bluuebunny/crossref_metadata_2025 huggingface dataset:
Altered Triggering of a Prepared Movement by a Startling Stimulus
Authors: Carlsen Anthony N. , Hunt Michael A. , Inglis J. Timothy , Sanderson David J. , Chua Romeo
Published: May 2006

An experiment is reported that investigated the effects of an auditory startling stimulus on a compound movement task. Previous findings have shown that, in a targeting task, a secondary movement can be initiated based on the proprioceptive information provided by a primary movement. Studies involving the presentation of a startling stimulus have shown that in reaction time (RT) tasks, prepared ballistic movements could be released early when participants are startled. In the present study we sought to determine whether the secondary component in an ongoing movement task, once prepared, could also be triggered by a startling stimulus. Participants performed a slow active elbow extension (22°/s), opening their hand when the arm passed 55° of extension from the starting point. An unexpected 124 dB startle stimulus was presented 5, 25, or 45° into the movement. Findings showed that, when participants were startled, the secondary component was triggered despite incongruent kinesthetic information. However, this only occurred when the startle was presented late in the primary movement. This suggests that the secondary movement was not prepared prior to task initiation, but was “loaded” into lower brain structures at some point during the movement in preparation to be triggered by the CNS. This occurred late in the movement sequence, but ≥400 ms prior to reaching the target. These findings indicate that, in addition to ballistic RT tasks, a startle can be used to probe response preparation in ongoing compound movement tasks.
Motor-Unit Coherence During Isometric Contractions Is Greater in a Hand Muscle of Older Adults
Authors: Semmler John G. , Kornatz Kurt W. , Enoka Roger M.
Published: May 2006

The purpose of this study was to quantify the strength of motor-unit coherence from the first dorsal interosseus muscle in young and old adults using data obtained in a previous study, where no differences in motor-unit synchronization between the two groups were observed. The strength of motor-unit coherence was quantified from 47 motor-unit pairs in 11 young adults (age 24.1 ± 4.1 yrs) and from 48 motor-unit pairs in 14 old adults (age 70.4 ± 5.9 yrs). The strength of motor-unit coherence was greater in old adults, particularly at low frequencies of 5–9 Hz (85% greater in old adults at 5 Hz). In addition, the older adults expressed an extra oscillation at approximately 12–13 Hz that was not present in the young subjects. These data demonstrate that common oscillatory inputs to motor neurons (motor-unit coherence) are enhanced in older adults despite no age-related difference in the strength of shared inputs (synchronization). Furthermore, the data emphasize that measures of motor-unit synchronization and coherence highlight different features of the same common input, and a coherence analysis may be a more sensitive tool to characterize shared input to motor neurons.
Effects of Expectations for Different Reward Magnitudes on Neuronal Activity in Primate Striatum
Authors: Cromwell Howard C. , Schultz Wolfram
Published: May 2006

In behavioral science, it is well known that humans and nonhuman animals are highly sensitive to differences in reward magnitude when choosing an outcome from a set of alternatives. We know that a realm of behavioral reactions is altered when animals begin to expect different levels of reward outcome. Our present aim was to investigate how the expectation for different magnitudes of reward influences behavior-related neurophysiology in the anterior striatum. In a spatial delayed response task, different instruction pictures are presented to the monkey. Each image represents a different magnitude of juice. By reaching to the spatial location where an instruction picture was presented, animals could receive the particular liquid amount designated by the stimulus. Reliable preferences in reward choice trials and differences in anticipatory licks, performance errors, and reaction times indicated that animals differentially expected the various reward amounts predicted by the instruction cues. A total of 374 of 2,000 neurons in the anterior parts of the caudate nucleus, putamen, and ventral striatum showed five forms of task-related activation during the preparation or execution of movement and activations preceding or following the liquid drop delivery. Approximately one-half of these striatal neurons showed differing response levels dependent on the magnitude of liquid to be received. Results of a linear regression analysis showed that reward magnitude and single cell discharge rate were related in a subset of neurons by a monotonic positive or negative relationship. Overall, these data support the idea that the striatum utilizes expectancies that contain precise information concerning the predicted, forthcoming level of reward in directing general behavioral reactions.
Role of Feedforward Control of Movement Stability in Reducing Slip-Related Balance Loss and Falls Among Older Adults
Authors: Pai Y.-C. , Wening J. D. , Runtz E. F. , Iqbal K. , Pavol M. J.
Published: May 2006

Human upright posture is inherently unstable. To counter the mechanical effect of a large-scale perturbation such as a slip, the CNS can make adaptive adjustments in advance to improve the stability of the body center-of-mass (COM) state (i.e., its velocity and position). Such feedforward control relies on an accurate internal representation of stability limits, which must be a function of anatomical, physiological, and environmental constraints and thus should be computationally deducible based on physical laws of motion. We combined an empirical approach with mathematical modeling to verify the hypothesis that an adaptive improvement in feedforward control of COM stability correlated with a subsequent reduction in balance loss. Forty-one older adults experienced a slip during a sit-to-stand task in a block of slip trials, followed by a block of nonslip trials and a re-slip trial. Their feedforward control of COM stability was quantified as the shortest distance between its state measured at seat-off ( slip onset) and the mathematically predicted feasible stability region boundary. With adaptation to repeated slips, older adults were able to exponentially reduce their incidence of falls and backward balance loss, attributable significantly to their improvement in feedforward control of stability. With exposure to slip and nonslip conditions, subjects began to select “optimal” movements that improved stability under both conditions, reducing the reliance on prior knowledge of forthcoming perturbations. These results can be fully accounted for when we assume that an internal representation of the COM stability limits guides the adaptive improvements in the feedforward control of stability.
Chemical Response Pattern of Different Classes of C-Nociceptors to Pruritogens and Algogens
Authors: Schmelz M. , Schmidt R. , Weidner C. , Hilliges Marita , Torebjörk H. E. , Handwerker H. O.
Published: May 2006

