bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of chaperonin CCTγ subunit as a determinant of retinotectal development by whole-genome subtraction cloning from zebrafishno tectal neuronmutant
Authors: Matsuda Naoto , Mishina Masayoshi
Published: April 2004

Zebrafish no tectal neuron (ntn) mutant obtained by trimethylpsoralen (TMP) mutagenesis showed defects in tectal neuropil formation and small eyes. We carried out whole-genome subtraction between wild-type and mutant zebrafish embryos using the representational difference analysis (RDA) method. Nineteen subtraction products enabled us to construct genetic and physical maps of the ntn region. Direct selection of cDNAs using a YAC clone encompassing the ntn locus and RT-PCR analysis of transcripts identified a 143 bp deletion in the cct3 gene encoding the γ subunit of chaperonin containing TCP-1 (CCT). Injection of antisense cct3 morpholino oligonucleotides into zebrafish embryos induced characteristic ntn phenotypes including defects in retinal ganglion cell (RGC) differentiation and tectal neuropil formation. Moreover,injection of cct3 mRNA successfully rescued ntn mutant embryos. Our results suggest that RDA is an efficient and widely applicable cloning strategy in zebrafish genetics. The strong expression of the cct3 mRNA started in the entire embryos by 12 hpf and was sustained thereafter, but there were no detectable abnormalities in body patterning and neurogenesis in ntn mutant embryos at 30 hpf. The expression patterns of transcription factor genes ath5 and brn3b that are essential for the development and maintenance of RGCs were indistinguishable between wild-type and ntn mutant embryos, but those of early and late differentiation markers of RGCs, nicotinic acetylcholine receptor β3 and zn5, were diminished in mutant embryos. Immunostaining of acetylated tubulin also revealed the impairment of RGC neurite extension. Thus, the ntnmutation of the cct3 gene impaired the differentiation of retinal neuroepithelial cells to RGCs. Similarly, the expression of brn3b was normal in the tectum of ntn mutants, but tectal neuropil formation was abolished. These results suggest that the γ subunit of chaperonin CCT plays an essential role in retinotectal development.
The T-box transcription factors TBX-37 and TBX-38 link GLP-1/Notch signaling to mesoderm induction inC. elegansembryos
Authors: Good Kathryn , Ciosk Rafal , Nance Jeremy , Neves Alexandre , Hill Russell J. , Priess James R.
Published: April 2004

The four-cell C. elegans embryo contains two sister cells called ABa and ABp that initially have equivalent abilities to produce ectodermal cell types. Multiple Notch-mediated interactions occur during the early cell divisions that diversify the ABa and ABp descendants. The first interaction determines the pattern of ectodermal cell types produced by ABp. The second interaction induces two ABa granddaughters to become mesodermal precursors. We show that T-box transcription factors called TBX-37 and TBX-38 are essential for mesodermal induction, and that these factors are expressed in ABa, but not ABp, descendants. We provide evidence that the first Notch interaction functions largely, if not entirely, to prevent TBX-37, TBX-38 expression in ABp descendants. Neither the second Notch interaction nor TBX-37, TBX-38 alone are sufficient for mesodermal induction, indicating that both must function together. We conclude that TBX-37, TBX-38 play a key role in distinguishing the outcomes of two sequential Notch-mediated interactions.
Apical accumulation of theDrosophilaPDGF/VEGF receptor ligands provides a mechanism for triggering localized actin polymerization
Authors: Rosin Dalia , Schejter Eyal , Volk Talila , Shilo Ben-Zion
Published: April 2004

Epithelial tissue functions depend largely on a polarized organization of the individual cells. We examined the roles of the DrosophilaPDGF/VEGF receptor (PVR) in polarized epithelial cells, with specific emphasis on the wing disc epithelium. Although the receptor is broadly distributed in this tissue, two of its ligands, PVF1 and PVF3 are specifically deposited within the apical extracellular space, implying that polarized apical activation of the receptor takes place. The apical localization of the ligands involves a specialized secretion pathway. Clones for null alleles of Pvr or expression of RNAi constructs showed no phenotypes in the wing disc or pupal wing, suggesting that Pvr plays a redundant role in this tissue. However, when uniform expression of a constitutively dimerizing receptor was induced, loss of epithelial polarity, formation of multiple adherens and septate junctions, and tumorous growth were observed in the wing disc. Elevation of the level of full-length PVR also gave rise to prominent phenotypes, characterized by higher levels of actin microfilaments at the basolateral areas of the cells and irregular folding of the tissue. Together,these results suggest that polarized PVR activation is necessary for the proper organization of the wing disc epithelium, by regulating the apical assembly of the actin cytoskeleton.
Polarity and lipid raft association of the components of the ciliary neurotrophic factor receptor complex in Madin-Darby canine kidney cells
Authors: Buk Deborah M. , Waibel Michaela , Braig Claudia , Martens Astrid S. , Heinrich Peter C. , Graeve Lutz
Published: April 2004

