bluuebunny/crossref_metadata_2025 huggingface dataset:
An In Situ Approach to Create Porous Ceramic Membrane: Polymerization of Acrylamide in a Confined Environment
Authors: Chen Xinwei , Hong Liang
Published: October 2009

A new processing method for the fabrication of porous ceramic membrane has been developed via a three‐step procedure: by uniformly distributing a solid vinyl monomer (e.g., acrylamide) into a green object of ceramic through wet chemistry mixing and compression molding; polymerizing the monomer in a highly compact surrounding, leading to the formation of embedded chain assemblies of polyacrylamide; and removing the polymer via carbonization and calcination. This in situ pore‐forming strategy grants less tortuous and well‐interconnected pore channels in contrast to the approach of using polymeric porogen such as starch or cellulose. The weight% of initiator and duration of polymerization were scrutinized using thermal analysis, electron microscopy, and Hg porosimetry to understand their influences on the porous structure of sintered ceramic membrane, e.g., a thin Yttria‐stabilized zirconia disc, and ultimately its gas permeability. The advantage of this pore‐forming method lies in the fact that the monomer can be homogenously distributed in the green object in a confined space and the polymer chains formed during the in situ solid state polymerization can develop space occupancy through chain penetration and association, thus leaving behind interconnecting pore channels and more open pores after they were removed eventually. In this study, it has been shown that the resulting porous ceramics manifests a marked improvement (20–80%) in gas permeability over those fabricated by using starch as the pore‐former. Furthermore, the porous ceramics fabricated by the new method exhibited higher rapture resistivity on the similar porosity basis.
Porous Photocatalytic TiO2 Thin Films by Aerosol Deposition
Authors: Ryu Jungho , Hahn Byung‐Dong , Choi Jong‐Jin , Yoon Woon‐Ha , Lee Byoung‐Kuk , Choi Joon Hwan , Park Dong‐Soo
Published: October 2009

Porous photocatalytic TiO2 thin films were fabricated by the leaching technique, followed by aerosol deposition. Mixed powders of TiO2 and β‐tricalcium phosphate (TCP) were aerosol deposited at room temperature for the initial fabrication of composite films. After the β‐TCP phases were leached out from the composite films in a diluted HCl aqueous solution for 24 h, porous TiO2 films remained on the substrate. To fabricate these porous films, the β‐TCP content was varied from 10 to 45 wt% and submicrometer‐sized pores were formed after leaching. The porous TiO2 films showed strong initial photocatalytic activities due to the adsorption effect of the pores and the enlarged surface area.
Study of the Cytochrome b Gene Sequence in Populations of Taiwan
Authors: Hwa Hsiao‐Lin , Ko Tsang‐Ming , Chen Yao‐Chang , Chang Yih‐Yuan , Tseng Li‐Hui , Su Yi‐Ning , Lee James Chun‐I
Published: October 2009

Abstract:  The cytochrome b gene (MTCYB) has been widely used in taxonomic research. In this study, the sequence polymorphism of the MTCYB gene was determined in 417 subjects of eight populations living in Taiwan (Taiwanese Han, indigenous Taiwanese, Tao, mainland Chinese, Filipino, Thai, Vietnamese, and Caucasian). Sequence variation from the revised Cambridge Reference Sequence and genetic distance between these populations were analyzed. There were 108 variable positions with a total of 99 haplotypes. Population‐specific positions of MTCYB gene were noted in Tao and Caucasian populations. There were statistically significant differences of genetic distance between Taiwanese Han and Caucasian, between Taiwanese Han and Tao, and between Taiwanese Han and Filipino. A phylogenetic tree presents the genetic distances between these populations. In conclusion, there are sufficient sequence polymorphisms of the MTCYB gene in individuals of different populations, which may be used in the analyses of human ethnic groups in forensic casework.
SLAP, a regulator of immunoreceptor ubiquitination, signaling, and trafficking
Authors: Dragone Leonard L. , Shaw Laura A. , Myers Margaret D. , Weiss Arthur
Published: October 2009

