bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple roles for CCR2 during fracture healing
Authors: Xing Zhiqing , Lu Chuanyong , Hu Diane , Yu Yan-yiu , Wang Xiaodong , Colnot Celine , Nakamura Mary , Wu Yalei , Miclau Theodore , Marcucio Ralph S.
Published: March 2010

Bone injury induces an inflammatory response that involves neutrophils, macrophages and other inflammatory cells. The recruitment of inflammatory cells to sites of injury occurs in response to specific signaling pathways. The CC chemokine receptor type 2 (CCR2) is crucial for recruiting macrophages, as well as regulating osteoclast function. In this study, we examined fracture healing in Ccr2−/− mice. We first demonstrated that the expression of Ccr2 transcripts and the filtration of macrophages into fracture calluses were most robust during the early phases of fracture healing. We then determined that the number of macrophages at the fracture site was significantly lower in Ccr2−/− mice compared with wild-type controls at 3 days after injury. As a result, impaired vascularization, decreased formation of callus, and delayed maturation of cartilage were observed at 7 days after injury in mutant mice. At day 14, Ccr2−/− mice had less bone in their calluses. At day 21, Ccr2−/− mice had larger calluses and more bone compared with wild-type mice, suggesting a delayed remodeling. In addition, we examined the effect of Ccr2 mutation on osteoclasts. We found that a lack of Ccr2 did not affect the number of osteoclasts within fracture calluses at 21 days after injury. However, Ccr2−/− osteoclasts exhibited a decreased ability to resorb bone compared with wild-type cells, which could contribute to the delayed remodeling of fracture calluses observed in Ccr2−/− mice. Collectively, these results indicate that a deficiency of Ccr2 reduces the infiltration of macrophages and impairs the function of osteoclasts, leading to delayed fracture healing.
SirT1 in muscle physiology and disease: lessons from mouse models
Authors: Vinciguerra Manlio , Fulco Marcella , Ladurner Andreas , Sartorelli Vittorio , Rosenthal Nadia
Published: March 2010

Sirtuin 1 (SirT1) is the largest of the seven members of the sirtuin family of class III nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylases, whose activation is beneficial for metabolic, neurodegenerative, inflammatory and neoplastic diseases, and augments life span in model organisms (Finkel et al., 2009; Lavu et al., 2008). In vitro studies show that SirT1 protects genome integrity and is involved in circadian physiological rhythms (Asher et al., 2008; Nakahata et al., 2008; Oberdoerffer et al., 2008). In the last few years, a fundamental role for SirT1 in the metabolism and differentiation of skeletal muscle cells has been uncovered (Fulco et al., 2003), and the use of specific transgenic or knockout SirT1 mouse models implicates it in the protection of heart muscle from oxidative and hypertrophic stresses (Alcendor et al., 2007). In this Perspective, we review the recent exciting findings that have established a key role for the ’longevity’ protein SirT1 in skeletal and heart muscle physiology and disease. Furthermore, given the multiple biological functions of SirT1, we discuss the unique opportunities that SirT1 mouse models can offer to improve our integrated understanding of the metabolism, as well as the regeneration and aging-associated changes in the circadian function, of skeletal and heart muscle.
The zebrafish as a model for cancer
Authors: Mione Marina C. , Trede Nikolaus S.
Published: March 2010

For the last three decades significant parts of national science budgets, and international and private funding worldwide, have been dedicated to cancer research. This has resulted in a number of important scientific findings. Studies in tissue culture have multiplied our knowledge of cancer cell pathophysiology, mechanisms of transformation and strategies of survival of cancer cells, revealing therapeutically exploitable differences to normal cells. Rodent animal models have provided important insights on the developmental biology of cancer cells and on host responses to the transformed cells. However, the rate of death from some malignancies is still high, and the incidence of cancer is increasing in the western hemisphere. Alternative animal models are needed, where cancer cell biology, developmental biology and treatment can be studied in an integrated way. The zebrafish offers a number of features, such as its rapid development, tractable genetics, suitability for in vivo imaging and chemical screening, that make it an attractive model to cancer researchers. This Primer will provide a synopsis of the different cancer models generated by the zebrafish community to date. It will discuss the use of these models to further our understanding of the mechanisms of cancer development, and to promote drug discovery. The article was inspired by a workshop on the topic held in July 2009 in Spoleto, Italy, where a number of new zebrafish cancer models were presented. The overarching goal of the article is aimed at raising the awareness of basic researchers, as well as clinicians, to the versatility of this emerging alternative animal model of cancer.
Prion-like disorders: blurring the divide between transmissibility and infectivity
Authors: Cushman Mimi , Johnson Brian S. , King Oliver D. , Gitler Aaron D. , Shorter James
Published: March 2010

