bluuebunny/crossref_metadata_2025_split huggingface dataset:
Minimal Disseminated Disease in Childhood T-Cell Lymphoblastic Lymphoma: A Report From the Children's Oncology Group
Authors: Coustan-Smith Elaine , Sandlund John T. , Perkins Sherrie L. , Chen Helen , Chang Myron , Abromowitch Minnie , Campana Dario 
Published: June 2009

Purpose Disease dissemination to the bone marrow is detected at diagnosis in approximately 15% of children with T-cell lymphoblastic lymphoma (T-LL). It is unclear whether the remaining patients have submicroscopic systemic disease and, if so, what is the clinical significance of this finding. Patients and Methods Using a flow cytometric method that can detect one T-LL cell among 10,000 normal cells, we examined bone marrow and peripheral-blood samples collected from 99 children with T-LL at diagnosis, as well as blood samples collected from 42 patients during treatment. Results In 71 (71.7%) of the 99 marrow samples obtained at diagnosis, T-LL cells represented 0.01% to 31.6% (median, 0.22%) of mononuclear cells; 57 of the 71 T-LL–positive samples were from patients with stage II/III disease. Results of studies in bilateral marrow aspirates were highly concordant. Two-year event-free survival (EFS) was 68.1% ± 11.1% (SE) for patients with ≥ 1% T-LL cells in bone marrow versus 90.7% ± 4.4% for those with lower levels of marrow involvement (P = .031); EFS for patients with ≥ 5% lymphoblasts was 51.9% ± 18.0% (P = .009). T-LL cells were as prevalent in blood as in marrow; monitoring residual T-LL cells in blood during remission induction therapy identified patients with slower disease clearance. Conclusion More than two thirds of children with T-LL have disseminated disease at diagnosis, a proportion much higher than previously demonstrated. Measurements of disease dissemination at diagnosis might provide useful prognostic information, which can be further refined by monitoring response to therapy through blood testing.
First structural insights into the TpsB/Omp85 superfamily
Authors: Jacob-Dubuisson Françoise , Villeret Vincent , Clantin Bernard , Delattre Anne-Sophie , Saint Nathalie 
Published: June 2009

Abstract
Proteins of the TpsB/Omp85 superfamily are involved in protein transport across, or assembly into, the outer membrane of Gram-negative bacteria, and their distant eukaryotic relatives exert similar functions in chloroplasts and mitochondria. The X-ray structure of one TpsB transporter, FhaC, provides the bases to decipher the mechanisms of action of these proteins. With two POTRA domains in the periplasm, a transmembrane β barrel and a large loop harboring a functionally important motif, FhaC epitomizes the conserved features of the super-family.
Protein targeting by the signal recognition particle
Authors: Grudnik Przemyslaw , Bange Gert , Sinning Irmgard 
Published: June 2009

Abstract
Protein targeting by the signal recognition particle (SRP) is universally conserved and starts with the recognition of a signal sequence in the context of a translating ribosome. SRP54 and FtsY, two multidomain proteins with guanosine triphosphatase (GTPase) activity, are the central elements of the SRP system. They have to coordinate the presence of a signal sequence with the presence of a vacant translocation channel in the membrane. For coordination the two GTPases form a unique, nearly symmetric heterodimeric complex in which the activation of GTP hydrolysis plays a key role for membrane insertion of substrate proteins. Recent results are integrated in an updated perception of the order of events in SRP-mediated protein targeting.
Protein transport across the peroxisomal membrane
Authors: Girzalsky Wolfgang , Platta Harald W. , Erdmann Ralf 
Published: June 2009

Abstract
The maintenance of peroxisome function depends on the formation of the peroxisomal membrane and the subsequent import of both membrane and matrix proteins. Without exception, peroxisomal matrix proteins are nuclear encoded, synthesized on free ribosomes and subsequently imported post-translationally. In contrast to other translocation systems that transport unfolded polypeptide chains, the peroxisomal import apparatus can facilitate the transport of folded and oligomeric proteins across the peroxisomal membrane. The peroxisomal protein import is mediated by cycling receptors that shuttle between the cytosol and peroxisomal lumen and depends on ATP and ubiquitin. In this brief review, we will summarize our current knowledge on the import of soluble proteins into the peroxisomal matrix.
Catalytic properties of recombinant dipeptidyl carboxypeptidase from Escherichia coli: a comparative study with angiotensin I-converting enzyme
Authors: Cunha Carlos Eduardo L. , de Fátima Magliarelli Helena , Paschoalin Thaysa , Nchinda Aloysius T. , Lima Jackson C. , Juliano Maria A. , Paiva Paulo B. , Sturrock Edward D. , Travassos Luiz R. , Carmona Adriana K. 
Published: June 2009