Summary:  Src‐like adapter proteins (SLAP and SLAP‐2) constitute a family of proteins that are expressed in a variety of cell types but are studied most extensively in lymphocytes. They have been shown to associate with proximal components of the T‐cell receptor (TCR) and B‐cell receptor (BCR) signaling complexes. An interaction of SLAP with c‐Cbl leads to the ubiquitination and degradation of phosphorylated components of the TCR‐ and BCR‐signaling complexes. The absence of this process in immature SLAP‐deficient T and B cells leads to increased immunoreceptor levels due to decreased intracellular retention and degradation. We propose a model in which SLAP‐dependent regulation of immunoreceptor levels allows for finer control of immunoreceptor signaling. Thus, SLAP functions to dampen immunoreceptor signaling, thereby influencing lymphocyte development and repertoire selection.
The T‐cell‐specific adapter protein family: TSAd, ALX, and SH2D4A/SH2D4B
Authors: Lapinski Philip E. , Oliver Jennifer A. , Bodie Jennifer N. , Marti Francesc , King Philip D.
Published: October 2009

Summary: Adapter proteins play key roles in intracellular signal transduction through complex formation with catalytically active signaling molecules. In T lymphocytes, the role of several different types of adapter proteins in T‐cell antigen receptor signal transduction is well established. An exception to this is the family of T‐cell‐specific adapter (TSAd) proteins comprising of TSAd, adapter protein of unknown function (ALX), SH2D4A, and SH2D4B. Only recently has the function of these adapters in T‐cell signal transduction been explored. Here, we discuss advances in our understanding of the role of this family of adapter proteins in T cells. Their function as regulators of signal transduction in other cell types is also discussed.
Regulation of T‐lymphocyte physiology by the Chat‐H/CasL adapter complex
Authors: Alexandropoulos Konstantina , Regelmann Adam G.
Published: October 2009

Summary:  The Cas family of proteins consists of at least four members implicated in the regulation of diverse cellular processes such as cell proliferation, adhesion, motility, and cancer cell metastasis. Cas family members have conserved C‐termini that mediate constitutive heterotypic interactions with members of a different group of proteins, the NSP family. Both the Cas and NSP proteins have conserved domains that mediate protein–protein interactions with other cytoplasmic intermediates. Signaling modules assembled by these proteins in turn regulate signal transduction downstream of a variety of receptors including integrin, chemokine, and antigen receptors. T lymphocytes express the NSP protein NSP3/Chat‐H and the Cas protein Hef1/CasL, which are found in a constitutive complex in naive T cells. We recently showed that Chat‐H and Hef1/CasL regulate integrin‐mediated adhesion and promote T‐cell migration and trafficking downstream of activated chemokine receptors. It is currently unclear if the Chat‐H/CasL module also plays a role in antigen receptor signaling. Here we review our current knowledge of how Chat‐H and Hef1/CasL regulate T‐cell physiology and whether this protein complex plays a functional role downstream of T‐cell receptor activation.
Inhibitory ITAMs as novel regulators of immunity
Authors: Blank Ulrich , Launay Pierre , Benhamou Marc , Monteiro Renato C.
Published: October 2009

Summary:  Immune homeostasis is regulated by a finely tuned network of positive–negative regulatory mechanisms that guarantees proper surveillance avoiding hyperactivity that would lead to autoimmunity and inflammatory diseases. Immune responses involve the activation of immunoreceptors that contain tyrosine‐based activation motifs (ITAMs). One arm of control involves immunoreceptor tyrosine‐based inhibitory motif (ITIM)‐bearing receptors, which upon co‐aggregation initiate an inhibitory signal through recruitment of signal‐aborting phosphatases. Recently, a new immunoregulatory function has been ascribed to ITAMs, which represent in fact dual function modules that, under specific configurations termed inhibitory ITAM (ITAMi), can propagate inhibitory signals. One paradigm is the immunoglobulin A (IgA) Fc receptor (FcαRI), which, upon interaction with IgA monomers in the absence of antigen, initiates a powerful inhibitory signal involving Src homology 2 domain‐containing phosphatase 1 (SHP‐1) recruitment that suppresses cell activation launched by a whole variety of heterologous receptors without co‐aggregation. This explains the long known function of IgA as an anti‐inflammatory isotype. The importance of this control mechanism in immune homeostasis is underlined by the high incidence of autoimmune and allergic diseases in IgA‐deficient patients. ITAMi is now described for an increasing number of immunoreceptors with multiple roles in immunity. ITAMi signaling is also exploited by Escherichia coli to achieve immune evasion during sepsis. Here, we review our current understanding of ITAMi regulatory mechanisms in immune responses and discuss its role in immune homeostasis.
Organization of proximal signal initiation at the TCR:CD3 complex
Authors: Guy Clifford S. , Vignali Dario A. A.
Published: October 2009