Vasoneuroactive substances were applied through intradermal microdialysis membranes and characterized as itch- or pain-inducing in psychophysical experiments. Histamine always provoked itching and rarely pain, capsaicin always pain but never itching. Prostaglandin E2(PGE2) led preferentially to moderate itching. Serotonin, acetylcholine, and bradykinin induced pain more often than itching. Subsequently the same substances were used in microneurography experiments to characterize the sensitivity profile of human cutaneous C-nociceptors. The responses of 89 mechanoresponsive (CMH, polymodal nociceptors), 52 mechanoinsensitive, histamine-negative (CMiHis−), and 24 mechanoinsensitive, histamine-positive (CMiHis+) units were compared. CMiHis+units were most responsive to histamine and to PGE2and less to serotonin, ACh, bradykinin, and capsaicin. CMH units (polymodal nociceptors) and CMiHis−units showed significantly weaker responses to histamine, PGE2, and acetylcholine. Capsaicin and bradykinin responses were not significantly different in the two classes of mechano-insensitive units. We conclude that CMiHis+units are “selective,” but not “specific” for pruritogenic substances and that the pruritic potency of a mediator increases with its ability to activate CMiHis+units but decreases with activation of CMH and CMiHis−units.
Gonadotropin Releasing Hormone (GnRH) Modulates Odorant Responses in the Peripheral Olfactory System of Axolotls
Authors: Park Daesik , Eisthen Heather L.
Published: May 2006

Peripheral signal modulation plays an important role in sensory processing. Activity in the vertebrate olfactory epithelium may be modulated by peptides released from the terminal nerve, such as gonadotropin releasing hormone (GnRH). Here, we demonstrate that GnRH modulates odorant responses in aquatic salamanders (axolotls, Ambystoma mexicanum). We recorded electrical field potentials (electro-olfactograms, or EOGs) in response to stimulation with four different amino acid odorants, l-lysine, l-methionine, l-cysteine, and l-glutamic acid. EOG responses were recorded from the main olfactory epithelium before, during, and after application of 10 μM GnRH. This protocol was repeated for a total of three trials with 60–80 min between trials. The effect of GnRH on EOG responses was broadly similar across odorants and across trials. In general, EOG responses were reduced to 79% of the initial magnitude during application of GnRH; in some trials in which glutamic acid served as the odorant, EOG responses were enhanced during the wash period. Although the 4-min inter-stimulus interval did not lead to adaptation of EOG responses during the first trial, we frequently observed evidence of adaptation during the second and third trials. In addition, we found that lower concentrations of GnRH produced a smaller effect. These results demonstrate that GnRH can modulate odorant responses in the peripheral olfactory system.
Optical Detection of Developmental Origin of Synaptic Function in the Embryonic Chick Vestibulocochlear Nuclei
Authors: Sato Katsushige , Momose-Sato Yoko
Published: May 2006

Functional organization of the brain stem vestibulocochlear nuclei during embryogenesis was investigated using a multiple-site optical recording technique with a fast voltage-sensitive dye. Brain stem slices with the cochlear and/or vestibular nerves attached were dissected from 6- to 8-day-old (E6–E8) chick embryos. Electrical responses evoked by cochlear or vestibular nerve stimulation were optically recorded simultaneously from many loci of the preparations. In E7 and E8 preparations, we identified two components of the optical response with cochlear or vestibular nerve stimulation; one was a fast spike-like signal related to the action potential, and the other was a slow signal related to the glutamate-mediated excitatory postsynaptic potential. The location of the cochlear nerve response area was mainly located on the dorsolateral region, while that of the vestibular nerve was deviated ventromedially. At E6, cochlear nerve stimulation evoked only the fast spike-like signals in normal Ringer solution. However, when we removed Mg2+from the extracellular solution, significant slow signals were elicited in the E6 preparation. The present results demonstrated that in the chick vestibulocochlear nuclei, functional synapses are already generated by the E7 embryonic stage and that postsynaptic activity related to N-methyl-d-aspartate receptors emerges latently, at least in the cochlear nerve-related nucleus, at the E6 embryonic stage. This chronological sequence of the emergence of postsynaptic function is different from that reported previously (E10–E11), suggesting that the developmental origin of sensory information transfer in the auditory pathway is much earlier than has been anticipated.
A review of randomized controlled trials comparing the effectiveness of hand held computers with paper methods for data collection
Authors: Lane Shannon J , Heddle Nancy M , Arnold Emmy , Walker Irwin
Published: May 2006

Background

Handheld computers are increasingly favoured over paper and pencil methods to capture data in clinical research.

Methods

This study systematically identified and reviewed randomized controlled trials (RCTs) that compared the two methods for self-recording and reporting data, and where at least one of the following outcomes was assessed: data accuracy; timeliness of data capture; and adherence to protocols for data collection.

