bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kyphosis recurrence after posterior short-segment fixation in thoracolumbar burst fractures
Authors: Wang Xiang-Yang , Dai Li-Yang , Xu Hua-Zi , Chi Yong-Long 
Published: February 2008

Object
Recurrent kyphosis has been commonly seen after posterior short-segment pedicle instrumentation for a thoracolumbar fracture, but studies on this issue are relatively scarce, and the clinical significance of recurrent deformity is uncertain. No study has addressed the associations between the reduction of a burst fracture vertebra and the final recurrent kyphosis after implant removal. The aim of this study was to investigate the recurrent kyphosis after short-segment pedicle screw fixation in thoracolumbar burst fractures and to evaluate the effect of the degree of a vertebral reduction on the recurrent kyphotic deformity after implant removal.

Methods
Twenty-seven patients who had undergone posterior short-segment pedicle screw fixation for thoracolumbar junction burst fractures (T12–L2) were investigated retrospectively. The minimum follow-up period was 2 years (mean 2.7 years). Pain status was evaluated using the Denis pain scale. Changes in the anterior vertebral height ratio, vertebral wedge angle, upper intervertebral angle, lower intervertebral angle, Cobb angle, regional angle, and sagittal index were measured preoperatively, postoperatively, before implant removal, and at final follow-up. The correlation between the reduction of a fractured vertebra and the recurrent kyphotic deformity was also analyzed.

Results
After the initial surgical correction, the reduced vertebral body (VB) height (anterior vertebral height ratio and vertebral wedge angle) remained stable until final follow-up, whereas the intervertebral disc space (the upper and lower intervertebral angles) collapsed, resulting in a progressive kyphotic deformity (Cobb angle, regional angle, and sagittal index). No significant correlation was found between the final kyphosis and pain scale, but the 8 patients with a sagittal index > 15° showed a higher incidence of moderate to severe pain (P3–5 on the Denis pain scale) compared with the remaining 19 patients with a sagittal index < 15°. Significant positive correlation was found between recurrent kyphosis and vertebral wedge angle (r = 0.850, p < 0.001) and the reduced vertebral height (r = −0.727, p < 0.001).

Conclusions
Given that the correction loss occurs primarily through disc space collapse, the amount of the final kyphotic deformity was predictable by the degree of the fractured vertebral reduction as seen on the lateral x-ray study. Surgeons who perform posterior reduction and fixation procedures should pay more attention to reducing the fractured vertebral wedge angle to its intact condition, rather than the segmental angular parameters. If the wedge angle of the fractured VB is unacceptable after reduction, additional reconstruction of the anterior column may be necessary.
Effect of intraoperative position used in posterior lumbar interbody fusion on the maintenance of lumbar lordosis
Authors: Lee Jae Hyup , Lee Ji-Ho , Yoon Kang-Sup , Kang Seung-Baik , Jo Chris H. 
Published: February 2008

ObjectThe objective in this study was to compare retrospectively the use of different operating tables with different positions for posterior lumbar interbody fusion (PLIF) and the effect on intraoperative and postoperative lumbar lordosis and segmental lordosis.MethodsOne hundred seventy-two patients with degenerative disease of the lumbar spine who underwent posterior decompression and PLIF in which a 0° polyetheretherketone cage and pedicle screw fixation were used were evaluated. Ninety-one patients underwent surgery on a Wilson table (Group I) and 81 patients were treated on an OSI Jackson spinal table (Group II). Preoperative standing, intraoperative prone, and postoperative standing lateral radiographs were obtained in each patient. The total lumbar and segmental lordosis were compared and analyzed according to the position in which the patients were placed for their operation.ResultsThe intraoperative total lumbar lordosis was significantly decreased compared with the preoperative value. The postoperative total lumbar lordosis was similar, however, to the preoperative values in both groups. In Group I, the intraoperative segmental lordosis of L2–3 and L3–4 was significantly decreased compared with the pre-operative segmental lordosis. In Group II, the intraoperative segmental lordosis of L3–4, L4–5, L5–S1, and L4–S1 was significantly decreased compared with the preoperative segmental lordosis. The postoperative segmental lordosis of L4–5 was significantly decreased and L2–3 was significantly increased compared with the preoperative lordosis in both groups.ConclusionsIntraoperative position does not affect postoperative total lumbar lordosis and segmental lordosis in short-segment PLIF of the lumbar spine in a retrospective analysis of the surgical procedure to maintain lordosis.
Does spinal surgery improve the quality of life for those with extradural (spinal) osseous metastases? An international multicenter prospective observational study of 223 patients
Authors: Ibrahim Ahmed , Crockard Alan , Antonietti Pierre , Boriani Stefano , Bünger Cody , Gasbarrini Alessandro , Grejs Anders , Harms Jürgen , Kawahara Norio , Mazel Christian , Melcher Robert , Tomita Katsuro 
Published: February 2008