Abstract
Dipeptidyl carboxypeptidase from Escherichia coli (EcDcp) is a zinc metallopeptidase with catalytic properties closely resembling those of angiotensin I-converting enzyme (ACE). However, EcDcp and ACE are classified in different enzyme families (M3 and M2, respectively) due to differences in their primary sequences. We cloned and expressed EcDcp and studied in detail the enzyme's S3 to S1′ substrate specificity using positional-scanning synthetic combinatorial (PS-SC) libraries of fluorescence resonance energy transfer (FRET) peptides. These peptides contain ortho-aminobenzoic acid (Abz) and 2,4-dinitrophenyl (Dnp) as donor/acceptor pair. In addition, using FRET substrates developed for ACE [Abz-FRK(Dnp)P-OH, Abz-SDK(Dnp)P-OH and Abz-LFK(Dnp)-OH] as well as natural ACE substrates (angiotensin I, bradykinin, and Ac-SDKP-OH), we show that EcDcp has catalytic properties very similar to human testis ACE. EcDcp inhibition studies were performed with the ACE inhibitors captopril (K
i=3 nm) and lisinopril (K
i=4.4 μm) and with two C-domain-selective ACE inhibitors, 5-S-5-benzamido-4-oxo-6-phenylhexanoyl-L-tryptophan (kAW; K
i=22.0 μm) and lisinopril-Trp (K
i=0.8 nm). Molecular modeling was used to provide the basis for the differences found in the inhibitors potency. The phylogenetic relationship of EcDcp and related enzymes belonging to the M3 and M2 families was also investigated and the results corroborate the distinct origins of EcDcp and ACE.
Mechanism of activation of Saccharomyces cerevisiae calcineurin by Mn2+
Authors: Ren Yan , Wang Zhi-Xin , Wei Qun 
Published: June 2009

Abstract

Saccharomyces cerevisiae calcineurin (CN) consists of a catalytic subunit CNA1 or CNA2 and a regulatory subunit CNB1. The kinetics of activation of yeast CN holoenzymes and their catalytic domains by Mn2+ were investigated. We report that the in vitro phosphatase reaction activated by Mn2+ typically has a pronounced initial lag phase caused by slow conformational rearrangement of the holoenzyme-Mn2+. A similar lag phase was detected using just the catalytic domain of yeast CN, indicating that the slowness of Mn2+-induced conformational change of CN results from a rearrangement within the catalytic domain. The Mn2+-activation of CN was reversible. The dissociation constant of the CN heterodimer containing the CNA2 subunit in the presence of Mn2+ was 3-fold higher than that of CN containing the CNA1 subunit and that of the catalytic domains of CNA1 and CNA2, pointing to differences between the residues surrounding the Mn2+-binding sites of CNA1 and CNA2.
The Rate-Limiting Mechanism for the Heterogeneous Burning of Cylindrical Iron Rods
Authors: Ward Nicholas R. , Steinberg Theodore A. 
Published: June 2009

Abstract
This paper presents the findings of an investigation into the rate-limiting mechanism for the heterogeneous burning in oxygen under normal gravity and microgravity of cylindrical iron rods. The original objective of the work was to determine why the observed melting rate for the burning of 3.2-mm-diameter iron rods is significantly higher in microgravity than in normal gravity. This work, however, also provided fundamental insight into the rate-limiting mechanism for heterogeneous burning. The paper includes a summary of normal-gravity and microgravity experimental results, heat transfer analysis, and post-test microanalysis of quenched samples. These results are then used to show that heat transfer across the solid/liquid interface is the rate-limiting mechanism for melting and burning, limited by the interfacial surface area between the molten drop and solid rod. In normal gravity, the work improves the understanding of trends reported during standard flammability testing for metallic materials, such as variations in melting rates between test specimens with the same cross-sectional area but different cross-sectional shape. The work also provides insight into the effects of configuration and orientation, leading to an improved application of standard test results in the design of oxygen system components. For microgravity applications, the work enables the development of improved methods for lower cost metallic material flammability testing programs. In these ways, the work provides fundamental insight into the heterogeneous burning process and contributes to improved fire safety for oxygen systems in applications involving both normal-gravity and microgravity environments.
Mitochondrial Superoxide Radicals Differentially Affect Muscle Activity and Neural Function
Authors: Godenschwege Tanja , Forde Renée , Davis Claudette P , Paul Anirban , Beckwith Kristopher , Duttaroy Atanu 
Published: June 2009