Results

A comprehensive key word search of NLM Gateway's database yielded 9 studies fitting the criteria for inclusion. Data extraction was performed and checked by two of the authors. None of the studies included all outcomes. The results overall, favor handheld computers over paper and pencil for data collection among study participants but the data are not uniform for the different outcomes. Handheld computers appear superior in timeliness of receipt and data handling (four of four studies) and are preferred by most subjects (three of four studies). On the other hand, only one of the trials adequately compared adherence to instructions for recording and submission of data (handheld computers were superior), and comparisons of accuracy were inconsistent between five studies.

Conclusion

Handhelds are an effective alternative to paper and pencil modes of data collection; they are faster and were preferred by most users.
The Potential Role of Roflumilast: The New Phosphodiesterase-4 Inhibitor
Authors: Karish Sarah B , Gagnon James M
Published: May 2006

Objective:

To review the pharmacology, pharmacokinetics, efficacy, and safety of roflumilast in the treatment of asthma and chronic obstructive pulmonary disease (COPD).

Data Sources:

Studies, review articles, and meeting abstracts evaluating roflumilast were obtained from MEDLINE (1966–May 16, 2006), EMBASE (1980–May 16, 2006), and International Pharmaceutical Abstracts (1970–May 16, 2006) databases. Key terms used in all of the database searches were roflumilast, phosphodiesterase-4 inhibitor, asthma, chronic obstructive pulmonary disease, and COPD. Company Web sites were reviewed, and bibliographies of selected articles were evaluated for pertinent articles.

Study Selection and Data Extraction:

In vitro, in vivo, and animal studies were selected, as were published human studies on the efficacy and safety of roflumilast. Due to limited published data on its safety, efficacy, pharmacokinetics, and drug interactions, meeting abstracts were also selected. Data retrieved from abstracts only is indicated in the references.

Data Synthesis:

Roflumilast is a phosphodiesterase-4 (PDE-4) inhibitor which, due to its selective inhibition of the PDE 4 isoenzyme, has potential antiinflammatory and antimodulatory effects in the pulmonary system. It has been studied as an oral tablet in doses of 250 or 500 μg/day. Animal data and clinical trials have demonstrated roflumilast's efficacy and safety as an antiinflammatory and antimodulatory agent for use in asthma and COPD, with no documented drug interactions and a favorable adverse effect profile.

Conclusions:

Roflumilast may be an additional option in the treatment of asthma and COPD due to its ease of administration and a seemingly favorable adverse event profile. However, more research is needed to solidify roflumilast's place in therapy.
Effect of Graves’ Disease and Methimazole on Warfarin Anticoagulation
Authors: Busenbark Laura A , Cushnie Sally A
Published: May 2006

Objective:

To describe a case of Graves’ disease treated with methimazole and examine the influence of thyroid hormone alteration on warfarin anticoagulation.

Case Summary:

A 54-year-old man presented to the emergency department with palpitations, fatigue, weight loss, and anxiety attacks. He was taking no medications at that time. An electrocardiogram showed new onset atrial fibrillation. His thyroid profile was consistent with hyperthyroidism. The patient was admitted to the intensive care unit and started on methimazole 30 mg/day, metoprolol, enoxaparin, and warfarin 5 mg/day. Postdischarge doses of warfarin and methimazole were adjusted over the next several months based on thyroid panel results indicative of hypothyroidism. Postdischarge changes in methimazole dose caused alterations in thyroid function and intensity of anticoagulation as measured by international normalized ratio.

Discussion:

Interactions between warfarin and drugs that alter thyroid hormone concentrations have been reported; however, the extent and significance of the interaction between methimazole and warfarin have been inadequately described. Thyroid hormone concentrations influence the metabolic rates of proteins and, thus, can alter the amount of vitamin K–dependent clotting factors, which in turn can alter the extent of inhibition by warfarin. This may lead to changes in the intensity of anticoagulation and thereby increase the risk of thromboembolic or hemorrhagic events.

Conclusions:

Changes in thyroid hormone concentrations have the potential to significantly alter the extent of warfarin-induced anticoagulation. Clinicians must be aware of the need for close anticoagulation monitoring and dosage adjustment in patients receiving concomitant warfarin and methimazole. The full extent of this interaction may be delayed following a change in methimazole dose.
Activation of Muscarinic and Nicotinic Acetylcholine Receptors in the Nucleus Accumbens Core Is Necessary for the Acquisition of Drug Reinforcement
Authors: Crespo Jose A. , Sturm Katja , Saria Alois , Zernig Gerald
Published: May 2006

Neurotransmitter release in the nucleus accumbens core (NACore) during the acquisition of remifentanil or cocaine reinforcement was determined in an operant runway procedure by simultaneous tandem mass spectrometric analysis of dopamine, acetylcholine, and remifentanil or cocaine itself. Run times for remifentanil or cocaine continually decreased over the five consecutive runs of the experiment. Intra-NACore dopamine, acetylcholine, and drug peaked with each intravenous remifentanil or cocaine self-administration and decreased to pre-run baseline with half-lives of ∼10 min. As expected, remifentanil or cocaine peaks did not vary between the five runs. Surprisingly, however, drug-contingent dopamine peaks also did not change over the five runs, whereas acetylcholine peaks did. Thus, the acquisition of drug reinforcement was paralleled by a continuous increase in acetylcholine overflow in the NACore, whereas the overflow of dopamine, the expected prime neurotransmitter candidate for conditioning in drug reinforcement, did not increase. Local intra-accumbens administration by reverse microdialysis of either atropine or mecamylamine completely and reversibly blocked the acquisition of remifentanil reinforcement. Our findings suggest that activation of muscarinic and nicotinic acetylcholine receptors in the NACore by acetylcholine volume transmission is necessary during the acquisition phase of drug reinforcement conditioning.
Repulsive Guidance Molecule Plays Multiple Roles in Neuronal Differentiation and Axon Guidance
Authors: Matsunaga Eiji , Nakamura Harukazu , Chédotal Alain
Published: May 2006

