bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural investigation of Ge3Sb2Te6, an intermetallic compound in the GeTe–Sb2Te3 homologous series
Authors: Matsunaga Toshiyuki , Kojima Rie , Yamada Noboru , Kifune Kouichi , Kubota Yoshiki , Takata Masaki
Published: April 2007

Ge 3 Sb 2 Te 6 was analyzed in detail using an x-ray diffraction method. The crystal of this material in the space group R3¯m is characterized as a 33-layered cubic close-packed stacking structure. Te atoms fully occupy their specific layers, whereas Ge and Sb atoms are located in other layers thus causing partial atomic disordering. Te and Ge∕Sb layers are laminated alternately 11 times to form a NaCl block. Electron density distributions in the crystal were obtained using the maximum entropy method and band calculation, which showed very good agreement with each other. Ge3Sb2Te6 is a compound semiconductor with a very narrow band gap.
Contact printed Co/insulator/Co molecular junctions
Authors: Fan Xiaojuan , Rogow David L. , Swanson Claudia H. , Tripathi Akhilesh , Oliver Scott R. J.
Published: April 2007

The authors report the contact printing of a Au∕Co double layer (total thickness ∼20–40nm) onto a self-assembled monolayer surface to form molecular junctions under ambient conditions. The feature size ranges from 50×50μm2to2×2mm2. Grazing incident x-ray diffraction of the multilayer junction shows all expected Au peaks, while elemental Co was confirmed by energy dispersive spectroscopy. Film thickness, roughness, and density were characterized by x-ray reflectivity. I-V measurements show a prominent hysteresis, likely associated with charge trapping at the metal-organic interface, not an intrinsic feature of alkanedithiol molecules.
Nanogap formation by palladium hydrogenation for surface conduction electron emitters fabrication
Authors: Tsai Chih-Hao , Pan Fu-Ming , Chen Kuan-Jung , Wei Cheng-Yang , Liu Mei , Mo Chi-Neng
Published: April 2007

Nanometer-scale gaps in Pd strips are obtained by hydrogen absorption under high pressure treatment. The resulting lattice constant increase due to the Pd phase transformation after hydrogen uptake results in a large compressive stress on the thin Pd films. Under proper geometric arrangement of the Pd electrode within a surface conduction electron (SCE) emitter structure, a single nanogap per SCE device is obtained. A turn-on voltage of 41V is observed for emitters with a 25nm gap.
Efficient energy transfer from silicon oxycarbide matrix to Er ions via indirect excitation mechanisms
Authors: Gallis Spyros , Huang Mengbing , Kaloyeros Alain E.
Published: April 2007

Efficient Er excitation was observed in Er-doped silicon oxycarbide with strong room-temperature photoluminescence of ∼1540nm within a broad (460–600nm) band. Er PL power dependence modeling yielded an effective Er excitation cross section of approximately four orders of magnitude higher than direct Er excitation. PL for undoped a-SiC0.5O1.0 extended from visible to near infrared (500–750nm), with intensity decreasing with Er doping. Er photoluminescence excitation overlapped with the Urbach edge in a-SiC0.5O1.0:Er absorption spectrum. Energy transfer from electron-hole recombination at band edges or/and defect levels in a-SiC0.5O1.0:Er may provide an efficient excitation route for Er ions via electron excitation from ground state (I15∕24) to 4f levels.
Roles of donor and acceptor nanodomains in 6% efficient thermally annealed polymer photovoltaics
Authors: Kim Kyungkon , Liu Jiwen , Namboothiry Manoj A. G. , Carroll David L.
Published: April 2007

The authors have fabricated thin film polymer photovoltaics using 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)C61 within regioregular poly(3-hexylthiophene) bulk heterojunction absorbing layers. Using thermal annealing at temperatures approaching the glass transition temperature, they have examined the formation of nanodomains within the matrix. These domains modify charge transport pathways in such a way as to allow for the efficient use of thicker absorbing layers. This results in a nearly 20% gain in overall performance for this polymer system with external power efficiencies exceeding 6%.
Genetic evidence for differences in the pathways of druse and prismatic calcium oxalate crystal formation in Medicago truncatula
Authors: Nakata Paul A. , McConn Michele M.
Published: April 2007

Current evidence supports a single pathway of oxalate biosynthesis utilising ascorbic acid as the precursor. In this study, we begin to address the possibility that more than one pathway of oxalate biosynthesis and calcium oxalate formation occurs in Medicago truncatula Gaertn. (cv. Jemalong genotype A17). Like the wild type, developing leaves of the calcium oxalate defective (cod) 4 mutant contain prismatic crystals along the vascular strand, but this mutant also hyper-accumulates druse crystals within the mesophyll cells. A second mutant, cod5, fails to accumulate prismatic crystals along the vascular strand, but is capable of wild type druse crystal accumulation in maturing leaves. To assess whether a single pathway of oxalate biosynthesis and calcium oxalate formation occurs in M. truncatula, we generated and characterised the cod4/cod5 double mutant. Microscopic examination of the cod4/cod5 revealed that the double mutant exhibits both cod4 and cod5 mutant crystal phenotypes simultaneously, suggesting there are differences in the pathways leading to the two crystal types. Measured ascorbic acid levels and ascorbate induction studies were consistent with the acid as precursor to oxalate in druse crystal formation but not necessarily prismatic crystal formation. On the basis of these findings, we propose a working model depicting possible pathways of oxalate biosynthesis and calcium oxalate formation.
Review: Nutrient loading of developing seeds
Authors: Zhang Wen-Hao , Zhou Yuchan , Dibley Katherine E. , Tyerman Stephen D. , Furbank Robert T. , Patrick John W.
Published: April 2007