Ciliary neurotrophic factor (CNTF) signals via a tripartite receptor complex consisting of the glycosyl-phosphatidylinositol (GPI)-anchored CNTF receptor (CNTF-R), the leukaemia inhibitory factor receptor (LIF-R) and the interleukin-6 (IL-6) signal transducer gp130. We have recently reported that gp130 is endogenously expressed in the polarised epithelial model cell line Madin-Darby canine kidney (MDCK) and we have demonstrated a preferential basolateral localisation of this protein. In the present study we show that MDCK cells also express the LIF-R and respond to stimulation with human LIF by activation of tyrosine phosphorylation of signal transducer and activator of transcription-3 (STAT3), both however in an unpolarised fashion. This suggests that MDCK cells may be target cells for LIF. We have furthermore stably expressed the human CNTF-R in MDCK cells and by two different assays we found an apical localisation. Consistent with these findings, stimulation of CNTF-R-positive cells resulted only in an activation of STAT3 when CNTF was added apically. These data demonstrate that each subunit of the CNTF receptor complex has a distinct distribution in polarised cells which may reflect the different roles the respective cytokines play in vivo.

Since it is currently believed that lipid rafts are involved in signal transduction as well as protein sorting we studied the association of the three receptor complex components with membrane rafts using different protocols. Whereas the CNTF-R cofractionated quantitatively with lipid rafts independently of the method used, gp130 and the LIF-R were found to associate with lipid rafts only partially when detergents were used for isolation. These findings could indicate that either the three receptor complex subunits are localised to the same kind of raft but with different affinities to the liquid-ordered environment, or that they are localised to different types of rafts. CNTF-, LIF-, and IL-6-dependent STAT3 activation was sensitive to the cholesterol-depleting drug methyl-β-cyclodextrin (MCD) suggesting that the integrity of lipid rafts is important for IL-6-type cytokine-induced STAT activation.
Anisomycin downregulates gap-junctional intercellular communication via the p38 MAP-kinase pathway
Authors: Ogawa Takahiko , Hayashi Tomonori , Kyoizumi Seishi , Kusunoki Yoichiro , Nakachi Kei , MacPhee Donald G. , Trosko James E. , Kataoka Katsuko , Yorioka Noriaki
Published: April 2004

Phosphorylation of connexin 43 (Cx43) molecules (e.g. by extracellular signal-regulated kinase) leads to reductions in gap-junctional intercellular communication (GJIC). GJIC levels also appear to be lower in the presence of p38 mitogen-activated protein (MAP) kinase, for unknown reasons. In this study, we used assays of the recovery of fluorescence by photobleached WB-F344 cells to demonstrate that GJIC levels are decreased by anisomycin [a protein synthesis inhibitor as well as an activator of p38 MAP kinase and c-Jun N-terminal kinases (JNK)] as a result of time-dependent depletion of the phosphorylated forms of Cx43. Using immunohistochemistry, we also detected far less of the Cx43 proteins at cell borders. These findings agree with the photobleaching assay results. Moreover, prior treatment with SB203580 (a specific inhibitor of p38 MAP kinase) appeared to be effective in preventing the loss of phosphorylated forms of Cx43 and the loss of Cx43 proteins at cell borders. Total protein labelling with [35S]-methionine and [32P]-orthophosphates labelling of Cx43 showed that anisomycin enhanced the phosphorylation level of Cx43 along with inhibition of protein synthesis. SB203580 prevented the former but not the latter. The effect of anisomycin on GJIC was not dependent on the inhibition of protein synthesis because the addition of SB203580 completely maintained the level of GJIC without restoring protein synthesis. The Cx43 phosphorylation level increased by anisomycin treatment, whereas the amount of phosphorylated forms of Cx43 decreased, suggesting that activation of Cx43 phosphorylation might lead to the loss of Cx43. These results suggest that activation of p38 MAP kinase leads to reduction in the levels of phosphorylated forms of Cx43, possibly owing to accelerated degradation, and that these losses might be responsible for the reduction in numbers of gap junctions and in GJIC.
EphA2 receptor tyrosine kinase regulates endothelial cell migration and vascular assembly through phosphoinositide 3-kinase-mediated Rac1 GTPase activation
Authors: Brantley-Sieders Dana M. , Caughron Justin , Hicks Donna , Pozzi Ambra , Ruiz Joseph C. , Chen Jin
Published: April 2004

Angiogenesis is critical for vascular remodeling during development and contributes to the pathogenesis of diseases such as cancer. Targeted disruption of several EphB class receptor tyrosine kinases results in vascular remodeling defects during embryogenesis. The role of EphA class receptors in vascular remodeling, however, is not well-characterized. We recently demonstrated that global inhibition of EphA receptors disrupts endothelial migration induced by ephrin, VEGF or tumor-derived signals, though the specific target remained undefined. Here, we report that EphA2 regulates endothelial cell assembly and migration through phosphoinositide (PI) 3-kinase-mediated activation of Rac1 GTPase in two model systems: primary bovine and murine pulmonary microvascular endothelial cells. EphA2-deficient endothelial cells fail to undergo vascular assembly and migration in response to ephrin-A1 in vitro. Ephrin-A1 stimulation induces PI3-kinase-dependent activation of Rac1 in wild-type endothelial cells, whereas EphA2-deficient cells fail to activate Rac1 upon stimulation. Expression of dominant negative PI3-kinase or Rac1 inhibits ephrin-A1-induced endothelial cell migration. Consistent with in vitro data, EphA2-deficient mice show a diminished angiogenic response to ephrin-A1 in vivo. Moreover, EphA2-deficient endothelial cells fail to assemble in vivo when transplanted into recipient mice. These data suggest that EphA2 is an essential regulator of post-natal angiogenesis.
Amplification and propagation of pacemaker Ca2+ signals by cyclic ADP-ribose and the type 3 ryanodine receptor in T cells
Authors: Kunerth Svenja , Langhorst Matthias F. , Schwarzmann Nadine , Gu Xianfeng , Huang Lijun , Yang Zhenjun , Zhang Liangren , Mills Steven J. , Zhang Li-he , Potter Barry V.L. , Guse Andreas H.
Published: April 2004

