bluuebunny/crossref_metadata_2025 huggingface dataset:
Telomere length changes after umbilical cord blood transplant
Authors: Pipes Brian L. , Tsang Tom , Peng Shu‐Xin , Fiederlein Roger , Graham Michael , Harris David T.
Published: May 2006

BACKGROUND:  The establishment of donor‐derived hematopoiesis in the recipients of hematopoietic stem cell (HSC) transplants involves extensive proliferation and differentiation of HSCs. Data from long‐term survivors of HSC transplants suggest that these transplanted HSCs may experience a debilitating replicative senescence. A significant posttransplant shortening of peripheral blood mononuclear cell (PBMNC) telomeres has been observed in both marrow transplant and peripheral blood progenitor cell transplant recipients. Similar studies have not been performed for umbilical cord blood (UCB) HSC transplants, which might be expected to exhibit increased posttransplant replicative potential due to their inherently greater telomere length.

STUDY DESIGN AND METHODS:  Blood was obtained from donor‐recipient pairs of allogeneic PBHSC transplant and UCB HSC transplant, both before transplant and at follow‐up treatments (minimum 1 year after transplant) after engraftment. Telomere restriction fragment length (TRFL) analysis was performed on the blood samples. The mean TRFL and posttransplant changes in the mean TRFL were analyzed.

RESULTS:  Measurements of telomere lengths in the PBMNCs of transplant patients revealed a significant net decrease in telomere length in all transplant recipients compared with their respective donors. Our results also revealed that the PBMNCs of umbilical cord stem cell transplant patients retain a significantly longer posttransplant telomere length.

CONCLUSION:  The significantly longer telomeres observed in the allogeneic UCB HSC transplant recipients compared to the allogeneic PBHSC transplant recipients in our study may be indicative of a replicative advantage inherent in the use of UCB HSC for transplant.
ceRA: an RH allele variant producing a new rare blood
Authors: Noizat‐Pirenne France , Tournamille Christophe , Gallon Philippe , Juszczak Geneviève , Rouger Philippe , Ansart‐Pirenne Hélène
Published: May 2006

BACKGROUND: Antibodies against RH antigens are clinically significant. Some rare RH phenotypes, for example, RH:−46 (RN), RH:−18 (Hrs–), RH:−34 (Hrb–), and homozygous partial RH5 (e), are found exclusively in black persons of African descent. Quantitative and qualitative RHCE variants require characterization because the presence of these alleles can lead to difficulties when transfusion is needed.

STUDY DESIGN AND METHODS: Here a new RH5 variant (ceRA) in an Indian patient is described and investigated by serology (agglutination and flow cytometry analysis) and molecular and immunoblot analysis.

RESULTS: Red blood cells (RBCs), typed as RH:‐1,‐2, ‐3,4,w5, expressed a very depressed RH5 antigen, with no expression of the RH19 (h) high‐frequency antigen. Molecular analysis revealed a new Rhce allele (homozygous state), hereafter called ceRA. This new allele exhibited a G48C mutation in exon 1 and a G538C mutation in exon 4, predicting, respectively, a Trp16Cys substitution and a Gly180Arg substitution, both in the intramembranous domain of the Rhce polypeptide. Immunoblot analysis showed that this defect results in a dramatic loss of the amount of RHCE polypeptides within the RBC membrane. No reactivity was evidenced with most of anti‐RH5, in agglutination as well as in flow cytometry techniques.

CONCLUSION: Both serologic results and localization of the Gly180Arg substitution emphasize the risk of anti‐RH5 alloimmunization for patients expressing this new allele ceRA at the homozygous state. These results point out the importance of obtaining blood donations for the frozen rare blood bank in case future transfusion is needed.
Organizing for Homeland Security after Katrina: Is Adaptive Management What’s Missing?
Authors: Wise Charles R.
Published: May 2006

This article analyzes performance and organizational issues revealed by the governmental response to Hurricane Katrina. It reviews and analyzes the organizational changes made in the federal government to address homeland security and presents several proposals for reorganization suggested by policy makers in the aftermath of Katrina. A management approach rooted in adaptive management is presented for use in the ongoing process of organizing for homeland security.
The Varieties of CitiStat
Authors: Abramson Mark A. , Behn Robert D.
Published: May 2006

Baltimore’s performance strategy, CitiStat, has been adapted by a number of cities in the United States. None of these adaptations is identical to the original or to any of the others. In fact, this analysis identifies five important features of CitiStat along with 20 sub‐traits of these features that can be used to specify the important differences among these various CitiStats.
Efforts to Improve Public Policy and Programs through Data Practice: Experiences in 15 Distressed American Cities
Authors: Weitzman Beth C. , Silver Diana , Brazill Caitlyn
Published: May 2006

Philanthropies and government agencies interested in children’s issues are encouraging localities to improve the process of collecting, linking, and sharing microdata and aggregated summary statistics. An implicit assumption of these efforts is that outcomes will improve as a result of the new approaches. However, there has been little systematic study of these efforts. In this article, we examine efforts to improve data practice in 15 distressed American cities. Interviews conducted in these cities revealed variation in the types of information collected, dissemination, and intended audiences. We identify significant challenges to these efforts, including adequate resources, turf battles, technical problems, access to information sources, inconsistent leadership, and absence of political will. We find that little is known about the impact of these initiatives on decision making. Assumptions that improved data practice will lead to improved policy making have not yet been realized in these cities.
The Impact of Nonprofit Collaboration in Early Child Care and Education on Management and Program Outcomes
Authors: Selden Sally Coleman , Sowa Jessica E. , Sandfort Jodi
Published: May 2006