Interest in nutrient loading of seeds is fuelled by its central importance to plant reproductive success and human nutrition. Rates of nutrient loading, imported through the phloem, are regulated by transport and transfer processes located in sources (leaves, stems, reproductive structures), phloem pathway and seed sinks. During the early phases of seed development, most control is likely to be imposed by a low conductive pathway of differentiating phloem cells serving developing seeds. Following the onset of storage product accumulation by seeds, and, depending on nutrient species, dominance of path control gives way to regulation by processes located in sources (nitrogen, sulfur, minor minerals), phloem path (transition elements) or seed sinks (sugars and major mineral elements, such as potassium). Nutrients and accompanying water are imported into maternal seed tissues and unloaded from the conducting sieve elements into an extensive post-phloem symplasmic domain. Nutrients are released from this symplasmic domain into the seed apoplasm by poorly understood membrane transport mechanisms. As seed development progresses, increasing volumes of imported phloem water are recycled back to the parent plant by process(es) yet to be discovered. However, aquaporins concentrated in vascular and surrounding parenchyma cells of legume seed coats could provide a gated pathway of water movement in these tissues. Filial cells, abutting the maternal tissues, take up nutrients from the seed apoplasm by membrane proteins that include sucrose and amino acid/H+ symporters functioning in parallel with non-selective cation channels. Filial demand for nutrients, that comprise the major osmotic species, is integrated with their release and phloem import by a turgor-homeostat mechanism located in maternal seed tissues. It is speculated that turgors of maternal unloading cells are sensed by the cytoskeleton and transduced by calcium signalling cascades.
PvUPS1 plays a role in source - sink transport of allantoin in French bean (Phaseolus vulgaris)
Authors: Pélissier Hélène C. , Tegeder Mechthild
Published: April 2007

Nodulated tropical legumes such as French bean (Phaseolus vulgaris L.) receive their nitrogen via N-fixing rhizobia. The principal products of fixed nitrogen are the ureides allantoin and allantoic acid that are synthesised in root nodules and then translocated to the mature leaves of the shoot via the xylem. By feeding [14C]allantoin to mature leaves and roots of French bean plants we showed that this ureide is transported over long distances by xylem and then phloem to developing organs such as pods, root tips and growing leaves. For analysis of allantoin partitioning within the plant, concentrations of allantoin in French bean organs and xylem sap were determined. The amounts of allantoin varied between organs, with the highest levels being detected in the stems. Differences in levels of allantoin were found between nodulated and non-nodulated plants, with generally higher allantoin concentrations in tissues and xylem sap of nodulated plants. RNA and protein expression of the recently identified French bean allantoin permease PvUPS1 (AY461734) was detected in all plant organs indicating a function in allantoin transport throughout the plant. The levels of PvUPS1 expression were consistent with the allantoin concentrations in the different organs. In situ RNA hybridisation studies were carried out and showed that PvUPS1 is expressed in the phloem throughout the plant. Together, our results indicate that in French bean allantoin is transported from source to sink and that PvUPS1 plays a role in phloem loading and in allantoin transport to developing sinks.
Physiological, anatomical and biochemical characterisation of photosynthetic types in genus Cleome (Cleomaceae)
Authors: Voznesenskaya Elena V. , Koteyeva Nuria K. , Chuong Simon D. X. , Ivanova Alexandra N. , Barroca João , Craven Lyndley A. , Edwards Gerald E.
Published: April 2007

C4 photosynthesis has evolved many times in 18 different families of land plants with great variation in leaf anatomy, ranging from various forms of Kranz anatomy to C4 photosynthesis occurring within a single type of photosynthetic cell. There has been little research on photosynthetic typing in the family Cleomaceae, in which only one C4 species has been identified, Cleome gynandra L. There is recent interest in selecting and developing a C4 species from the family Cleomaceae as a model C4 system, since it is the most closely related to Arabidopsis, a C3 model system (Brown et al. 2005). From screening more than 230 samples of Cleomaceae species, based on a measure of the carbon isotope composition (δ13C) in leaves, we have identified two additional C4 species, C. angustifolia Forssk. (Africa) and C. oxalidea F.Muell. (Australia). Several other species have δ13C values around –17‰ to –19‰, suggesting they are C4-like or intermediate species. Eight species of Cleome were selected for physiological, anatomical and biochemical analyses. These included C. gynandra, a NAD–malic enzyme (NAD–ME) type C4 species, C. paradoxa R.Br., a C3–C4 intermediate species, and 6 others which were characterised as C3 species. Cleome gynandra has C4 features based on low CO2 compensation point (Γ), C4 type δ13C values, Kranz-type leaf anatomy and bundle sheath (BS) ultrastructure, presence of C4 pathway enzymes, and selective immunolocalisation of Rubisco and phosphoenolpyruvate carboxylase. Cleome paradoxa was identified as a C3–C4 intermediate based on its intermediate Γ (27.5 μmol mol–1), ultrastructural features and selective localisation of glycine decarboxylase of the photorespiratory pathway in mitochondria of BS cells. The other six species are C3 plants based on Γ, δ13C values, non-Kranz leaf anatomy, and levels of C4 pathway enzymes (very low or absent) typical of C3 plants. The results indicate that this is an interesting family for studying the genetic basis for C4 photosynthesis and its evolution from C3 species.
Influence of cucumber mosaic virus infection on the mRNA population present in the phloem translocation stream of pumpkin plants
Authors: Ruiz-Medrano Roberto , Moya Jesús Hinojosa , Xoconostle-Cázares Beatriz , Lucas William J.
Published: April 2007