Ligation of the T-cell receptor/CD3 complex results in global Ca2+ signals that are essential for T-cell activation. We have recently reported that these global Ca2+ signals are preceded by localized pacemaker Ca2+ signals. Here, we demonstrate for the first time for human T cells that an increase in signal frequency of subcellular pacemaker Ca2+ signals at sites close to the plasma membrane, in the cytosol and in the nucleus depends on the type 3 ryanodine receptor (RyR) and its modulation by cyclic ADP-ribose. The spatial distribution of D-myo-inositol 1,4,5-trisphosphate receptors and RyRs indicates a concerted action of both of these receptors/Ca2+ channels in the generation of initial pacemaker signals localized close to the plasma membrane. Inhibition or knockdown of RyRs resulted in significant decreases in (1) the frequency of initial pacemaker signals localized close to the plasma membrane, and (2) the frequency of localized pacemaker Ca2+ signals in the inner cytosol. Moreover, upon microinjection of cyclic ADP-ribose or upon extracellular addition of its novel membrane-permeant mimic N-1-ethoxymethyl-substituted cyclic inosine diphosphoribose, similarly decreased Ca2+ signals were observed in both type 3 RyR-knockdown cells and in control cells microinjected with the RyR antagonist Ruthenium Red. Taken together, our results show that, under physiological conditions in human T cells, RyRs play crucial roles in the local amplification and the spatiotemporal development of subcellular Ca2+ pacemaker signals.
Shh-dependent differentiation of intestinal tissue from embryonic pancreas by activin A
Authors: van Eyll Jonathan M. , Pierreux Christophe E. , Lemaigre Frédéric P. , Rousseau Guy G.
Published: April 2004

The pancreas develops from the endoderm to give rise to ducts, acini and islets of Langerhans. This process involves extracellular signals of the Transforming Growth Factor β (TGFβ) family. The aim of this work was to study the effects of activin A, a member of this family, whose potential role in pancreas differentiation is controversial. To this end, we used pancreatic explants from E12.5 mouse embryos. In culture these explants exhibited spontaneous growth, epithelial morphogenesis and endocrine and exocrine differentiation. Exposure to activin A did not affect exocrine or endocrine differentiation. Surprisingly, activin A induced in the explants the appearance of a large contractile structure surrounded by a cylindrical epithelium, a thick basal lamina and a smooth muscle layer. This structure, the formation of which was prevented by follistatin, was typical of an intestinal wall. Consistent with this interpretation, activin A rapidly induced in the explants the mRNAs for fatty acid binding proteins (FABPs), which are markers of the intestine, but not of the pancreas. We also found that induction of the FABPs was preceded by induction of Sonic hedgehog (Shh), a known inducer of intestinal differentiation in the endoderm. Activin B induced neither Shh nor intestinal differentiation. The activin A-mediated intestinal differentiation was blocked by cyclopamine, an inhibitor of Hedgehog signaling, and it was mimicked by Shh. We conclude that activin A does not appear to affect the exocrine or endocrine components of the pancreas, but that it can promote differentiation of pancreatic tissue into intestine via a Shh-dependent mechanism. These findings illustrate the plasticity of differentiation programs in response to extracellular signals in the pancreas and they shed new light on the regulation of pancreas and intestinal development.
Sensitivity of finite helical axis parameters to temporally varying realistic motion utilizing an idealized knee model
Authors: Johnson T S , Andriacchi T P , Erdman A G
Published: April 2004

Various uses of the screw or helical axis have previously been reported in the literature in an attempt to quantify the complex displacements and coupled rotations of in vivo human knee kinematics. Multiple methods have been used by previous authors to calculate the axis parameters, and it has been theorized that the mathematical stability and accuracy of the finite helical axis (FHA) is highly dependent on experimental variability and rotation increment spacing between axis calculations. Previous research has not addressed the sensitivity of the FHA for true in vivo data collection, as required for gait laboratory analysis. This research presents a controlled series of experiments simulating continuous data collection as utilized in gait analysis to investigate the sensitivity of the three-dimensional finite screw axis parameters of rotation, displacement, orientation and location with regard to time step increment spacing, utilizing two different methods for spatial location. Six-degree-of-freedom motion parameters are measured for an idealized rigid body knee model that is constrained to a planar motion profile for the purposes of error analysis. The kinematic data are collected using a multicamera optoelectronic system combined with an error minimization algorithm known as the point cluster method. Rotation about the screw axis is seen to be repeatable, accurate and time step increment insensitive. Displacement along the axis is highly dependent on time step increment sizing, with smaller rotation angles between calculations producing more accuracy. Orientation of the axis in space is accurate with only a slight filtering effect noticed during motion reversal. Locating the screw axis by a projected point onto the screw axis from the mid-point of the finite displacement is found to be less sensitive to motion reversal than finding the intersection of the axis with a reference plane. A filtering effect of the spatial location parameters was noted for larger time step increments during periods of little or no rotation.
Development and experimental validation of a three-dimensional finite element model of the human scapula
Authors: Gupta S , van der Helm F C T , Sterk J C , van Keulen F , Kaptein B L
Published: April 2004