The use of interorganizational relationships such as collaboration, partnerships, and alliances between public, private, and nonprofit organizations for the delivery of human services has increased. This article contributes to the growing body of knowledge on collaboration by exploring one kind of interorganizational relationship—interagency collaboration—in the field of early care and education. It examines variations within interagency collaborations and their impact on management and program outcomes. The findings show that interagency collaboration has a clear impact on management, program, and client outcomes: Specifically, the intensity of the collaborative relationship has a positive and statistically significant impact on staff compensation, staff turnover, and school readiness.
Democratic Governance: Systems and Radical Perspectives
Authors: Bevir Mark
Published: May 2006

How might we think about democratic governance? This paper distinguishes between system governance and radical democracy. System governance borrows the language of radical democracy while missing its spirit. It advocates increased participation through networks because new institutionalists suggest networks are an efficient means of service delivery. It advocates increased consultation to build consensus because communitarians suggest consensus is needed for effective political institutions. System governance is, then, a top‐down discourse based on the alleged expertise of social scientists. Radical democrats concentrate instead on the self‐government of citizens. Instead of the incorporation of established groups in networks, they promote a pluralism within which aspects of governance are handed over to associations in civil society. And instead of consultation prior to decision making, they promote a dialogue in which citizens play an active role in making and implementing public policy.
Citizen Participation in Budgeting Theory
Authors: Ebdon Carol , Franklin Aimee L
Published: May 2006

Citizen participation in government budgeting processes is a topic that has received attention for many decades. Despite prescriptive exhortations to cities, research in this area has significant limitations. We identify four elements that are believed to influence the participation process. The variables within each element have received attention in the empirical literature, but no systematic effort has been made to uncover interaction effects and extend theory to make it more robust. We consider the weaknesses of our knowledge, suggest an impact model of citizen participation in budgeting, and identify hypotheses that may be tested in future research.
Controlling Internal Controls
Authors: Roberts Nancy , Candreva Philip J.
Published: May 2006

Two recent examinations of management practices in three federal departments provide contemporary evidence of the need to incorporate procedures like those of the Sarbanes‐Oxley Act in the public sector. Although each department established what appeared to be well‐designed internal controls, all lacked sufficient monitoring and assessment of the efficacy of those controls. By requiring senior management to attest to the strength of their control mechanisms, as required by the newly revised OMB Circular A‐123, the quality of this monitoring should improve. Findings from a recent study of private‐sector implementation of these reforms are described, along with suggestions for public administration research and practice at all levels of government.
Cavotricuspid Isthmus Conduction is Dependent on Underlying Anatomic Bundle Architecture: Observations Using a Maximum Voltage‐Guided Ablation Technique
Authors: REDFEARN DAMIAN P. , SKANES ALLAN C. , GULA LORNE J. , KRAHN ANDREW D. , YEE RAYMOND , KLEIN GEORGE J.
Published: May 2006

Objectives: We hypothesized an ablation strategy directly targeting muscle bundles might demonstrate functionally distinct “routes” of conduction, potentially shortening ablation times.

Background: Pathological study demonstrated that the cavotricuspid isthmus is composed of distinct anatomically defined bundles, many with intervening gaps of connective tissue.

Methods: A line was mapped in the “6 o'clock” region and bipolar electrogram amplitude measured during pullback. Zones of peak voltage were ablated first regardless of position. RF was delivered using either a 5‐mm externally irrigated catheter, or an 8‐mm nonirrigated catheter. The zone of largest remaining voltage was then sequentially targeted until conduction.

Results: Eighteen patients were recruited and followed for 7.9 ± 1.9 months block occurred (mean age 64 ± 11.6 years, male:female ratio 14:4). Bi‐directional block was achieved in all patients with recurrence of atrial flutter in 1 patient. Mean total RF times was 4.7 ± 2.8 minutes with a mean of 6.1 ± 3.3 applications, procedure time was 127.3 ± 37.7 minutes, and fluoroscopy time was 25.5 ± 12.0 minutes. Two patterns of block were observed in the study group. Pattern A described no change in conduction times until block, observed in 6 (33%); pattern B described a stepwise block with discrete “jumps,” observed in 12 (67%).

Conclusions: An ablation strategy targeting high‐voltage isthmus electrograms obviates the need for a complete anatomic line. This finding together with discrete “jumps” during ablation is consistent with the concept of conduction over discrete bundles rather than a diffuse sheet of muscle.
Analysis of Location and Pattern of Target Vessel Failure in Chronic Total Occlusions after Stent Implantation and Its Potential for the Efficient Use of Drug‐Eluting Stents
Authors: BETGE STEFAN , KRACK ANDREAS , FIGULLA HANS R. , WERNER GERALD S.
Published: May 2006

Objectives: The recanalization of chronic total occlusions (CTOs) is a complex procedure with high rates of target vessel failure (TVF), i.e., restenosis or reocclusion. Little is known about the localization of lesion recurrence, and whether extensive stenting should be performed. In this prospective analysis, the area at high risk for restenoses after recanalization of CTO was localized.

Methods: Angiograms of 97 consecutive patients and control angiograms after a mean period of 5 ± 1.3 months were analyzed for location and length of the CTO and the sites of recurrences.