Prions are proteins that access self-templating amyloid forms, which confer phenotypic changes that can spread from individual to individual within or between species. These infectious phenotypes can be beneficial, as with yeast prions, or deleterious, as with mammalian prions that transmit spongiform encephalopathies. However, the ability to form self-templating amyloid is not unique to prion proteins. Diverse polypeptides that tend to populate intrinsically unfolded states also form self-templating amyloid conformers that are associated with devastating neurodegenerative disorders. Moreover, two RNA-binding proteins, FUS and TDP-43, which form cytoplasmic aggregates in amyotrophic lateral sclerosis, harbor a ‘prion domain’ similar to those found in several yeast prion proteins. Can these proteins and the neurodegenerative diseases to which they are linked become ‘infectious’ too? Here, we highlight advances that define the transmissibility of amyloid forms connected with Alzheimer's disease, Parkinson's disease and Huntington's disease. Collectively, these findings suggest that amyloid conformers can spread from cell to cell within the brains of afflicted individuals, thereby spreading the specific neurodegenerative phenotypes distinctive to the protein being converted to amyloid. Importantly, this transmissibility mandates a re-evaluation of emerging neuronal graft and stem-cell therapies. In this Commentary, we suggest how these treatments might be optimized to overcome the transmissible conformers that confer neurodegeneration.
Breaking down the barriers: siRNA delivery and endosome escape
Authors: Dominska Monika , Dykxhoorn Derek M.
Published: March 2010

RNA interference (RNAi)-based technologies offer an attractive strategy for the sequence-specific silencing of disease-causing genes. The application of small interfering (si)RNAs as potential therapeutic agents requires safe and effective methods for their delivery to the cytoplasm of the target cells and tissues. Recent studies have shown significant progress in the development of targeting reagents that facilitate the recognition of and siRNA delivery to specific cell types. However, most of these delivery approaches are not optimized to enable the intracellular trafficking of the siRNAs into the cytoplasm where they must associate with the RNA-induced silencing complex (RISC) to direct the cleavage of mRNAs bearing complementary binding sites. In particular, the trafficking of siRNAs from endosomes into the cytoplasm represents a major rate-limiting step for many delivery approaches. This Commentary focuses on novel strategies designed to enhance endosomal escape and thereby increase the efficacy of siRNA-mediated gene silencing.
A Novel Closed-Loop Electromechanical Stimulator to Enhance Osseointegration with Immediate Loading of Dental Implant Restorations
Authors: Meswania J M , Bousdras V A , Ahir S P , Cunningham J L , Blunn G W , Goodship A E
Published: March 2010

The degree of osseomechanical integration of dental implants is acutely sensitive to their mechanical environment. Bone, both as a tissue and structure, adapts its mass and architecture in response to loading conditions. Therefore, application of predefined controlled loads may be considered as a treatment option to promote early maturation of bone/implant interface prior to or in conjunction with crown/prosthesis attachment. Although many studies have established that the magnitude, rate of the applied strain, and frequency have significant effects on the osteogenic response, the actual specific relationships between strain parameters and frequency have not yet been fully defined. The purpose of this study was to develop a stimulator to apply defined mechanical stimuli to individual dental implants in vivo immediately after implantation, exploring the hypothesis that immediate controlled loading could enhance implant integration. An electromechanical device was developed, based on load values obtained using a two-dimensional finite element analysis of the bone/implant interface generating 1000 to 4000 με and operated at 30 and 3 Hz respectively. The device was then tested in a cadaveric pig mandible, and periosteal bone surface strains were recorded for potential future comparison with a three-dimensional finite element model to determine loading regimens to optimize interface strains and iterate the device for clinical use.
Study of a high rotational speed shrouded centrifugal fan: Aerodynamics and effects of a shroud-associated cavity on the performance
Authors: Khelladi S , Sarraf C , Bakir F , Rey R
Published: March 2010

A centrifugal fan with a high rotational velocity and compact dimension is studied numerically and experimentally in this paper. The fan consists of a shrouded impeller rotating at 34 000 r/min with a small cavity between the impeller and outer casing. The overall performance and the major flow features have been numerically and experimentally investigated. For the numerical simulation, two computational models with/without the cavity were tested. The modelling of a very-small-size cavity is generally time-consuming, compared with the outer domain. However, it has been shown that its effect can be taken into account with a simple method discussed in this study. A simple volumetric loss model coupled to a numerical modelling of the fan without the cavity gives a very interesting approximation of the global performance of the fan. In the present work, the overall performance and the major flow features of each component inside the fan were numerically investigated. The numerical results at different locations were compared with experimental ones. It is shown that the results obtained by the simplified method and the full numerical simulation both predict the global performance obtained experimentally. Furthermore, in terms of the flow restriction obtained for the centrifugal fan, new empirical coefficients accounting for the effects of the cavity were set.
Influence of prime mover size and operational strategy on the performance of combined cooling, heating, and power systems under different cost structures
Authors: Hueffed A K , Mago P J
Published: March 2010