A new modelling approach, using a combination of shell and solid elements, has been adopted to develop a realistic three-dimensional finite element (FE) model of the human scapula. Shell elements were used to represent a part of the compact bone layer (i.e. the outer cortical layer) and the very thin and rather flat part of the scapula—infraspinous fossa and supraspinous fossa respectively. Solid elements were used to model the remaining part of the compact bone and the trabecular bone. The FE model results in proper element shapes without distortion. The geometry, material properties and thickness were taken from quantitative computed tomography (CT) data. A thorough experimental set-up for strain gauge measurement on a fresh bone serves as a reference to assess the accuracy of FE predictions. A fresh cadaveric scapula with 18 strain gauges fixed at various locations and orientations was loaded in a mechanical testing machine and supported at three locations by linkage mechanisms interconnected by ball joints. This new experimental set-up was developed to impose bending and deflection of the scapula in all directions unambiguously, in response to applied loads at various locations. The measured strains (experimental) were compared to numerical (FE) strains, corresponding to several load cases, to validate the proposed FE modelling approach. Linear regression analysis was used to assess the accuracy of the results. The percentage error in the regression slope varies between 9 and 23 per cent. It appears, as a whole, that the two variables (measured and calculated strains) strongly depend on each other with a confidence level of more than 95 per cent. Considering the complicated testing procedure on a fresh sample of scapula, the high correlation coefficients (0.89-0.97), the low standard errors (29-105 μeP) and percentage errors in the regression slope, as compared to other studies, strongly suggest that the strains calculated by the FE model can be used as a valid predictor of the actual measured strain. The model is therefore an alternative to a rigorous three-dimensional model based on solid elements only, which might often be too expensive in terms of computing time.
Trade Liberalization and Poverty: The Evidence So Far
Authors: Winters L. Alan , McCulloch Neil , McKay Andrew
Published: April 2004

This paper assesses the current state of evidence on the impact of trade policy reform on poverty in developing countries. There is little empirical evidence addressing this question directly, but a lot of related evidence on specific aspects. We summarize this evidence using an analytic framework addressing four key areas: economic growth and stability; households and markets; wages and employment and government revenue. Twelve key questions are identified and empirical studies and results are discussed. We argue that there is no simple generalizable conclusion about the relationship between trade liberalization and poverty, and the picture is much less negative than is often suggested. In the long run and on average, trade liberalization is likely to be strongly poverty alleviating, and there is no convincing evidence that it will generally increase overall poverty or vulnerability. But there is evidence that the poor may be less well placed in the short run to protect themselves against adverse effects and take advantage of favorable opportunities.
The Chinese Saving Puzzle and the Life-Cycle Hypothesis
Authors: Modigliani Franco , Cao Shi Larry
Published: April 2004

China's per capita income ranks below 100th in the world. Its saving rate, however, has been one of the highest worldwide in recent decades. In this paper, we attempt to explain the seeming paradox within the framework of the Life-Cycle Hypothesis developed by Franco Modigliani. The key LCH variables are income and population growth. Our results based on data we put together from official sources show that income growth has been the dominant factor behind the dramatic increase in China's saving rate, as predicted by the LCH. Demographic structure and inflation also had significant impact on the fluctuations of the saving rate.
Constitutions and Economic Policy
Authors: Persson Torsten , Tabellini Guido
Published: April 2004

This paper discusses theoretical and empirical research on how two constitutional features, electoral rules and forms of government, affect economic policymaking. The authors begin by outlining some key objectives of democratic political constitutions and by pointing out the inertia and systematic selection that characterize real-world constitutions. They then introduce the main concepts used to categorize work on constitutions: different kinds of electoral rules and forms of government. They then discuss how these elements of constitutions affect the accountability of government and the size of political rents and corruption, as well as the representativeness of government and a variety of fiscal policy choices.
Legislative Organization
Authors: Krehbiel Keith
Published: April 2004

With an emphasis on the U.S. Congress, this essay addresses political economy approaches to the study of legislative organization. Simple models provide a foundation for more sophisticated studies of one of two problems: how coalitions of intense minorities pass policies that reflect gains from trade (efficiency in distributive policies) and how the legislature obtains gains from specialization (efficiency in information acquisition and dissemination). The recurring impediment to solutions to these problems is that legislatures are self-organizing and, therefore, have difficulty in committing to potentially effective institutional solutions.
Choosing the Federal Reserve Chair: Lessons from History
Authors: Romer Christina D , Romer David H
Published: April 2004