Results: In total, 158 stents were implanted (1.6 ± 0.9 per lesion). Restenoses occurred in 39% and reocclusions in 17% of the patients. Patients with a TVF had a longer CTO than patients without TVF (17.9 ± 10.2 vs 13.9 ± 8.6 mm; P = 0.023). The TVF rate increased with the number of implanted stents. The stent diameter was smaller in lesions with subsequent reocclusions than in restenotic and nonrestenotic lesions (2.8 ± 0.5 vs 3.0 ± 0.4 and 3.2 ± 0.4 mm resp.; P = 0.007). Analyzing the localization of the 38 restenoses, we only found 45% restricted to the area of the former CTO, while 82% were located in the area of the former CTO plus 10 mm in proximal and distal direction.

Conclusions: Stents should not only cover the site of the CTO, but should enclose the high‐risk area of recurrence within 10 mm proximal and distal of the former CTO. This may guide the rational use of drug‐eluting stents.
Factors That Influence Radiation Dose in Percutaneous Coronary Intervention
Authors: TSAPAKI VIRGINIA , MAGGINAS ATHANASSIOS , VANO ELISEO , KOTTOU SOPHIA , PAPADAKIS EMMANOUIL , DAFNOMILI PARASKEVI , KYROZI ELENA , KOLLAROS NIKOLAOS , NEOFOTISTOU VASSILIKI , COKKINOS DENNIS
Published: May 2006

Aim: To explore the factors that may influence the radiation dose imparted to the patient in PCI, and investigate whether the use of the latest digital X‐ray system based on FP detector technology can have an impact on dose.

Materials and Method: Demographic and clinical data such as number of lesions treated, number of stents placed, grade of tortuosity, and stage of occlusion, as well as use of double wire and double balloon technique, ostial stenting or bifurcation stenting, and presence of major complications were recorded, together with radiation parameters.

Results: The factors that increased patient radiation dose were (1) patient gender, as men exhibited higher doses than women; (2) complex lesion; (3) increasing number of stents; (4) position of stent; (5) grade of tortuosity; and (6) stage of occlusion. The FP digital system appeared to be settled in a lower‐dose rate for fluoroscopy (a factor of 6) and higher for dose per frame in cine (a factor of 3) in comparison with the image intensifier (II) system. There was a marked reduction of DAP when the FP technology was introduced.

Conclusion: More extensive studies should be performed in the future so as to further investigate the influence of the FP detector in IC.
Proceedings of the TCT: Balloon Aortic Valvuloplasty Appropriate for Elderly Valve Patients
Authors: FELDMAN TED
Published: May 2006

Balloon aortic valvuloplasty (BAV) has been a highly successful therapy for children and young adults with aortic valve stenosis, resulting in both symptomatic improvement and durable increases in the aortic valve area.
Despite enthusiasm for BAV in older adult patients with aortic valve stenosis in the mid‐1980s, the therapy has had disappointing medium‐ and long‐term outcomes. Survival of patients with aortic valve stenosis does not increase with BAV, and restenosis occurs in the vast majority of patients within 6–24 months after therapy. Despite these limitations, most patients are symptomatically improved for a year or more. BAV remains an effective palliative therapy for selected patients.
Fabrication of Cf/SiC Composites by Vapor Silicon Infiltration
Authors: Zhou Qing , Dong Shaoming , Zhang Xiangyu , Ding Yusheng , Jiang Dongliang
Published: May 2006

Carbon fiber reinforced silicon carbide matrix composites were fabricated by the vapor silicon infiltration process. The density and the open porosity of the composite infiltrated at 1973 K were 2.25 g/cm3 and ∼6%, respectively. The flexural strength of the composite at ambient conditions was 300 MPa. When the infiltration temperature decreased, the density and flexural strength of the composite also decreased. However, the resulting composite materials exhibited non‐brittle fracture behavior.
Continuous Sol–Gel Coating of Ceramic Multifilaments: Evaluation of Fiber Bridging by Three‐Point Bending Test
Authors: Krüger Reinhard , Bockmeyer Matthias J. , Dutschke Anke , Löbmann Peer C.
Published: May 2006

Nextel™ 610 multifilaments were continuously coated with aqueous sols of yttria‐stabilized zirconia (8YSZ). For the transformation of the sol–gel precursor to a crystalline oxide coating detailed microstructural characterization is given. The main subject of the study was the bridging of fibers by interphase material, a general phenomenon of sol–gel coatings. A three‐point bending test is proposed as a semi‐quantitative method to determine the characteristic stiffening of bridged fiber bundles. This method is successfully used to evaluate the influence of sol concentration on fiber bridging and to prove the benefit of additional surfactants to aqueous sols. Differences in film formation on the individual fiber surfaces leading to homogeneous or inhomogeneous film thickness and variation in degree of fiber surface coverage are explained with a three‐fiber model. Based on model and experiment it is shown that even surface coverage and homogeneous film thickness can better be accomplished by multiple coatings from low concentrated sols than by single coatings from high concentrated sols. Finally, the three‐point bending test is used to qualitatively investigate the mechanical properties of the material bridges which can be correlated with results from structural investigations.
Controlled Elemental Depth Profile in Sol–Gel‐Derived PZT Films
Authors: Etin Aleksey , Shter Gennady E. , Baltianski Sioma , Grader Gideon S. , Reisner George M.
Published: May 2006