Combined cooling, heating, and power (CCHP) systems use waste heat from on-site electricity generation to meet the thermal demand of the facility, which includes cooling, heating, and hot water. When compared with traditional set-ups of grid-generated electricity and an on-site boiler for heat, CCHP systems are capable of improving fuel utilization and lowering emissions. One of the critical components affecting the performance of CCHP systems is the prime mover. The objective of this investigation is to study the effect of the prime mover size and operational strategy on the energy, economical, and environmental performance of CCHP systems under different pricing structures. Three different sizes for the prime mover, a natural gas engine, are simulated under different operational strategies such as: following the electric demand of the facility, following the thermal demand of the facility, and following a constant load. The results obtained for the CCHP system will be compared with a reference building operating under conventional technologies to determine the advantages or disadvantages of the CCHP system's operation. In addition, a simple optimization of the system's operation determines the best engine load for each hour during the simulation that minimizes cost, primary energy consumption (PEC), or carbon dioxide emissions (CDEs). For this study, three locations in different climate zones that have different electricity rate structures were chosen: one with a constant flat rate; one that uses seasonal rates; and one that incorporates block charges. Historical monthly natural gas rates were also used. Since most authors perform cost analyses using a fixed constant rate for both electricity and natural gas, a comparison is made between the cost results from using the actual cost data to those that use an average fixed rate. In general, among the three engine sizes that were simulated, the smallest engine yielded the lowest costs and lowest PEC; but, no such trend was found with regard to the CDE. The results also showed that the performance of the evaluated CCHP system can be improved by optimizing the system based on cost or primary energy.
Numerical simulation of a wind turbine airfoil: Dynamic stall and comparison with experiments
Authors: Yu G H , Zhu X C , Du Z H
Published: March 2010

Unsteady aerodynamic characteristics of the National Renewable Energy Laboratory S809 airfoil, undergoing sinusoidal pitch oscillations at various reduced frequencies, mean angles of attack, and pitch oscillation amplitudes at Re = 106, are investigated through solutions of two-dimensional Navier—Stokes equations. It is found that there is an encouraging agreement between the computational fluid dynamics (CFD)-predicted aerodynamic force coefficient hysteresis loops and the Ohio State University wind tunnel experimental data, although discrepancies still exist at higher angles of attack and during downstroke pitch motion. The effects of some parameters are studied, and the flow behaviour and dynamic stall vortex development of a typical case are represented in great detail by streamline distribution and pressure coefficient plots. CFD methodology is proved to be promising in predicting airfoil dynamic stall characteristics, and the impact of dynamic stall on the practical operation of wind turbines is analysed. It is necessary to take this into consideration in the prediction of wind turbine performance.
Facile Preparation Method of a Disposable Capillary Biosensor Using an Ion-selective Optode Membrane and a Dissolvable Enzyme Membrane and Its Application to Urea Sensing
Authors: Tsutsumi Erina , Henares Terence G , Kawamura Kunio , Yao Toshio , Hisamoto Hideaki
Published: March 2010

A facile preparation method of a disposable capillary biosensor immobilizing a plasticized poly(vinyl chloride) (PVC) membrane ion-selective optode containing a lipophilic pH indicator dye and an ionophore, and a dissolvable poly(ethylene glycol) (PEG) membrane containing an enzyme is developed. The method involves the sequential introduction of membrane cocktail solution followed by air introduction. Repeating this process allowed facile preparation of a capillary biosensor comprised of two layer structure, which can be used for single-step biosensing just by sipping the sample with capillary action. Here a urea biosensor was prepared as a proof-of-concept.
Synthesis and Immobilization of Amylose Derivatives Bearing a 4-tert-Butylbenzoate Group at the 2-Position and 3,5-Dichlorophenylcarbamate/3-(Triethoxysilyl)propylcarbamate Groups at 3- and 6-Positions as Chiral Packing Material for HPLC
Authors: Shen Jun , Ikai Tomoyuki , Shen Xiande , Okamoto Yoshio
Published: March 2010

Two novel amylose derivatives 2a and 2b bearing 4-tert-butylbenzoate at the 2-position and 3,5-dichlorophenylcarbamate/3-(triethoxysilyl)propylcarbamate residues at 3- and 6-positions were successfully synthesized and immobilized onto silica gel, and their chiral recognition abilities were evaluated as chiral packing materials (CPMs) for high-performance liquid chromatography. These immobilized CPMs exhibited recognition ability similar to conventional coated CPM, and for some racemates, comparable or better resolutions were observed even compared to commercial immobilized amylose- or cellulose-based columns.
Preparation of Carbon-supported Pt–Co Alloy Nanoparticles for Oxygen Reduction Reaction: Promotion of Pt–Co Alloy Formation by Coverage with Silica
Authors: Takenaka Sakae , Hirata Akiko , Matsune Hideki , Kishida Masahiro
Published: March 2010

Carbon-supported Pt–Co catalyst for the oxygen reduction reaction was covered with silica layers to inhibit sintering of the metal particles. Coverage of the Pt–Co catalyst with silica layers promoted the formation of alloys with small diameters during treatment at 973 K. The silica-coated Pt–Co electrocatalyst showed a large electrochemically active surface area (ECSA) and excellent durability.
Nitroxide Radicals for Highly Efficient Redox Mediation in Dye-sensitized Solar Cells
Authors: Kato Fumiaki , Hayashi Naoki , Murakami Takaya , Okumura Chie , Oyaizu Kenichi , Nishide Hiroyuki
Published: March 2010

A robust nitroxide radical, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and its 4-subsituted derivatives (R-TEMPO) exhibit electrochemically reversible redox properties with tunable half-wave potentials (E1/2) based on the substituent effect. Dye-sensitized solar cells using R-TEMPO as mediators with electron-withdrawing R groups showed significantly enhanced photovoltages compared with those obtained using iodides. The linearity between the open-circuit voltage (Voc) and E1/2 revealed that Voc was dominated by the energy gap between the Fermi level of TiO2 and the SOMO level of R-TEMPO.
Moderately Increased Risks of Down's Syndrome (1/51–1/270) Identified on First Trimester Sequential Screening: What do Patients do with this Information?
Authors: Wagner Danielle , Pargas Carol , Donnenfeld Alan E
Published: March 2010

Objective

To document patient decisions after being informed of a first trimester sequential screen Down's syndrome risk between 1/51 and 1/270.

