bluuebunny/crossref_metadata_2025 huggingface dataset:
Scale of interest versus scale of estimation: comparing alternative estimators for the incremental costs of a comorbidity
Authors: Basu Anirban , Arondekar Bhakti V. , Rathouz Paul J.
Published: March 2006

We investigate how the scale of estimation in risk‐adjustment models for health‐care costs affects the covariate effect, where the scale of interest for the covariate effect may be different from the scale of estimation. As an illustrative example, we use claims data to estimate the incremental costs associated with heart failure within one year subsequent to myocardial infarction. Here, the scale of interest for the effect of heart failure on costs is additive. However, traditional methods for modeling costs use predetermined scale of estimation – for example, ordinary least squares (OLS) regression assumes an additive scale while log‐transformed OLS and generalized linear models with log‐link assume a multiplicative scale of estimation. We compare these models with a new flexible model that lets the data determine the appropriate scale of estimation. We use a variety of goodness‐of‐fit measures along with a modified Copas test to assess robustness, lack of fit, and over‐fitting properties of the alternative estimators. Biases up to 19% in the scale of interest are observed due to the misrepresentation of the scale of estimation. The new flexible model is found to appropriately represent the scale of estimation and less susceptible to over‐fitting despite estimating additional parameters in the link and the variance functions. Copyright © 2006 John Wiley & Sons, Ltd.
Job displacement and stress‐related health outcomes
Authors: Browning Martin , Moller Dano Anne , Heinesen Eskil
Published: March 2006

We investigate whether job loss as the result of displacement causes hospitalization for stress‐related diseases which are widely thought to be associated with unemployment. In doing this, we use much better data than any previous investigators. Our data are a random 10% sample of the male population of Denmark for the years 1981–1999 with full records on demographics, health and work status for each person, and with a link from every working person to a plant. We use the method of ‘matching on observables’ to estimate the counter‐factual of what would have happened to the health of a particular group of displaced workers if they had not in fact been displaced. Our results indicate unequivocally that being displaced in Denmark does not cause hospitalization for stress‐related disease. An analysis of the power of our test suggests that even though we are looking for a relatively rare outcome, our data set is large enough to show even quite small an effect if there were any. Supplementary analyses do not show any causal link from displacement or unemployment to our health outcomes for particular groups that might be thought to be more susceptible. Copyright © 2006 John Wiley & Sons, Ltd.
Functional role of VDR in the activation of p27Kip1 by the VDR/Sp1 complex
Authors: Cheng Hsuen‐Tsen , Chen Jing‐Yi , Huang Yu‐Chun , Chang Hui‐Chiu , Hung Wen‐Chun
Published: March 2006

Our previous study demonstrate that vitamin D3 induces the binding of vitamin D3 receptor (VDR) to Sp1 transcription factor and stimulates p27Kip1 expression via the Sp1 consensus sequences in the promoter. Both VDR and Sp1 are transcriptional activators, it is unclear which protein functions as the transcription component of the VDR/Sp1 complex. To address this issue, we constructed the AF‐2 deletion mutant of VDR and tested the effect of vitamin D3 on p27Kip1 expression. In consistent with our previous results, we found that expression of wild‐type VDR in SW620 colon cancer cells, which expressed very low level of endogenous VDR, increased vitamin D3‐stimulated p27Kip1 promoter activity and protein expression. On the contrary, expression of AF‐2 deletion mutant had little effect. DNA affinity precipitation assay (DAPA) showed that both wild‐type and deletion mutant of VDR bound to the DNA probe corresponding to the Sp1 binding site in the p27Kip1 promoter in a vitamin D3‐dependent manner indicating deletion of AF‐2 domain does not affect the interaction between VDR and Sp1. Chromatin immunoprecipitation (CHIP) assay also confirmed that VDR and its AF‐2 deletion mutant bound to p27Kip1 promoter in vivo. We found that deletion of AF‐2 domain abolished the interaction of coactivators SRC‐1 and DRIP205 with VDR. Taken together, our results suggest that VDR functions as the transactivation component of the VDR/Sp1 complex to trigger gene expression. © 2006 Wiley‐Liss, Inc.
Delayed treatment with sildenafil enhances neurogenesis and improves functional recovery in aged rats after focal cerebral ischemia
Authors: Zhang Rui Lan , Zhang Zhenggang , Zhang Li , Wang Ying , Zhang Chunling , Chopp Michael
Published: March 2006

Increasing age decreases the number of new neurons in the dentate gyrus and the subventricular zone (SVZ). Sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, enhances neurogenesis in young rats. The present study tested the hypothesis that sildenafil augments neurogenesis in aged rats after focal cerebral ischemia. Nonischemic aged (18 months, n = 6) Wistar rats exhibited a significant reduction of actively proliferating and relatively quiescent cells in the SVZ measured by the number of minichromosome maintenance protein‐2‐positive (MCM‐2+) cells, a marker of the proliferating cells, compared with nonischemic young (3–4 months, n = 8) rats. Occlusion of the middle cerebral artery did not increase the number of MCM‐2+ cells in the SVZ of aged rats at 3 months after focal ischemia. However, treatment with sildenafil at a dose of 3 mg/kg (n = 8) daily for 7 consecutive days starting 7 days after focal ischemia significantly increased the number of MCM‐2+ cells in the SVZ of aged rats compared with aged rats treated with saline (n = 8). Double immunostaining revealed that substantially more Ki67+ cells (a marker of proliferating cells) were doublecortin+ (a marker of migrating neuroblasts) in sildenafil‐treated than in saline‐treated aged animals. In addition, treatment with sildenafil significantly improved functional recovery compared with saline‐treated rats. These data suggest that inhibition of PDE5 activity by sildenafil augments neurogenesis in the SVZ of aged ischemic rats, although these rats have reduced numbers of neural progenitor and stem cells in the SVZ. © 2006 Wiley‐Liss, Inc.
Electrodiagnostic criteria for carpal tunnel syndrome in axonal polyneuropathy
Authors: Ubogu Eroboghene E. , Benatar Michael
Published: February 2006