The effect of cucumber mosaic virus (CMV) infection on the phloem sap mRNA population was investigated in pumpkin Cucurbita maxima Duch. cv. Big Max, through analysis of a suppressive subtractive hybridisation (SSH) library. Analysis of the infected phloem library identified 91 highly diverse mRNA species, including enzymes involved in general metabolism, transcription factors and signalling agents. Our analysis indicated that, quantitatively, the effect of CMV infection on the composition of the phloem sap transcriptome was minor in nature. Virtual northern analysis was used to confirm the specific upregulation of these transcripts in the phloem of CMV-infected plants. In silico northern analysis also confirmed that none of the transcripts identified in the SSH library was contained in the population of mRNA species present in the phloem sap of healthy plants. Induction levels ranged from low to high and in situ hybridisation studies showed that transcripts displayed a range of accumulation patterns. Collectively, our findings suggest that plants have evolved a highly robust mechanism for the exchange of information macromolecules between the companion cell (CC) and the sieve tube system. Production of viral movement protein (MP) in the CC is not sufficient for the indiscriminate transport of mRNA into the sieve element. Our findings are discussed in the context of symptom development and likely strong selection pressure, on the viral genome, to encode for a MP that does not adversely interfere with the phloem long-distance trafficking system.
Nonmammalian orthologs of prestin (SLC26A5) are electrogenic divalent/chloride anion exchangers
Authors: Schaechinger Thorsten J. , Oliver Dominik
Published: April 2007

Individual members of the mammalian SLC26 anion transporter family serve two fundamentally distinct functions. Whereas most members transport different anion substrates across a variety of epithelia, prestin (SLC26A5) is special, functioning as a membrane-localized motor protein that generates electrically induced motions (electromotility) in auditory sensory hair cells of the mammalian inner ear. The transport mechanism of SLC26 proteins is not well understood, and a mechanistic relation between anion transport and electromotility has been suggested but not firmly established so far. To address these questions, we have cloned prestin orthologs from chicken and zebrafish, nonmammalian vertebrates that presumably lack electromotility in their auditory systems. Using patch-clamp recordings, we show that these prestin orthologs, but not mammalian prestin, generate robust transport currents in the presence of the divalent anions sulfate or oxalate. Transport is blocked by salicylate, an inhibitor of electromotility generated by mammalian prestin. The dependence of transport equilibrium potentials on sulfate and chloride concentration gradients shows that the prestin orthologs are electrogenic antiporters, exchanging sulfate or oxalate for chloride in a strictly coupled manner with a 1:1 stoichiometry. These data identify transport mode and stoichiometry of electrogenic divalent/monovalent anion exchange and establish a reliable and simple method for the quantitative determination of the various transport modes that have been proposed for other SLC26 transport proteins. Moreover, the sequence conservation between mammalian and nonmammalian prestin together with a common pharmacology of electromotility and divalent antiport suggest that the molecular mechanism behind electromotility is closely related to an anion transport cycle.
Coherent neural representation of hand speed in humans revealed by MEG imaging
Authors: Jerbi Karim , Lachaux Jean-Philippe , N′Diaye Karim , Pantazis Dimitrios , Leahy Richard M. , Garnero Line , Baillet Sylvain
Published: April 2007

The spiking activity of single neurons in the primate motor cortex is correlated with various limb movement parameters, including velocity. Recent findings obtained using local field potentials suggest that hand speed may also be encoded in the summed activity of neuronal populations. At this macroscopic level, the motor cortex has also been shown to display synchronized rhythmic activity modulated by motor behavior. Yet whether and how neural oscillations might be related to limb speed control is still poorly understood. Here, we applied magnetoencephalography (MEG) source imaging to the ongoing brain activity in subjects performing a continuous visuomotor (VM) task. We used coherence and phase synchronization to investigate the coupling between the estimated activity throughout the brain and the simultaneously recorded instantaneous hand speed. We found significant phase locking between slow (2- to 5-Hz) oscillatory activity in the contralateral primary motor cortex and time-varying hand speed. In addition, we report long-range task-related coupling between primary motor cortex and multiple brain regions in the same frequency band. The detected large-scale VM network spans several cortical and subcortical areas, including structures of the frontoparietal circuit and the cerebello–thalamo–cortical pathway. These findings suggest a role for slow coherent oscillations in mediating neural representations of hand kinematics in humans and provide further support for the putative role of long-range neural synchronization in large-scale VM integration. Our findings are discussed in the context of corticomotor communication, distributed motor encoding, and possible implications for brain–machine interfaces.
Dihydrogen complexes as prototypes for the coordination chemistry of saturated molecules
Authors: Kubas Gregory J.
Published: April 2007

The binding of a dihydrogen molecule (H2) to a transition metal center in an organometallic complex was a major discovery because it changed the way chemists think about the reactivity of molecules with chemically “inert” strong bonds such as HH and CH. Before the seminal finding of side-on bonded H2in W(CO)3(PR3)2(H2), it was generally believed that H2could not bind to another atom in stable fashion and would split into two separate H atoms to form a metal dihydride before undergoing chemical reaction. Metal-bound saturated molecules such as H2, silanes, and alkanes (σ-complexes) have a chemistry of their own, with surprisingly varied structures, bonding, and dynamics. H2complexes are of increased relevance for H2production and storage in the hydrogen economy of the future.
Agostic interactions in transition metal compounds
Authors: Brookhart Maurice , Green Malcolm L. H. , Parkin Gerard
Published: April 2007