This paper demonstrates that the key determinants of policy success have been policymakers' views about how the economy works and what monetary policy can accomplish. In the first major section of the paper, the authors analyze the narrative record of the Federal Reserve to discover what policymakers believed and why they chose the policies they did. The authors find that the well-tempered monetary policies of the 1950s and of the 1980s and 1990s stemmed from a conviction that inflation has high costs and few benefits, together with realistic views about the sustainable level of unemployment and the determinants of inflation. In contrast, the profligate policies of the late 1960s and 1970s stemmed initially from a belief in a permanent tradeoff between inflation and unemployment, and later from a natural rate framework with a highly optimistic estimate of the natural rate of unemployment and a highly pessimistic estimate of the sensitivity of inflation to economic slack. And the deflationary policies of the late 1930s stemmed from a belief that the economy could overheat at low levels of capacity utilization and that monetary ease could do little to stimulate a depressed economy.
Witchcraft, Weather and Economic Growth in Renaissance Europe
Authors: Oster Emily
Published: April 2004

This paper explores the possibility that the witchcraft trials are a large-scale example of violence and scapegoating prompted by a deterioration in economic conditions. In this case, the downturn was brought on by a decrease in temperature and resulting food shortages. The most active period of the witchcraft trials coincides with a period of lower than average temperature known to climatologists as the “little ice age.” The colder temperatures increased the frequency of crop failure, and colder seas prevented cod and other fish from migrating as far north, eliminating this vital food source for some northern areas of Europe (Fagan, 2000).
Retrospectives Gender in Classical Economics
Authors: Dimand Robert W , Forget Evelyn L , Nyland Chris
Published: April 2004

This feature addresses the history of economic words and ideas. The hope is to deepen the workaday dialogue of economists, while perhaps also casting new light on ongoing questions. If you have suggestions for future topics or authors, please write to Joseph Persky, c/o Journal of Economic Perspectives, Department of Economics (M/C 144), University of Illinois at Chicago, 601 South Morgan Street, Room 2103, Chicago, Illinois 60607-7121.
The most severe forms of Perthes’ disease associated with the homozygous Factor V Leiden mutation
Authors: Szepesi K. , Pòsán E. , Hársfalvi J. , Ajzner É , Szücs G. , Gáspár L. , Csernátony Z. , Udvardy M.
Published: April 2004

It has recently been postulated that thrombophilia may have a role in the aetiology of Perthes’ disease. The published reports, however, remain conflicting. In this study a retrospective analysis of the coagulation parameters was made in 47 patients with Perthes’ disease and the results compared with the clinical data. Five patients with Factor V Leiden mutation were found (10.6%) and surprisingly four of them had a homozygous pattern. These four patients showed the most severe form of the disease, Catterall group IV, with flattening of the entire epiphysis, involvement of the metaphysis, shortening and broadening of the femoral neck, trochanteric overgrowth and developed mushroom-shaped aspherical laterally displaced femoral heads in dysplastic acetabula.

We would like to suggest that the homozygous form of Factor V Leiden mutation has some role in the clinical course of Perthes’ disease and particularly its most severe form.
The accuracy of image-guided knee replacement based on computed tomography
Authors: Nabeyama R. , Matsuda S. , Miura H. , Mawatari T. , Kawano T. , Iwamoto Y.
Published: April 2004

Our study evaluated the accuracy of an image-guided total knee replacement system based on CT with regard to preparation of the femoral and tibial bone using nine limbs from five cadavers. The accuracy was assessed by direct measurement using an extramedullary alignment rod without radiographs.

The mean angular errors of the femur and tibia, which represent angular gaps from the real mechanical axis in the coronal plane, were 0.3° and 1.1°, respectively. The CT-based system, provided almost perfect alignment of the femoral component with less than 1° of error and excellent alignment with less than 3° of error for the tibial component. Our results suggest that standardisation of knee replacement by the use of this system will lead to improved long-term survival of total knee arthroplasty.
The Ferguson medial approach for open reduction of developmental dysplasia of the hip
Authors: Kiely N. , Younis U. , Day J.B. , Meadows T.M.
Published: April 2004

The results of the Ferguson medial approach for open reduction of developmental dysplasia of the hip (DDH) were reviewed for 49 hips with a follow-up of more than 48 months. The mean age at operation was 12.3 months (6 to 23). The mean length of clinical and radiological follow-up was 82 months (48 to 148). Three redislocations occurred. Group I avascular necrosis according to the classification of Kalamchi and MacEwen was seen in four hips, group II in two hips and group III in one hip; 92% of the hips were classified as Severin class I and II. The acetabular index and centre edge (CE) angles were within normal limits at final follow-up, but were still significantly different from the unaffected side.