Repulsive guidance molecule (RGM) is a membrane-bound protein originally isolated as a guidance molecule for retinal axons. Three RGM isoforms (RGMa–RGMc) exist in vertebrates. We showed previously that RGMa is a cell-survival factor in the neuroepithelium of chick embryos that suppresses the proapoptotic activity of its receptor neogenin. In the present study, we performed gain- and loss-of-function analysis of RGMa in chick embryos to further investigate RGMa function. We found that RGMa overexpression promotes neuronal differentiation, whereasRGMasmall interference RNA represses it. Similar experiments conducted at later developmental stages using retroviral vectors reveal that perturbation ofRGMaexpression disturbs the retinotectal projection. Our work provides the first evidence for a role for RGMs in axon guidancein vivo. In addition, these results suggest that RGMa exerts multiple functions during neural development.
Relationship Among Gender, Race, Age, Gingival Width, and Probing Depth in Primary Teeth
Authors: Gomes‐Filho Isaac Suzart , Miranda Dario Augusto Oliveira , Trindade Soraya Castro , de Souza Teles Santos Carlos Antônio , de Freitas Camila Oliveira Teixeira , da Cruz Simone Seixas , de Macêdo Taíze Cássia Nascimento , de Santana Passos Johelle
Published: May 2006

Background: Limited information is available regarding the attached keratinized tissue, probing depth, and sociodemographic characteristics of primary teeth. This study was carried out to evaluate the relationship among age, gender, race, gingival width, and probing depth in each primary tooth type.

Methods: The study population consisted of 300 children, aged 4 to 6 years, with clinically healthy gingiva, who were enrolled in an oral health program. Gingival width and probing depth were measured with a standard Williams periodontal probe in the middle of the keratinized gingiva and at six gingival sites (mesio‐buccal, mid‐buccal, disto‐buccal, mesio‐lingual, mid‐lingual, and disto‐lingual), respectively. Schiller's solution was used to establish the limits of keratinized gingiva.

Results: The gingival width (mean ± SD) on the buccal surfaces decreased from anterior to posterior positions in both arches; in the lower lingual surfaces, the inverse was observed. The gingival width (mean ± SD) ranged from 2.95 ± 0.15 mm to 6.16 ± 0.20 mm and the probing depth from 1.03 ± 0.91 mm to 2.08 ± 0.07 mm. There was a tendency toward increased probing depth as age increased from 4 to 6 years. There was also an increase in the probing depth from anterior to posterior teeth.

Conclusions: In the majority of observations, it was concluded that there was a relationship among age, gingival width, and probing depth, but generally not among race and gender and these measurements, respectively. Furthermore, there is no relation between gender and gingival width and race and probing depth.
Conjugates of polyhedral boron compounds with carbohydrates. 4. hydrolytic stability of carborane–lactose conjugates depends on the structure of a spacer between the carborane cage and sugar moiety
Authors: Orlova A. V. , Kononov L. O. , Kimel B. G. , Sivaev I. B. , Bregadze V. I.
Published: May 2006

A novel 1,2‐dicarba‐closo‐dodecaborane–lactose conjugate (4a) with an N‐glycosidic linkage was synthesized. This conjugate was found to be much more stable against hydrolytic deboronation (closo to nido tranformation of the carborane cage) under neutral conditions than a related carborane–lactose conjugate (1a) with an O‐glycosidic linkage. This result demonstrates that the hydrolytic stability of carborane–carbohydrate conjugates in neutral aqueous solutions may depend dramatically on the chemical nature of the spacer that links the carbohydrate moiety with the boron cage, the rate of hydrolysis varying by orders of magnitude. We relate a significant decrease in the deboronation rate to the formation of more strongly bound supramolecular aggregates, in which the boron cage is less accessible to nucleophilic attack by solvent molecules, in the solution of the carborane–N‐lactoside conjugate 4a. Copyright © 2006 John Wiley & Sons, Ltd.
Immunoregulatory effects of allogeneic mixed chimerism induced by nonmyeloablative bone marrow transplantation on chronic inflammatory arthritis and autoimmunity in interleukin‐1 receptor antagonist–deficient mice
Authors: Cho Seok Goo , Min So‐Youn , Park Min Jung , Lee Kyung Wha , Cho Young‐Gyu , Cho Mi‐La , Chang Hong Seok , Park Se‐Ho , Lee Jong Wook , Min Woo Sung , Kim Chun Choo , Kim Ho‐Youn
Published: May 2006

Objective

To investigate the immunoregulatory effects of allogeneic mixed chimerism induced by T cell–depleted, nonmyeloablative bone marrow transplantation (BMT) on chronic inflammatory arthritis and autoimmunity in mice deficient in interleukin‐1 receptor antagonist (IL‐1Ra).