Summary:  The series of events leading to T‐cell activation following antigen recognition has been extensively investigated. Although the exact mechanisms of ligand binding and transmission of this extracellular interaction into a productive intracellular signaling sequence remains incomplete, it has been known for many years that the immunoreceptor tyrosine activation motifs (ITAMs) of the T‐cell receptor (TCR):CD3 complex are required for initiation of this signaling cascade because of the recruitment and activation of multiple protein tyrosine kinases, signaling intermediates, and adapter molecules. It however remains unclear why the TCR:CD3 complex requires 10 ITAMs, while many other ITAM‐containing immune receptors, such as Fc receptors (FcRs) and the B cell receptor (BCR), contain far fewer ITAMs. We have recently demonstrated that various parameters of T cell development and activation are influenced by the number, as well as location and type, of ITAMs within the TCR:CD3 complex and hence propose that the TCR is capable of ‘scalable signaling’ that facilitates the initiation and orchestration of diverse T‐cell functions. While many of the underlying mechanisms remain hypothetical, this review intends to amalgamate what we have learned from conventional biochemical analyses regarding initiation and diversification of T‐cell signaling, with more recent evidence from molecular and fluorescent microscopic analyses, to propose a broader purpose for the TCR:CD3 ITAMs. Rather than simply signal initiation, individual ITAMs may also be responsible for the differential recruitment of signaling and regulatory molecules which ultimately affects T‐cell development, activation and differentiation.
HIV Nef is Secreted in Exosomes and Triggers Apoptosis in Bystander CD4+ T Cells
Authors: Lenassi Metka , Cagney Gerard , Liao Maofu , Vaupotič Tomaž , Bartholomeeusen Koen , Cheng Yifan , Krogan Nevan J. , Plemenitaš Ana , Peterlin B. Matija
Published: October 2009

The HIV accessory protein negative factor (Nef) is one of the earliest and most abundantly expressed viral proteins. It is also found in the serum of infected individuals (Caby MP, Lankar D, Vincendeau‐Scherrer C, Raposo G, Bonnerot C. Exosomal‐like vesicles are present in human blood plasma. Int Immunol 2005;17:879–887). Extracellular Nef protein has deleterious effects on CD4+ T cells (James CO, Huang MB, Khan M, Garcia‐Barrio M, Powell MD, Bond VC. Extracellular Nef protein targets CD4+ T cells for apoptosis by interacting with CXCR4 surface receptors. J Virol 2004;78:3099–3109), the primary targets of HIV, and can suppress immunoglobulin class switching in bystander B cells (Qiao X, He B, Chiu A, Knowles DM, Chadburn A, Cerutti A. Human immunodeficiency virus 1 Nef suppresses CD40‐dependent immunoglobulin class switching in bystander B cells. Nat Immunol 2006;7:302–310). Nevertheless, the mode of exit of Nef from infected cells remains a conundrum. We found that Nef stimulates its own export via the release of exosomes from all cells examined. Depending on its intracellular location, these Nef exosomes form at the plasma membrane, late endosomes or both compartments in Jurkat, SupT1 and primary T cells, respectively. Nef release through exosomes is conserved also during HIV‐1 infection of peripheral blood lymphocytes (PBLs). Released Nef exosomes cause activation‐induced cell death of resting PBLs in vitro. Thus, HIV‐infected cells export Nef in bioactive vesicles, which facilitate the depletion of CD4+ T cells that is a hallmark of acquired immunodeficiency syndrome (AIDS).
Design and statistical analysis of oral medicine studies: common pitfalls
Authors: Baccaglini L , Shuster JJ , Cheng J , Theriaque DW , Schoenbach VJ , Tomar SL , Poole C
Published: October 2009