Elemental depth profiles of PZT films prepared by two sol–gel formulations, differing in the zirconium precursor stabilization, were investigated by SIMS analysis. Early decomposition of the zirconium precursor yielded opposing gradients of zirconium and titanium, while simultaneous late decomposition of zirconium and titanium precursors provided profile uniformity. The gradients formed during initial crystallization are irreversible. Both types of films showed excellent hysteresis; however, uniform films exhibited a much higher dielectric constant, indicating superior piezoelectric properties. Non‐uniform films displayed a complex CV pattern, consistent with an inhomogeneous structure. Finally, thermal decomposition of the individual metal precursors is crucial for controlling film uniformity.
Microstructure and Properties of Spark Plasma‐Sintered ZrO2–ZrB2 Nanoceramic Composites
Authors: Basu Bikramjit , Venkateswaran T. , Kim Doh‐Yeon
Published: May 2006

In a recent work,1 we have reported the optimization of the spark plasma sintering (SPS) parameters to obtain dense nanostructured 3Y‐TZP ceramics. Following this, the present work attempts to answer some specific issues: (a) whether ZrO2‐based composites with ZrB2 reinforcements can be densified under the optimal SPS conditions for TZP matrix densification (b) whether improved hardness can be obtained in the composites, when 30 vol% ZrB2 is incorporated and (c) whether the toughness can be tailored by varying the ZrO2–matrix stabilization as well as retaining finer ZrO2 grains. In the present contribution, the SPS experiments are carried out at 1200°C for 5 min under vacuum at a heating rate of 600 K/min. The SPS processing route enables retaining of the finer t‐ZrO2 grains (100–300 nm) and the ZrO2–ZrB2 composite developed exhibits optimum hardness up to 14 GPa. Careful analysis of the indentation data provides a range of toughness values in the composites (up to 11 MPa·m1/2), based on Y2O3 stabilization in the ZrO2 matrix. The influence of varying yttria content, t‐ZrO2 transformability, and microstructure on the properties obtained is discussed. In addition to active contribution from the transformation‐toughening mechanism, crack deflection by hard second phase brings about appreciable increment in the toughness of the nanocomposites.
Experimental Investigation of Ultrasonic Machining of an Alumina‐Based Ceramic Composite
Authors: Kumar Vinod , Khamba J. S.
Published: May 2006

The aim of this article is to present the ultrasonic machining of an alumina‐based engineering ceramic composite. The machining mechanism and the behavior of certain tool material and work material combinations with respect to penetration rate and tool‐wear rate under the influence of different parameters in ultrasonic machining are discussed in this paper. The shocking movement and cutting mechanics of the abrasive particle under the tip of the vibrating tool have been observed using high‐speed photographic equipment. The machined surface has been analyzed by using a scanning electron microscope. Surface roughness values were measured and plotted at entry and at exit of the holes for different types and sizes of holes using the surface roughness‐measuring instrument “Perthometer.”
Fabrication of a Porous Bioactive Glass–Ceramic Using Room‐Temperature Freeze Casting
Authors: Song Ju‐Ha , Koh Young‐Hag , Kim Hyoun‐Ee , Li Long‐Hao , Bahn Hyo‐Jin
Published: May 2006

The room‐temperature freeze‐casting method was used to fabricate porous bioactive glass–ceramics. In this method, a glass/camphene slurry prepared at 60°C was cast into a mold at 20°C, resulting in the production of a rigid green body that was comprised of three‐dimensional dendritic camphene networks surrounded by highly concentrated glass powder walls. After the sublimation of camphene, the samples were sintered for 3 h at elevated temperatures ranging from 700° to 1100°C. As the sintering temperature was increased to 1000°C, the densification of the glass–ceramic wall was remarkably enhanced, while its highly porous structure was preserved. The sample sintered at 1000°C showed a high porosity of 53% and pore channels with a size of several tens of micrometers, as well as dense glass–ceramic walls. In addition, the fabricated samples effectively induced the deposition of apatite on their surfaces when immersed in simulated body fluid, implying that they are very bioactive.
Particle Redistribution During Dendritic Solidification of Particle Suspensions
Authors: Shanti Noah O. , Araki Kiyoshi , Halloran John W.
Published: May 2006

Solidification of the liquid medium in ceramic suspensions containing less than a critical volume fraction powder leads to the formation of particle‐free dendrites of the frozen medium. These particle‐free dendrites create, after sublimation of the frozen vehicle, large dendrite pores. We define the conditions under which particle‐free dendrites form, and relate the size and volume fraction of the dendrites to the volume fraction powder and the solidification rate.
Effect of Rare Earth Oxide Additives on the Phase Transformation Rates of Si3N4
Authors: Kitayama Mikito , Hirao Kiyoshi , Kanzaki Shuzo
Published: May 2006

Fully dense Si3N4 sintered with rare‐earth (RE=La, Nd, Gd, and Yb) oxide additives were fabricated by hot pressing. They were mainly composed of the α‐phase, which enabled the investigation of the α–β transformation kinetics without the effect of porosity. The phase transformation kinetics was found to be linear. The activation energies for the phase transformation were 677, 546, 487, and 424 kJ/mol for RE=La, Nd, Gd, and Yb, respectively, and showed a good correlation with the ionic radii of RE atoms, which was discussed in conjunction with the segregation behaviors of RE atoms at the interface.
Dislocation‐Containing Planar Faults in Metastably Retained Hexagonal Barium Titanate
Authors: Wu Yu‐Chuan , Lu Hong‐Yang
Published: May 2006