Object
Opinions vary widely as to the role of surgery (from none to wide margin excision) in the management of spinal metastases. In this study the authors set out to ascertain if surgery improves the quality of remaining life in patients with spinal metastatic and tumor-related systemic disease.

Methods
The authors included 223 patients in this study who were referred by oncologists and physicians over a 2-year period. All underwent surgery. Surgery was classified according to extent of excision ranging from en bloc excision or debulking to palliative surgery. All patients had a histologically confirmed diagnosis of epithelial spinal metastasis, and an oncology specialist undertook appropriately indicated adjuvant therapy in almost half of the patients.

Results
The mean patient age was 61 years. Excisional en bloc or debulking surgery was performed in 74%; the rest had (minimal) palliative decompression. All patients considered for surgery were included in the study. Patients presented with pain in 92% of cases, paraparesis in 24%, and abnormal urinary sphincter function in 22% (5% were incontinent). Breast, renal, lung, and prostate accounted for 65% of the cancers, and in 60% of patients there were widespread spinal metastases (Tomita Type 6 or 7).
The incidence of perioperative death (within 30 days of surgery) was 5.8%. Postoperatively 71% of the entire group had improved pain control, 53% regained or maintained their independent mobility, and 39% regained urinary sphincter function. The median survival for the cohort was 352 days (11.7 months); those who underwent excision survived significantly longer than those in the palliative group (p = 0.003). As with survival results, functional improvement outcome was better in those who underwent excision.

Conclusions
Surgical treatment was effective in improving quality of life by providing better pain control, enabling patients to regain or maintain mobility, and offering improved sphincter control. Although not a treatment of the systemic cancer, surgery is feasible, has acceptably low mortality and morbidity rates, and for many will improve the quality of their remaining life.
Genome evolution among cruciferous plants: a lecture from the comparison of the genetic maps of three diploid species—Capsella rubella, Arabidopsis lyrata subsp. petraea, and A. thaliana
Authors: Koch Marcus A. , Kiefer Markus 
Published: February 2008

Comparative mapping in cruciferous plants is ongoing, and recently two additional genetic maps of diploid Capsella and Arabidopsis lyrata subsp. petraea have been presented. We compared both maps with each other using the sequence map and genomic data resources from Arabidopsis thaliana as a reference. The ancestors of the species pair Capsella–Arabidopsis diverged from one another approximately 10–14 million years ago (mya), whereas Arabidopsis thaliana and Arabidopsis lyrata have been separated since roughly 5–6 mya. Our analysis indicated that among diploid Capsella and Arabidopsis lyrata all eight genetic linkage groups are totally colinear to each other, with only two inversions significantly differentiating these two species.By minimizing the number of chromosomal rearrangements during genome evolution, we presented a model of chromosome evolution involving all three species. From this scenario, it is obvious that Arabidopsis thaliana underwent a dramatic genome reconstruction, with a base chromosome number reduction from five to eight and with approximately 1.3 chromosomal rearrangements per million years. In contrast, the terminal lineage leading to Capsella has only undergone less than 0.09 rearrangements per million years. This is the same rate as calculated for Arabidopsis lyrata since its separation from the Capsella lineage 10–14 mya. These results are in strong contrast to all overestimated rates calculated from comparisons of the systems Arabidopsis thaliana and Brassica, and our data demonstrate the problematic nature of both model systems.
Xanthine Oxidoreductase
Authors: Nishino Takeshi , Pai Emil F 
Published: March 2008