Median–ulnar comparative studies (MUCSs) play an important role in the electrodiagnosis of carpal tunnel syndrome (CTS), but diagnostic criteria in patients with underlying axonal polyneuropathy have not been established. We prospectively evaluated 28 patients with axonal polyneuropathy (48 hands), blindly dichotomized into CTS cases and controls, using the lumbrical–interosseous motor (LIM), mixed palmar sensory (MPS), and digit 4 sensory (D4S) MUCS. LIM, MPS, and D4S MUCS latency differences could be calculated in 98%, 69%, and 48% of hands. Based on the maximum combination of sensitivity and specificity, diagnostic cutoffs were ≥0.8, ≥0.5, and ≥0.4 ms for the LIM, MPS, and D4S studies, respectively. The LIM study was the most accurate test and the only MUCS that yielded a positive likelihood ratio greater than 10 (16.25 for a cut‐off value of 1 ms) and a negative likelihood ratio less than 0.1 (0.09 for a cut‐off value of 0.4 ms), resulting in meaningful differences in pretest and posttest probabilities of CTS in patients with axonal polyneuropathy. These novel MUCS electrodiagnostic criteria should facilitate more accurate electrodiagnostic confirmation of CTS in this population. Muscle Nerve, 2006
Pentoxifylline fails to attenuate fibrosis in dystrophic (mdx) diaphragm muscle
Authors: Gosselin Luc E. , Williams Jacqueline E.
Published: February 2006

Fibrosis is a common pathological feature observed in muscle from patients with Duchenne muscular dystrophy and in mdx diaphragm. The purpose of this study was to determine whether pentoxifylline (PTX) treatment for 4 weeks (16 mg/kg/day) could significantly attenuate the process of fibrosis in diaphragm muscle from mdx mice. PTX treatment had no impact on in vitro diaphragm muscle contractile function. In addition, diaphragm muscle hydroxyproline concentration and the level of type I and III collagen and TGF‐β1 mRNA were unaffected by PTX treatment. These findings do not support the use of PTX as an antifibrotic drug for the treatment of muscular dystrophy. Muscle Nerve, 2006
High‐dose cyclophosphamide without stem cell rescue for refractory multifocal motor neuropathy
Authors: Brannagan Thomas H. , Alaedini Armin , Gladstone Douglas E.
Published: February 2006

Patients with multifocal motor neuropathy (MMN) respond to intravenous immune globulin (IVIg) and cyclophosphamide, although the benefit is not sustained. High‐dose cyclophosphamide can induce a remission in patients with autoimmune diseases, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We describe a patient with refractory MMN who improved with high‐dose cyclophosphamide (50 mg/kg for 4 days) without stem cell rescue. Following treatment she discontinued IVIg. At a 6‐month examination, her strength had improved and she had regained the ability to write. High‐dose cyclophosphamide may be a successful treatment for patients with MMN refractory to other therapies. Muscle Nerve, 2006
Familial idiopathic hyper‐CK‐emia: An underrecognized condition
Authors: Capasso Margherita , De Angelis Maria Vittoria , Di Muzio Antonio , Scarciolla Oronzo , Pace Marta , Stuppia Liborio , Comi Giacomo Pietro , Uncini Antonino
Published: February 2006

Persistent elevation of serum creatine kinase (CK) in individuals with normal neurological and laboratory examinations has been called idiopathic hyperCKemia (IH). IH has been reported in rare families and was recently ascribed to caveolin‐3 gene mutations. We retrospectively found that IH was familial in 13 of 28 subjects in whom serum CK was measured in relatives. These 13 families had a total of 41 subjects with IH, including six over 60 years of age. In eight families there was male‐to‐male transmission and a higher prevalence of males with hyperCKemia. Muscle biopsy in one member of all families was normal or showed minimal, nonspecific changes. Morphometric examination disclosed different patterns of changes in fiber size and distribution. Caveolin‐3 expression was normal and in five families molecular genetics excluded caveolin‐3 gene mutations. Our findings suggest that IH is familial in 46% of cases. Familial IH is a benign genetically heterogeneous condition that is autosomal‐dominant in at least 60% of cases, with a higher penetrance in men. Muscle Nerve, 2006
Levetiracetam suppresses long‐loop reflexes at the cortical level
Authors: Kofler Markus
Published: March 2006

Posthypoxic coma is often associated with cortical and brainstem hyperexcitability. Five months following cardiopulmonary resuscitation after myocardial infarction and ventricular arrhythmia, a 47‐year‐old man presented with posthypoxic cerebral dysfunction, minimal responsiveness, severe spastic‐dystonic tetraparesis, and stimulus‐sensitive muscle spasms upon acoustic and sensory stimulation. Neurophysiological examination revealed increased long‐loop reflexes in abductor pollicis brevis muscle following median nerve stimulation at the wrist, consistent with cortical hyperexcitability. Exaggerated startle responses provided evidence of concomitant brainstem disinhibition. Levetiracetam up to 3,000 mg per day suppressed transcortical long‐loop reflexes in a dose‐dependent manner without concomitant suppression of the H‐reflex and only mild attenuation of the startle response. The present findings suggest a suppressive effect of levetiracetam on cortical neurons in the absence of a spinal effect on monosynaptic reflexes, and thus support the drug's efficacy in posthypoxic cortical hyperexcitability. Muscle Nerve, 2006
Minimum multiple message broadcast graphs
Authors: Harutyunyan Hovhannes A.
Published: March 2006

