Eu, Tb and Lu, respectively. In the case of TbIII, the stability constants for [Tb(HL)]− and [Tb(H2L)] are logβ111 = 22.0(2) and logβ121 = 29.8(1), giving a pTb of 10.0. In the pH range 4−7, more than 90% of the TbIII ions are in the form of the neutral species [Tb(H2L)]. Lifetime determinations of the Eu(5D0) and Tb(5D4) excited levels in both H2O and D2O at pH 5.3 indicate 4.8 ± 0.5 (Eu) and 4.5 ± 0.5 (Tb) water molecules being bound in the inner coordination sphere of the LnIII. The triplet state of the ligand in water lies at around 26000 cm−1, resulting in a sizeable sensitisation of the Tb‐centred luminescence (absolute quantum yield: φabs = 10.3%), while the luminescence of EuIII is only poorly sensitised (φabs = 1.5%). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Manganese in Precipitated Hydroxyapatites
Authors: Mayer Isaac , Jacobsohn Orit , Niazov Tamara , Werckmann Jacques , Iliescu Monica , Richard‐Plouet Mireille , Burghaus Olaf , Reinen Dirk
Published: March 2003

The synthesis of Mn‐containing hydroxyapatite (HA) samples was carried out by precipitation from an aqueous solution with and without carbonate at pH 5.8−6.0. Chemical analyses have shown that Mn uptake (about 70%) is proportional to the amount of initially added Mn. The molar Ca/P ratios of the samples (1.53−1.63) indicate the formation of nonstoichiometric HA, with the higher values being obtained for the carbonated samples. Powder X‐ray diffraction (XRD) and IR spectroscopy have shown well‐defined patterns with structural data characteristic of HA. The calculated lattice constants were found to be similar to those known for HA, without any effect of the varying Mn content. High temperature treatment of selected samples was studied by XRD and IR and showed that the apatite structure is stable up to 400 °C for all samples. At 600 °C samples with low carbonate content transform partially, and at 800 °C completely, to β‐Ca3(PO4)2, while for samples with higher carbonate content (3.5−6.0%) the apatite structure is stable up to 800 °C, and a colour change to blue occurs. EPR spectroscopy reveals that manganese is divalent in all precipitated samples and present in a cubic impurity phase. After heating above 600 °C it is partially oxidized to MnV in the samples with high carbonate content and enters the HA lattice as the blue MnO43− ion. In the carbonate‐poor solids Mn2+ seems to partly occupy the Ca2+ sites in β‐Ca3(PO4)2 when sintered at temperatures above 400 °C. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A new data model for XML databases
Authors: Ho Richard , Bai Li , Elliman David
Published: March 2003

The widespread activity involving the Internet and the Web causes large amounts of electronic data to be generated every day. This includes, in particular, semi‐structured textual data such as electronic documents, computer programs, log files, transaction records, literature citations, and emails. Storing and manipulating the data thus produced has proven difficult. As conventional DBMSs are not suitable for handling semi‐structured data, there is a strong demand for systems that are capable of handling large volumes of complex data in an efficient and reliable way. The Extensible Markup Language (XML) provides such solution. In this paper, we present the concept of a ‘vertical view model’ and its uses as a mapping mechanism for converting complex XML data to relational database tables, and as a standalone data model for storing complex XML data. Copyright © 2003 John Wiley & Sons, Ltd.
Geometry optimization with QM/MM, ONIOM, and other combined methods. I. Microiterations and constraints
Authors: Vreven Thom , Morokuma Keiji , Farkas Ödön , Schlegel H. Bernhard , Frisch Michael J.
Published: March 2003

Hybrid energy methods such as QM/MM and ONIOM, that combine different levels of theory into one calculation, have been very successful in describing large systems. Geometry optimization methods can take advantage of the partitioning of these calculations into a region treated at a quantum mechanical (QM) level of theory and the larger, remaining region treated by an inexpensive method such as molecular mechanics (MM). A series of microiterations can be employed to fully optimize the MM region for each optimization step in the QM region. Cartesian coordinates are used for the MM region and are chosen so that the internal coordinates of the QM region remain constant during the microiterations. The coordinates of the MM region are augmented to permit rigid body translation and rotation of the QM region. This is essential if any atoms in the MM region are constrained, but it also improves the efficiency of unconstrained optimizations. Because of the microiterations, special care is needed for the optimization step in the QM region so that the system remains in the same local valley during the course of the optimization. The optimization methodology with microiterations, constraints, and step‐size control are illustrated by calculations on bacteriorhodopsin and other systems. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 760–769, 2003
Statistical analysis of the estimation of distance measures
Authors: Pinsky Mark , Yogev‐Einot Dina , Avnir David
Published: March 2003