We conclude that the Ferguson procedure is safe and reliable for low dislocations in children aged six to 18 months.
Inter- and intra-measurer error in the measurement of Reimers’ hip migration percentage
Authors: Faraj S. , Atherton W. G. , Stott N. S.
Published: April 2004

Reimers’ hip migration percentage is commonly used to document the extent of subluxation of the hip in children with spasticity. In this study, two measurers, with six months paediatric orthopaedic experience, measured the migration percentage on 44 pelvic radiographs of children with cerebral palsy, aged between two and eight years. Unknown to the measurers, each radiograph was duplicated, giving 22 non-identical radiographs (44 hips) which were measured twice at time 0 and twice six weeks later. The intra-measurer, intra-sessional absolute differences between the first and second measurements ranged from 0% to 23%, with median values of 2.5% to 3.6%. The intra-sessional median absolute differences were not statistically different between the two measurers and measuring sessions (p = 0.42, Kruskal-Wallis test). The inter-sessional absolute differences for measurements made by the same measurers ranged from 0% to 18% with a median absolute difference of 1.7% to 3.2%. Overall, only 5% of the intra-measurer measurement differences, within and between sessions, were above 13%. Repeated measurements by one measurer over time must, therefore, vary by more than 13% in order to be 95% confident of a true change. The inter-measurer error was higher with median absolute differences between the two measurers’ measurements of the same hip of 3.25% to 5% (0% to 26%) and a 95th upper confidence interval of 21% to 23%. Averaging the four separate measurements over the two sessions reduced the inter-measurer error to a median absolute difference of 2.8%, but did not improve the 95th upper confidence interval, which measured 22.4%.

Such inter-measurer errors may be clinically unacceptable.
The effects of calcitonin on acute bone loss after pertrochanteric fractures
Authors: Karachalios T. , Lyritis G. P. , Kaloudis J. , Roidis N. , Katsiri M.
Published: April 2004

We investigated the effect of calcitonin in the prevention of acute bone loss after a pertrochanteric fracture and its ability to reduce the incidence of further fractures in the same patient.

Fifty women aged between 70 and 80 years who had a pertrochanteric fracture of the hip were randomly allocated to group A (200 IU of nasal salmon calcitonin daily for three months) or group B (placebo).

Patients in group A showed a significantly higher level of total alkaline phosphatase and osteocalcin on the 15th day after injury and a significantly higher level of bone alkaline phosphatase on the 90th day after surgery. These patients also had significantly lower levels of urinary C-telopeptide (CrossLaps) on the 15th, 45th and 90th days after injury and lower levels of urinary hydroxyproline on the 15th and 45th days after injury. Patients in group A had significantly higher bone mineral density at all recorded sites except the greater trochanter at three months and one year after operation. After a four-year period of clinical observation, five patients (24%) in group B sustained a new fracture, in four of whom (20%) it was of the contralateral hip.

Our findings show that calcitonin reduces acute bone loss in patients with pertrochanteric fractures and may prevent the occurrence of new fractures of the contralateral hip in the elderly.
Transient claw hand owing to a bee sting
Authors: Saravanan R. , King R. , White J.
Published: April 2004

We describe two patients with claw hand as a result of a bee sting. It is likely that this was caused by the apamin in the sting which has an effect on the upper limb, at the spinal cord and on the peripheral nerves. It is important to recognise that the claw hand is not owing to compartment syndrome. Both patients were treated conservatively with full resolution within 48 hours, without any lasting effects.
The significance of radiolucent zones surrounding pedicle screws
Authors: Sandén B. , Olerud C. , Petrén-Mallmin M. , Johansson C. , Larsson S.
Published: April 2004

We examined the radiographs from a prospective clinical study of fixation by pedicle screws and those from an experimental study in a sheep model. In the clinical study, instruments were removed from 21 patients after implantation for 11 to 16 months and the extraction torques of the screws were recorded. A structured protocol was used for the radiological examinations. In the experimental study, loaded pedicle screw instrumentations were implanted in the sheep for six or 12 weeks. After radiological examination the pull-out resistance and the histological characteristics were studied.

In the clinical study, all screws with radiolucent zones had a significantly reduced mean extraction torque compared with screws without radiolucent zones (16 ± 10 Ncm v 403 ± 220 Ncm; p < 0.0001). In the experimental study the mean maximum pull-out resistance for the screws with radiolucent zones was significantly lower than for those with no radiolucency (243 ± 156 N v 2214 ± 578 N; p = 0.0006) and the mean bone-to-screw contact was reduced for screws with zones compared with those without zones (8 ± 9% v 55 ± 29%; p = 0.0002).

Our findings showed that all screws with radiolucent zones had low extraction torques or low pull-out resistance. A radiolucent zone is a good indicator of loosening of a pedicle screw.
Complex fracture-dislocation of the proximal interphalangeal joint of the hand
Authors: Deshmukh S. C. , Kumar D. , Mathur K. , Thomas B.
Published: April 2004

We reviewed 13 patients with a complex fracture-dislocation of the proximal interphalangeal joint of a finger and one patient with a complex fracture-dislocation of the interphalangeal joint of thumb. We had treated these injuries using a pins and rubbers traction system which had been modified to avoid friction of the pins against the bone during mobilisation of the joint in order to minimise the risk of osteolysis. A Michigan hand outcome questionnaire was used for subjective assessment. The active range of movement (AROM) of the proximal and distal interphalangeal joints and the grip strength were used for objective assessment.

The mean follow-up was 34 months (12 to 49). The mean normalised Michigan hand outcome score was 84. The mean AROM of the proximal interphalangeal joint was 85° and that of the distal interphalangeal joint 48°. The mean grip strength was 92% of the uninvolved hand.