Multiple message broadcasting is the process of multiple message dissemination in a communication network in whichmmessages, originated by one vertex, are transmitted to all vertices of the network. A graphGwithnvertices is called a m‐message broadcast graph if its broadcast time is the theoretical minimum.Bm(n) is the minimum number of edges in any m‐message broadcast graph onnvertices. An m‐message minimum broadcast graph is a broadcast graphGonnvertices havingBm(n) edges. This article presents several lower and upper bounds onBm(n). In particular, it is shown that modified Knödel graphs are m‐message broadcast graphs form≤ min⌊logn⌋,n− 2⌊logn⌋. From the Cartesian product of some broadcast graphs we obtain better upper bounds onBm(n), and in some cases we can prove thatBm(n) =O(n). The exact value ofB2(2k) is also established. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 47(4), 218–224 2006
Studies of TL peaks recorded with hyperbolic heating function
Authors: Bhattacharya Manabesh
Published: March 2006

For the first time thermoluminescence peaks corresponding to a hyperbolic heating function are studied in a model which takes into account not only the existence of thermally disconnected deep traps but also their interactions with the conduction band through the capture of electrons. The predictions of the present model are compared with those of other existing models, which are special cases of the present one. It is found that the Kirsh method, which is always valid, is applicable to all the models considered in the present paper. The quality of simulation of glow peaks is further tested by a rigorous method of curve fitting. The strong variation of the order of kinetics in the different models considered is due to the shift of the order of kinetics with dose. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
TL and PL in BaSr(SO4)2:Eu mixed sulphate
Authors: Salah Numan , Sahare P. D. , Kumar Pratik
Published: March 2006

A highly sensitive thermoluminescent (TL) phosphor based on BaSr(SO4)2:Eu has been developed. The phosphor was recrystallized from H2SO4 solution by evaporation. Photoluminescence studies of this mixed‐sulphate phosphor show that Eu is incorporated in the host in its divalent (emission at 383 nm) as well as trivalent (emissions at 575 and 731 nm) form due to 4f65d → 8S7/2 and 5D0 → 7Fj transitions, respectively. The intensity of the 383 nm band increases with increasing irradiation, while that of the 731 nm band decreases, showing Eu3+ → Eu2+ conversion. The TL glow curve of the BaSr(SO4)2:Eu material shows a single peak at 470 K along with a small shoulder at around 428 K. The relative intensities of these peaks are found to vary with γ‐ray exposure. The TL sensitivity of the mixed‐sulphate phosphor is nearly 2.5, 7 and 1.2 times higher than those of BaSO4:Eu, SrSO4:Eu and CaSO4:Dy phosphors, respectively. The annealing temperature and the impurity concentration effects are also studied. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab initio MO study of potential energy surface of NH2 with CN reaction
Authors: Du Benni , Zhang Weichao
Published: March 2006

An extensive quantum chemical study of the potential energy surfaces (PES) for the association reaction of NH2 with CN and the subsequent isomerization and dissociation reactions has been carried out using density functional theory (DFT)/B3LYP/6‐311++G(3df,2p) level of theory on both singlet and triplet states. The reaction mechanism on the triplet surface is more complicated than that on the singlet surface. A total of 19 isomers and 46 transition states have been identified and characterized on the triplet PES. Among them, IM2 (IM2a), IM3 (IM3a, IM3b), and IM10 are the lowest‐lying isomers with thermodynamic stability. Twenty available dissociation channels, depending on the different initial isomers, have been identified. On the singlet surface, only 12 isomers and 16 transition states have been found, and among them IM1(S) and IM2(S) are the lowest‐lying isomers. The higher isomerization and dissociation barriers on the singlet surface indicate that the addition and the subsequent reactions of NH2+CN are most likely to occur on the triplet PES because of the lower barriers. A prediction can be made for the possible mechanism explaining the production of H+HNCN. Besides HNCN, other major products are NH+HCN and NH+HNC, which are produced by direct dissociation reactions from triplet IM2 and IM3, respectively. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Building or bodging? Attitudes to sustainability in UK public sector housing construction development
Authors: Hall Mark , Purchase David
Published: March 2006

The UK government has established an agenda for ‘greening’ government activity and, as it accounts for approximately 40% of all UK construction procurement, is actively encouraging sustainability initiatives in this particular sector. However, there have been criticisms of its approach. The UK government anticipates investing approximately £3 billion in the social housing sector over the next three years and, as a prelude to this, has asked the Housing Corporation to promote a raft of sustainable development initiatives. This paper draws on two tranches of data in order to examine the impact of the UK government's sustainability policy on the way the public sector procures housing construction. The first of these is the sustainability improvement targets from 143 public sector housing associations. The evidence from this first tranche of data suggests that sustainability is currently seen as a low priority and that government initiatives have yet to make a significant impact. The second tranche of data uses comments from housing association development managers to examine the reasons for this apparent lack of impact. This focuses on their views and opinions of sustainability as an issue in social housing development and enables inferences to be made about their attitudes to this issue. There has been criticism about the lack of progress so far seen and the results in this paper suggest that this criticism is justified. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Moral voices of politically engaged urban youth
Authors: Kirshner Ben
Published: March 2006

School‐based character education tends toward a negative orientation (for example, preventing delinquency). Is there a better way to go—engaging the kinds of moral commitments exemplified by student activists?
Internet lives: Social context and moral domain in adolescent development
Authors: Bradley Karen
Published: March 2006

The author examines the thinking and behavior of adolescents within the digital world—an environment that is largely not mediated by adults—and considers the applicability of the literature on youth ethics that is based on more traditional contexts.
Care of the Self and Patient Participation in Genetic Discourse: A Foucauldian Reading of the Surgeon General's “My Family Health Portrait” Program
Authors: Bates Benjamin R.
Published: February 2006