AbstractA single gene product has been identified as responsible for the two catalytic activities, xanthine dehydrogenase, XDH (EC 1.1.1.204), and xanthine oxidase, XO (EC 1.2.3.2). Synthesized as XDH (ultimate electron acceptor NAD+), the protein can be converted to XO (ultimate electron acceptor oxygen) either reversibly by oxidation of cysteine residues or irreversibly by proteolysis. Xanthine oxidoreductase (XOR) is a ubiquitous enzyme; its physiological role is the oxidation of hypoxanthine to xanthine and further to uric acid, althoughin vitrothe enzyme's specificity is rather broad, accepting a large number of purines, pteridines, and aldehydes as substrates. XOR, in contrast to most other hydroxylases, incorporates water‐derived oxygen into its substrate. The electrons are transferred from xanthine to a Mopterin center and from there via two Fe2–S2clusters and FAD to NAD+or oxygen, respectively. The enzyme is the target of the antigout drug allopurinol; it is involved in hyperuricemia and xanthinuria and postulated to participate in postischemic reperfusion injury. Crystal structures have been determined for native and mutant XDHs and XOs from man, cow, rat, andRhodobacter capsulatus. The conformational changes linked to the dehydrogenase/oxidase transition have been identified and interpreted. A structure‐based explanation for the catalytic mechanism is emerging.
CO
Dehydrogenase/Acetyl‐
Co
A
Synthase
Authors: Fontecilla‐Camps Juan C , Volbeda Anne 
Published: March 2008

Abstract

The bifunctional tetrameric (α
2
β
2
) enzyme carbon monoxide dehydrogenase (CODH)/acetyl‐CoA synthase (ACS) is a central component of the Wood‐Ljungdahl pathway of acetogenic bacteria. In this pathway, two CO
2
molecules are reduced to a methyl group by folate‐containing enzymes and to CO by CODH, respectively. These two substrates are subsequently combined in ACS to form an Ni‐bound acetyl group that is reductively eliminated as acetyl‐CoA. The CODH and ACS active sites are about 70 Å apart and are connected by a network of hydrophobic tunnels. Thus, CO produced at the former enzyme migrates inside the bifunctional protein to the ACS site. Site‐directed mutagenesis has confirmed the functional role of the tunnels. The ACS subunit undergoes a conformational change that blocks the tunnel near the active site, preventing the escape of the toxic CO from within the enzyme upon methyl binding to nickel.
Association of PIP5K2A with schizophrenia: A study in an indonesian family sample
Authors: Saggers‐Gray L. , Heriani H. , Handoko H.Y. , Irmansyah I. , Kusumawardhani A.A.A.A. , Widyawati I. , Amir N. , Nasrun M.W.S. , Schwab S.G. , Wildenauer D.B. 
Published: March 2008

AbstractPIP5K2A variants have been shown to be associated with schizophrenia in Caucasian populations. This study tested 12 PIP5K2A SNPs for association with schizophrenia in a sample of 152 sib‐pair families of Indonesian descent. All SNPs had previously been tested for association with schizophrenia in a German family sample by Schwab et al. [2006; Mol Psychiatry] and seven SNPs were nominally associated with schizophrenia in this previous study. The purpose of the study was to examine whether previously implicated PIP5K2A variants influence susceptibility to schizophrenia in populations of non‐European descent. No single markers showed nominal association with schizophrenia in this Indonesian family sample, however multi‐marker haplotypes including a previously associated exonic SNP marker revealed nominally significant association (P = 0.03). Power to detect association was greater than 80% for all previously implicated variants except for rs11013052, where power was greatly reduced due to the low minor allele frequency of this marker in the Indonesian sample. An explorative study combining the results of this study with those of our previous study indicated that rs11013052 was significantly associated with schizophrenia in the combined sample (P = 0.002). The results of this study suggest that any contribution of previously implicated DNA variants within the PIP5K2A gene to schizophrenia susceptibility in the Indonesian population is only minor. © 2008 Wiley‐Liss, Inc.
Recognition of rhesus macaque (Macaca mulatta) noisy screams: evidence from conspecifics and human listeners
Authors: Fugate Jennifer M.B. , Gouzoules Harold , Nygaard Lynne C. 
Published: March 2008