Oral Diseases (2010) 16, 233–241

A growing number of articles are emerging in the medical and statistics literature that describe epidemiologic and statistical flaws of research studies. Many examples of these deficiencies are encountered in the oral, craniofacial, and dental literature. However, only a handful of methodologic articles have been published in the oral literature warning investigators of potential errors that may arise early in the study and that can irreparably bias the final results. In this study, we briefly review some of the most common pitfalls that our team of epidemiologists and statisticians has identified during the review of submitted or published manuscripts and research grant applications. We use practical examples from the oral medicine and dental literature to illustrate potential shortcomings in the design and analysis of research studies, and how these deficiencies may affect the results and their interpretation. A good study design is essential, because errors in the analysis can be corrected if the design was sound, but flaws in study design can lead to data that are not salvageable. We recommend consultation with an epidemiologist or a statistician during the planning phase of a research study to optimize study efficiency, minimize potential sources of bias, and document the analytic plan.
Living Arrangements During Childrearing Years and Later Health of African American Mothers
Authors: Fothergill Kate E. , Ensminger Margaret E. , Green Kerry M. , Thorpe Roland J. , Robertson Judy , Kasper Judith D. , Juon Hee‐Soon
Published: October 2009

Using longitudinal data from the Woodlawn Project (N=680), this study examined how patterns of living arrangements among a community cohort of African American mothers were associated with later physical and emotional health. We identified eight patterns of stability and transition in living arrangements during the childrearing years. Health outcomes include SF‐36 Physical Functioning, SF‐36 Bodily Pain, depressed mood, and anxious mood. Specific patterns of living arrangements were related to later health, controlling for age, earlier health, education, and poverty. Poverty explained many, but not all, of the relationships between living arrangements and health. Findings underscored the benefits of social support and social integration and highlighted the negative effects of marital dissolution on health.
Comparison of the canal centring ability of K3, Liberator and EZ Fill Safesiders by using spiral computed tomography
Authors: Venkateshbabu Nagendrababu , Emmanuel Satish , Santosh Goud K. , Kandaswamy Deivanayagam
Published: October 2009

The purpose of the study was to compare the canal centring ability of K3, Liberator and EZ Fill Safesiders by using spiral computed tomography (SCT). Forty curved mandibular premolars were selected. Before and after instrumentation teeth were scanned by spiral computed tomography and nine cross‐sectional views of each tooth were obtained at 1.5 mm intervals from the apex. Canal centring ratio was calculated. Mean values were compared between different study groups by using one‐way anova followed by Tukey – HSD procedure. At 1st, 2nd and 3rd levels, there was no statistical difference between groups. From 4th to 9th levels Safesider showed higher centring ratio, followed by Liberator and K3. Safesider showed better canal centring ability followed by Liberator and K3.
Safety and immunogenicity of an inactivated thimerosal‐free influenza vaccine in infants and children
Authors: Nolan Terry , Richmond Peter C. , McVernon Jodie , Skeljo Maryanne V. , Hartel Gunter F. , Bennet Jillian , Basser Russell L.
Published: October 2009

Objective  Few prospective studies of inactivated split virion influenza vaccine have been conducted in infants and children. Our objective was to evaluate the safety, reactogenicity and immunogenicity of a thimerosal‐free inactivated influenza vaccine (Fluvax®; CSL Limited, Parkville, Australia) in children aged 6 months to <9 years.

Methods  A prospective, open‐label, phase III clinical trial was conducted in 298 healthy children previously unvaccinated with influenza, commencing in the Southern Hemisphere 2005 autumn. Participants were divided into two groups (Group A: ≥6 months to <3 years; Group B: ≥3 years to <9 years), and received two doses of the 2005 vaccine, and one dose of the 2006 vaccine one year later (Group A: 0·25 ml per dose; Group B: 0·5 ml per dose). Vaccine safety and reactogenicity was evaluated for 30 days after each dose. Immunogenicity was assessed using hemagglutination inhibition and single radial hemolysis assays.

Results  There were no withdrawals due to adverse events (AEs). The majority of solicited local and systemic AEs were of mild severity. A maximum intensity of severe was reported for injection site pain and fever by only 3·0% and 3·4% of participants, respectively. The vaccine was immunogenic for all antigens, with ≥95% of both younger and older children achieving seroprotection after dose 2.