Setting

A database analysis of sequential screen results for patients seen in the Philadelphia, PA (USA) area between January 2006 and March 2008 was examined.

Methods

All patients with first trimester sequential screen Down's syndrome risks in the 1/51–1/270 range were identified. Patient decisions regarding invasive testing (prior to completing the second trimester stage of the sequential screen), completion of the second trimester blood draw or no additional testing were tabulated.

Results

A total of 10,850 patients underwent first trimester sequential screening during this interval. Five hundred and fifty-seven patients (5.1%) met the study inclusion criteria and had risks between 1/51 and 1/270. Ninety-three percent of these patients completed the sequential screening process before making any decisions regarding invasive testing. Four percent did not elect an invasive prenatal diagnosis procedure, but also did not complete the second trimester sequential screening blood draw and only 3.2% elected an invasive procedure based on their first trimester risk without completing the second trimester blood draw. Five women (0.9%) with low risks after the second stage screen chose to have an amniocentesis.

Conclusion

The vast majority (97%) of patients in the moderately increased Down's syndrome risk range (1/51–1/270) following first trimester sequential screening did not pursue an invasive procedure based on their first trimester sequential screen risk. Using a ≥ 1/50 risk cut-off in the first trimester is an effective screening policy for sequential screening.
Prostate Cancer Incidence Rates Have Started to Decrease in Central Italy
Authors: Crocetti Emanuele , Ciatto Stefano , Buzzoni Carlotta , Zappa Marco
Published: March 2010

The widespread use of prostate-specific antigen (PSA) testing has dramatically changed the epidemiology of prostate cancer. Growing incidence rates have been documented in almost all western countries following the increased usage of PSA screening. In the United States after a period of huge increase in incidence, rates have decreased to values lower than those of the pre-PSA era. Similar changes have been documented also in the area of the Tuscany Cancer Registry, central Italy, where prostate cancer incidence rates doubled from the early 1990s to 2003 and afterwards decreased. This is the first evidence, to our knowledge, of a decline in prostate cancer incidence in Italy following the screening-related increase.
Evaluation of a Proposed Mixture Model to Specify the Distributions of Nuchal Translucency Measurements in Antenatal Screening for Down's Syndrome
Authors: Bestwick J P , Huttly W J , Wald N J
Published: March 2010

Objectives

A mixture model of crown-rump length (CRL)-dependent and CRL-independent nuchal translucency (NT) measurements has been proposed for antenatal screening for Down's syndrome. We here compare the efficacy of the mixture model method with the standard method, which uses NT multiple of the median (MoM) values in a single distribution.

Settings

A routine antenatal screening programme for Down's syndrome comprising 104 affected and 22,284 unaffected pregnancies.

Methods

The ability of NT to distinguish between affected and unaffected pregnancies was compared using the mixture model method and the standard MoM method by using published distribution parameters for the mixture model of NT and parameters derived from these for the standard MoM method. The accuracy of the two methods was compared for NT and maternal age by comparing the median estimated risk with the prevalence of Down's syndrome in different categories of estimated risk.

Results

Using NT alone observed estimates of discrimination using the two methods are similar; at a 70% detection rate the false-positive rates were 12% using the mixture model method and 10% using the MoM method. Risk estimation was marginally (but not statistically significantly) more accurate using the standard MoM method.

Conclusions

The mixture model method offers no advantage over the standard MoM method in antenatal screening for Down's syndrome, is more complicated and less generalizable to other datasets. The standard MoM method remains the method of choice.
Microdialysis as a method for biochemical and physiological studies of the porcine and human disc
Authors: Liljensten E , Skog G , Sönnergren H , Jensen-Waern M
Published: March 2010