AbstractVocalizations are among the diverse cues that animals use to recognize individual conspecifics. For some calls, such as noisy screams, there is debate over whether such recognition occurs. To test recognition of rhesus macaque noisy screams, recorded calls were played back to unrelated and related conspecific group members as either single calls or short bouts. Higher‐ranking, but not lower‐ranking, monkeys looked longer toward the playback speaker in trials containing screams from kin than in those composed of screams from nonkin. In a second study, human listeners performed a “same/different” discrimination task between presentations of rhesus screams from either the same or two different monkeys. Listeners discriminated between “same” and “different” callers above an established empirical threshold, whether screams were presented singly or in short bouts. Together, these results suggest that rhesus monkeys can distinguish noisy screams between kin and nonkin, and humans are able to discriminate different individuals' noisy screams, even when the duration of the bout is short. Whether noisy screams are ideally designed signals for individual recognition is discussed with respect to possible evolutionary origins of the calls. Am. J. Primatol. 70:594–604, 2008. © 2008 Wiley‐Liss, Inc.
Exogene Wirkstoffe zur Erkennung von Transmembrandomänen von Proteinen
Authors: Yin Hang 
Published: March 2008

AbstractUngefähr ein Drittel aller im menschlichen Genom codierten Proteine sind Membranproteine. Funktion und Struktur ihrer Transmembrandomänen sind weitaus weniger gut verstanden als die der wasserlöslichen Regionen. Die größte Hürde bei der Untersuchung dieser Domänen ist der Mangel an geeigneten exogenen Substanzen, die als spezifisch bindende Sonden eingesetzt werden könnten. Trotz dieser Schwierigkeiten ist es in jüngster Zeit mehrfach gelungen, die Transmembrandomänen verschiedener Membranproteine gezielt anzusteuern. In biophysikalischen Modellsystemen, bakteriellen Membranen und Säugerzellen konnten hohe Affinitäten und Selektivitäten erzielt werden.
Generalized Inferences on the Overall Treatment Effect in Meta‐analysis with Normally Distributed Outcomes
Authors: Tian Lili 
Published: March 2008

AbstractThis paper focuses on inferences about the overall treatment effect in meta‐analysis with normally distributed responses based on the concepts of generalized inference. A refined generalized pivotal quantity based on t distribution is presented and simulation study shows that it can provide confidence intervals with satisfactory coverage probabilities and perform hypothesis testing with satisfactory type‐I error control at very small sample sizes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Mixed Approach for Proving Non‐Inferiority in Clinical Trials with Binary Endpoints
Authors: Rousson Valentin , Seifert Burkhardt 
Published: March 2008

AbstractWhen a new treatment is compared to an established one in a randomized clinical trial, it is standard practice to statistically test for non‐inferiority rather than for superiority. When the endpoint is binary, one usually compares two treatments using either an odds‐ratio or a difference of proportions. In this paper, we propose a mixed approach which uses both concepts. One first defines the non‐inferiority margin using an odds‐ratio and one ultimately proves non‐inferiority statistically using a difference of proportions. The mixed approach is shown to be more powerful than the conventional odds‐ratio approach when the efficacy of the established treatment is known (with good precision) and high (e.g. with more than 56% of success). The gain of power achieved may lead in turn to a substantial reduction in the sample size needed to prove non‐inferiority. The mixed approach can be generalized to ordinal endpoints. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Holding period effect and home price indexes: a dynamic analysis
Authors: He Ling T. 
Published: March 2008

AbstractFour major home price indexes have been used in this study, and are based on different calculation methods and from different sources. The descriptive statistics indicate no meaningful differences among them. However, by analysing the orthogonalized impulse response and variance decomposition matrixes from the vector autoregressions, this study found some noticeable differences in the dynamic relationships between these indexes and three other housing factors – mortgage rates, existing home sales and new home sales – in addition to the inflation factor. The results may reflect the holding period effect in repeat sales house price indexes. Copyright © 2008 John Wiley & Sons, Ltd.
Small Molecule Inhibitors Targeting HIV‐1 Reverse Transcriptase Dimerization
Authors: Grohmann Dina , Corradi Valentina , Elbasyouny Mira , Baude Annika , Horenkamp Florian , Laufer Sandra D. , Manetti Fabrizio , Botta Maurizio , Restle Tobias 
Published: March 2008