Conclusions  This thimerosal‐free inactivated influenza vaccine had a favorable safety profile and was immunogenic in children aged ≥6 months and <9 years. Primary and booster vaccination produced consistently immunogenic responses including in children under 3 years of age receiving 0·25 ml doses of vaccine.
Genetic cardiovascular risk factors and age‐related macular degeneration
Authors: Haas Paulina , Aggermann Tina , Steindl Kerstin , Krugluger Walter , Pühringer Helene , Oberkanins Christian , Frantal Sophie , Binder Susanne
Published: October 2009

Purpose:  To investigate the association between genetic cardiovascular risk factors and exudative age‐related macular degeneration (AMD) in a White Austrian population.

Methods:  Seventy‐five unrelated AMD patients and 75 unrelated healthy, sex‐ and age‐matched control patients were genotyped for the following 19 single nucleotide polymorphisms (SNPs) in 14 different genes: blood coagulation factor V (FV) R506Q, factor II (prothrombin) G20210A and factor XIII (FXIII) V34L; 5,10‐methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C; plasminogen activator inhibitor 1 (PAI‐1) 4G/5G; endothelial protein C receptor (EPCR) 4600 A>G (A3 haplotype), 4678 G>C (A1 haplotype); apolipoprotein B (ApoB) R3500Q; apolipoprotein E (ApoE) E2/E3/E4; β‐fibrinogen −455 G>A; human platelet antigen 1 (HPA1) a/b; angiotensin‐converting enzyme (ACE) I/D; endothelial nitric oxide synthase (eNOS) 786 T>C, 894 G>T; lymphotoxin alpha (LTA) 804 C>A and 9p21 rs10757278. Genotyping was carried out by polymerase chain reaction (PCR) followed by reverse hybridization (CVD StripAssays; ViennaLab Diagnostics, Vienna, Austria).

Results:  No statistically significant association could be observed between AMD and the investigated genetic risk factors for cardiovascular disease (CVD). All factors seem to be uniformly distributed in the two groups of AMD patients and healthy controls. Two variables –β‐fibrinogen: −455 G>A (p = 0.0786) and apolipoprotein E4 (p = 0.0636) – were not as far from association as the others.

Conclusion:  Our data show that the 19 tested CVD risk markers do not play a significant role in AMD. β‐Fibrinogen and apolipoprotein E4 should be examined in a larger cohort.
Day 1 postoperative intraocular pressure spike in vitreoretinal surgery (VDOP1)
Authors: Wong Roger , Gupta Bhaskar , Williamson Thomas H. , Laidlaw D. Alistair H.
Published: October 2009

Purpose:  To classify the clinical characteristics that might identify patients who may not require next‐day follow‐up following routine vitreoretinal intervention.

Methods:  Prospective case series.

Results:  The only statistically significant factors for raised intraocular pressure (IOP) were gas tamponade and preoperative raised IOP. 44.7% (17/38) of patients with preoperative IOP ≥ 20 mmHg had postoperative IOP ≥ 30 mmHg while 8.6% (17/197) of patients with preoperative IOP < 20 mmHg had postoperative IOP ≥ 30 mmHg (p = 0.0001). Phacoemulsification did not increase risk for a postoperative IOP spike. There was a 20–21% risk of postoperative IOP > 30 mmHg for patients with gas tamponade. All patients with no tamponade with IOP > 30 mmHg had preoperative IOP ≥ 20 mmHg.

Conclusion:  Uncomplicated vitreoretinal procedures with preoperative IOP of< 20 mmHg and no gas tamponade are unlikely to have uncontrolled IOP spike at day 1.
Prevention of Fracture of Cracked Steel Bars Using Laser: Part III—Case of High Carbon Steel
Authors: Kato Akira
Published: October 2009

The effect of laser welding on prevention of the fracture of cracked shafts of a high carbon steel are presented. Static tensile strength and rotary bending fatigue strength were obtained using shaft specimens of AISI W1 which were welded by a CO2 laser around a precrack. Since the welded region became extremely hard and brittle, both the strengths of laser-welded specimens were lower than those of non-welded specimens. However, the strengths were increased higher than those of non-welded specimens after tempering the specimens. It was found that when tempered at 600°C after laser welding, the rotary bending fatigue strength of specimens with a crack smaller than 12 mm rose similar to that of the base metal, and when tempered at 700° C, the static tensile strength of specimens with a crack smaller than 12mm rose similar to that of the base metal. Therefore, it was shown that the laser welding is very effective to prevent fracture of high carbon steels.
Measurement of Non-Uniform Residual Stresses Using the Hole-Drilling Method. Part I—Stress Calculation Procedures
Authors: Schajer G. S.
Published: October 2009