At present, no minimally invasive technique exists for the continuous evaluation of the biochemistry of animal and human intervertebral discs, but for research purposes microdialysis may be such a new technique. Thus, the aims of this study were to (1) evaluate if microdialysis can be used successfully in lumbar porcine disc and (2) develop a suitable procedure for the application of microdialysis in the human disc. Conventional specific pathogen-free pigs were used to evaluate cannulation ( n = 2) and then insertion of a 10 mm microdialysis membrane, including recovery of a dialysate from the nucleus pulposus ( n = 6). The procedure was performed immediately after euthanasia and aided by fluoroscopy to guide the needle and confirm catheter placement. Access to lumbar porcine disc was obtained with an 18 G 2 in. needle applied at a 35–45° angle from the sagittal plane, and took less than 8 min to perform. At a 0.5 μL/min flush rate, dialysates could be recovered and analysable amounts of glucose, lactate and pyruvate were obtained. In one human cadaver, the L4–L5 disc was accessed by a 19 G 3 in. needle inserted at a 35–40° angle. It was possible to apply 10 mm as well as 30 mm microdialysis membranes in the nucleus. In both species the position of the membranes was verified by direct fluoroscopy and with contrast fluid. The results obtained from porcine and human cadavers are promising, and encourage further in vivo studies using microdialysis technique on intervertebral discs.
On the role of Hoogsteen:Hoogsteen interactions in RNA: Ab initio investigations of structures and energies
Authors: Sharma Purshotam , Chawla Mohit , Sharma Sitansh , Mitra Abhijit
Published: March 2010

We use a combination of database analysis and quantum chemical studies to investigate the role of cis and trans Hoogsteen:Hoogsteen (H:H) base pairs and associated higher-order structures in RNA. We add three new examples to the list of previously identified base-pair combinations belonging to these families and, in addition to contextual classification and characterization of their structural and energetic features, we compare their interbase interaction energies and propensities toward participation in triplets and quartets. We find that some base pairs, which are nonplanar in their isolated minimum energy geometries, attain planarity and stability upon triplet formation. A:A H:H trans is the most frequent H:H combination in RNA structures. This base pair occurs at many distinct positions in known rRNA structures, where it helps in the interaction of ribosomal domains in the 50S subunit. It is also present as a part of tertiary interaction in tRNA structures. Although quantum chemical studies suggest an intrinsically nonplanar geometry for this base pair in isolated form, it has the tendency to attain planar geometry in RNA crystal structures by forming higher-order tertiary interactions or in the presence of additional base–phosphate interactions. The tendency of this base pair to form such additional interactions may be helpful in bringing together different segments of RNA, thus making it suitable for the role of facilitator for RNA folding. This also explains the high occurrence frequency of this base pair among all H:H interactions.
Induced fit or conformational selection for RNA/U1A folding
Authors: Qin Fang , Chen Yue , Wu Maoying , Li Yixue , Zhang Jian , Chen Hai-Feng
Published: March 2010

The hairpin II of U1 snRNA can bind U1A protein with high affinity and specificity. NMR spectra suggest that the loop region of apo-RNA is largely unstructured and undergoes a transition from unstructured to well-folded upon U1Abinding. However, the mechanism that RNA folding coupled protein binding is poorly understood. To get an insight into the mechanism, we have performed explicit-solvent molecular dynamics (MD) to study the folding kinetics of bound RNA and apo-RNA. Room-temperature MD simulations suggest that the conformation of bound RNA has significant adjustment and becomes more stable upon U1A binding. Kinetic analysis of high-temperature MD simulations shows that bound RNA and apo-RNA unfold via a two-state process, respectively. Both kinetics and free energy landscape analyses indicate that bound RNA folds in the order of RNA contracting, U1A binding, and tertiary folding. The predicted Φ-values suggest that A8, C10, A11, and G16 are key bases for bound RNA folding. Mutant Arg52Gln analysis shows that electrostatic interaction and hydrogen bonds between RNA and U1A (Arg52Gln) decrease. These results are in qualitative agreement with experiments. Furthermore, this method could be used in other studies about biomolecule folding upon receptor binding.
The reliability and variation of measurements of the os calcis angles in children
Authors: Clint S. A. , Morris T. P. , Shaw O. M. , Oddy M. J. , Rudge B. , Barry M.
Published: March 2010

The databases of the Picture Archiving and Communication Systems of two hospitals were searched and all children who had a lateral radiograph of the ankle during their attendance at the emergency department were identified. In 227 radiographs, Bohler’s and Gissane’s angles were measured on two separate occasions and by two separate authors to allow calculation of inter- and intra-observer variation. Intraclass correlation coefficients were used to assess the reliability of the measurements.

For Bohler’s angle the overall inter-observer reliability, the intraclass correlation coefficient was 0.90 and the intra-observer reliability 0.95, giving excellent agreement. This reliability was maintained across the age groups. For Gissane’s angle, inter- and intra-observer reliability was only fair or poor across most age groups.

Further analysis of the Bohler’s angle showed a significant variation in the mean angle with age. Contrary to published opinion, the angle is not uniformly lower than that of adults but varies with age, peaking towards the end of the first decade before attaining adult values. The age-related radiologic changes presented here may help in the interpretation of injuries to the hindfoot in children.
Survival and functional outcome after revision of a unicompartmental to a total knee replacement
Authors: Pearse A. J. , Hooper G. J. , Rothwell A. , Frampton C.
Published: March 2010

We reviewed the rate of revision of unicompartmental knee replacements (UKR) from the New Zealand Joint Registry between 1999 and 2008. There were 4284 UKRs, of which 236 required revision, 205 to a total knee replacement (U2T) and 31 to a further unicompartmental knee replacement (U2U). We used these data to establish whether the survival and functional outcome for revised UKRs were comparable with those of primary total knee replacement (TKR). The rate of revision for the U2T cohort was four times higher than that for a primary TKR (1.97 vs 0.48; p < 0.05). The mean Oxford Knee Score was also significantly worse in the U2T group than that of the primary TKR group (30.02 vs 37.16; p < 0.01). The rate of revision for conversion of a failed UKR to a further UKR (U2U cohort) was 13 times higher than that for a primary TKR.