AbstractThe enzymatic activities of human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase (RT) are strictly correlated with the dimeric forms of this vital retroviral enzyme. Accordingly, the development of inhibitors targeting the dimerization of RT represents a promising alternative antiviral strategy. Based on mutational studies, we applied a structure‐based ligand design approach generating pharmacophoric models of the large subunit connection subdomain to possibly identify small molecules from the ASINEX database, which might interfere with the RT subunit interaction. Docking studies of the selected compounds identified several candidates, which were initially tested in an in vitro subunit association assay. One of these molecules (MAS0) strongly reduced the association of the two RT subunits p51 and p66. Most notably, the compound simultaneously inhibited both the polymerase as well as the RNase H activity of the retroviral enzyme, following preincubation with t1/2 of about 2 h, indicative of a slow isomerization step. This step most probably represents a shift of the RT dimer equilibrium from an active to an inactive conformation. Taken together, to the best of our knowledge, this study represents the first successful rational screen for a small molecule HIV RT dimerization inhibitor, which may serve as attractive hit compound for the development of novel therapeutic agents.
1,2‐Alkyl Migration as a Key Element in the Invention of Cascade Reactions Catalyzed by π‐Acids
Authors: Crone Benedikt , Kirsch Stefan F. 
Published: March 2008

AbstractThis brief overview highlights recent progress in the field of cascade reactions that are initiated by the activation of a π‐system using platinum and gold catalysts and that are coupled with a 1,2‐alkyl migration step. While the reactions discussed aim to rapidly evolve molecular complexity, they are experimentally straightforward and easy to perform. Primarily guided by the type of 1,2‐alkyl migration, methods are categorized as shifts to metal carbenoid centers and pinacol‐type rearrangements.
Adsorption d'un colorant textile réactif sur un biosorbant non‐conventionnel : Les fibres de Posidonia oceanica (L.) delile
Authors: Mahjoub Borhane , Ncibi Mohamed Chaker , Seffen Mongi 
Published: March 2008

AbstractLes fibres du végétal marin Posidonia oceanica (L.) ont été utilisées en tant que matrice adsorbante d'un colorant textile réactif (Cibacron Red) pour son élimination des solutions aqueuses. Des essais en batch ont été réalisés pour déterminer les cinétiques et les isothermes d'adsorption. Les variables expérimentales étudiées sont la taille des particules, la quantité de fibres, la température, le pH et les prétraitements chimiques. L'état d'équilibre est atteint au bout de 48 h. La capacité de biosorption semble être maximisée par une augmentation de la quantité de support. La température a également un effet stimulant sur la biosorption du colorant. Le maximum de biosorption a été observé à un pH de 5,5. Le prétraitement préalable des fibres à l'acide phosphorique et nitrique permet d'augmenter considérablement leur capacité d'adsorption. La modélisation des données expérimentales a montré que les modèles du pseudo‐second ordre et de Freundlich décrivent, respectivement, les cinétiques et les isothermes d'adsorption d'une façon satisfaisante. L'étude des aspects thermodynamiques a montré que l'adsorption du colorant par la biomasse P. oceanica est un phénomène favorable, endothermique et spontané.
Theoretical modelling of the electrode thickness effect on maximum power point of dye‐sensitized solar cell
Authors: Ni Meng , Leung Michael K. H. , Leung Dennis Y. C. 
Published: March 2008

AbstractThe maximum power point (MPP) of a dye‐sensitized solar cell (DSSC) is often more important than the open‐circuit voltage and the short‐circuit current as MPP better represents the DSSC power output and energy conversion efficiency. In this investigation, the DSSC J–V characteristics and MPP were studied using a simple theoretical electron diffusion model. Parametric analyses were performed to determine the particular effect of electrode thickness on the MPP output. The analytical results are well consistent with the experimental results published in the literature. In the optimization analysis, it was specially found that the optimal electrode thickness for the highest MPP is rather insensitive to the operating conditions. It implies that an optimally designed DSSC can be always operated at its highest MPP regardless of any geographical, seasonal, and solar hour factors. Such an important attribute facilitates the design and manufacture of DSSC for worldwide commercialization at competitive costs.