Methods

IL‐1Ra−/− mice (H‐2Kd) were treated with antibody to asialoganglioside GM1 (anti–natural killer cell), total body irradiation (500 cGy), and T cell–depleted, nonmyeloablative BMT derived from C57BL/6 mice (H‐2Kb). Engraftment and chimerism were evaluated in peripheral blood, lymph nodes, and spleen by multicolor flow cytometry. The severity of arthritis was evaluated by clinical scoring and histopathologic assessment. Levels of IgG1 and IgG2a subtypes of anti–type II collagen (anti‐CII) antibodies were measured in serum samples. After T cells were stimulated with CII, ovalbumin, and phytohemagglutinin, T cell proliferative responses and levels of cytokine production (interferon‐γ [IFNγ], tumor necrosis factor α [TNFα], interleukin‐10 [IL‐10], and IL‐17) were assayed in culture supernatants.

Results

All IL‐1Ra−/− mice receiving BMT showed marked improvement in arthritis within 3 weeks, as well as successful induction of mixed chimerism. These mice showed higher levels of IgG1, and lower levels of IgG2a anti‐CII antibodies and weaker T cell proliferative responses than did mice in the control groups (either no treatment or conditioning alone without bone marrow rescue). In mixed chimeras, the levels of IFNγ, TNFα, and IL‐17 produced from CII‐stimulated T cells were significantly suppressed and IL‐10 production was significantly higher as compared with controls.

Conclusion

The introduction of allogeneic mixed chimerism showed a strong immunoregulatory potential to correct established chronic inflammatory arthritis and autoimmunity originating from a dysregulated proinflammatory cytokine network.
Immunohistochemical analysis of hip arthritis in ankylosing spondylitis: Evaluation of the bone–cartilage interface and subchondral bone marrow
Authors: Appel Heiner , Kuhne Maren , Spiekermann Simone , Köhler Dorothee , Zacher Josef , Stein Harald , Sieper Joachim , Loddenkemper Christoph
Published: May 2006

Objective

Previous histopathologic and magnetic resonance imaging studies suggest that the subchondral bone marrow might be the primary site of inflammation in patients with ankylosing spondylitis (AS) and that this might be reflected by inflammation found in hip joints. The aim of this study was to conduct an immunohistologic assessment of the bone–cartilage interface and subchondral bone marrow in AS patients with hip arthritis.

Methods

We collected femoral heads from patients with AS, osteoarthritis (OA), and rheumatoid arthritis (RA) who were undergoing hip replacement. The subchondral bone marrow and bone–cartilage interface were assessed immunohistochemically by evaluating infiltrating T cells, microvessel density, and osteoclasts. Areas of the femoral head surface with and without cartilage were assessed separately.

Results

At sites with surface cartilage, we found subchondral infiltration of CD3+ T cell aggregates at significantly higher numbers in AS patients as compared with OA patients, but not RA patients. At sites of complete cartilage destruction, the frequency of CD3+ T cell aggregates was significantly reduced as compared with sites with cartilage on the surface in AS patients, but not in RA patients. Similar differences were found for CD4+ and CD8+ T cells. Only at sites with surface cartilage, but not those without, angiogenesis and osteoclastic foci in the subchondral bone marrow in AS patients were significantly increased as compared with RA patients and with OA patients.

Conclusion

These findings suggest that the subchondral bone marrow and bone–cartilage interface are primary sites of inflammation in AS and that cartilage might be necessary for the induction of inflammation.
Influence of physicochemical properties of laser‐modified polystyrene on bovine serum albumin adsorption and rat C6 glioma cell behavior
Authors: Wang Xuefeng , Ohlin C. André , Lu Qinghua , Hu Jun
Published: May 2006

Biomaterial surface modification is an efficient way of improving cell‐material interactions. In this study, sub‐micrometer laser‐induced periodic surface structures (LIPSS) were produced on polystyrene by laser irradiation. FT‐IR analysis confirmed that this treatment also led to surface oxidation and anisotropic orientation of the produced carbonyl groups. As a consequence, the surface energy of the laser‐treated polystyrene was 1.45 times that of the untreated polystyrene, as measured by contact‐angle goniometry. Protein adsorption and rat C6 glioma cell behavior on the two substrates were investigated, showing that the changed physicochemical properties of laser‐modified polystyrene surface led to an increase in the quantity of adsorbed bovine serum albumin and significantly affected the behavior of rat C6 glioma cells. In the early stages of cell spreading, cells explored their microenvironment using filopodium as the main sensor. Moreover, cells actively aligned themselves along the direction of LIPSS gradually and cell attachment and proliferation were significantly enhanced. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
A multiple time step algorithm compatible with a large number of distance classes and an arbitrary distance dependence of the time step size for the fast evaluation of nonbonded interactions in molecular simulations
Authors: Kräutler Vincent , Hünenberger Philippe H.
Published: May 2006