The Incremental Strain, Average Stress, Power Series, and Integral methods are examined as procedures for determining non-uniform residual stress fields using strain relaxation data from the hole drilling method. Some theoretical shortcomings in the Incremental Strain and Average Stress methods are described. It is shown that these two traditional methods are in fact approximations of the Integral Method. Theoretical estimates of the errors involved are presented for various stress fields. Also, some simple transformations of stress and strain variables are introduced so as to decouple the stress/strain equations and simplify the numerical solution.
Resonant structures based on amorphous silicon suboxide doped with Er3+ with silicon nanoclusters for an efficient emission at 1550nm
Authors: Figueira D. S. L. , Mustafa D. , Tessler L. R. , Frateschi N. C.
Published: October 2009

The authors present a resonant approach to enhance 1550nm emission efficiency of amorphous silicon suboxide doped with Er3+ (a-SiOx⟨Er⟩) layers with silicon nanoclusters (Si-NC). Our results show an important result toward enabling the use of silicon-based material for active photonic component fabrication. Two distinct techniques were combined to fabricate a structure that allowed increasing approximately 12 times the 1550nm emission. First, layers of SiO2 were obtained by conventional wet oxidation and a-SiOx⟨Er⟩ matrix was deposited by reactive rf cosputtering. Second, an extra pump channel (I15∕24 to I9∕24) of Er3+ was created due to Si-NC formation on the same a-SiOx⟨Er⟩ matrix via a hard annealing at 1150°C. The SiO2 and the a-SiOx⟨Er⟩ thicknesses were designed to support resonances near the pumping wavelength (∼500nm), near the Si-NC emission (∼800nm) and near the a-SiOx⟨Er⟩ emission (∼1550nm) enhancing the optical pumping process.
Complete Reconstitution of a Highly Reducing Iterative Polyketide Synthase
Authors: Ma Suzanne M. , Li Jesse W.-H. , Choi Jin W. , Zhou Hui , Lee K. K. Michael , Moorthie Vijayalakshmi A. , Xie Xinkai , Kealey James T. , Da Silva Nancy A. , Vederas John C. , Tang Yi
Published: October 2009

Dissecting Megaenzyme Mechanisms

Filamentous fungi contain a class of multidomain enzymes, the highly-reducing iterative polyketide synthases (HR-IPKSs), which produce important natural products such as the cholesterol-lowering drug lovastatin. To produce their complex products, these megasynthases use multiple catalytic domains repeatedly in different combinations, but mechanistic details remain unclear.

Ma
et al.

(p.
589
) now report in vitro reconstitution of the complete catalytic function of lovastatin nonaketide synthase (LovB), the megasynthase that works together with a partner enzyme LovC to complete nearly 40 chemical steps required to construct the core of lovastatin. Analyses of the dependency of enzyme function on cofactors and on the partner enzyme elucidate the programming rules for this system.
Carbenes As Catalysts for Transformations of Organometallic Iron Complexes
Authors: Lavallo Vincent , Grubbs Robert H.
Published: October 2009

Stretching Carbene Versatility

Stable N-heterocyclic carbene (NHC) molecules are versatile catalysts for organic reactions (see the Perspective by

Albrecht

).
Lavallo and Grubbs
(p.
559
) now show that these molecules can also catalyze organometallic transformations. Specifically, the carbenes induce coupling of monomeric iron olefin complexes to form clusters incorporating three or four bonded iron centers. Initial coordination of carbene to iron may facilitate formation of an iron-iron bond with a second complex. In a related development,

Aldeco-Perez
et al.

(p.
556
) prepared an NHC isomer in which the divalent carbon is shifted so that it no longer lies between the nitrogens. The compound forms stable complexes with both gold and CO
2
.
Carbenes in Action
Authors: Albrecht Martin
Published: October 2009

Chemists are taming a highly reactive class of molecules for use in catalysis and synthesis.
Structural Mechanism of Abscisic Acid Binding and Signaling by Dimeric PYR1
Authors: Nishimura Noriyuki , Hitomi Kenichi , Arvai Andrew S. , Rambo Robert P. , Hitomi Chiharu , Cutler Sean R. , Schroeder Julian I. , Getzoff Elizabeth D.
Published: October 2009

ABA Receptor Up Close

Plants face a variety of environmental stresses, including drought, salinity, and cold. In the face of such stresses, the plant hormone abscisic acid (ABA) triggers adaptive physiological responses.