Critics of genetic discourse are concerned that deterministic and discriminatory views of genetics are increasingly becoming adopted. These views argue that current genetic discourse becomes a source of power whereby powerful institutions harm people with so‐called “bad” genes. This essay argues that current analyses of the power of genetics discourse are grounded in an improper reading that disempowers patients. Deploying Michel Foucault's concept “care of the self,” this essay claims that genetics discourse is better understood as a way that patients take on power through rhetoric rather than a force that has power over patients. Through a close reading of the “My Family Health Portrait” program, this paper argues that patients experience a process of “subjection” wherein they become agents of and objects of genetics discourse both. This alternative mode of analyzing the power of genetics discourse has implications for our collective understanding of the operations of the care of the self and the uses of genetic information that we propose.
Positive solutions of semilinear elliptic problems in unbounded domains with unbounded boundary
Authors: Cerami Giovanna , Molle Riccardo , Passaseo Donato
Published: February 2006

This paper is concerned with the existence and multiplicity of positive solutions of the equation−\mathrm{\Delta }u + u = u^{p−1},2 < p < 2^{ \ast } = \frac{2N}{N−2}, with Dirichlet zero data, in an unbounded smooth domain\Omega \subset \mathbb{R}^{N}having unbounded boundary. Under the assumptions:

(h_1)\ \exists \tau _{1},\tau _{2},…,\tau _{k} \in \mathbb{R}^+ \setminus \{0\},\ 1⩽k⩽N−2,\text{ such that }

(x_{1},x_{2},…,x_{N}) \in \Omega \:\iff \:(x_{1},…,x_{i−1},x_{i} + \tau _{i},…,x_{N}) \in \Omega ,\:\forall i = 1,2,…,k,

(h_2)\ \exists R \in \mathbb{R}^{ + }\! \setminus\! \{0\} \text{ such that }\mathbb{R}^{N} \!\setminus\! \Omega\! \subset\! \{(x_{1},x_{2},…,x_{N}) \in \mathbb{R}^{N}\text{:}\sum\limits _{j = k + 1}^{N}\! x_{j}^{2}⩽R^{2}\}

the existence of at leastk + 1solutions is proved.

Dans cet article on étudie l'existence et la multiplicité de solutions positives pour l'équation−\mathrm{\Delta }u + u = u^{p−1},2 < p < 2^{ \ast } = \frac{2N}{N−2}, avec la condition de Dirichletu = 0sur∂Ω. Le domaine\Omega \subset \mathbb{R}^{N}est non borné et∂Ωest non borné aussi. En supposant que les conditions

(h_1)\ \exists \tau _{1},\tau _{2},…,\tau _{k} \in \mathbb{R}^+ \setminus \{0\},\ 1⩽k⩽N−2,\text{ tels que }

(x_{1},x_{2},…,x_{N}) \in \Omega \:\iff \:(x_{1},…,x_{i−1},x_{i} + \tau _{i},…,x_{N}) \in \Omega ,\:\forall i = 1,2,…,k,

(h_2)\ \exists R \in \mathbb{R}^{ + }\! \setminus\! \{0\} \text{ tel que }\mathbb{R}^{N} \!\setminus\! \Omega\! \subset\! \{(x_{1},x_{2},…,x_{N}) \in \mathbb{R}^{N}\text{:}\sum\limits _{j = k + 1}^{N}\! x_{j}^{2}⩽R^{2}\}

soient vérifiées, on démontre que le problème possède au moinsk + 1solutions.
Active Ras‐induced effects on skeletal myoblast differentiation and apoptosis are independent of constitutive PI3‐kinase activity
Authors: Karasarides M. , Dee K. , Schulman D. , Wolfman A. , Weyman C.M.
Published: February 2006

23A2 myoblasts expressing GAP‐resistant, constitutively active G12V:H‐Ras (A2:G12V:H‐Ras myoblasts) display a transformed morphology and do not undergo mitogen‐deprivation‐induced differentiation or the associated apoptosis. To determine the phenotype induced by F156L:H‐Ras, a constitutively active mutant with enhanced nucleotide exchange activity rather than impaired GAP‐stimulated GTPase activity, myoblast cell lines were established that stably express F156L:H‐Ras at levels of H‐Ras comparable to the A2:G12V:H‐Ras myoblasts. These A2:F156L:H‐Ras myoblast cell lines do not possess a transformed morphology, and while differentiation and apoptosis are impaired, these processes are not abrogated as in the A2:G12V:H‐Ras myoblasts. Surprisingly, while expression of either G12V:H‐Ras or F156L:H‐Ras results in constitutive signaling through PI3‐kinase, only cells expressing G12V:H‐Ras additionally possess constitutive signaling through MAPK, and NFκB. Pharmacological abrogation of the Ras‐induced constitutive PI3‐kinase signal, however, is not responsible for the impaired differentiation or apoptosis in either A2:G12V:H‐Ras myoblasts or A2:F156L:H‐Ras myoblasts. Thus, our data suggest that a pathway distinct from those that signals through MAPK, NFκB or PI3‐kinase is responsible for the impaired differentiation and apoptosis in 23A2 skeletal myoblasts expressing constitutively active Ras.
Stress and tissue Doppler echocardiographic evidence of effectiveness of myoblast transplantation in patients with ischaemic heart failure
Authors: Biagini Elena , Valgimigli Marco , Smits Pieter C. , Poldermans Don , Schinkel Arend F.L. , Rizzello Vittoria , Onderwater‐ Emile E.M. , Bountioukos Manolis , Serruys Patrick W.
Published: March 2006

Background

There is experimental evidence that transplanting skeletal myoblasts (SM) into the post‐infarction myocardial scar improves regional and global left ventricular (LV) function.