A new algorithm is introduced to perform the multiple time step integration of the equations of motion for a molecular system, based on the splitting of the nonbonded interactions into a series of distance classes. The interactions between particle pairs in successive classes are updated at a progressively decreasing frequency. Unlike previous multiple time‐stepping schemes relying on distance classes, the present algorithm sorts interacting particle pairs by their next update times rather than by their update frequencies. For this reason, the proposed scheme is extremely flexible with respect to the number of classes that can be employed (up to hundred or more) and the distance dependence of the relative time step size (arbitrary integer function of the distance). It can also easily be adapted to classes defined based on a criterion other than the interparticle distance (e.g., interaction magnitude). Different variants of the algorithm are tested in terms of accuracy and efficiency for simulations of a pure water system (6167 molecules) under truncated‐octahedral periodic boundary conditions, and compared to the twin‐range method standardly used with GROMOS96 (short‐ and long‐range cutoff distances of 0.8 and 1.4 nm, pair list and intermediate‐range interactions updated every five steps). In particular, multiple time‐stepping schemes with an accuracy comparable to that of the twin‐range method can be designed, that permit to increase the effective (long‐range) cutoff distance from 1.4 to 3.0 nm with a performance loss of only about a factor 2. This result is quite encouraging, considering the benefits of doubling the cutoff radius in the context of (bio‐)molecular simulations. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1163–1176, 2006
Advanced approach for intraoperative MRI guidance and potential benefit for neurosurgical applications
Authors: Busse Harald , Schmitgen Arno , Trantakis Christos , Schober Ralf , Kahn Thomas , Moche Michael
Published: May 2006

Purpose

To present an advanced approach for intraoperative image guidance in an open 0.5 T MRI and to evaluate its effectiveness for neurosurgical interventions by comparison with a dynamic scan‐guided localization technique.

Materials and Methods

The built‐in scan guidance mode relied on successive interactive MRI scans. The additional advanced mode provided real‐time navigation based on reformatted high‐quality, intraoperatively acquired MR reference data, allowed multimodal image fusion, and used the successive scans of the built‐in mode for quick verification of the position only. Analysis involved tumor resections and biopsies in either scan guidance (N = 36) or advanced mode (N = 59) by the same three neurosurgeons. Technical, surgical, and workflow aspects were compared.

Results

The image quality and hand‐eye coordination of the advanced approach were improved. While the average extent of resection, neurologic outcome after functional MRI (fMRI) integration, and diagnostic yield appeared to be slightly better under advanced guidance, particularly for the main surgeon, statistical analysis revealed no significant differences. Resection times were comparable, while biopsies took around 30 minutes longer.

Conclusion

The presented approach is safe and provides more detailed images and higher navigation speed at the expense of actuality. The surgical outcome achieved with advanced guidance is (at least) as good as that obtained with dynamic scan guidance. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Protective effects of solvent extracts from Taiwanese Agrocybe cylindracea strain B against DNA damage induced by environmental mutagens
Authors: Lin Shwu‐Yuann , Wang Lien‐Hui , Lee Huei , Chiang Ben‐Tzu , Tsai Shun‐Jen , Lin Meei‐Yn
Published: May 2006

Antioxidant activity of a water extract from Agrocybe cylindracea strain B (ACB) against iron‐mediated lipid peroxidation has been demonstrated. In addition, the protective effect of water extracts from ACB (WAC) on hydroxyl radical‐mediated DNA strand breaks was better than that of the shiitake mushroom (Lentinula edodes). Therefore, we decided to investigate whether different solvent extracts from ACB (ACES) protect DNA against oxidative stress induced by environmental mutagens, such as cooking oil fumes (COF) and benzo[a]pyrene (BaP). Oxidative DNA damage and intercellular DNA migration (tail length) were quantified by determining the decrease of extracellular supercoiled (SC) plasmid DNA and by using the ‘comet assay’ in the human adenocarcinoma CL‐3 cell line, respectively. IC50 values of water, boiled water, methanol and acetone extracts from ACB were 108.97, 87.21, 970.52 and 1005.87 µg mL−1, respectively, for the decrease in cupric/COF‐mediated SC plasmid DNA damage. The boiled water extract has the best protective effect. The ethyl acetate and ether extracts did not inhibit plasmid DNA damage. By using the comet assay, IC50 values of the ether, methanol and acetone extracts from ACB were 672.95, 64.34, and 397.77 µg mL−1, respectively, for the decrease in COF‐mediated DNA migration in CL‐3 cells. The methanol extract had the best protective effect. However, water, boiled water and ethyl acetate extracts from ACB showed no protective effect on COF‐mediated DNA migration. These results indicate that the protective capacity of ACES on DNA damage induced by environmental mutagens is different in pUC18 plasmid DNA and CL‐3 cell DNA. Copyright © 2006 Society of Chemical Industry
The p53 codon 72 polymorphism, sunburns, and risk of skin cancer in US caucasian women
Authors: Han Jiali , Cox David G. , Colditz Graham A. , Hunter David J.
Published: May 2006

The p53 gene is involved in the control of cell‐cycle arrest and apoptosis. The germline Arg72Pro polymorphism alters the protein's biochemical functions, and may confer individual susceptibility to skin cancer. We evaluated the association of the Arg72Pro polymorphism with skin cancer risk among Caucasians in a nested case‐control study within the Nurses' Health Study (NHS) (219 melanoma, 286 squamous cell carcinoma (SCC), and 300 basal cell carcinoma (BCC) and 874 controls). Compared to the Arg/Arg genotype, the Pro/Pro genotype had an OR of 1.57 (95%CI, 0.81–3.06) for melanoma risk, and an OR of 1.79 (95%CI, 1.01–3.17) for BCC risk. The positive association of the Pro allele with BCC risk was only limited to women with two or fewer lifetime sunburns (P, trend, 0.002; P, interaction, 0.02). No association was observed between the polymorphism and SCC risk. We also observed that the Pro allele was inversely associated with the risk of childhood sunburn among Caucasian participants pooled from four nested case‐control studies within the NHS. This study suggests that the Arg72Pro polymorphism may play a role in skin carcinogenesis. © 2006 Wiley‐Liss, Inc.
Proteomic analysis of glutamine‐treated human intestinal epithelial HCT‐8 cells under basal and inflammatory conditions
Authors: Thébault Sandrine , Deniel Nicolas , Marion Rachel , Charlionet Roland , Tron François , Cosquer David , Leprince Jérôme , Vaudry Hubert , Ducrotté Philippe , Déchelotte Pierre
Published: May 2006