Twelve patients have returned to their original occupations. There has been no radiological osteolysis or clinical osteomyelitis. This modified traction system has given acceptable results with a low rate of complications. It is light, cheap, effective and easy to apply.
Curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head
Authors: Sakano S. , Hasegawa Y. , Torii Y. , Kawasaki M. , Ishiguro N.
Published: April 2004

We reviewed the outcome of curved intertrochanteric varus osteotomy in the treatment of osteonecrosis of the femoral head in 20 hips. A mean varus angulation of 31° was obtained by the osteotomy. The ratio of intact area on the weight-bearing portion increased from 19% to 61%. The mean elevation and lateral displacement of the greater trochanter were 1.2 cm and 0.5 cm, respectively. These changes in the position of the greater trochanter were very small when compared with those after conventional varus wedge osteotomy. Nonunion or delayed union was not observed. Quantitative analyses showed aggressive bone remodelling in the medial intertrochanteric region. Eighteen hips survived without collapse after a mean follow-up of 48 months.

We conclude that curved varus osteotomy can be used to preserve the hip joint in patients with osteonecrosis of the femoral head.
A three-dimensional classification for fractures of the proximal humerus
Authors: Edelson G. , Kelly I. , Vigder F. , Reis N. D.
Published: April 2004

Existing classifications of fractures of the head of the humerus are inadequate in terms of interobserver reliability and the predictability of the clinical outcome. From a combined study of 73 fracture specimens in museums and 84 CT-three-dimensional reconstructions in patients, we have devised a classification which appears to be more useful clinically. Common patterns of fracture and a plausible mechanism of injury were observed.

In 3-D most proximal humeral fractures can be organised into five basic types. These correspond in some degree to the Codman/Neer classification, but differ significantly in regard to the more complex patterns of fracture. We observed a logical progression from simple to complex fractures. An interobserver reliability study was carried out which indicated the improved usefulness of this new 3-D concept in providing a common language among clinicians for classifying these injuries. When surgery is indicated, the 3-D concept is also invaluable in guiding the restitution of anatomy through either open or percutaneous means.
Heterotopic ossification of the elbow in patients with burns
Authors: Tsionos I. , Leclercq C. , Rochet J-M.
Published: April 2004

Heterotopic ossification which may develop around the elbow in patients with burns may lead to severe functional impairment. We describe the outcome of early excision of such heterotopic ossification in 28 patients (35 elbows), undertaken as soon as the patient’s general and local condition allowed. The mean age at operation was 42 years. The mean area of burnt body surface was 49%. The mean pre-operative range of movement was 22° in flexion/extension and 94° in pronation/supination. The mean time between the burn and operation was 12 months with the median being 9.5. The mean follow-up period was for 21 months.

At the last review, the mean range of movement was 123° in flexion/extension and 160° in pronation/supination. Clinical evidence of recurrence was seen in four patients, occurring within the first two months after operation. Nevertheless, three of these elbows gained 60° or more in flexion/extension and in pronation/supination. Based on this experience, we recommend early surgical treatment of heterotopic ossification of the elbow in patients with severe burns.
A comparison of polyethylene wear rates between cemented and cementless cups
Authors: McCombe P. , Williams S. A.
Published: April 2004

We selected randomly a consecutive series of 162 patients requiring hip replacement to receive either a cementless, hemispherical, modular, titanium acetabular cup or a cemented, all-polyethylene cup. These replacements were performed by two surgeons in four general hospitals. The same surgical technique was used and a 26 mm metal-head femoral component was used in every case.

After exclusions, 115 hips were studied for differences in rates of wear and osteolysis. The mean clinical follow-up was eight years and the mean radiological follow-up, 6.5 years. The cementless cups wore at a mean rate of 0.15 mm per year and the cemented cups at 0.07 mm per year. This difference was significant (p < 0.0001).

Our findings in this mid-term study suggest that cementless cups wear more than cemented cups.
Computer-assisted knee arthroplasty versus a conventional jig-based technique
Authors: Chauhan S. K. , Scott R. G. , Breidahl W. , Beaver R. J.
Published: April 2004

We have compared a new technique of computer-assisted knee arthroplasty with the current conventional jig-based technique in 70 patients randomly allocated to receive either of the methods. Post-operative CT was performed according to the Perth CT Knee Arthroplasty protocol and pre- and post-operative Maquet views of the limb were taken. Intra-operative and peri-operative morbidity data were collected and blood loss measured.

Post-operative CT showed a significant improvement in the alignment of the components using computer-assisted surgery in regard to femoral varus/valgus (p = 0.032), femoral rotation (p = 0.001), tibial varus/valgus (p = 0.047) tibial posterior slope (p = 0.0001), tibial rotation (p = 0.011) and femorotibial mismatch (p = 0.037). Standing alignment was also improved (p = 0.004) and blood loss was less (p = 0.0001). Computer-assisted surgery took longer with a mean increase of 13 minutes (p = 0.0001).
Weakness of extensor hallucis longus after removal of non-vascularised fibula as an autograft
Authors: Shingade V. U. , Jagtap S. M. , Ranade A. B.
Published: April 2004

The upper three-quarters of the fibula is commonly used as a non-vascularised autograft. Subsequent to this isolated weakness of extensor hallucis longus may occur. We have studied 26 patients in whom the upper and middle thirds of the fibula had been harvested as a graft through Henry’s posterolateral approach.