Aims

To evaluate short‐ and long‐term regional and global LV functional effects of percutaneously transplanted SM in patients with ischaemic heart failure.

Methods and results

Ten patients (mean age 60 ± 10 years, 8 males) with dilated ischaemic cardiomyopathy underwent percutaneous injection of autologous myoblasts. Regional and global LV function was evaluated by 2‐dimensional echocardiography and tissue Doppler imaging (TDI) at rest and during low‐dose dobutamine infusion to assess contractile reserve. After a baseline examination, sequential follow‐ups were performed at 1, 3, and 6 months and 1 year. NYHA functional class decreased from 2.7 ± 0.5 to 1.9 ± 0.5 (p < 0.01) at one year. LV function and volumes at rest remained unchanged while contractile reserve significantly improved during follow‐up. At low‐dose dobutamine infusion, the peak systolic velocity in the regions of myoblasts injection significantly increased at TDI examination (from 7.7 ± 2.1 to 8.6 ± 1.8 cm/s, p = 0.02); LV ejection fraction improved (from 40 ± 9% to 46 ± 8%, p < 0.0001) and end‐systolic volumes decreased (from 56 ± 28 to 50 ± 25 ml/m2, p = 0.001) at 1 year.

Conclusion

In patients with ischaemic heart failure, percutaneous injection of autologous myoblasts may improve regional and global LV systolic function during dobutamine infusion, at 1‐year follow‐up.
Sulforaphane, an activator of Nrf2, suppresses cellular accumulation of arsenic and its cytotoxicity in primary mouse hepatocytes
Authors: Shinkai Yasuhiro , Sumi Daigo , Fukami Ikuo , Ishii Tetsuro , Kumagai Yoshito
Published: February 2006

Sulforaphane (SFN) is an activator of the transcription factor Nrf2, which plays a critical role in metabolism and excretion of xenobiotics. Exposure of primary mouse hepatocytes to SFN resulted in activation of Nrf2 and significant elevation of protein expressions responsible for excretion of arsenic into extracellular space. Pretreatment with SFN 24 h prior to arsenite exposure reduced not only arsenic accumulation in the cells but also cellular toxicity of this metalloid. Therefore, our findings indicate a potential function of SFN in reducing cellular arsenic levels, thereby diminishing arsenic toxicity.
Cysteine misincorporation in bacterially expressed human α‐synuclein
Authors: Masuda Masami , Dohmae Naoshi , Nonaka Takashi , Oikawa Takayuki , Hisanaga Shin-ichi , Goedert Michel , Hasegawa Masato
Published: February 2006

Bacterially expressed human α‐synuclein (α‐syn) has been widely used in structural and functional studies. Here we show that ∼20% of human α‐syn expressed in Escherichia coli is mistranslated and that a Cys residue is incorporated at position 136 instead of a Tyr. Site‐directed mutagenesis of codon 136 (TAC to TAT) resulted in the expression of α‐syn lacking Cys. Although wild‐type (Y136‐TAC and Y136‐TAT) and mutant (C136‐TGC) α‐syn had similar propensities to assemble into filaments, the levels of dimeric α‐syn were increased by misincorporation. To avoid potential artefacts, we recommend use of the Y136‐TAT construct for the expression of human α‐syn.
Insight into the structure of Mesorhizobium loti arylamine N‐acetyltransferase 2 (MLNAT2): A biochemical and computational study
Authors: Dairou Julien , Flatters Delphine , Chaffotte Alain F. , Pluvinage Benjamin , Sim Edith , Dupret Jean-Marie , Rodrigues-Lima Fernando
Published: February 2006

The arylamine N‐acetyltransferases (NAT; EC 2.3.1.5) are xenobiotic‐metabolizing enzymes (XME) that catalyze the transfer of an acetyl group from acetylCoA (Ac‐CoA) to arylamine, hydrazines and their N‐hydroxylated metabolites. Eukaryotes may have up to three NAT isoforms, but Mesorhizobium loti is the only prokaryote with two functional NAT isoforms (MLNAT1 and MLNAT2). The three‐dimensional structure of MLNAT1 has been determined (Holton, S.J., Dairou, J., Sandy, J., Rodrigues‐Lima, F., Dupret, J.M., Noble, M.E.M. and Sim, E. (2005) Structure of Mesorhizobium loti arylamine N‐acetyltransferase 1. Acta Cryst, F61, 14–16). No MLNAT2 crystals have yet been produced, despite the production of sufficient quantities of pure protein. Using purified recombinant MLNAT1 and MLNAT2, we showed here that MLNAT1 was intrinsically more stable than MLNAT2. To test whether different structural features could explain these differences in intrinsic stability, we constructed a high‐quality homology model for MLNAT2 based on far UV‐CD data. Despite low levels of sequence identity with other prokaryotic NAT enzymes (≈28% identity), this model suggests that MLNAT2 adopts the characteristic three‐domain NAT fold. More importantly, molecular dynamics simulations on the structures of MLNAT1 and MLNAT2 suggested that MLNAT2 was less stable than MLNAT1 due to differences in amino‐acid sequence/structure features in the α/β lid domain.
Identification of multiple actin‐binding sites in cofilin‐phosphatase Slingshot‐1L
Authors: Yamamoto Masahiro , Nagata-Ohashi Kyoko , Ohta Yusaku , Ohashi Kazumasa , Mizuno Kensaku
Published: February 2006