Planar faults, designated F1–F6 and Fa, with intermixed dislocations in metastably retained hexagonal‐BaTiO3 ceramics, were found and analyzed by transmission electron microscopy. Only faults with one, two, and four extra c‐layers parallel to the basal plane have been identified. Fault vectors
RF1=RFa=1/6[0221], RF2=RF3=1/3[0111], RF4=1/3[0112], and RF′1=RF5= RF6=RF′a=1/6[0221] were determined adopting the 2πg·R=0 (or 2nπ) criteria in combination with high‐resolution imaging. Further, the embedded dislocations were half‐partials with Burgers vectors b=1/3〈1010〉 determined by the g·b=0 effective invisibility criteria in conjunction with the eligible fault vectors. A rotation by 60° about the c‐axis was found between fault segments with RF1=1/6[0221] and
RF′1=1/6[2021] located on either side of a partial. Basal dislocations with bB=1/3〈1210〉 have dissociated into two prism‐plane Shockley half‐partials with
bPr=1/3〈1100〉 by glide in the fault plane (0002) according to 1/3〈1210〉→1/3〈1100〉+1/3〈0110〉. The fault segment F′1 encompassed by two half‐partials is an extrinsic complex stacking fault.
Processing and Performance of Hydroxyapatite/Fluorapatite Double Layer Coating on Zirconia by the Powder Slurry Method
Authors: Kim Hae‐Won , Yoon Byung‐Ho , Koh Young‐Hag , Kim Hyoun‐Ee
Published: May 2006

A hydroxyapatite/fluorapatite (HA/FA) double layer was coated on ZrO2 by a powder slurry method. The FA layer between the HA layer and the ZrO2 substrate was effective in suppressing the reaction between HA and ZrO2. The rheological properties of the slurry and the thermal treatment conditions were optimized. Addition of small amounts of tri‐ethyl phosphate dispersant and polyvinylbutyral binder (up to 5 wt%) was effective in reducing the slurry viscosity, even at high loadings of HA powder. Each layer (HA, FA) was deposited on ZrO2 repeatedly to induce a uniform layer, and the final heat treatment was carried out above 1200°C to consolidate the coating layer. During this process, without the FA‐intermediate layer, a severe reaction between HA and ZrO2 occurred to form tri‐calcium phosphate and CaZrO3 products. However, the presence of the FA layer between HA and ZrO2 effectively suppressed the reaction up to 1300°C. The obtained HA/FA double coating layer was micro‐porous and relatively rough, but was firmly adhered to the ZrO2 substrate, having a bonding strength of approximately 25 MPa after heat treatment above 1200°C. The osteoblast‐like cells cultured on the HA/FA coating layer spread and proliferated favorably, having a cell proliferation rate comparable to that of a plastic control and HA bulk ceramic.
Fracture Toughness of a Crystalline Silicon Carbide Fiber (Tyranno‐SA3®)
Authors: Morishita Kohei , Ochiai Shojiro , Okuda Hiroshi , Inshikawa Toshihiro , Sato Mitsuhiko , Inoue Tadanobu
Published: May 2006

The fracture toughness of a crystalline silicon carbide fiber, Tyranno‐SA®, was determined by introducing an artificial notch directly into the fiber test specimens using a focused‐ion (Ga+) beam. The relation between fracture strength and notch size was determined experimentally, while the relation among the notch size, fiber diameter, applied stress at infinity, and stress intensity factor was analyzed by the finite element method. By applying the analyzed result to the experimental results, the fracture toughness of the fiber was determined to be
.
Preparation of Ultrathin‐Walled Carbon‐Based Nanoporous Structures by Etching Pseudo‐Amorphous Silicon Oxycarbide Ceramics
Authors: Peña‐Alonso Raquel , Sorarù Gian Domenico , Raj Rishi
Published: May 2006

Etching polymer‐derived silicon‐oxycarbide ceramics with hydrofluoric acid creates nanoporous structures of specific surface areas as high as 600 m2/g. The change in composition upon etching shows the removal of silica, not carbon. The structure remaining after etching is postulated to consist of a scaffolding of graphene networks with their surfaces decorated with mixed bonds of tetrahedral silicon bonded to both oxygen and carbon (SiOmC4−m, where m=1, 2, or 3). The pores existing within such scaffoldings are presumed to have been filled with SiO2 tetrahedra, which are removed by etching. The measurement of the average pore size and pore volumes permits us to estimate the width of the graphitic domain walls, δW, left behind by the etching process. The smallest value of δW, which corresponds to the specimen with the highest surface area, is approximately 1 nm, which is about equal to the total width of one graphene layer and two SiOmC4–m tetrahedra, one on either side of the graphene sheet. This highest surface area specimen is also believed to have the largest size of the silica domains in the unetched samples. In specimens with smaller domains, the etching is only partially successful in removing the silica, presumably because their small size hinders the access of the etchant to the silica tetrahedra. The above behavior is found for samples with low to moderate carbon content. In one sample with a very high carbon content, the etching process removes some carbon as well as silica.
Prospective studies of suicidal behavior in major depressive and bipolar disorders: what is the evidence for predictive risk factors?
Authors: Oquendo M. A. , Currier D. , Mann J. J.
Published: May 2006

Objective:  Prospective studies over the past 30 years have identified an array of predictive indicators for suicidal acts in mood disorders. However, prediction of suicidal behavior remains an elusive goal. This paper reviewed evidence from prospective studies for clinical factors that elevate risk of suicidal acts in that group.

Method:  English language prospective studies of suicidal behavior in major depressive and bipolar disorders were examined.