Distance functions serve for quantitative evaluation of the degree of similarity, shape content, symmetry, chirality, and so on. We have developed a general methodology and a general computational tool for the estimation of the value of the distance function and of the error in that estimation, which originates in the experimental uncertainty in the location of the set of points of the studied structure (such as that expressed by the atomic displacement factor in X‐ray data analysis). © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 786–796, 2003
Rice Ageing. I. Effect of Changes in Protein on Starch Behaviour
Authors: Zhou Zhongkai , Robards Kevin , Helliwell Stuart , Blanchard Chris , Baxterb Graeme
Published: March 2003

Pasting properties of starch were affected by storage at 37 °C; the most significant changes were seen in peak viscosity and breakdown. In contrast, storage at 4 °C retarded the changes. The composition of the leachate from the RVA pastes was significantly affected by storage temperature (P < 0.01) with a lesser proportion of amylose in samples stored at 37 °C. Thus, ageing was associated with decreased leaching of starch and particularly amylose. Protease treatment increased the ratio of amylose to amylopectin in the hot‐water soluble fraction significantly (P < 0.05) for samples following storage at 37 °C while the ratio did not change for samples stored at 4 °C. Of greater significance was that the ratio was the same for samples stored at both temperatures following protease treatment. Similarly, after protease treatment the peak temperatures of the gelatinisation endotherm (Tp) of samples stored at 37 °C were identical to those of the samples stored at 4 °C. Protein was considered an important factor in the ageing process and the changes in proteins associated with storage were investigated. Higher storage temperature caused a reduction in the amount of prolamin and glutelin in the propanol‐extractable fractions.
Blurring the lines: Expanding learning opportunities for children and youth
Authors: Irby Merita , Pittman Karen J. , Tolman Joel
Published: March 2003

This chapter explores why expanding commitments to learning is critical and presents a framework for broadening definitions of learning.
On stability of uniformly‐accelerated motions of an axially‐symmetric heavy rigid body in an ideal fluid
Authors: Deryabin M.V.
Published: March 2003

We consider the problem of heavy rigid body dynamics in an infinite volume of an ideal incompressible fluid performing a potential motion. If the body is axially‐symmetric, then the system admits partial solutions, when the axis of symmetry is vertical, and the body sinks and rotates around its symmetry axis. These solutions were found by V.A.Steklov already at the end of the 19th century, and he also pointed out that in general these motions are unstable (as they are uniformly accelerated).

Here we consider the more delicate question, namely we derive the conditions for stability of the rotation axis direction. The method of c onstructing the Lyapunov function may be generalized for deriving stability conditions for mechanical systems with nonstationary force‐fields.
Oxothiazolidine Carboxylate Provides Protection against Hepatocellular Injury Seen after Porta Hepatis Occlusion (Pringle Maneuver) under Hypovolemic Conditions
Authors: Özgüç Halil , Tokyay Rifat , Kahveci Nevzat , Serdar Zehra , Gur Esma Surmen , Korfali Ender
Published: March 2003