Nishimura
et al.

(p.
1373
, published online 22 October; see the Perspective by

Sussman and Phillips

) have now analyzed the crystal structure of one member of the ABA receptor family, PYR1 (pyrabactin resistance 1). The ABA molecule binds within an internal pocket of PYR1, where it probably induces a conformational change.
The Promise of Drought-Tolerant Corn
Authors: Service Robert F.
Published: October 2009

The biofuels drive is just one of several factors that are increasing the demand for corn and other crops. Seed companies are responding by creating seed varieties able to tolerate drought, which could be particularly useful in reducing water demand in areas dependent on declining groundwater reserves.
Experimental Infection of Reindeer with Cervid Herpesvirus 2
Authors: das Neves Carlos G. , Mørk Torill , Godfroid Jacques , Sørensen Karen K. , Breines Eva , Hareide Ellinor , Thiry Julien , Rimstad Espen , Thiry Etienne , Tryland Morten
Published: October 2009

Cervid herpesvirus 2 (CvHV2) has been isolated from reindeer (
Rangifer tarandus tarandus
), and serological data indicate that in reindeer this virus is endemic in Fennoscandia, Alaska, Canada, and Greenland. CvHV2 has been described as a cause of subclinical genital infections in reindeer, but little information on primary infections exists. In this study, six seronegative and presumably pregnant reindeer were allocated to one of two groups. Two animals were inoculated with CvHV2 intratracheally, and two animals intravaginally, with one control animal in each group receiving sterile water. Mild hyperthermia and serous discharges from the vagina and nose were observed. No abortions were recorded, but one calf died shortly after birth. Inoculated animals seroconverted and had neutralizing antibodies after days 7 to 10 postinfection. CvHV2 was detected by PCR in nasal and vaginal swabs from animals in both groups but could be isolated only from nasal swabs in the respiratory group and from vaginal swabs in the genital group. CvHV2 was detected by PCR in various organs and tissues postmortem. In control animals, the virus could not be isolated in spite of PCR-positive nasal and vaginal swab samples and some degree of positive immunostaining. One of the animals that were inoculated intratracheally developed a hemorrhagic, necrotizing bronchopneumonia, which was CvHV2 positive by PCR and immunohistochemistry. We conclude that CvHV2 can cause systemic infection, that both genital and respiratory inoculations can lead to virus shedding, and that the virus can infect the fetus in utero.
Monocyte-Derived Interleukin-10 Depresses the
Bordetella pertussis
- Specific Gamma Interferon Response in Vaccinated Infants
Authors: Dirix V. , Verscheure V. , Goetghebuer T. , Hainaut M. , Debrie A. S. , Locht C. , Mascart F.
Published: October 2009

Antigen-specific gamma interferon (IFN-γ) has been demonstrated to participate in protection against
Bordetella pertussis
infection. Circulating mononuclear cells from
B. pertussis
-infected and from pertussis-vaccinated infants secrete high amounts of IFN-γ after in vitro stimulation by
B. pertussis
antigens, but with a large variation in the secreted IFN-γ levels between individuals. We show here that the inhibition of the specific IFN-γ response can be at least partially attributed to IL-10 secretion by monocytes. This IL-10 secretion was not associated with polymorphisms at positions −1082, −819, and −592 of the IL-10 gene promoter, suggesting that other genetic or environmental factors affect IL-10 expression and secretion.
Immunologic Paradox in the Diagnosis of Tuberculous Meningitis
Authors: Kim Sung-Han , Kim Yang Soo
Published: October 2009