The impact of agostic interactions (i.e., 3-center–2-electron MHC bonds) on the structures and reactivity of organotransition metal compounds is reviewed.
Conversion of Prevalence Survey Data on Nosocomial Infections to Incidence Estimates: A Simplified Tool for Surveillance?
Authors: Berthelot Philippe , Garnier Maud , Fascia Pascal , Guyomarch Stéphane , Jospé Richard , Lucht Frédéric , Zéni Fabrice , Auboyer Christian , Pozzetto Bruno
Published: April 2007

We calculated the incidence of nosocomial infection in 2 intensive care units (ICUs) on the basis of prevalence data recorded from 1997 through 2002 and compared these estimates to cumulative incidences measured in the 2 ICUs during the same period to investigate the feasibility and the reliability of converting prevalence data to incidence estimates. Decreases in the calculated and measured incidences over time in the ICUs were found to be statistically significantly related.
Risk of Rabies Infection and Adverse Effects of Postexposure Prophylaxis in Healthcare Workers and Other Patient Contacts Exposed to a Rabies Virus–Infected Lung Transplant Recipient
Authors: Mattner Frauke , Henke-Gendo Cornelia , Martens Andreas , Drosten Christian , Schulz Thomas F. , Heim Albert , Suerbaum Sebastian , Kuhn Sabine , Bruderek Juliane , Gastmeier Petra , Strueber Martin
Published: April 2007

Background.

Rabies virus was inadvertently transmitted to a lung transplant recipient through donor lungs. The patient was given ventilatory assistance and cared for postoperatively for 6 weeks before a diagnosis of rabies virus infection was made. Postexposure prophylaxis (PEP) was offered to potentially exposed healthcare workers (HCWs).

Methods.

Only HCWs classified as belonging to possible and/or proven contact groups (according to a standardized interview) received PEP. The risk of individual HCWs being exposed to rabies virus was reassessed on the basis of viral concentrations measured in the patient's excretions and body fluids. HCWs who were vaccinated as part of PEP were followed up prospectively according to a standardized procedure.

Results.

Of 179 HCWs and other patient contacts, 132 met the eligibility criteria for PEP (118 [89.4%] with possible contact and 14 [10.6%] with proven contact with the patient's excretions and/or body fluids). One hundred thirty-one individuals started PEP, and 126 met the inclusion criteria for analysis. Of these, 48 (38%) developed at least 1 adverse effect (8 [6.3%] had fever, 37 [29.4%] had headache, 3 [2.4%] had lymphadenopathy, 17 [13.5%] had dizziness, and 6 [4.8%] had paresthesia). No HCW or other patient contact developed rabies or serious PEP-related adverse effects. Reassessment of the individual's risk of infection as a function of the viral concentration in the patient's excretions and/or body fluids (up to 5.12 × 107 copies/mL) revealed that 103 HCWs (78.0%) had contact with high-risk substances (89 [67.40%] had possible contact and 14 [10.7%] had proven contact).

Conclusion.

HCWs can be exposed to significant viral concentrations in excretions and/or body fluids from rabies virus-infected lung transplant recipients. Because widespread use of PEP entails the possibility of significant health problems for HCWs considered to be at risk of contracting rabies, applying a rational indication for PEP is crucial.
Healthcare Costs Associated with Hemodialysis Catheter–Related Infections: A Single-Center Experience
Authors: Ramanathan Venkataraman , Chiu Edwin J. , Thomas Jim T. , Khan Ahmad , Dolson George M. , Darouiche Rabih O.
Published: April 2007

In patients undergoing hemodialysis, catheter-related bacteremia results in expensive hospitalizations. In our study, the mean cost was $23,451 per hospitalization. When itemized, housing (“bed-related”) costs accounted for 66% of the total; laboratory costs accounted for 4%, radiologic costs accounted for 9%, and procedure-related costs accounted for 21%. Hypoalbuminemia and bacteremia due to methicillin-resistant Staphylococcus aureus (MRSA) are associated with higher healthcare costs; bacteremia due to MRSA is also associated with poor survival rates.
Circumstances of Patient Falls and Injuries In 9 Hospitals In a Midwestern Healthcare System
Authors: Krauss Melissa J. , Nguyen Sheila L. , Dunagan Wm. Claiborne , Birge Stanley , Costantinou Eileen , Johnson Shirley , Caleca Barbara , Fraser Victoria J.
Published: April 2007

Objective.

Preventing hospital falls and injuries requires knowledge of fall and injury circumstances. Our objectives were to determine whether reported fall circumstances differ among hospitals and to identify predictors of fall-related injury.

Design.

Retrospective cohort study. Adverse event data on falls were compared according to hospital characteristics. Logistic regression was used to determine adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for risk factors for fall-related injury.

Setting.

Nine hospitals in a Midwestern healthcare system.

Patients.

Inpatients who fell during 2001-2003.

Results.