Isolated weakness of extensor hallucis longus was found after operation in ten patients but not in the remainder. EMG and nerve-conduction studies confirmed injury of the nerve to extensor hallucis longus in those with weakness. We dissected 40 cadaver limbs and found that those in which the nerve to extensor hallucis longus ran close to the fibular periosteum were at risk. The injury is mostly incomplete and recovery occurs within four to six months.
Whatever happened to local government?: local labour market policy in the UK and Denmark
Authors: Etherington David , Jones Martin
Published: April 2004

English

This article builds on the emerging body of work concerned with local state restructuring under New Labour. Set within the context of labour market and welfare state restructuring, we suggest that there is an emerging consensus for a more robust and proactive involvement by local government. The article argues that initiatives for reactivating the local state have been deployed and tested in Denmark, with local government playing a central role in socioeconomic governance. The article unpacks what we term Denmark's ‘welfare-through-work’ model – a policy-making system built around negotiated and inclusive systems of regulation and governance – and then highlights some lessons for re-engaging local authorities in the UK.
State modernisation and local strategic selectivity after Local Agenda 21: evidence from three northern English localities
Authors: Jonas Andrew E.G. , Gibbs David C. , While Aidan
Published: April 2004

English

Over the last decade all English local authorities have developed strategies for a sustainable local environment in line with Local Agenda 21 (LA21) principles. Under New Labour, local government is being modernised, creating opportunities to advance LA21 from process to strategy. The article examines local environmental governance after LA21 in three local authority areas in northern England: Manchester, Leeds and Lancashire. Drawing on neo-Gramscian state theory and its concept of the spatial selectivity of the national state, emphasis is placed on an actual local politics of environmental policy making vis-à-vis the ideal of ecological modernisation. Local environmental strategies are not only linked to changing national priorities but also reflect the particular economic, environmental and political challenges impacting on decision making in each locality. The concept of local state strategic selectivity is proposed.
Democratic governance and bureaucratic politics: a case of pension reform in Korea
Authors: Yang Jae-jin
Published: April 2004

English

Governance theories have two theoretical tendencies: downplaying the role of the state and overemphasis on cooperative relationships among participants in the policy-making process. This article seeks to redress the balance by paying more attention to bureaucratic politics and conflicting policy networks, using the case study of Korean pension reform. This orientation enables us to understand the effect of governance not only on relations between the state and civil society, but also on the relative power among state bureaucracies. The Korean case demonstrates that the establishment of democratic governance under the leadership of President Kim Dae Jung reinforces social bureaucrats’ power over the social policy domain, which had long been within the power of economic bureaucrats in the heyday of the Korean developmental state.
The micropolitics of clinical guidelines: an empirical study
Authors: McDonald Ruth , Harrison Stephen
Published: April 2004

English

This article analyses data from a participant observation study of decision making in local National Health Service institutions, focusing on the construction of local clinical guidelines. We found that guideline construction departed significantly from the ‘bureaucratic-scientific’ model. Although clinical guidelines are often seen as constraining the practice of medicine, our study suggests that there is nothing intrinsically corrosive of professional autonomy about guidelines. It is not likely to be guidelines per se which diminish physician autonomy but rather the manner in which they are implemented. Participation in the guidelines process functioned primarily as a device by which actors hoped to pursue their existing opinions, either through imposing them on others, or by creating a framework of legitimation for themselves.
Charities, civil society and the charity law reviews on the island of Ireland
Authors: O'Halloran Kerry
Published: April 2004

English

This article considers the opportunity, presented by the coincidence of simultaneous charity law reviews in the two jurisdictions on the island of Ireland, for an adjustment of charity law frameworks to maximise appropriate and effective charitable activity within each jurisdiction, while also facilitating the coordination of some such activity between both. It examines the nature of civil society and charity law, and the relationship between them. The article argues that a creative legislative response to this opportunity could address themes of social inclusion common to both jurisdictions and thereby contribute to the consolidation of civil society on this island.
ELA-max: A New Topical Lidocaine Formulation
Authors: Goldman Ran D
Published: April 2004

OBJECTIVE

To evaluate the role of a new formulation of lidocaine (ELA-max) in local anesthesia in children and compare it with the eutectic mixture of local anesthetics (EMLA).

DATA SOURCES

Relevant literature was identified by a MEDLINE search (1966—November 2003) using the search terms ELA-max and EMLA. Bibliographies of selected articles were also examined to include all relevant investigations. The product manufacturer was contacted for inclusion of the most recent data available.

DATA SYNTHESIS

Topical anesthesia in children is clinically challenging. ELA-max has been shown to be as effective as EMLA for venipuncture in children, but with faster onset. Adverse effects, such as transient blanching with redness and erythema, have been reported.

CONCLUSIONS

Further investigation is needed to determine the effectiveness of ELA-max on other painful procedures in children, as well as its safety.