AbstractCellular superoxide radicals (O2−) are mostly generated during mitochondrial oxygen metabolism. O2− serves as the raw material for many reactive oxygen species (ROS) members like H2O2 and OH.− radicals following its catalysis by superoxide dismutase (SOD) enzymes and also by autocatalysis (autodismutation) reactions. Mitochondrial ROS generation could have serious implications on degenerative diseases. In model systems overproduction of mitochondrial O2− resulting from the loss of SOD2 function leads to movement disorders and drastic reduction in life span in vertebrates and invertebrates alike. With the help of a mitochondrial SOD2 loss-of-function mutant, Sod2n283, we measured the sensitivity of muscles and neurons to ROS attack. Neural outputs from flight motor neurons and sensory neurons were unchanged in Sod2n283 and the entire neural circuitry between the giant fiber (GF) and the dorsal longitudinal muscles (DLM) showed no overt defect due to elevated ROS. Such insensitivity of neurons to mitochondrial superoxides was further established through neuronal expression of SOD2, which failed to improve survival or locomotive ability of Sod2n283. On the other hand, ultrastructural analysis of Sod2n283 muscles revealed fewer mitochondria and reduced muscle ATP production. By targeting the SOD2 expression to the muscle we demonstrate that the early mortality phenotype of Sod2n283 can be ameliorated along with signs of improved mobility. In summary, muscles appear to be more sensitive to superoxide attack relative to the neurons and such overt phenotypes observed in SOD2-deficient animals can be directly attributed to the muscle.
Frequency Spectrum Neutrality Tests: One for All and All for One
Authors: Achaz Guillaume 
Published: June 2009

AbstractNeutrality tests based on the frequency spectrum (e.g., Tajima's D or Fu and Li's F) are commonly used by population geneticists as routine tests to assess the goodness-of-fit of the standard neutral model on their data sets. Here, I show that these neutrality tests are specific instances of a general model that encompasses them all. I illustrate how this general framework can be taken advantage of to devise new more powerful tests that better detect deviations from the standard model. Finally, I exemplify the usefulness of the framework on SNP data by showing how it supports the selection hypothesis in the lactase human gene by overcoming the ascertainment bias. The framework presented here paves the way for constructing novel tests optimized for specific violations of the standard model that ultimately will help to unravel scenarios of evolution.
Mosaic Genetic Screen for Suppressors of the de2f1 Mutant Phenotype in Drosophila
Authors: Ambrus Aaron M , Rasheva Vanya I , Nicolay Brandon N , Frolov Maxim V 
Published: June 2009

Abstract
The growth suppressive function of the retinoblastoma (pRB) tumor suppressor family is largely attributed to its ability to negatively regulate the family of E2F transcriptional factors and, as a result, to repress E2F-dependent transcription. Deregulation of the pRB pathway is thought to be an obligatory event in most types of cancers. The large number of mammalian E2F proteins is one of the major obstacles that complicate their genetic analysis. In Drosophila, the E2F family consists of only two members. They are classified as an activator (dE2F1) and a repressor (dE2F2). It has been previously shown that proliferation of de2f1 mutant cells is severely reduced due to unchecked activity of the repressor dE2F2 in these cells. We report here a mosaic screen utilizing the de2f1 mutant phenotype to identify suppressors that overcome the dE2F2/RBF-dependent proliferation block. We have isolated l(3)mbt and B52, which are known to be required for dE2F2 function, as well as genes that were not previously linked to the E2F/pRB pathway such as Doa, gfzf, and CG31133. Inactivation of gfzf, Doa, or CG31133 does not relieve repression by dE2F2. We have shown that gfzf and CG31133 potentiate E2F-dependent activation and synergize with inactivation of RBF, suggesting that they may act in parallel to dE2F. Thus, our results demonstrate the efficacy of the described screening strategy for studying regulation of the dE2F/RBF pathway in vivo.
Fork Stalling and Template Switching As a Mechanism for Polyalanine Tract Expansion Affecting the DYC Mutant of HOXD13, a New Murine Model of Synpolydactyly
Authors: Cocquempot Olivier , Brault Véronique , Babinet Charles , Herault Yann 
Published: June 2009