Slingshot‐1L (SSH1L) is a phosphatase that specifically dephosphorylates and activates cofilin, an actin‐severing and ‐depolymerizing protein. SSH1L binds to and is activated by F‐actin in vitro, and co‐localizes with F‐actin in cultured cells. We examined the F‐actin‐binding activity, F‐actin‐mediated phosphatase activation, and subcellular distribution of various mutants of SSH1L. We identified three sites involved in F‐actin binding of SSH1L: Trp‐458 close to the C‐terminus of the phosphatase domain, an LHK motif in the N‐terminal region, and an LKR motif in the C‐terminal region. These sites play unique roles in the control of subcellular localization and F‐actin‐mediated activation of SSH1L.
Silencing of filamin A gene expression inhibits Ca2+‐sensing receptor signaling
Authors: Huang Chunfa , Wu Zhenzhen , Hujer Kristine M. , Miller R. Tyler
Published: February 2006

Filamin plays an important role in actin cytoskeleton organization, membrane stabilization, and anchoring of transmembrane proteins. Using short interfering RNA (siRNA) to selectively target the filamin A gene and silence its expression, we studied the role of filamin A in G protein coupled receptor (GPCR) signaling. Silencing of filamin A protein expression was determined by immunoblotting and immunofluorescence. Functional consequences of filamin A gene silencing were measured by studying its role in MAPK signaling pathways activated by the Ca2+‐sensing receptor. This work defines filamin A involvement in GPCR signaling pathways and describes an additional method for studying its function.
Normal specification of the extraembryonic lineage after somatic nuclear transfer
Authors: Kishigami Satoshi , Hikichi Takafusa , Van Thuan Nguyen , Ohta Hiroshi , Wakayama Sayaka , Bui Hong-Thuy , Mizutani Eiji , Wakayama Teruhiko
Published: February 2006

To examine the establishment and maintenance of trophectoderm (TE) lineage in somatic cloned blastocysts, the expression of Cdx2, a key molecule for specification of TE fate, was immunohistochemically examined simultaneously with Oct4 expression. Cloned mouse embryos were made by nuclear transfer using cumulus cells, tail‐tip fibroblasts, and embryonic stem cells. After 96 h of culture, the rates of Oct4‐expressing blastocysts were as low as 50% and 60% for cumulus and fibroblast clones, respectively. However, regardless of Oct4 expression, the majority of those cloned blastocysts (>90%) normally expressed Cdx2. Thus, even though somatic cloned embryos have reduced potential to produce the inner cell mass lineage, the TE lineage can be established and maintained.
The pur3 gene from the pur cluster encodes a monophosphatase essential for puromycin biosynthesis in Streptomyces
Authors: Sánchez María Blanca , Barrado Patricia , Jiménez Antonio , Fernández Lobato María
Published: February 2006

The pur3 gene of the puromycin (pur) cluster from Streptomyces alboniger is essential for the biosynthesis of this antibiotic. Cell extracts from Streptomyces lividans containing pur3 had monophosphatase activity versus a variety of mononucleotides including 3′‐amino‐3′‐dAMP (3′‐N‐3′‐dAMP), (N
6,N
6)‐dimethyl‐3′‐amino‐3′‐dAMP (PAN‐5′‐P) and AMP. This is in accordance with the high similarity of this protein to inositol monophosphatases from different sources. Pur3 was expressed in Escherichia coli as a recombinant protein and purified to apparent homogeneity. Similar to the intact protein in S. lividans, this recombinant enzyme dephosphorylated a wide variety of substrates for which the lowest K
m values were obtained for the putative intermediates of the puromycin biosynthetic pathway 3′‐N‐3′‐dAMP (K
m
= 1.37 mM) and PAN‐5′‐P (K
m
= 1.40 mM). The identification of this activity has allowed the revision of a previous proposal for the puromycin biosynthetic pathway.
Identification of the nuclear export signal in the helix–loop–helix inhibitor Id1
Authors: Makita Jun , Kurooka Hisanori , Mori Kentaro , Akagi Yoshio , Yokota Yoshifumi
Published: February 2006

Id proteins play important roles in cellular differentiation and proliferation by negatively regulating basic helix–loop–helix transcription factors. Although their intracellular localization may change depending on the biological situation, little is known about the molecular determinants underlying such changes. Here we report the identification of a nuclear export signal (NES) in Id1. The identified NES was different from that of Id2, but had the ability to confine heterologous green fluorescent protein to the cytoplasm. Thus, our results indicate that the intracellular localization of Id1 is regulated differently from that of Id2.
Flavohemoglobin requires microaerophilic conditions for nitrosative protection of Staphylococcus aureus
Authors: Gonçalves Vera L. , Nobre Lígia S. , Vicente João B. , Teixeira Miguel , Saraiva Lígia M.
Published: February 2006

Flavohemoglobins and flavodiiron proteins are two families of enzymes involved in nitrosative detoxification. However, the physiological oxygen‐related conditions under which they work and their relative role are still a matter of debate. To address this question we analyzed the function of the putative flavohemoprotein of Staphylococcus aureus, an organism that lacks a flavodiiron‐like gene. In this report we show that the recombinant protein contains all features typical of canonical flavohemoglobins and that the transcription of flavohemoglobin gene was upregulated by nitrosative stress in an oxygen‐dependent manner. However, and in contrast to other bacterial flavohemoglobins, the S. aureus protein has no apparent role in aerobic nitrosative protection, being only beneficial when cells of S. aureus are submitted to nitrosative stress in a microaerophilic environment. The in vivo data corroborates the proposal that Hmp acts physiologically as a denitrosylase.
The ribosomal protein L32‐2 (RPL32‐2) of S. pombe exhibits a novel extraribosomal function by acting as a potential transcriptional regulator
Authors: Jing Wang , Sheng Yuan , Jang Shibo
Published: February 2006