The poor outcome of a UKR converted to a primary TKR compared with a primary TKR should contra-indicate the use of a UKR as a more conservative procedure in the younger patient.
Total hip replacement in patients with multiple epiphyseal dysplasia with a mean follow-up of 15 years and survival analysis
Authors: Ramaswamy R. , Kosashvili Y. , Cameron H.
Published: March 2010

The hip joint is commonly involved in multiple epiphyseal dysplasia and patients may require total hip replacement before the age of 30 years.

We retrospectively reviewed nine patients (16 hips) from four families. The diagnosis of multiple epiphyseal dysplasia was based on a family history, genetic counselling, clinical features and radiological findings. The mean age at surgery was 32 years (17 to 63), with a mean follow-up of 15.9 years (5.5 to 24).

Of the 16 hips, ten required revision at a mean of 12.5 years (5 to 15) consisting of complete revision of the acetabular component in three hips and isolated exchange of the liner in seven. No femoral component has loosened or required revision during the period of follow-up.

With revision for any reason, the 15-year survival was only 11.4% (95% confidence interval 1.4 to 21.4). However, when considering revision of the acetabular shell in isolation the survival at ten years was 93.7% (95% confidence interval 87.7 to 99.7), reducing to 76.7% (95% confidence interval 87.7 to 98.7) at 15 and 20 years, respectively.
A comparison of early and delayed arthroscopically-assisted reconstruction of the anterior cruciate ligament using hamstring autograft
Authors: Raviraj A. , Anand A. , Kodikal G. , Chandrashekar M. , Pai S.
Published: March 2010

Delayed rather than early reconstruction of the anterior cruciate ligament is the current recommended treatment for injury to this ligament since it is thought to give a better functional outcome. We randomised 105 consecutive patients with injury associated with chondral lesions no more severe than grades 1 and 2 and/or meniscal tears which only required trimming, to early (< two weeks) or delayed (> four to six weeks) reconstruction of the anterior cruciate ligament using a quadrupled hamstring graft. All operations were performed by a single surgeon and a standard rehabilitation regime was followed in both groups. The outcomes were assessed using the Lysholm score, the Tegner score and measurement of the range of movement. Stability was assessed by clinical tests and measurements taken with the KT-1000 arthrometer, with all testing performed by a blinded uninvolved experienced observer. A total of six patients were lost to follow-up, with 48 patients assigned to the delayed group and 51 to the early group. None was a competitive athlete. The mean interval between injury and the surgery was seven days (2 to 14) in the early group and 32 days (29 to 42) in the delayed group. The mean follow-up was 32 months (26 to 36).

The results did not show a statistically significant difference for the Lysholm score (p = 0.86), Tegner activity score (p = 0.913) or the range of movement (p = 1). Similarly, no distinction could be made for stability testing by clinical examination (p = 0.56) and measurements with the KT-1000 arthrometer (p = 0.93).

Reconstruction of the anterior cruciate ligament gave a similar clinical and functional outcome whether performed early (< two weeks) or late at four to six weeks after injury.
Effect of lumbar disc replacement on the height of the disc space and the geometry of the facet joints
Authors: Kafchitsas K. , Kokkinakis M. , Habermann B. , Rauschmann M.
Published: March 2010

In a study on ten fresh human cadavers we examined the change in the height of the intervertebral disc space, the angle of lordosis and the geometry of the facet joints after insertion of intervertebral total disc replacements. SB III Charité prostheses were inserted at L3-4, L4-5, and L5-S1. The changes studied were measured using computer navigation sofware applied to CT scans before and after instrumentation.

After disc replacement the mean lumbar disc height was doubled (p < 0.001). The mean angle of lordosis and the facet joint space increased by a statistically significant extent (p < 0.005 and p = 0.006, respectively). By contrast, the mean facet joint overlap was significantly reduced (p < 0.001). Our study indicates that the increase in the intervertebral disc height after disc replacement changes the geometry at the facet joints. This may have clinical relevance.
Complications associated with distraction osteogenesis for infected nonunion of the femoral shaft in the presence of a bone defect
Authors: Blum A. L. L. , Bongiovanni J. C. , Morgan S. J. , Flierl M. A. , dos Reis F. Baldy
Published: March 2010

We undertook a retrospective study of 50 consecutive patients (41 male, 9 female) with an infected nonunion and bone defect of the femoral shaft who had been treated by radical debridement and distraction osteogenesis. Their mean age was 29.9 years (9 to 58) and they had a mean of 3.8 (2 to 19) previous operations. They were followed for a mean of 5.9 years (2.0 to 19.0). The mean duration of the distraction osteogenesis was 24.5 months (2 to 39). Pin-track infection was observed in all patients. The range of knee movement was reduced and there was a mean residual leg-length discrepancy of 1.9 cm (0 to 8) after treatment. One patient required hip disarticulation to manage intractable sepsis. In all, 13 patients had persistant pain. Bony union was achieved in 49 patients at a mean of 20.7 months (12 to 35).