Abstract

The sensitivity of liver to warm ischemia has always been a concern for surgeons. To monitor the ischemia and/or reperfusion injury after the Pringle maneuver (occlusion of porta hepatis) in livers subjected to hemorrhage, blood pressure, blood pH, base deficit (BE), serum alanine aminotransferase (ALT), serum and liver malondialdehyde (MDA), and liver glutathione (GSH) levels were measured. MDA is a by‐product of oxidant induced lipid peroxidation, and GSH is an endogenous antioxidant. The effect of lactated Ringer’s (LR) resuscitation with or without the addition of 2‐oxothiazolidine‐4‐carboxylate (OTC), a cysteine prodrug (enhancing glutathione production) on liver injury, if any, were investigated. Rats in the sham group (n = 8) and five other groups (n = 8) underwent femoral artery and vein catheterization and laparotomy. The hemorrhage group was bled 30% of their blood volume and the ischemia group underwent occlusion of the porta hepatis 30 minutes. The hemorrhage‐ischemia (HI), LR, and OTC groups underwent both hemorrhage and occlusion. The LR and OTC groups, 30 minutes after hemorrhage, received either LR resuscitation (equivalent to three times the shed blood) or LR resuscitation plus IV OTC (100 mg/kg before clamping and 100 mg/kg after de‐clamping). Porta hepatis occlusion in the presence of hypovolemia (HI group) caused an increase in serum ALT, plasma MDA, liver MDA, and base deficit and a decrease in blood pH levels. LR resuscitation lowered only MDA (plasma and liver) and base deficit but did not reduce ALT and increase blood pH. Although liver GSH did not change, OTC kept all parameters at control levels. OTC prevents the deleterious effects of total hepatic inflow occlusion under hypovolemic conditions, but this does not occur through enhancement liver glutathione production. OTC may protect the liver by accelerating hepatic glutathione turnover, but further studies are needed to explain its mechanism of action.
Preoperative Normal Level of Parathyroid Hormone Signifies an Early and Mild Form of Primary Hyperparathyroidism
Authors: Bergenfelz Anders , Lindblom Pia , Lindergård Birger , Valdemarsson Stig , Westerdahl Johan
Published: March 2003

Abstract

Contemporary patients are often diagnosed with mild or intermittent hypercalcemia. In addition, most studies demonstrate patients with parathyroid (PTH) levels in the upper normal range. The aim of the present investigation was to define subgroups of patients with mild primary hyperparathyroidism (pHPT), which could be of importance in the decision for or against surgical treatment. Two‐hundred and eleven patients, operated for pHPT were investigated with biochemical variables known to reflect PTH activity, renal function, and bone mineral content. The preoperative diagnosis of pHPT was based on the presence of hypercalcemia combined with an inappropriate serum concentration of PTH. The mean age of the patients was 64 ± 14 years and the mean serum level of calcium was 2.78 ± 0.19 mmol/L. One hundred and sixty‐two patients (77%) had raised levels of calcium and PTH the day before surgery (overt pHPT), 25 patients (12%) had a normal level of calcium and a raised PTH level (normal calcium group), and 20 patients (9%) had a raised level of calcium and a normal level of PTH (normal PTH group). In four patients the level of calcium and PTH was normal. Between‐group analysis demonstrated no major difference in symptom and signs of pHPT. Except for lower adenoma weight, patients in the normal calcium group did not essentially differ from the patients in the overt pHPT group. However, patients in the normal PTH group were a decade younger, and had better renal function, lower bone turnover, and a preserved bone density compared with patients in the overt pHPT group. In conclusion, the data from the present investigation show that pHPT patients with a preoperative normal PTH level have an early and mild form of the disease. Furthermore, the serum calcium concentration does not reflect disease severity in pHPT.
Enhanced Tumor Necrosis Factor‐α Expression in Small Sized Abdominal Aortic Aneurysms
Authors: Hamano Kimikazu , Li Tao‐Sheng , Takahashi Mutsuo , Kobayashi Toshiro , Shirasawa Bungo , Ito Hiroshi , Zempo Nobuya
Published: March 2003

Abstract

Circulating levels of tumor necrosis factor α (TNF‐α) are elevated in the patients with abdominal aortic aneurysm (AAA). We investigated TNF‐α expression and cellular infiltration in the walls of AAAs of different sizes. Twenty‐seven surgical specimens of AAAs were categorized according to the maximum aneurysm diameter into a small size group (less than 50 mm in diameter, n = 8; S group), a medium‐sized group (50 to 59 mm in diameter, n = 11; M group), and a large size group (larger than 59 mm in diameter, n = 8; L group). The level of TNF‐α and interleukin‐1β(IL‐1β) in the aneurysm wall was measured by ELISA. Immunohistochemical staining was performed to observe the TNF‐α expression and the infiltration of macrophages and lymphocytes in aneurysm walls. Enzyme‐linked immunosorbent assay showed that the level of TNF‐α in the S group (5.47 ± 3.48 pg/mg protein) was significantly higher (p < 0.05) than that in the M group (2.70 ± 1.33 pg/mg protein) or the L group (1.82 ± 1.21 pg/mg protein). No significant difference in IL‐1β was observed between the S, M, and L groups. Immunohistochemical analysis also showed that TNF‐α was expressed strongly in the S group but was negative or weakly positive in the M and L groups. Furthermore, the expression of TNF‐α was seen mainly where the aneurysm wall showed atheromatous change and macrophage infiltration. These results indicated that the expression of TNF‐α in the aneurysm wall was enhanced in small AAAs, and this enhancement might be related to the infiltration of macrophages.
Factors Affecting Mortality in Generalized Postoperative Peritonitis: Multivariate Analysis in 96 Patients
Authors: Mulier Stefaan , Penninckx Freddy , Verwaest Charles , Filez Ludo , Aerts Raymond , Fieuws Steffen , Lauwers Peter
Published: March 2003