The 9 hospitals reported 8,974 falls that occurred in patient care areas, involving 7,082 patients; 7,082 falls were included in our analysis. Assisted falls (which accounted for 13.3% of falls in the academic hospital and 9.8% of falls in the nonacademic hospitals;P<.001) and serious fall-related injuries (which accounted for 3.7% of fall-related injuries in the academic hospital and 2.2% of fall-related injuries in the nonacademic hospitals;P<.001) differed by hospital type. In multivariate analysis for the academic hospital, increased age (aOR, 1.006 [95% CI, 1.000-1.012]), falls in locations other than patient rooms (aOR, 1.53 [95% CI, 1.03-2.27]), and unassisted falls (aOR, 1.70 [95% CI, 1.23-2.36]) were associated with increased injury risk. Altered mental status was associated with a decreased injury risk (aOR, 0.72 [95% CI, 0.58-0.89]). In multivariate analysis for the nonacademic hospitals, increased age (aOR, 1.007 [95% CI, 1.002-1.013]), falls in the bathroom (aOR, 1.46 [95% CI, 1.06-2.01]), and unassisted falls (aOR, 1.83 [95% CI, 1.37-2.43]) were associated with injury. Female sex (aOR, 0.83 [95% CI, 0.71-0.97]) was associated with a decreased risk of injury.

Conclusion.

Some fall characteristics differed by hospital type. Further research is necessary to determine whether differences reflect true differences or merely differences in reporting practices. Fall prevention programs should target falls involving older patients, unassisted falls, and falls that occur in the patient's bathroom and in patient care areas outside of the patient's room to reduce injuries.
Reduction in Surgical Site Infections in Neurosurgical Patients Associated With a Bedside Hand Hygiene Program in Vietnam
Authors: Thu Le Thi Arm , Dibley Michael J. , Nho Vo Van , Archibald Lennox , Jarvis William R. , Sohn Annette H.
Published: April 2007

Objective.

We conducted an intervention study to assess the impact of the use of an alcohol-chlorhexidine-based hand sanitizer on surgical site infection (SSI) rates among neurosurgical patients in Ho Chi Minh City, Vietnam.

Design.

A quasi-experimental study with an untreated control group and assessment of neurosurgical patients admitted to 2 neurosurgical wards at Cho Ray Hospital between July 11 and August 15, 2000 (before the intervention), and July 14 and August 18, 2001 (after the intervention). A hand sanitizer with 70% isopropyl alcohol and 0.5% Chlorhexidine gluconate was introduced, and healthcare workers were trained in its use on ward A in September 2000. No intervention was made in ward B. Centers for Disease Control and Prevention definitions of SSI were used. Patient SSI data were collected on standardized forms and were analyzed using Stata software (Stata).

Results.

A total of 786 patients were enrolled: 377 in the period before intervention (156 in ward A and 221 in ward B) and 409 in the period after intervention (159 in ward A and 250 in ward B). On ward A after the intervention, the SSI rate was reduced by 54% (from 8.3% to 3.8%; P = .09), and more than half of superficial SSIs were eliminated (7 of 13 vs 0 of 6 in ward B; P = .007). On ward B, the SSI rate increased by 22% (from 7.2% to 9.2%; P = .8). In patients without SSI, the median postoperative length of stay and the duration of antimicrobial use were reduced on ward A (both from 8 to 6 days; P <.001) but not on ward B.

Conclusions.

Our study demonstrates that introduction of a hand sanitizer can both reduce SSI rates in neurosurgical patients, with particular impact on superficial SSIs, and reduce the overall postoperative length of stay and the duration of antimicrobial use. Hand hygiene programs in developing countries are likely to reduce SSI rates and improve patient outcomes.
Politically Incorrect: Legislation Must Not Mandate Specific Healthcare Epidemiology and Infection Prevention and Control Practices
Authors: Fraser Victoria , Murphy Denise , Brennan P. J. , Frain Janet , Arias Kathleen Meehan , Perl Trish M. ,   Boards of Directors of APIC and SHEA
Published: April 2007

In this issue of the journal, Dr. Farr offers his perspective on the recent position statement from the Joint SHEA and APIC Task Force regarding legislative mandates for use of active surveillance cultures to screen for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The position statement specifically addresses the issue of whether the use of MRSA and VRE surveillance cultures in healthcare settings should be mandated by legislation. It does not attempt to address whether or not, when, or for whom active surveillance cultures should be performed. A broad range of experts and the Boards of Directors of the Society for Healthcare Epidemiology (SHEA) and the Association of Professionals in Infection Control (APIC) reviewed this position statement, which summarizes the effectiveness of active surveillance culturing as it pertains to potential legislation. Both Boards agree the position statement represents a well-reasoned, systematic, and fair review of the literature. Of course, no single document, group, or individual should ever be viewed as having the final word on this or any subject. Thoughtful debate regarding the scientific evidence, when conducted in a professional and constructive manner, is a critical and necessary step in the translation of research and clinical observations into bedside practices. Such debate should also lead to a research agenda that will help fill gaps in knowledge that become apparent in the discussion.
The Conserved Spc7 Protein Is Required for Spindle Integrity and Links Kinetochore Complexes in Fission Yeast
Authors: Kerres Anne , Jakopec Visnja , Fleig Ursula
Published: April 2007

Spc7, a member of the conserved Spc105/KNL-1 family of kinetochore proteins, was identified as an interaction partner of the EB1 homologue Mal3. Spc7 associates with the central centromere region of the chromosome but does not affect transcriptional silencing. Here, we show that Spc7 is required for the integrity of the spindle as well as for targeting of MIND but not of Ndc80 complex components to the kinetochore. Spindle defects in spc7 mutants were severe ranging from the inability to form a bipolar spindle in early mitosis to broken spindles in midanaphase B. spc7 mutant phenotypes were partially rescued by extra α-tubulin or extra Mal2. Thus, Spc7 interacts genetically with the Mal2-containing Sim4 complex.
Ihh/Gli2 Signaling Promotes Osteoblast Differentiation by Regulating Runx2 Expression and Function
Authors: Shimoyama Atsuko , Wada Masahiro , Ikeda Fumiyo , Hata Kenji , Matsubara Takuma , Nifuji Akira , Noda Masaki , Amano Katsuhiko , Yamaguchi Akira , Nishimura Riko , Yoneda Toshiyuki
Published: April 2007