Although distraction osteogenesis is commonly used for the treatment of infected femoral nonunion with bone defects, it is associated with a high rate of complications.
Charnley low-friction arthroplasty in teenage patients
Authors: Wroblewski B. M. , Purbach B. , Siney P. D. , Fleming P. A.
Published: March 2010

Increasing follow-up identifies the outcome in younger patients who have undergone total hip replacement (THR) and reveals the true potential for survival of the prosthesis. We identified 28 patients (39 THRs) who had undergone cemented Charnley low friction arthroplasty between 1969 and 2001. Their mean age at operation was 17.9 years (12 to 19) and the maximum follow-up was 34 years. Two patients (4 THRs) were lost to follow-up, 13 (16 THRs) were revised at a mean period of 19.1 years (8 to 34) and 13 (19 THRs) continue to attend regular follow-up at a mean of 12.6 years (2.3 to 29). In this surviving group one acetabular component was radiologically loose and all femoral components were secure. In all the patients the diameter of the femoral head was 22.225 mm with Charnley femoral components used in 29 hips and C-stem femoral components in ten. In young patients who require THR the acetabular bone stock is generally a limiting factor for the size of the component. Excellent long-term results can be obtained with a cemented polyethylene acetabular component and a femoral head of small diameter.
Successful Treatment of Daptomycin-Nonsusceptible Methicillin-Resistant Staphylococcus Aureus Bacteremia with the Addition of Rifampin to Daptomycin
Authors: Ahmad Nasir M , Rojtman Albert D
Published: March 2010

OBJECTIVE:

To report a case in which daptomycin-nonsusceptible methicillin-resistant Staphylococcus aureus (MRSA) bacteremia was successfully treated with the addition of rifampin to daptomycin.

CASE SUMMARY:

An 84-year-old male presented with fever and chills following cystoscopy. After culturing was conducted, the patient received single doses of vancomycin and gentamicin and then continued on vancomycin plus ceftazidime. Blood cultures grew MRSA, with vancomycin and daptomycin minimum inhibitory concentrations (MICs) of ≤1 μg/mL and 0.25 μg/mL, respectively. Vancomycin was continued, with trough concentrations maintained >15 pg/mL, but results of blood cultures remained positive. On day 10, therapy was switched to daptomycin 6 mg/kg/day, but culture results remained positive. On day 13, testing for vancomycin heteroresistance was negative, with the MIC unchanged. The vancomycin MIC remained unchanged on day 19, but the daptomycin MIC had increased to 2 μg/mL. Rifampin 300 mg orally twice daily was added on day 20; blood cultures obtained 2 days later were sterile. The patient was discharged to complete a 6-week course of antibiotics and was doing well 4 months following therapy.

DISCUSSION:

Analysis of MRSA isolates obtained on days 1 and 19 showed an increase in the daptomycin MIC from 0.25 to 2 μg/mL. Because intervening isolates were not available for susceptibility testing, it is not possible to associate this increase with exposure to either vancomycin or daptomycin. Although in vitro synergy was not seen in this case, addition of rifampin to daptomycin therapy resolved the bacteremia.

CONCLUSIONS:

In patients with persistent MRSA bacteremia, isolates should be retested for susceptibility to both daptomycin and vancomycin, including assessment for vancomycin heteroresistance. Addition of rifampin to daptomycin may be effective for persistent MRSA bacteremia, even if daptomycin MICs are elevated. Prospective studies are needed to define the role of combination therapy.
Introduction: Toward an Understanding of Epistemology and Deafness
Authors: Paul Peter V. , Moores Donald F.
Published: March 2010

The major concept of epistemology—or epistemologies—is discussed, as well as related terms such as paradigm and science . Also covered are two broad paradigms, the clinical and the cultural, that seem to drive theorizing, research, and practice regarding individuals who are d/Deaf or hard of hearing. The two paradigms emanate from different epistemologies and might account for much of the tension in research and practice. Finally, the authors present their view on the nature of scholarly inquiries—namely, that theory, research, and practice should adhere to the principles of a multiparadigmatic science.
Epistemology and People Who Are Deaf: Deaf Worldviews, Views of the Deaf World, or My Parents Are Hearing
Authors: Miller Margery S.
Published: March 2010

Epistemology is examined from two different perspectives within the framework of a broader evolutionary epistemology. Within this framework, reality is not absolute, and truth is a relative concept. People construct individual or personal epistemologies through their experiences, and develop or receive group or socially constructed epistemologies through their interactions with others with shared or similar experiences. There is a common perception that Deaf culture and Deaf epistemologies have been transmitted primarily by Deaf children and Deaf adults who have Deaf parents and who have grown up in a linguistically rich signing environment. The author posits that the far more numerous deaf children of hearing parents may be an even greater force in transmitting some of the strongest views of Deaf epistemology.
Without Boundaries: An Inquiry Into Deaf Epistemologies Through a Metaparadigm
Authors: Wang Ye
Published: March 2010