Abstract

Mortality of generalized postoperative peritonitis remains high at 22% to 55%. The aim of the present study was to identify prognostic factors by means of univariate and multivariate analysis in a consecutive series of 96 patients. Mortality was 30%. Inability to clear the abdominal infection or to control the septic source, older age, and unconsciousness were significant factors related to mortality in the multivariate analysis. Failure to control the peritoneal infection (15%) was always fatal and correlated with failed septic source control, high Acute Physiology and Chronic Health Evaluation (APACHE) II score, and male gender. Failure to control the septic source (8%) also was always fatal and correlated with high APACHE II score and therapeutic delay. In patients with immediate source control, residual peritonitis occurred in 9% after purulent or biliary peritonitis and in 41% after fecal peritonitis (p = 0.002). In patients without immediate control of the septic source, delayed control was still achieved in 100% after a planned relaparotomy (PR) strategy versus 43% after an on‐demand relaparotomy (ODR) strategy (p = 0.018). In the same patients, mortality was 0% in the PR group versus 64% in the ODR group (p = 0.007). Early relaparotomy is related to improved septic source control. After relaparotomy for generalized postoperative peritonitis, a PR strategy is indicated whenever source control is uncertain. It also might decrease mortality in fecal peritonitis. An ODR approach is adequate for purulent and biliary peritonitis with safe septic source control.
Prognostic Factors after Resection for Hepatocellular Carcinoma in Noncirrhotic Livers: Univariate and Multivariate Analysis
Authors: Chen Miin‐Fu , Tsai Hsiu‐Pei , Jeng Long‐Bin , Lee Wei‐Chen , Yeh Chun‐Nan , Yu Ming‐Chin , Hung Chao‐Ming
Published: March 2003

Abstract

The aim of this study was to investigate the prognostic factors for hepatocellular carcinoma (HCC) in patients without cirrhosis who underwent hepatectomy. Between 1986 and 1998 a total of 197 men and 57 women with noncirrhotic HCC underwent hepatic resection in the Department of Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan. We determined their surgical mortality and the disease‐free and overall cumulative survival rates. The surgical mortality was 4.7% and the 5‐year disease‐free survival rate 24.01%. By Cox regression analysis, serum alkaline phosphatase [relative risk (RR) 1.761; 95% confidence interval (CI) 1.037–2.985)], albumin (RR 2.179; CI 1.215–3.908), multiple tumor status (RR 2.288; CI 1.272–4.115), and blood urea nitrogen (RR 4.651; CI 1.116–19.38) were shown to be independent prognostic factors for the 5‐year disease‐free survival rates. The 5‐year overall cumulative survival rate was 25.91%. By Cox regression analysis, serum albumin (RR 1.656, CI 1.005–2.730), blood transfusion (RR 2.075, CI 1.153–3.731), resection margin (RR 2.562, CI 1.436–4.572), and multiple tumors (RR 2.801, CI 1.727–4.545) were shown to be significant independent factors that influenced cumulative survival rates. Hence in patients with a noncirrhotic HCC who underwent hepatectomy the prognosis depended on preoperative hepatic function, the presence of multiple tumors, the need for blood transfusion, and the surgical resection margin.
Measurement of Surgical Dexterity Using Motion Analysis of Simple Bench Tasks
Authors: Bann Simon D. , Khan Mansoor S. , Darzi Ara W.
Published: March 2003