Ribosomal proteins play important roles in stabilizing the rRNA structure to facilitate protein synthesis in ribosome. In the present study, we analyzed the potential extraribosomal function of the ribosomal protein L32‐2 (RPL32‐2), which was expressed by a gene clone isolated from a cDNA library of Schizosaccharomyces pombe (S. pombe). RPL32‐2 fused with the GAL4 DNA‐bind domain or the GAL4 transcriptional activating domain could, respectively, activate transcriptions of reporter genes in yeast strain AH109. The RPL32‐2 mutants with truncation of either the N‐ or the C‐terminal domain resulted in abolishment of this regulatory effect. The DNA binding site for RPL32‐2 of S. pombe was identified by using a random oligonucleotide selection strategy and gel motility shift assay and Western blotting confirmed its binding specificity. Moreover, we found RPL32‐2 was also able to interact with a to‐be‐identified AT sequence binding protein. These data suggest that RPL32‐2 of S. pombe, besides its ribosomal function, may also act as a potential transcriptional regulator in nucleus.
Reduced activity of the hypertension‐associated Lys528Arg mutant of human adipocyte‐derived leucine aminopeptidase (A‐LAP)/ER‐aminopeptidase‐1
Authors: Goto Yoshikuni , Hattori Akira , Ishii Yasuhiro , Tsujimoto Masafumi
Published: February 2006

The adipocyte‐derived leucine aminopeptidase (A‐LAP)/ER aminopeptidase‐1 is a multi‐functional enzyme belonging to the M1 family of aminopeptidases. It was reported that the polymorphism Lys528Arg in the human A‐LAP gene is associated with essential hypertension. In this study, the role of Lys528 in the enzymatic activity of human A‐LAP was examined by site‐directed mutagenesis. Among non‐synonymous polymorphisms tested, only Lys528Arg reduced enzymatic activity. The replacement of Lys528 with various amino acids including Ala, Met, His and Arg caused a significant decrease in the enzymatic activity. Molecular modeling of the enzyme suggested that Lys528 is located near the entrance of the substrate pocket. These results suggest that Lys528 is important for maximal activity of A‐LAP by maintaining the appropriate structure of the substrate pocket of the enzyme. The reduced enzymatic activity of A‐LAP may cause high blood pressure and the observed association between the polymorphism and hypertension.
NMR solution structure and characterization of substrate binding site of the PPIase domain of PrsA protein from Bacillus subtilis
Authors: Tossavainen Helena , Permi Perttu , Purhonen Susanna L. , Sarvas Matti , Kilpeläinen Ilkka , Seppala Raili
Published: February 2006

PrsA is a peptidyl‐prolyl isomerase (PPIase) from Bacillus subtilis belonging to the parvulin family of PPIases. It is a membrane bound lipoprotein at the membrane–wall interface, involved in folding of exported proteins. We present the NMR solution structure of the PPIase domain of PrsA, the first from a Gram‐positive bacterium. In addition we mapped out the active site with NMR titration experiments. A high degree of conservation with other members of the parvulin family was revealed in the structure and binding site. Interactions with substrate peptides were also characterized by mutated domains revealing that H122 is indispensable for overall correct folding.
The diverse involvement of heterogeneous nuclear ribonucleoprotein K in mitochondrial response to insulin
Authors: Dzwonek Artur , Mikula Michał , Ostrowski Jerzy
Published: February 2006

Heterogeneous nuclear ribonucleoprotein K (hnRNP K protein) is an RNA/DNA‐binding protein that acts in several compartments, including mitochondria. It integrates cellular signaling cascades with multiple processes of gene expression mechanisms. Our studies demonstrate that: (1) insulin activates the import of hnRNP K protein into mitochondria in vitro and in vivo; (2) overexpression of hnRNP K protein modulates insulin‐activated mitochondrial gene expression; and (3) insulin treatment stimulates binding of hnRNP K protein to mitochondrial DNA. Based on these and our previously reported results we conclude that hnRNP K protein may be a mediator of mitochondrial response to insulin.
The chitin synthase involved in marine bivalve mollusk shell formation contains a myosin domain
Authors: Weiss Ingrid M. , Schönitzer Veronika , Eichner Norbert , Sumper Manfred
Published: February 2006

Chitin is a key component in mollusk nacre formation. However, the enzyme complex responsible for chitin deposition in the mollusk shell remained unknown. We cloned and characterized the chitin synthase of the marine bivalve mollusk Atrina rigida. We present here the first chitin synthase sequence from invertebrates containing an unconventional myosin motor head domain. We further show that a homologous gene for chitin synthase is expressed in the shell forming tissue of larval Mytilus galloprovincialis even in early embryonic stages. The new data presented here are the first clear‐cut indication for a functional role of cytoskeletal forces in the precisely controlled mineral deposition process of mollusk shell biogenesis.
Highly efficient protein trans‐splicing by a naturally split DnaE intein from Nostoc punctiforme
Authors: Iwai Hideo , Züger Sara , Jin Jennifer , Tam Pui-Hang
Published: February 2006

Protein trans‐splicing by the naturally split intein of the gene dnaE from Nostoc punctiforme (Npu DnaE) was demonstrated here with non‐native exteins in Escherichia coli. Npu DnaE possesses robust trans‐splicing activity with an efficiency of >98%, which is superior to that of the DnaE intein from Synechocystis sp. strain PCC6803 (Ssp DnaE). Both the N‐ and C‐terminal parts of the split Npu DnaE intein can be substituted with the corresponding fragment of Ssp DnaE without loss of trans‐splicing activity. Protein splicing with the Npu DnaEN is also more tolerant of amino acid substitutions in the C‐terminal extein sequence.
Glycogen synthase kinase 3β together with 14‐3‐3 protein regulates diabetic cardiomyopathy: Effect of losartan and tempol
Authors: Gurusamy Narasimman , Watanabe Kenichi , Ma Meilei , Prakash Paras , Hirabayashi Kenichi , Zhang Shaosong , Muslin Anthony J. , Kodama Makoto , Aizawa Yoshifusa
Published: March 2006