The ongoing debate on Deaf epistemologies reflects two major paradigms in deaf education: positivism and constructivism. The present article investigates Deaf epistemologies through a metaparadigm, which should blur the boundaries among different paradigms and connect the epistemological inquiry to instructional practice for d/Deaf students. The author states that researchers and educators should not be obsessed with defending a particular paradigm and attacking others, but should move toward paradigmatic integration. If successful instructional practices are to be fully understood, each paradigm needs insights from the others. Furthermore, effective classroom instruction should be based on the goal of the educational activity and the ability of the students in the classroom. Mainstream theories and research in English literacy education can and should be applicable to d/Deaf students; furthermore, using appropriate instructional tools, teachers of the d/Deaf can and should teach phonologically related skills to their students.
Deaf Epistemology: Deafhood and Deafness
Authors: Hauser Peter C. , O’Hearn Amanda , McKee Michael , Steider Anne , Thew Denise
Published: March 2010

Deaf epistemology constitutes the nature and extent of the knowledge that deaf individuals acquire growing up in a society that relies primarily on audition to navigate life. Deafness creates beings who are more visually oriented compared to their auditorily oriented peers. How hearing individuals interact with deaf individuals shapes how deaf individuals acquire knowledge and how they learn. Aspects of the Deaf episteme, not caused by deafness but by Deafhood, have a positive impact on how deaf individuals learn, resist audism, stay healthy, and navigate the world. Research on psychology, health, and education are reviewed to illustrate how visually oriented beings think and view the world differently from the majority. The article provides support to the theory of multiple epistemologies, and has implications for families, teachers, and researchers.
Deaf Epistemologies as a Critique and Alternative to the Practice of Science: An Anthropological Perspective
Authors: De Clerck Goedele A. M.
Published: March 2010

In the last decade, and responding to the criticism of orientalism, anthropology has engaged in a self-critical practice, working toward a postcolonial perspective on science and an epistemological stance of partial and situated knowledge (Pinxten, 2006; Pinxten & Note, 2005). In deaf studies, anthropological and sociological studies employing qualitative and ethnographic methods have introduced a paradigm shift. Concepts of deaf culture and deaf identity have been employed as political tools, contributing to the emancipation process of deaf people. However, recent anthropological studies in diverse local contexts indicate the cultural construction of these notions. From this viewpoint, deaf studies faces a challenge to reflect on the notions of culture, emancipation, and education from a nonexclusive, noncolonial perspective. Deaf studies research in a global context needs to deal with cultural and linguistic diversity in human beings and academia. This calls for epistemological reflection and new research methods.
African Musicology: A Bibliographical Guide to Nigerian Art Music (1927–2009)
Authors: Sadoh Godwin
Published: March 2010

This article provides a brief introduction to the history of art music in Nigeria, a concise discussion of three generations of music composition in Nigeria as well as an extensive bibliography of Nigerian art music comprised of articles, books, and discographic materials. The article is primarily set to present a list of sources on Nigerian art music, showcasing the depth and breadth of scholarly activities on this music. As such, this article is not focused on an overarching historical account of art music in Nigeria; this is outside the scope of this study. The bibliography encapsulates the focus of the extensive bibliographies which represent the scholarly contributions on modern Nigerian art music by various musicologists from Africa, Europe, and the United States. Most of the Nigerian authors are composers, ethnomusicologists, performers, and music educators, whose research is largely based on fieldwork, and their personal experiences in composing and performing this music. The bibliography includes articles, both published and unpublished, books, theses, and discographies, as well as papers presented at international conferences and symposia from 1927 to 2009. The topics cover every area pertinent to the study of art music in Nigeria—piano, organ, chamber, orchestra, vocal solo, choral, percussion, music and culture, music and dance, music and politics, music and text, music education, analytical and compositional techniques, theory, history, criticism, sacred and secular music, interculturalism, and composer biographies. The sound recordings of selected works were done by African, European, and American solo artists and orchestras.
A Revival of the Music Conspectus: A Multi-Dimensional Assessment for the Score Collection
Authors: Lai Katie
Published: March 2010

With an innovative use of the music conspectus, the Hong Kong Baptist University library conducted a score collection assessment to identify not only the strengths and weaknesses of the collection, but also problems with the choice of score publishers and formats in the acquisitions process. Because of its flexible application, this modified music conspectus can be easily adopted by libraries of all sizes and libraries that use any classification system. This article provides a detailed description of the techniques used, and highlights the findings and benefits received, as well as actions done following the project.
Reclaiming Revolution in Light of the “Mexican Miracle”:Celestino Gasca and the Federacionistas Leales Insurrection of 1961
Authors: Servín Elisa
Published: March 2010

“If they want me to give my life in order to get their attention, I'll give it to them.”

In the hours before dawn on September 15, 1961, various groups of men armed with machetes, pistols and rifles attempted to take over military posts, police stations and municipal offices throughout Mexico, proclaiming “justice for the poor.” The uprising of the so-calledFederacionistas Lealeswas part of a strategy coordinated by an old revolutionary general, Celestino Gasca Villaseñor, who planned to take power in order to carry out a new agrarian program to benefit the campesinos of Mexico.