Abstract
Polyalanine expansion diseases are proposed to result from unequal crossover of sister chromatids that increases the number of repeats. In this report we suggest an alternative mechanism we put forward while we investigated a new spontaneous mutant that we named “Dyc” for “Digit in Y and Carpe” phenotype. Phenotypic analysis revealed an abnormal limb patterning similar to that of the human inherited congenital disease synpolydactyly (SPD) and to the mouse mutant model Spdh. Both human SPD and mouse Spdh mutations affect the Hoxd13 gene within a 15-residue polyalanine-encoding repeat in the first exon of the gene, leading to a dominant negative HOXD13. Genetic analysis of the Dyc mutant revealed a trinucleotide expansion in the polyalanine-encoding region of the Hoxd13 gene resulting in a 7-alanine expansion. However, unlike the Spdh mutation, this expansion cannot result from a simple duplication of a short segment. Instead, we propose the fork stalling and template switching (FosTeS) described for generation of nonrecurrent genomic rearrangements as a possible mechanism for the Dyc polyalanine extension, as well as for other polyalanine expansions described in the literature and that could not be explained by unequal crossing over.
Percutaneous transhepatic metallic stent placement for the treatment of post-transplantation portal vein stenosis
Authors: Doros Attila , Nemes Balázs , Fehérvári Imre , Görög Dénes , Gerlei Zsuzsa , Németh Andrea , Hartmann Erika , Deák Pál , Fazakas János , Tóth Szabolcs , Kóbori László 
Published: June 2009

A májátültetés rutinszerűen, jó eredménnyel alkalmazott eljárás a végstádiumú májelégtelenség kezelésében. A transzplantáció után kialakuló éreredetű szövődmények közül a legritkább a májkapuér-szűkület. Ennek intervenciós radiológiai megoldását mutatjuk be három eset kapcsán.
Célkitűzés:
A portalis véna szűkületének sebészi kezelése kockázatos, különösen a korai poszttranszplantációs időszakban. Az intervenciós radiológiai beavatkozások általában kis megterheléssel, kevés szövődménnyel alkalmazhatók. Célunk bemutatni a percutan transhepaticus fémstentbehelyezés biztonságosságát, eredményességét.
Módszer:
Háromszázkilencvenhat májátültetés után összesen három esetben (0,07%) észleltük az anasztomózis korai beszűkülését. Ezekben az esetekben ultrahangvezérelt percutan transhepaticus venaportae-punkciót végeztünk vékony tűvel, majd koaxiális tágítókatétert alkalmazva stent behelyezésére alkalmas introducert vezettünk át a májszöveten. A szűk anasztomózisba nitinol (2 esetben), illetve acél (1 esetben) öntáguló fémstentet helyeztünk. Az introducer eltávolítása közben a parenchymás járatot egy alkalommal embolizációs spirállal, egyszer pedig sebészi szivacsrészecskékkel embolizáltuk. A harmadik esetben embolizáció nem történt.
Eredmények:
A kezelés mindhárom esetben sikeres volt. A beavatkozással kapcsolatban szövődményt nem észleltünk. Két esetben az indikációt jelentő hasi folyadék mennyiségének csökkenése, egy esetben a nyelőcső-varicositas visszafejlődése jelentette a klinikai kép javulását. Mindhárom esetben ultrahangos és komputeres rétegvizsgálat is igazolta a szűkületek sikeres kezelését. Két beteg a beavatkozás után 10, illetve 39 hónappal jól van. Egy beteget a beavatkozás után egy hónappal többszervi elégtelenség miatt elvesztettünk.
Következtetés:
A venaportae-anasztomózis szűkületeinek kezelésére a percutan transhepaticus kanülálás és öntáguló fémstent behelyezése biztonságosan és sikeresen alkalmazható.
Impact of lipid lowering therapy on liver function
Authors: Paragh György , Fülöp Péter 
Published: June 2009

A cardiovascularis megbetegedések hazánkban is vezetik a morbiditási és mortalitási statisztikákat. Ezen betegségek kialakulásában jelentős szerepet játszik a hyperlipidaemia. A korábbi nagy prospektív multicentrikus tanulmányok azt igazolták, hogy a hatékony lipidcsökkentő kezelés jelentős mértékű cardiovascularis halálozás-összhalálozás csökkenést eredményez. Ez a hatás függ az LDL-C-csökkentés mértékétől, amely gyakran csak a nagy dózisban alkalmazott statinkészítményekkel éri el a kívánt szintet. A nagy dózisban alkalmazott statinok a betegek körülbelül 3%-ában hozhatnak létre májkárosító hatást. A szerzők jelen munkájukban röviden ismertetik a lipidcsökkentő gyógyszerek hatásait, azokat a mechanizmusokat, amelyek a szerek potenciális májkárosító hatásának hátterében állhatnak. Felhívják a figyelmet arra, hogy a korábbi gyakorlattól eltérően, emelkedett transzaminázszintek esetén, sőt, bizonyos májbetegségekben is biztonságosan alkalmazhatóak a lipidcsökkentő készítmények. Természetesen akkor, ha megfelelő dózisban vagy kombinációban alkalmazzuk a gyógyszereket, és figyelemmel vagyunk azon tényezőkre, amelyek fokozhatják a nem kívánt mellékhatásokat. Ezen szempontok betartása mellett magas cardiovascularis rizikójú, egyébként krónikus májbetegségben szenvedők számára is biztosíthatjuk a lipidcsökkentők nyújtotta kedvező hatásokat anélkül, hogy fokoznánk a máj károsodását.
Ketoacidosis at Diabetes Onset Is Still Frequent in Children and Adolescents
Authors: Neu Andreas , Hofer Sabine E. , Karges Beate , Oeverink Rudolf , Rosenbauer Joachim , Holl Reinhard W. ,   for the DPV Initiative and the German BMBF Competency Network for Diabetes Mellitus
Published: June 2009