Results:  The predictors with the best support were a past history of suicidal behavior and the presence of refractory or recurrent depressions. For other risk factors, there was either not enough data to consider them robust or findings were contradictory.

Conclusion:  Future studies must not only be comprehensive in their inclusion of potentially contributing factors, but must also address their relative importance towards the goal of developing predictive models and enhance suicide prevention efforts.
Lung adenocarcinoma with a micropapillary pattern: a clinicopathological study of 25 cases
Authors: KURODA N. , HAMAGUCHI N. , TAKEUCHI E. , OHARA M. , HIROUCHI T. , MIZUNO K.
Published: May 2006

Lung adenocarcinoma with a micropapillary pattern has recently been described, but its biological behavior is as yet uncertain. In this article we present a clinicopathological study of lung adenocarcinoma with micropapillary morphology. We selected 25 patients with lung adenocarcinoma with micropapillary morphology from the 2001–2004 pathology files (age range 54 to 81 years; mean 64.5 years). Micropapillary carcinoma is predominantly located at the periphery of the tumor nodule or mass and occurs irrespective of the subtype of the adenocarcinoma. A micropapillary component was seen against a mucinous background in three cases and microcalcifications resembling psammoma bodies were seen in one case. Four cases showed intensive invasive growth such as micropapillary adenocarcinoma of the breast and 21 showed alveolar type morphology with piling‐up of the neoplastic cells with or without stromal invasion. Seven of twenty‐three (30.4%) showed lymph node metastases at time of operation. Twelve of twenty‐five (48%) showed pleural invasion. Regarding clinical outcome, 14 patients were alive without disease, 5 were alive with disease, and 5 died of the lung adenocarcinoma. No significant relationship was found between the extent of the micropapillary component and prognosis. However, the carcinoma seen in the five patients who died showed breast type histology with intensive invasive growth in three cases and alveolar type histology with intensive stromal invasion in two. Lung micropapillary carcinoma of breast type may behave more aggressively than the alveolar type.
In vitro functional test of two subclasses of an anti‐RhD antibody produced by transient expression in COS cells
Authors: NIELSEN LEIF KOFOED , NORDERHAUG LARS , SANDLIE INGER , DZIEGIEL MORTEN HANEFELD
Published: May 2006

For over 35 years hemolytic disease of the fetus and newborn (HDFN) due to RhD has been effectively prevented by anti‐RhD antibodies obtained from alloimmunized women or deliberately immunized men. However, due to the reduced number of immunized women and for ethical reasons it is foreseen that other sources of anti‐RhD will be needed. One such source is recombinant human antibodies. Here we describe the construction of plasmids encoding two subclasses (IgG1 and IgG3) of an anti‐RhD antibody, their transient expression in COS cells, and subsequent functional characterization of the antibodies with regard to specificity and ability to mediate a respiratory burst. The recombinant anti‐RhD antibodies were specific for the RhD antigen and were able to mediate a respiratory burst. Thus these antibodies might be of use as future rhesus prophylaxis.
Response of IgG1 and IgG2 subclasses to Helicobacter pylori in subjects with chronic inflammation of the gastric mucosa, atrophy and gastric cancer in a country with high Helicobacter pylori infection prevalence
Authors: VOROBJOVA TAMARA , REN ZHIGANG , DUNKLEY MARGARET , CLANCY ROBERT , MAAROOS HEIDI‐INGRID , LABOTKIN RAIT , KULL KARL , UIBO RAIVO
Published: May 2006

Polarized immune response to Helicobacter pylori and induction of chronic inflammation may increase the risk of gastric atrophy and adenocarcinoma. We studied the association of the response of IgG1 and IgG2 antibodies to H. pylori with grade of gastric chronic inflammation and atrophy in a population with a high prevalence of H. pylori, and compared these data with the data obtained from the study of gastric cancer patients, as well as with the data for CagA positivity. Altogether, 114 persons from two adult population samples from Estonia and 45 consecutive gastric cancer patients were studied. All patients were positive for the H. pylori antibody determined by ELISA. Adenocarcinoma was classified histologically according to the Laurén's system. The response of the IgG subclasses to H. pylori (acid glycine‐extracted whole cell proteins) was determined by ELISA and the results were compared with the ELISA results for the recombinant fragment of the CagA protein. Helicobacter pylori IgG level was lower in atrophic gastritis compared with nonatrophic gastritis (chronic inflammation) (p=0.001). In the group of cancer patients, the response of IgG and IgG1 was lower compared with both gastritis groups (p=0.01 and p=0.0002 for IgG, and p=0.001 and p=0.0005 for IgG1). IgG2 was lower for gastric cancer localized in the corpus (p=0.03). In conclusion, atrophic gastritis and gastric cancer were associated with a significant decline in IgG and IgG1 response to H. pylori compared with nonatrophic gastritis. Higher value of CagA antibodies was seen in gastric cancer and in gastric atrophy compared with nonatrophic gastritis; in gastric cancer patients, IgG1 response to H. pylori was correlated with CagA status.
The insertion of a full‐length Bos taurus LINE element is responsible for a transcriptional deregulation of the Normande Agouti gene
Authors: Girardot Michael , Guibert Sylvain , Laforet Marie‐Pierre , Gallard Yves , Larroque Hélène , Oulmouden Ahmad
Published: May 2006