Glycogen synthase kinase (GSK) 3β is a multifunctional protein that positively regulates myocardial apoptosis and negatively regulates hypertrophy. However, the role of GSK3β in the diabetic myocardium is largely unknown. We found that GSK3β became more active (less phosphorylated at serine 9) via decreased Akt phosphorylation, in parallel to c‐Jun NH2 terminal kinase activation, which correlated with increased activated caspase 3 and myocardial apoptosis 3 days after streptozotocin (STZ) injection in mice. However, 28 days after STZ injection, GSK3β became inactive, which correlated with the enhanced protein kinase C β2 and p38 mitogen activated protein kinase expression, nuclear translocation of nuclear factor of activated T cells c3, cardiac hypertrophy and fibrosis. All of the above parameters were exacerbated in dominant‐negative 14‐3‐3 transgenic mice. Our results suggest that GSK3β together with 14‐3‐3 protein plays essential roles in the signaling of diabetic cardiomyopathy, and treatment with either losartan or tempol prevents these changes.
Women Give Birth and Pizzas Are Delivered: Language and Western Childbirth Paradigms
Authors: Hunter Lauren P.
Published: March 2006

This article examines two differing health paradigms, their language, and their effect on the culture of Western childbirth practices. Specifically, the differences in perspectives and language between the dominant paradigm/culture (the biomedical model of curing) and the alternative paradigm/culture (a holistic model of caring) are explored. Examples of language from the medical, midwifery, and nursing literature that affect childbirth culture and the care of childbearing women and their families are examined. The use of language as a tool of power and its known and postulated effects on the childbirth experience, nursing care, midwifery practice, and holistic care are explored. The author argues for the use of a woman‐centered paradigm for childbirth experiences.
Congenital Dermatofibrosarcoma Protuberans of the Hand
Authors: Schvarcz Livia Warszawer
Published: March 2006

A case of congenital dermatofibrosarcoma protuberans is presented. It was treated by local radical surgical excision, the function of the hand remaining normal. Six months post operatively the child is in excellent health, and there are no signs of recurrence.
Diurnal temperature range over the United States: A satellite view
Authors: Sun Donglian , Pinker Rachel T. , Kafatos Menas
Published: March 2006

Diurnal temperature range (DTR) is an important climate change index. Information on this parameter comes primarily from sparse and unevenly distributed observations of shelter air temperature. In this study, five years of GOES‐8 based estimates of land surface temperature (LST) over the United States are used to evaluate DTR at high spatial resolution. The spatial and temporal patterns that emerged show a high degree of consistency with independent satellite estimates of the Normalized Difference Vegetation Index (NDVI). Specifically, the arid regions in the western and central U.S. have larger DTRs than the eastern United States or the northwest coast. When stratified by four major surface types, the western U. S. DTRs over these surface types are larger than over the eastern part. It is also observed that urban areas have the lowest DTRs especially over the polluted eastern U. S. The similarity of the DTR spatial and temporal patterns and variations of the independent satellite based vegetation index are encouraging and suggest that satellite based estimates of DTR carry a strong signal on surface conditions which are responsive to climate change.
Instantaneous geodetic positioning with 10–50 Hz GPS measurements: Noise characteristics and implications for monitoring networks
Authors: Genrich Joachim F. , Bock Yehuda
Published: March 2006

Recent earthquake recordings from high‐rate (1 Hz) continuous GPS stations in California indicate that even higher temporal resolution provided by modern GPS receivers is desirable. We measured seven baselines during time intervals devoid of detectable transient signals at sampling rates of 1–50 Hz with geodetic receivers from four manufacturers to investigate the noise characteristics of these data. Our tests over short distances (meters) to typical station spacing (tens of kilometers) of regional GPS networks show no loss of spatial resolution compared to 1‐Hz samples. Measurement noise is red with the typical ramp profile of log‐log spectra below about 0.5 Hz. Above this frequency, noise is essentially white. Low‐pass filtering of high‐rate positions achieves improved spatial resolution compared to decimated raw samples. Averaging 20‐Hz measurements to 2‐Hz samples on a 40‐km baseline, for example, yields about 0.5 mm horizontal and about 3–4 mm vertical accuracy at high frequencies. These estimates are a factor of 2–2.5 better than for 2‐Hz raw samples. The improvements in spatial resolution due to averaging at high frequencies are substantial and approach the theoretical “square‐root‐of‐n” expectation for independent samples. However, since noise spectral densities rise rapidly below about 0.5‐Hz, low‐pass filtering is only effective above this frequency. These results have important implications for the design of continuous GPS networks for crustal deformation and structural monitoring and for positioning and attitude determination of dynamic platforms.
The chromatin remodelling complex WSTF–SNF2h interacts with nuclear myosin 1 and has a role in RNA polymerase I transcription
Authors: Percipalle Piergiorgio , Fomproix Nathalie , Cavellán Erica , Voit Renate , Reimer Georg , Krüger Tim , Thyberg Johan , Scheer Ulrich , Grummt Ingrid , Östlund Farrants Ann‐Kristin
Published: March 2006

Nuclear actin and myosin 1 (NM1) are key regulators of gene transcription. Here, we show by biochemical fractionation of nuclear extracts, protein–protein interaction studies and chromatin immunoprecipitation assays that NM1 is part of a multiprotein complex that contains WICH, a chromatin remodelling complex containing WSTF (Williams syndrome transcription factor) and SNF2h. NM1, WSTF and SNF2h were found to be associated with RNA polymerase I (Pol I) and ribosomal RNA genes (rDNA). RNA interference‐mediated knockdown of NM1 and WSTF reduced pre‐rRNA synthesis in vivo, and antibodies to WSTF inhibited Pol I transcription on pre‐assembled chromatin templates but not on naked DNA. The results indicate that NM1 cooperates with WICH to facilitate transcription on chromatin.