Genetic and cell biological studies have indicated that Indian hedgehog (Ihh) plays an important role in bone development and osteoblast differentiation. However, the molecular mechanism by which Ihh regulates osteoblast differentiation is complex and remains to be fully elucidated. In this study, we investigated the role of Ihh signaling in osteoblast differentiation using mesenchymal cells and primary osteoblasts. We observed that Ihh stimulated alkaline phosphatase (ALP) activity, osteocalcin expression, and calcification. Overexpression of Gli2- but not Gli3-induced ALP, osteocalcin expression, and calcification of these cells. In contrast, dominant-negative Gli2 markedly inhibited Ihh-dependent osteoblast differentiation. Ihh treatment or Gli2 overexpression also up-regulated the expression of Runx2, an essential transcription factor for osteoblastogenesis, and enhanced the transcriptional activity and osteogenic action of Runx2. Coimmunoprecipitation analysis demonstrated a physical interaction between Gli2 and Runx2. Moreover, Ihh or Gli2 overexpression failed to increase ALP activity in Runx2-deficient mesenchymal cells. Collectively, these results suggest that Ihh regulates osteoblast differentiation of mesenchymal cells through up-regulation of the expression and function of Runx2 by Gli2.
A Mutation in the SH2 Domain of STAT2 Prolongs Tyrosine Phosphorylation of STAT1 and Promotes Type I IFN-induced Apoptosis
Authors: Scarzello Anthony J. , Romero-Weaver Ana L. , Maher Stephen G. , Veenstra Timothy D. , Zhou Ming , Qin Angel , Donnelly Raymond P. , Sheikh Faruk , Gamero Ana M.
Published: April 2007

Type I interferons (IFN-α/β) induce apoptosis in certain tumor cell lines but not others. Here we describe a mutation in STAT2 that confers an apoptotic effect in tumor cells in response to type I IFNs. This mutation was introduced in a conserved motif, PYTK, located in the STAT SH2 domain, which is shared by STAT1, STAT2, and STAT3. To test whether the tyrosine in this motif might be phosphorylated and affect signaling, Y631 of STAT2 was mutated to phenylalanine (Y631F). Although it was determined that Y631 was not phosphorylated, the Y631F mutation conferred sustained signaling and induction of IFN-stimulated genes. This prolonged IFN response was associated with sustained tyrosine phosphorylation of STAT1 and STAT2 and their mutual association as heterodimers, which resulted from resistance to dephosphorylation by the nuclear tyrosine phosphatase TcPTP. Finally, cells bearing the Y631F mutation in STAT2 underwent apoptosis after IFN-α stimulation compared with wild-type STAT2. Therefore, this mutation reveals that a prolonged response to IFN-α could account for one difference between tumor cell lines that undergo IFN-α–induced apoptosis compared with those that display an antiproliferative response but do not die.
A Cytosolic Splice Variant of Cab45 Interacts with Munc18b and Impacts on Amylase Secretion by Pancreatic Acini
Authors: Lam Patrick P.L. , Hyvärinen Kati , Kauppi Maria , Cosen-Binker Laura , Laitinen Saara , Keränen Sirkka , Gaisano Herbert Y. , Olkkonen Vesa M.
Published: April 2007

We identified in a yeast two-hybrid screen the EF-hand Ca2+-binding protein Cab45 as an interaction partner of Munc18b. Although the full-length Cab45 resides in Golgi lumen, we characterize a cytosolic splice variant, Cab45b, expressed in pancreatic acini. Cab45b is shown to bind45Ca2+, and, of its three EF-hand motifs, EF-hand 2 is demonstrated to be crucial for the ion binding. Cab45b is shown to interact with Munc18b in an in vitro assay, and this interaction is enhanced in the presence of Ca2+. In this assay, Cab45b also binds the Munc18a isoform in a Ca2+-dependent manner. The endogenous Cab45b in rat acini coimmunoprecipitates with Munc18b, syntaxin 2, and syntaxin 3, soluble N-ethylmaleimide-sensitive factor attachment protein receptors with key roles in the Ca2+-triggered zymogen secretion. Furthermore, we show that Munc18b bound to syntaxin 3 recruits Cab45b onto the plasma membrane. Importantly, antibodies against Cab45b are shown to inhibit in a specific and dose-dependent manner the Ca2+-induced amylase release from streptolysin-O–permeabilized acini. The present study identifies Cab45b as a novel protein factor involved in the exocytosis of zymogens by pancreatic acini.
Developmental and Cell Cycle Regulation of theDrosophilaHistone Locus Body
Authors: White Anne E. , Leslie Michelle E. , Calvi Brian R. , Marzluff William F. , Duronio Robert J.
Published: April 2007