Abstract

The possibility of using quantitative motion analysis for objective assessment of simple surgical dexterity is investigated using the Imperial College Surgical Assessment Device (ICSAD) with qualitative analysis undertaken by inspection. Bench‐top knot tying and suturing skills were performed and examined for the ability to discriminate between surgeons of varying experience. These exercises were found to discriminate significantly between junior and senior surgeons in terms of both time taken and the number of movements required. The relation between time and motion was found to be variable depending on what skill was being undertaken: simple suturing, suturing at depth, or knot tying (1.71 vs. 1.86 vs. 2.36; p = 0.002 for 1 vs. 2; p < 0.001 for others). When the number of movements in a minute (standardized movements per minute) were considered, both groups were found to work at a similar rate, depending on the task, implying that the more experienced surgeon is more economical, performing the same exercise with fewer moves rather than with higher speed. Motion analysis exhibits face and construct validity and is a reliable assessment of simple surgical dexterity. Its use for objective assessment of dexterity and competence should be encouraged.
T‐0901317, a synthetic liver X receptor ligand, inhibits development of atherosclerosis in LDL receptor‐deficient mice
Authors: Terasaka Naoki , Hiroshima Ayano , Koieyama Tadashi , Ubukata Naoko , Morikawa Yuka , Nakai Daisuke , Inaba Toshimori
Published: March 2003

Liver X receptors (LXRα and LXRβ) are nuclear receptors, which are important regulators of cholesterol and lipid metabolism. LXRs control genes involved in cholesterol efflux in macrophages, bile acid synthesis in liver and intestinal cholesterol absorption. LXRs also regulate genes participating in lipogenesis. To determine whether the activation of LXR promotes or inhibits development of atherosclerosis, T‐0901317, a synthetic LXR ligand, was administered to low density lipoprotein receptor (LDLR)−/− mice. T‐0901317 significantly reduced the atherosclerotic lesions in LDLR−/− mice without affecting plasma total cholesterol levels. This anti‐atherogenic effect correlated with the plasma concentration of T‐0901317, but not with high density lipoprotein cholesterol, which was increased by T‐0901317. In addition, we observed that T‐0901317 increased expression of ATP binding cassette A1 in the lesions in LDLR−/− mice as well as in mouse peritoneal macrophages. T‐0901317 also significantly induced cholesterol efflux activity in peritoneal macrophages. These results suggest that LXR ligands may be useful therapeutic agents for the treatment of atherosclerosis.
Angiostatin and endostatin inhibit endothelial cell migration in response to FGF and VEGF without interfering with specific intracellular signal transduction pathways
Authors: Eriksson Kerstin , Magnusson Peetra , Dixelius Johan , Claesson-Welsh Lena , Cross Michael J
Published: March 2003

The anti‐angiogenic agents angiostatin and endostatin have been shown to affect endothelial cell migration in a number of studies. We have examined the effect of these agents on intracellular signalling pathways known to regulate endothelial cell migration and proliferation/survival. Both agents inhibited fibroblast growth factor (FGF)‐, and vascular endothelial growth factor (VEGF)‐mediated migration of primary human microvascular endothelial cells and affected vascular formation in the embryoid body model. However, using phosphospecific antibodies we could not detect any effect of angiostatin or endostatin on phospholipase C‐γ (PLC‐γ), Akt/PKB, p44/42 mitogen‐activated protein kinase (MAPK), p38 MAPK and p21‐activated kinase (PAK) activity. Furthermore, using a glutathione S‐transferase (GST)‐PAK pull‐down assay, we could not detect any effect on Rac activity. We conclude that angiostatin and endostatin inhibit chemotaxis, without affecting intracellular signalling pathways known to regulate endothelial migration and proliferation/survival.
Smad mediates BMP‐2‐induced upregulation of FGF‐evoked PC12 cell differentiation
Authors: Hayashi Hisaki , Ishisaki Akira , Imamura Toru
Published: March 2003

We previously reported that bone morphogenetic protein (BMP)‐2 augments fibroblast growth factor (FGF)‐induced neuronal differentiation of PC12 cells by selectively upregulating FGF receptor (FGFR)‐1 expression. Here we describe the underlying mechanism. BMP‐2 activated Smad proteins in PC12 cells. Overexpression of Smad7 or Smad1, inhibitory and receptor‐regulated isoforms, respectively, suppressed or enhanced BMP‐2‐induced upregulation of FGFR‐1 expression. Smad 7 also inhibited the FGF‐induced PC12 differentiation. Our findings indicate that activation of a Smad signaling pathway is required for upregulation of FGFR‐1 expression by BMP‐2 and for the synergistic induction of PC12 differentiation by BMP‐2 and FGF.
Mitochondrial ATP‐sensitive K+ channel opening decreases reactive oxygen species generation
Authors: Ferranti Renato , da Silva Mirian M , Kowaltowski Alicia J
Published: March 2003