Mammalian pigmentation is controlled by the concerted action of Tyr, Tyrp1 and Dct producing eumelanin and/or pheomelanin in melanocytes. The ratio of these two pigments is determined by the agonist α‐melanocyte stimulating hormone and the antagonist Agouti protein acting on the Mc1r. Here we show that the Agouti gene is over‐expressed in Normande breed compared with Prim'Holstein breed. The Normande cattle have a characteristic coat color phenotype with a variable presence of black (eumelanin) hair over a red/brown background. We have found a previously undescribed full‐length L1‐BT element inserted in the 5′‐genomic sequence of the Agouti gene in Normande cattle which promotes the over‐expression of alternative transcripts. The variable expression of the alternative transcript directed by the long interspersed nuclear element promoter may be the origin of the brindle coat color pattern of the Normande breed. This new bovine Agouti allele isolated in Normande breed has been named Abr. Finally, as ectopic over‐expression of Agouti in Ay mice is responsible for the obesity syndrome, we discuss the possible consequences of Abr for meat and milk production in cattle.
A Multimeric Membrane Protein Reveals 14‐3‐3 Isoform Specificity in Forward Transport in Yeast
Authors: Michelsen Kai , Mrowiec Thomas , Duderstadt Karl E. , Frey Steffen , Minor Daniel L. , Mayer Matthias P. , Schwappach Blanche
Published: May 2006

Arginine (Arg)‐based endoplasmic reticulum (ER) localization signals are sorting motifs involved in the quality control of multimeric membrane proteins. They are distinct from other ER localization signals like the C‐terminal di‐lysine [‐K(X)KXX] signal. The Pmp2p isoproteolipid, a type I yeast membrane protein, reports faithfully on the activity of sorting signals when fused to a tail containing either an Arg‐based motif or a ‐KKXX signal. This reporter reveals that the Arg‐based ER localization signals from mammalian Kir6.2 and GB1 proteins are functional in yeast. Thus, the machinery involved in recognition of Arg‐based signals is evolutionarily conserved. Multimeric presentation of the Arg‐based signal from Kir6.2 on Pmp2p results in forward transport, which requires 14‐3‐3 proteins encoded in yeast by BMH1 and BMH2 in two isoforms. Comparison of a strain without any 14‐3‐3 proteins (▵bmh1▵bmh2) and the individual ▵bmh1 or ▵bmh2 shows that the role of 14‐3‐3 in the trafficking of this multimeric Pmp2p reporter is isoform‐specific. Efficient forward transport requires the presence of Bmh1p. The specific role of Bmh1p is not due to differences in abundance or affinity between the isoforms. Our results imply that 14‐3‐3 proteins mediate forward transport by a mechanism distinct from simple masking of the Arg‐based signal.
Influence of administration methods on the accumulation of ALA‐induced Pp‐IX in mouse tongue tumors
Authors: Ogasawara T , Miyoshi N , Sano K , Kitagawa Y , Yamada T , Ogawa T , Miyauchi K , Kinoshita H
Published: May 2006

Objective:  5‐Aminolevulinic acid (ALA)‐induced protoporphyrin IX (PpIX) has been used as a photosensitizer in photodynamic therapy (PDT) for oral cancer. This study investigates the optimal method of administrating ALA by analyzing PpIX fluorescence in tongue tumor tissue.

Methods:  Protoporphyrin IX intensities in the mouse (C3H)‐transplanted tongue cancer (NR‐S1) were compared with those in normal tongue after intraperitoneal (i.p.), oral (p.o.) or topical administration of ALA. Tongues were sampled at various times after ALA administration. PpIX intensities were obtained from frozen sections of each sample by using a spectrophotometer.

Results:  Protoporphyrin IX intensity in the tumor group peaked at 3 h after the i.p. and 5 h after the p.o. administration of ALA, and these levels were about twice as high as those in the normal group. Maximum PpIX accumulation in the tongue tumor tissue was seen at 5 h after p.o. administration of ALA. In contrast, the topical administration of 20% ALA cream was associated with the lowest PpIX accumulation in the tumor throughout the experiments.

Conclusion:  These results suggested that p.o. administration of ALA was the most effective method in ALA‐PDT for oral cancer.
Constitutive expression of the human peroxiredoxin V gene contributes to protection of the genome from oxidative DNA lesions and to suppression of transcription of noncoding DNA
Authors: Kropotov Andrey , Serikov Vladimir , Suh Jung , Smirnova Alexandra , Bashkirov Vladimir , Zhivotovsky Boris , Tomilin Nikolai
Published: May 2006

Peroxiredoxins belong to a family of antioxidant proteins that neutralize reactive oxygen species. One member of this family, peroxiredoxin I (PRDX1), suppresses DNA oxidation. Peroxiredoxin V (PRDX5) has been cloned as a transcriptional corepressor, as a peroxisomal/mitochondrial antioxidant protein, and as an inhibitor of p53‐dependent apoptosis. Promoters of mammalian PRDX5 genes contain clusters of antioxidant response elements, which can bind the transcription factor NRF2. However, we found that expression of the human PRDX5 gene in situ was not stimulated by the oxidative agent menadione. Silencing of the NRF2 gene in the absence of oxidative stress by specific siRNA did not decrease PRDX5 protein concentration. We also constructed clones of human lung epithelial cells A549 with siRNA‐mediated knockdown of the PRDX5 gene. This led to a significant increase in 8‐oxoguanine formation in cell DNA. In the PRDX5 knockdown clone, an increase in transcripts containing sequences of alpha‐satellite and satellite III DNAs was also detected, suggesting that this protein may be required for silencing of heterochromatin. Together, these results suggest that constitutively expressed PRDX5 gene plays an important role in protecting the genome against oxidation and may also be involved in the control of transcription of noncoding DNA.
Isolation, characterization, sequencing and crystal structure of charybdin, a type 1 ribosome‐inactivating protein from Charybdis maritima agg.
Authors: Touloupakis Eleftherios , Gessmann Renate , Kavelaki Kalliopi , Christofakis Emmanuil , Petratos Kyriacos , Ghanotakis Demetrios F.
Published: May 2006