Glutamine (Gln) promotes intestinal growth and maintains gut structure and function, especially in situations of injury and during inflammation. Several mechanisms could contribute to Gln protective effects on gut. Proteomics enable us to characterize differentially expressed proteins in tissues in response to modifications of the biological or nutritional environment. Gln effects on the human intestinal epithelial HCT‐8 cell line proteome were assessed under basal and proinflammatory conditions. The 2‐DE gels were obtained and compared. Proteins were identified by MS and using databases. About 1200 spots were detected in both 2‐ and 10‐mM Gln concentrations. Under basal conditions, 24 proteins were differentially expressed in response to Gln. Half of these proteins were implicated in protein biosynthesis or proteolysis and 20% in membrane trafficking. Under proinflammatory conditions, 27 proteins were up‐ or down‐regulated by Gln 10 mM. From these proteins, 40% were involved in protein biosynthesis or proteolysis, 16% in membrane trafficking, 8% in cell cycle and apoptosis mechanisms and 8% in nucleic acid metabolism. This study provides the first holistic picture of proteome modulation by Gln in a human enterocytic cell line under basal and proinflammatory conditions, and supports further evaluation of nutritional modulation of intestinal proteome in humans.
Proteomic analysis of factors released from p21‐overexpressing tumour cells
Authors: Currid Caroline A. , O'Connor Darran P. , Chang Bey‐Dih , Gebus Caroline , Harris Nathan , Dawson Kenneth A. , Dunn Michael J. , Pennington Stephen R. , Roninson Igor B. , Gallagher William M.
Published: May 2006

The p21Waf1/Cip1/Sdi1 cyclin‐dependent kinase inhibitor is a key regulator of cell cycle progression and has also been observed to influence the expression of genes associated with several age‐related disorders. Previous work has shown that expression of p21 in tumour cells mediates an antiapoptotic and mitogenic paracrine effect, which is in contrast to the arrested state of p21‐expressing cells. Here, we have employed SELDI‐MS technology to characterise, at a proteomic level, factors released from HT‐1080 human fibrosarcoma cells displaying inducible p21 expression. Conditioned media from induced and noninduced cells were profiled on a range of diverse ProteinChip arrays and subjected to SELDI‐MS analysis. Evaluation of proteins binding onto IMAC, Q10 or CM10 surfaces led to the discovery of a number of putative p21‐regulated factors. We further validated three p21‐regulated proteins observed at 10.2, 11.7 and 13.4 kDa. Using Q Ceramic HyperD fractionation columns, we were able to selectively enrich for each of these three proteins. Subsequent SDS‐PAGE and MS analysis of tryptic digests identified the 13.4 kDa protein as cystatin C and the 10.2 kDa protein as pro‐platelet basic protein (PPBP). Judging by the apparent MW and the pI of the 11.7 kDa protein, we reasoned that it may be β‐2‐microglobulin, which was confirmed by subsequent identification. Increased levels of cystatin C and β‐2‐microglobulin in conditioned media from p21‐expressing cells was confirmed by antibody capture experiments using anticystatin C and anti‐β‐2‐microglobulin antibodies on preactivated PS‐20 arrays. Western blot analysis demonstrated increased expression of intracellular and extracellular cystatin C and β‐2‐microglobulin in p21‐expressing cells, compared to noninduced controls. Increased levels of PPBP were validated in cell lysates from p21‐expressing cells. The three secreted factors that we have identified in this study, have all been shown previously to have growth modulating effects and, as such, may contribute to the observed mitogenic and anti‐apoptotic paracrine activity of p22‐expressing cells.
Proteomic identification of a role for the von Hippel Lindau tumour suppressor in changes in the expression of mitochondrial proteins and septin 2 in renal cell carcinoma
Authors: Craven Rachel A. , Hanrahan Sarah , Totty Nick , Harnden Patricia , Stanley Anthea J. , Maher Eamonn R. , Harris Adrian L. , Trimble William S. , Selby Peter J. , Banks Rosamonde E.
Published: May 2006