Mitochondrial ATP‐sensitive K+ channel (mitoKATP) opening was shown previously to slightly increase respiration and decrease the membrane potential by stimulating K+ cycling across the inner membrane. Here we show that mitoKATP opening reduces reactive oxygen species generation in heart, liver and brain mitochondria. Decreased H2O2 release is observed when mitoKATP is active both with respiration stimulated by oxidative phosphorylation and when ATP synthesis is inhibited. In addition, decreased H2O2 release is observed when mitochondrial ΔpH is enhanced, an effect expected to occur when mitoKATP is open. We conclude that mitoKATP is an effective pathway to trigger mild uncoupling, preventing reactive oxygen species release.
Requirement of autophosphorylated tyrosine 992 of EGF receptor and its docking protein phospholipase Cγ1 for membrane ruffle formation
Authors: Nogami Masahiro , Yamazaki Masakazu , Watanabe Hiroshi , Okabayashi Yoshinori , Kido Yoshiaki , Kasuga Masato , Sasaki Takehiko , Maehama Tomohiko , Kanaho Yasunori
Published: March 2003

Stimulation of the epidermal growth factor receptor (EGFR) produces membrane ruffles through the small G protein Rac1; however, the signaling pathway from EGFR to Rac1 has not yet been clarified. Here, we show that autophosphorylation of EGFR at tyrosine 992 is required for EGF‐induced membrane ruffle formation in CHO cells. Signaling from the autophosphorylated tyrosine 992 appears to be mediated by phospholipase C (PLC) γ1. Furthermore, activation of Rac1 by EGF is inhibited by a PLC inhibitor. These results, taken together, suggest that autophosphorylation of EGFR at tyrosine 992 and the subsequent PLCγ1 activation transduce the signal to Rac1 to induce membrane ruffle formation.
Expression of syntaxin 1C, an alternative splice variant of HPC‐1/syntaxin 1A, is enhanced by phorbol‐ester stimulation in astroglioma: participation of the PKC signaling pathway1
Authors: Nakayama Takahiro , Mikoshiba Katsuhiko , Yamamori Tetsuo , Akagawa Kimio
Published: March 2003

Syntaxin 1C is an alternative splice variant of HPC‐1/syntaxin 1A; the latter participates in neurotransmitter release and is assigned to the gene domain responsible for Williams’ syndrome (WS). It is expressed in the soluble fraction extracted from human astroglioma cell lines T98G and U87MG. Quantitative immunoblot and indirect immunofluorescence analyses revealed that the expression of syntaxin 1C was upregulated by phorbol 12‐myristate 13‐acetate (PMA), but not by forskolin. A protein kinase C (PKC) inhibitor suppressed this enhancement. These results suggest that syntaxin 1C expression is regulated via the PKC signal pathway. This is the first report of a signal transduction system that directly affects the expression of syntaxin protein.
The crystal structure of a plant lectin in complex with the Tn antigen
Authors: Babino Alvaro , Tello Diana , Rojas Adriana , Bay Sylvie , Osinaga Eduardo , Alzari Pedro M
Published: March 2003

The structure of the tetrameric Vicia villosa isolectin B4 (VVLB4) in complex with a cancer antigen, the Tn glycopeptide (GalNAc‐O‐Ser), was determined at 2.7 Å resolution. The N‐acetylgalactoside moiety of the ligand binds to the primary combining site of VVLB4 in a similar way as observed for other Gal/GalNAc‐specific plant lectins. The amino acid moiety of the Tn antigen is largely exposed to the solvent and makes few contacts with the protein. The structure of the complex provides a framework to understand the differences in the strength of VVLB4 binding to different sugars and emphasizes the role of a single protein residue, Tyr127, as a structural determinant of Tn‐binding specificity.
Beringia as an Ice Age genetic museum
Authors: Shapiro Beth , Cooper Alan
Published: March 2003

Thousands of Late Pleistocene remains are found in sites throughout Beringia. These specimens comprise an Ice Age genetic museum, and the DNA contained within them provide a means to observe evolutionary processes within populations over geologically significant time scales. Phylogenetic analyses can identify the taxonomic positions of extinct species and provide estimates of speciation dates. Geographic and temporal divisions apparent in the genetic data can be related to ecological change, human impacts, and possible landscape mosaics in Beringia. The application of ancient DNA techniques to traditional paleontological studies provides a new perspective to long-standing questions regarding the paleoenvironment and diversity of Late Pleistocene Beringia.