A novel, type 1 ribosome‐inactivating protein designated charybdin was isolated from bulbs of Charybdis maritima agg. The protein, consisting of a single polypeptide chain with a molecular mass of 29 kDa, inhibited translation in rabbit reticulocytes with an IC50 of 27.2 nm. Plant genomic DNA extracted from the bulb was amplified by PCR between primers based on the N‐terminal and C‐terminal sequence of the protein from dissolved crystals. The complete mature protein sequence was derived by partial DNA sequencing and terminal protein sequencing, and was confirmed by high‐resolution crystal structure analysis. The protein contains Val at position 79 instead of the conserved Tyr residue of the ribosome‐inactivating proteins known to date. To our knowledge, this is the first observation of a natural substitution of a catalytic residue at the active site of a natural ribosome‐inactivating protein. This substitution in the active site may be responsible for the relatively low in vitro translation inhibitory effect compared with other ribosome‐inactivating proteins. Single crystals were grown in the cold room from PEG6000 solutions. Diffraction data collected to 1.6 Å resolution were used to determine the protein structure by the molecular replacement method. The fold of the protein comprises two structural domains: an α + β N‐terminal domain (residues 4–190) and a mainly α‐helical C‐terminal domain (residues 191–257). The active site is located in the interface between the two domains and comprises residues Val79, Tyr117, Glu167 and Arg170.
EmbR, a regulatory protein with ATPase activity, is a substrate of multiple serine/threonine kinases and phosphatase in Mycobacterium tuberculosis
Authors: Sharma Kirti , Gupta Meetu , Krupa Ananth , Srinivasan Narayanaswamy , Singh Yogendra
Published: May 2006

Phosphorylation of the mycobacterial transcriptional activator, EmbR, is essential for transcriptional regulation of the embCAB operon encoding cell wall arabinosyltransferases. This signaling pathway eventually affects the resistance to ethambutol (a frontline antimycobacterial drug) and the cell wall Lipoarabinomannan/Lipomannan ratio (an important determinant for averting the host immune response). In this study, further biochemical characterization revealed that EmbR, as a transcriptional regulator, interacts with RNA polymerase and possesses a phosphorylation‐dependent ATPase activity that might play a role in forming an open complex between EmbR and RNA polymerase. EmbR was recently shown to be phosphorylated by the cognate mycobacterial serine/threonine (Ser/Thr) kinase, PknH. Using bioinformatic analysis and in vitro assays, we identified additional novel regulators of the signaling pathway leading to EmbR phosphorylation, namely the Ser/Thr protein kinases PknA and PknB. A previously unresolved question raised by this signaling scheme is the fate of phosphorylated kinases and EmbR at the end of the signaling cycle. Here we show that Mstp, a mycobacterial Ser/Thr phosphatase, antagonizes Ser/Thr protein kinase–EmbR signaling by dephosphorylating Ser/Thr protein kinases, as well as EmbR, in vitro. Additionally, dephosphorylation of EmbR reduced its ATPase activity, interaction with Ser/Thr protein kinases and DNA‐binding activity, emphasizing the antagonistic role of Mstp in the EmbR–Ser/Thr protein kinase signaling system.
GHP, a new c‐type green heme protein from Halochromatium salexigens and other proteobacteria
Authors: Van Driessche Gonzalez , Devreese Bart , Fitch John C. , Meyer Terrance E. , Cusanovich Michael A. , Van Beeumen Jozef J.
Published: May 2006

We have isolated a minor soluble green‐colored heme protein (GHP) from the purple sulfur bacterium, Halochromatium salexigens, which contains a c‐type heme. A similar protein has also been observed in the purple bacteria Allochromatium vinosum and Rhodopseudomonas cryptolactis. This protein has wavelength maxima at 355, 420, and 540 nm and remains unchanged upon addition of sodium dithionite or potassium ferricyanide, indicating either an unusually low or high redox potential, respectively. The amino‐acid sequence indicates one heme per peptide chain of 72 residues and reveals weak similarity to the class I cytochromes. The usual sixth heme ligand methionine in these proteins appears to be replaced by a cysteine in GHP. Only one known cytochrome has a cysteine sixth ligand, SoxA (cytochrome c‐551) from thiosulfate‐oxidizing bacteria, which is low‐spin and has a high redox potential because of an un‐ionized ligand. The native size of GHP is 34 kDa, its subunit size is 11 kDa, and the net charge is −12, accounting for its very acidic nature. A database search of complete genome sequences reveals six homologs, all hypothetical proteins, from Oceanospirillum sp., Magnetococcus sp., Thiobacillus denitrificans, Dechloromonas aromatica, Thiomicrospira crunogena and Methylobium petroleophilum, with sequence identities of 35–64%. The genetic context is different for each species, although the gene for GHP is transcriptionally linked to several other genes in three out of the six species. These genes, coding for an RNAse, a protease/chaperone, a GTPase, and pterin‐4a‐carbinolamine dehydratase, appear to be functionally related to stress response and are linked in at least 10 species.