OBJECTIVE
We aimed at analyzing the frequency, clinical characteristics, and trends associated with the occurrence of diabetic ketoacidosis (DKA) at the onset of type 1 diabetes on the basis of long-term follow-up data.

RESEARCH DESIGN AND METHODS
A total of 106 pediatric diabetes centers in Germany and Austria participated in this study. Data from14,664 patients with type 1 diabetes collected between 1995 and 2007 were suitable for evaluation. DKA was defined and classified according to the International Society for Pediatric and Adolescent Diabetes consensus guidelines.

RESULTS
DKA was observed in 21.1% of patients. The frequency of DKA, including the severe form, remained unchanged throughout the 13-year observation period. The frequency of DKA was particularly striking among children &lt;5 years of age (26.5%).

CONCLUSIONS
Ketoacidosis occurring at diabetes onset continues to be a difficult problem. Our data show no significant change in the frequency and magnitude of DKA over the last 13 years.
Dissociative excitation of HD
+, D
2+, and DT
+ by electron impact
Authors: Duca Mariana , Fifirig Magda 
Published: June 2009

Abstract
In the framework of the Multi-Channel Quantum Defect Theory (MQDT), a theoretical study of the dissociative excitation is presented. Numerical results for the dissociative excitation cross sections of HD
+, D
2+, and DT
+ with electrons of energy between 2 and 12 eV are reported. The contribution of the vibrational continua of the two lowest electronic states as explicit ionization channels has been considered. Within a quasi-diabatic representation of the molecular electronic states, the Born expansion of second order is done in the K-matrix evaluation.
Plasma treatment studies of MIS devices
Authors: Basa Deepak 
Published: June 2009

Abstract
Silicon nitride films have emerged as the possible future dielectrics for ultra large scale integration (ULSI). Because the interface state density of silicon nitride/silicon interface in metal insulator semiconductor (MIS) configuration is more than an order of magnitude larger than that of silicon dioxide/silicon interface, plasma treatment studies on silicon nitride films have been undertaken for the possible improvement. Accordingly, silicon nitride films of various composition have been prepared by plasma enhanced chemical vapor deposition (PECVD) system using silane(SiH4) and ammonia(NH3) with nitrogen(N2) as the diluent and MIS devices have been fabricated with as well as without plasma treated silicon nitride as the insulator. A considerable improvement in the silicon nitride/silicon interface is observed on ammonia plasma treatment while nitrous oxide(N2O) plasma treatment studies have resulted in the establishment of a novel plasma oxidation process.
Brain monoamine oxidase A in hyperammonemia is regulated by NMDA receptors
Authors: Kosenko Elena , Kaminsky Yury 
Published: June 2009

AbstractMitochondrial enzyme monoamine oxidase A (MAO-A) generates hydrogen peroxide (H2O2) and is up-regulated by Ca2+ and presumably by ammonia. We hypothesized that MAO-A may be under the control of NMDA receptors in hyperammonemia. In this work, the in vivo effects of single dosing with ammonia and NMDA receptor antagonist MK-801 and the in vitro effect of Ca2+ on MAO-A activity in isolated rat brain mitochondria were studied employing enzymatic procedure. Intraperitoneal injection of rats with ammonia led to an increase in MAO-A activity in mitochondria indicating excessive H2O2 generation. Calcium added to isolated mitochondria stimulated MAO-A activity by as much as 84%. MK-801 prevented the in vivo effect of ammonia, implying that MAO-A activation in hyperammonemia is mediated by NMDA receptors. These data support the conclusion that brain mitochondrial MAO-A is regulated by the function of NMDA receptors. The enzyme can contribute to the oxidative stress associated with hyperammonemic conditions such as encephalopathy and Alzheimer’s disease. The attenuation of the oxidative stress highlights MAO-A inactivation and NMDA receptor antagonists as sources of novel avenues in the treatment of mental disorders.