The von Hippel Lindau (VHL) tumour suppressor gene, VHL, plays a central role in development of sporadic conventional renal cell carcinomas (RCCs). Studying VHL function may, therefore, increase understanding of the pathogenesis of RCC and identify markers/therapeutic targets. Comparison of 2‐DE protein profiles of VHL‐defective RCC cells (UMRC2) transfected with control vector or wild‐type VHL showed differences in 30 proteins, including several novel changes. One of the findings confirmed by Western blotting was up‐regulation of the mitochondrial protein ubiquinol cytochrome c reductase complex core protein 2 following VHL transfection, a change that was also observed in two other cell line backgrounds. A marked decrease in expression of this and several other mitochondrial proteins was demonstrated in RCC tissues and using VHL‐transfectants, several were shown to exhibit VHL‐dependent regulation. Thus, VHL may contribute to the decreased mitochondrial function seen in RCC. A form of septin 2 down‐regulated following VHL transfection was also identified. Septin 2 was up‐regulated in 12/16 RCCs, while alteration of the form present was also observed in 1/3 tumours analysed. Thus, increased expression of septin 2 is a common event in RCC and protein modification may also alter septin 2 function in a subset of tumours.
Utah Medical Products Inc. and the FDA: Regulatory Dogma versus Flexible Interpretation
Authors: Burgess C. , McDowall R. D.
Published: May 2006

This paper reviews the regulatory compliance background and the 2005 court case between the Food and Drug Administration (FDA) and Utah Medical Products Incorporated which supported the company's and not the Agency's interpretation of 21 Code of Federal Regulations (CFR) Part 820, the Quality System Regulations (QSR). This is the first time that the Agency has lost such a court case; the key issues in the case are presented and discussed. The judgement also shows the value of re‐reading the regulations to interpret what is actually required rather than custom and practice. Copyright © 2006 John Wiley & Sons, Ltd.
Bioanalytical quality assurance: concepts and concerns
Authors: Jones Anthony B.
Published: May 2006

The BioAnalytical Specialty Section (BASS) of the Society of Quality Assurance is a group of Quality Assurance professionals who have an interest and expertise in assuring the quality of bioanalytical data. This paper presents an overview of the regulatory requirements for bioanalysis and some of the topics that have been discussed by the BASS group. This initial article will be followed by more specific articles that we hope will contribute to better understanding and consistency in the conduct, audit and reporting of bioanalytical studies. Copyright © 2006 John Wiley & Sons, Ltd.
Development of new hydrogen storage material FeTi(Ni) for improved hydrogenation characteristics
Authors: Singh Binod Kumar , Ryu Hojin
Published: May 2006

The present study deals with the hydrogen storage characteristics of a transition metal composition Fe0.5Ni0.5Ti1.3 synthesized by melting the metal powders in a previously outgassed graphite crucible using radio frequency (r.f.) induction furnace (12 kW) in an argon atmosphere. X‐ray diffraction (XRD) studies revealed that the as‐synthesized sample is multiphasic in nature and embodies FeTi, FeO and Ti phases. Microstructural features (SEM) signify the presence of secondary phases and cracks. The hydrogen storage capacity and kinetics determined at different temperatures were found to be 1.26 wt% at 350°C. Fe0.5Ni0.5Ti1.3 exhibits faster hydrogen desorption kinetic (5 × 10−4 m3 s−1 kg−1), which is about two times higher than that of the parent FeTi1.3. Thermodynamic parameters ΔH (change in enthalpy) and ΔS (change in entropy) were found to be −35.07 kJmol−1 and 72.07 Jmol−1 K−1 respectively. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Energy model based loss‐minimized speed control of induction motor with a full‐order observer
Authors: Mannan Mohammad Abdul , Murata Toshiaki , Tamura Junji , Tsuchiya Takeshi
Published: May 2006

In this paper, a loss‐minimization algorithm is developed to achieve maximum efficiency in terms of slip frequency. The optimal value of slip frequency can be obtained by minimizing all controllable losses of the induction motor (IM). The ratio of magnetic energy converted to torque (WT) to magnetic energy stored in the rotating field (Wq) is defined in terms of slip frequency to obtain an error function that is used to design a controller to achieve the desired speed. Since the energy model of the IM can be expressed by the multi‐input and multi‐output (MIMO) system, an MIMO optimal regulator is proposed to achieve the desired speed with maximum efficiency. To design an optimal regulator, it is necessary to measure all state quantities. But WT and Wq cannot be measured directly. Therefore, a full‐order observer is proposed to estimate these state quantities. The gains of the observer system are calculated by using the pole placement technique. Consequently, the observer system becomes stable. The performance of the proposed controller and observer system are verified by using simulation. With regard to the simulation results, it can be concluded that the desired speed can be achieved by using the proposed controller and the unknown state quantities can be estimated properly by using the proposed observer system. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Propagation characteristics of a positive surface streamer
Authors: Kumada Akiko , Fukuda Yoshinori , Kamada Yoshifumi , Hidaka Kunihiko
Published: May 2006

The potential distribution of a developing positive surface streamer was measured by the Pockels effect. The transient potential distribution along a linear path was measured at minimum resolutions of 20 µm and 2 ns. Additionally, velocity of a streamer, average electric field along a streamer, and the developing length were measured while changing the insulator thickness from 0.8 to 5.0 mm. The potential along a positive surface streamer decreases linearly with the distance from the high‐potential electrode, and its gradient is about 500–650 V/mm, which is independent of the inception voltage and the insulator thickness. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Multi‐point Tabu Search for traveling salesman problems
Authors: Niizuma Daichi , Yasuda Keiichiro , Ishigame Atsushi
Published: May 2006

This paper proposes an algorithm—multipoint Tabu Search (MPTS) based on POP—which has several advantages for solving combinatorial optimization problems. The proposed algorithm is applied to some problems of traveling salesmen, which are typical combinatorial optimization problems, in order to verify the performance of the proposed algorithm. The simulation results indicate that the proposed method has higher optimality than the conventional Tabu Search (TS). © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.