Cyclin E/Cdk2 is necessary for replication-dependent histone mRNA biosynthesis, but how it controls this process in early development is unknown. We show that in Drosophila embryos the MPM-2 monoclonal antibody, raised against a phosphoepitope from human mitotic cells, detects Cyclin E/Cdk2-dependent nuclear foci that colocalize with nascent histone transcripts. These foci are coincident with the histone locus body (HLB), a Cajal body-like nuclear structure associated with the histone locus and enriched in histone pre-mRNA processing factors such as Lsm11, a core component of the U7 small nuclear ribonucleoprotein. Using MPM-2 and anti-Lsm11 antibodies, we demonstrate that the HLB is absent in the early embryo and occurs when zygotic histone transcription begins during nuclear cycle 11. Whereas the HLB is found in all cells after its formation, MPM-2 labels the HLB only in cells with active Cyclin E/Cdk2. MPM-2 and Lsm11 foci are present in embryos lacking the histone locus, and MPM-2 foci are present in U7 mutants, which cannot correctly process histone pre-mRNA. These data indicate that MPM-2 recognizes a Cdk2-regulated protein that assembles into the HLB independently of histone mRNA biosynthesis. HLB foci are present in histone deletion embryos, although the MPM-2 foci are smaller, and some Lsm11 foci are not associated with MPM-2 foci, suggesting that the histone locus is important for HLB integrity.
MTOC Reorientation Occurs during FcγR-mediated Phagocytosis in Macrophages
Authors: Eng Edward W. , Bettio Adam , Ibrahim John , Harrison Rene E.
Published: April 2007

Cell polarization is essential for targeting signaling elements and organelles to active plasma membrane regions. In a few specialized cell types, cell polarity is enhanced by reorientation of the MTOC and associated organelles toward dynamic membrane sites. Phagocytosis is a highly polarized process whereby particles >0.5 μm are internalized at stimulated regions on the cell surface of macrophages. Here we provide detailed evidence that the MTOC reorients toward the site of particle internalization during phagocytosis. We visualized MTOC proximity to IgG-sRBCs in fixed RAW264.7 cells, during live cell imaging using fluorescent chimeras to label the MTOC and using frustrated phagocytosis assays. MTOC reorientation in macrophages is initiated by FcγR ligation and is complete within 1 h. Polarization of the MTOC toward the phagosome requires the MT cytoskeleton and dynein motor activity. cdc42, PI3K, and mPAR-6 are all important signaling molecules for MTOC reorientation during phagocytosis. MTOC reorientation was not essential for particle internalization or phagolysosome formation. However Golgi reorientation in concert with MTOC reorientation during phagocytosis implicates MTOC reorientation in antigen processing events in macrophages.
Differential Association of Phosphatidylinositol 3-Kinase, SHIP-1, and PTEN with Forming Phagosomes
Authors: Kamen Lynn A. , Levinsohn Jonathan , Swanson Joel A.
Published: April 2007

In macrophages, enzymes that synthesize or hydrolyze phosphatidylinositol (3,4,5)-trisphosphate [PI(3,4,5)P3] regulate Fcγ receptor-mediated phagocytosis. Inhibition of phosphatidylinositol 3-kinase (PI3K) or overexpression of the lipid phosphatases phosphatase and tensin homologue (PTEN) and Src homology 2 domain-containing inositol phosphatase (SHIP-1), which hydrolyze PI(3,4,5)P3to phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2], respectively, inhibit phagocytosis in macrophages. To examine how these enzymes regulate phagosome formation, the distributions of yellow fluorescent protein (YFP) chimeras of enzymes and pleckstrin homology (PH) domains specific for their substrates and products were analyzed quantitatively. PTEN-YFP did not localize to phagosomes, suggesting that PTEN regulates phagocytosis globally within the macrophage. SHIP1-YFP and p85-YFP were recruited to forming phagosomes. SHIP1-YFP sequestered to the leading edge and dissociated from phagocytic cups earlier than did p85-cyan fluorescent protein, indicating that SHIP-1 inhibitory activities are restricted to the early stages of phagocytosis. PH domain chimeras indicated that early during phagocytosis, PI(3,4,5)P3was slightly more abundant than PI(3,4)P2at the leading edge of the forming cup. These results support a model in which phagosomal PI3K generates PI(3,4,5)P3necessary for later stages of phagocytosis, PTEN determines whether those late stages can occur, and SHIP-1 regulates when and where they occur by transiently suppressing PI(3,4,5)P3-dependent activities necessary for completion of phagocytosis.
Christian Identity in the Jewish and Graeco-Roman World
Authors: Lieu Judith
Published: April 2007

Early Christianity took shape through its texts, and is only available to us in the earliest centuries through its texts. Using contemporary models of how identity is constructed, the construction of Christian identity through texts of the first two centuries can be placed alongside that of Greeks, Romans, and Jews. Particularly important are a sense of history, defining boundaries, a distinctive practice, conceptualized space to inhabit, constructions of gender, the use of ethnic categories, and the manipulation of ‘the other’, alongside the explicit development of a technical terminology. Close analysis demonstrates the strong continuities in strategies in identity-construction between overtly Christian texts and those of their contemporaries, and provides a clearer framework for considering texts and situations that resist easy categorization. This approach offers a radical alternative to explanations of the development of early Christianity through the growth of institutions, doctrine or ritual, and allows exploration of diversity without prejudice regarding orthodoxy or canonicity. It also offers a way forward towards an understanding of the continuities of Christianity across time and place.
History, Memory, and the Invention of Tradition
Authors: Lieu Judith
Published: April 2007

The ‘invention’ of a past, an acknowledged feature in the construction of identity, can be illustrated by Graeco-Roman and Jewish writings. Conflicting claims to, and re-writings of, the same history are common. Various strategies for the appropriation of Israel’s history characterize early Christian writings, alongside the creation of new histories reaching back to Jesus. Here too, different accounts reflect competing claims to represent the true heirs of the past.
The Grammar Of Practice
Authors: Lieu Judith
Published: April 2007

Bourdieu’s concept of Habitus provides a framework for understanding the nexus of practice and belief in early Judaism and how a shared set of practices and world-view can encompass multiple interpretations. From this perspective, we can explore how self-understandings in so-called early Christian writings both overlap with each other and with Jewish patterns and differentiate themselves from them. A language of mutuality was particularly important in Christian writings, which often emphasize practice more than belief. Although these distinguish themselves from Jews and ‘pagans’, many of their values were shared in common, and perhaps lived out in cooperation more than conflict.
Embodiment and Gender
Authors: Lieu Judith
Published: April 2007

The construction of masculinity and of woman as ‘the other’ are integral to an idealized self-identity in the ancient world. These take a distinctive form in Jewish writings when combined with Biblical images of sexual immorality and anxieties about intermarriage. Despite the emphasis on the body in the incarnation, many early Christian writings continue this pattern, combined with Graeco-Roman anxieties about the body. Although some have found traces of a greater egalitarianism in early Christianity, a developing ascetical tradition reflects a conviction of the importance of the body as a site of identity but a widespread ambiguity about its expression.
Detection of antibodies to Pseudomonas aeruginosa in serum and oral fluid from patients with cystic fibrosis
Authors: Weisner Abbie M. , Chart Henrik , Bush Andrew , Davies Jane C. , Pitt Tyrone L.
Published: April 2007

Cystic fibrosis (CF) patients who are chronically infected withPseudomonas aeruginosamake serum antibodies to bacterial surface LPS as well as other pseudomonas antigens. This study investigated the feasibility of using oral fluid samples for the detection of pseudomonas antibodies in CF patients and compared these results with corresponding serum antibodies. Most strains ofP. aeruginosaproduce two forms of LPS molecule, termed A-band (described as a common antigen) and B-band (O-serotype-specific antigen), apparently bound to a common core oligosaccharide moiety. A-band LPS was demonstrated in 45 out of 49 clinical isolates ofP. aeruginosaby SDS-PAGE and immunoblotting with a specific antibody. Oral fluids were collected from 17 adult CF patients, all of whom were sputum culture positive forP. aeruginosa(13 also provided serum samples), 11 primary ciliary dyskinesia (PCD) patients and 37 healthy volunteers. Antibodies to A-band LPS were detected by immunoblotting in all of the CF patients’ oral fluids but 10 of the volunteer samples gave weak reactions with immunoblotting. Six of the PCD patients gave a weak reaction with A-band antibodies and only one demonstrated antibodies to core LPS. In a quantitative ELISA, 15 of the 17 CF patients’ oral fluids were shown to contain antibodies to A-band LPS, whilst none of the volunteer samples contained antibodies to A-band LPS. All serum samples from the CF patients were positive by both methods. Thus this is a sensitive procedure for the detection of antibodies to A-band LPS ofP. aeruginosain oral fluid and serum from patients with CF.
A case of severe pancreatitis complicated by Raoultella planticola infection
Authors: Alves M. S. , Riley L. W. , Moreira B. M.
Published: April 2007

A 45-year-old-male presented with severe pancreatitis. Two bacterial isolates obtained from peritoneal fluid and abdominal purulent secretion were identified to the species level by 15 biochemical tests and four supplementary tests as Raoultella planticola. Identification was confirmed by rpoB gene sequencing. R. planticola is difficult to identify in the clinical laboratory, and the clinical significance of this isolation remains uncharacterized. This is the first report of pancreatitis with a primary infection by R. planticola.
Enhancement of the in vitro activity of amphotericin B against the biofilms of non-albicans
Candida spp. by rifampicin and doxycycline
Authors: El-Azizi Mohamed
Published: April 2007

The in vitro activity of amphotericin B (AMB) alone and in combination with rifampicin (RIF) and doxycycline (DOX) was tested against the biofilms of 30 clinical isolates of non-albicans
Candida (NAC) species namely, Candida parapsilosis, Candida krusei and Candida glabrata. The killing activity of AMB at 10×MIC was significantly increased in combination with either antibiotic. With RIF, the killing activity increased by 20.6, 23.5 and 14 % against the biofilms of C. parapsilosis, C. krusei and C. glabrata, respectively; with DOX, the killing activity increased by 30.64, 35.28 and 31.13 %, respectively. Pre-exposure of the isolates to the same combinations significantly reduced the number of colonized cells in the biofilms by 20, 25.14 and 13.07 % with RIF for C. parapsilosis, C. krusei and C. glabrata, respectively, and by 18.94, 24.52 and 29.15 % with DOX, respectively. The data showed that combination of RIF or DOX with AMB enhanced the killing activity of the antifungal agent against biofilms of NAC species. Whether such an effect operates against biofilm-associated infections needs to be clarified by further in vivo studies.
Drug-resistant genital tuberculosis of the penis in a human immunodeficiency virus non-reactive individual
Authors: Baveja C. P. , Vidyanidhi Gumma , Jain Manisha , Kumari Trishla , Sharma V. K.
Published: April 2007

The genitourinary tract is the most common site for extrapulmonary tuberculosis (TB). Penile TB is extremely rare comprising less than 1 % of all genital TB cases in males. It most commonly presents either as a superficial ulcer on the glans or around the corona. Diagnosis of penile TB is often difficult because it can mimic numerous other diseases. The association of TB with AIDS, and the increasing incidence of multiple drug resistance has further compounded the problem. The case described herein involves a patient with multidrug-resistant smear-positive penile TB that was undiagnosed initially due to the lack of clinical suspicion of TB, and once diagnosed failed to respond to first line antitubercular drugs because of multiple drug resistance.