We report a patient with microbiologically documented tuberculous meningitis showing that the therapeutic paradox, a therapy-induced switch to a neutrophil-predominant situation in the differential cell counts of cerebrospinal fluid specimens, had a correlation with an immunologic paradox, an increased
Mycobacterium tuberculosis
-specific gamma interferon-producing T-cell response.
Presence of Genes Encoding the Panton-Valentine Leukocidin Exotoxin Is Not the Primary Determinant of Outcome in Patients with Complicated Skin and Skin Structure Infections Due to Methicillin-Resistant
Staphylococcus aureus
: Results of a Multinational Trial
Authors: Bae In-Gyu , Tonthat Giang T. , Stryjewski Martin E. , Rude Thomas H. , Reilly Lindsay F. , Barriere Steven L. , Genter Fredric C. , Corey G. Ralph , Fowler Vance G.
Published: October 2009

The role of Panton-Valentine leukocidin (PVL) in determining the severity and outcome of complicated skin and skin structure infections (cSSSI) caused by methicillin (meticillin)-resistant
Staphylococcus aureus
(MRSA) is controversial. We evaluated potential associations between clinical outcome and PVL status by using MRSA isolates from patients enrolled in two large, multinational phase three clinical trials assessing telavancin for the treatment of cSSSI (the ATLAS program). MRSA isolates from microbiologically evaluable patients were genotyped by pulsed-field gel electrophoresis (PFGE) and PCR for
pvl
and 31 other putative virulence determinants. A single baseline pathogen of MRSA was isolated from 522 microbiologically evaluable patients (25.1%) among 2,079 randomized patients. Of these MRSA isolates, 83.2% (432/519) exhibited the USA300 PFGE genotype and 89.1% (465/522) were
pvl
positive. Patients with
pvl
-positive MRSA were more likely than those with
pvl
-negative MRSA to be young, to be North American, and to present with major abscesses (
P
< 0.001 for each). Patients were significantly more likely to be cured if they were infected with
pvl
-positive MRSA than if they were infected with
pvl
-negative MRSA (91.6% versus 80.7%;
P
= 0.015). This observation remained statistically significant after adjustment for presence of abscess, fever, or leukocytosis; infection size; diabetes; patient age; and study medication received. The
fnbA
,
cna
,
sdrC
,
map-eap
,
sed
,
seg
,
sei
,
sej
, SCC
mec
type IV, and
agr
group II genes were also associated with clinical response (
P
< 0.05). This contemporary, international study demonstrates that
pvl
was not the primary determinant of outcome in patients with MRSA cSSSI.
MDA5 and MAVS Mediate Type I Interferon Responses to Coxsackie B Virus
Authors: Wang Jennifer P. , Cerny Anna , Asher Damon R. , Kurt-Jones Evelyn A. , Bronson Roderick T. , Finberg Robert W.
Published: October 2009

Coxsackie B viruses (CVB) are enteroviruses that have been associated with a variety of human diseases, including myocarditis. In the present study, we found that MDA5 and its adaptor molecule MAVS are critical for type I interferon responses to CVB, since the absence of either MAVS or MDA5 leads to deficient type I interferon production and early mortality in mice infected with CVB. Pancreatic and hepatic necrosis were observed on histopathological examination of MAVS and MDA5 knockout mice infected with CVB. Inflammatory cytokine production in response to systemic CVB infection was independent of MAVS. Surprisingly, virus titers were not elevated in MAVS-deficient mice, despite significant reductions in type I interferon levels. These data highlight the importance of type I interferon in host defense and provide insight on the mechanisms of innate immune responses following coxsackievirus infection.
The Rubella Virus Capsid Protein Inhibits Mitochondrial Import
Authors: Ilkow Carolina S. , Weckbecker Daniel , Cho Woo Jung , Meier Stephan , Beatch Martin D. , Goping Ing Swie , Herrmann Johannes M. , Hobman Tom C.
Published: October 2009

The rubella virus (RV) capsid is an RNA-binding protein that functions in nucleocapsid assembly at the Golgi complex, the site of virus budding. In addition to its role in virus assembly, pools of capsid associate with mitochondria, a localization that is not consistent with virus assembly. Here we examined the interaction of capsid with mitochondria and showed that this viral protein inhibits the import and processing of mitochondrial precursor proteins in vitro. Moreover, RV-infected cells were found to contain lower intramitochondrial levels of matrix protein p32. In addition to inhibiting the translocation of substrates into mammalian mitochondria, capsid efficiently blocked import into yeast mitochondria, thereby suggesting that it acts by targeting a highly conserved component of the translocation apparatus. Finally, mutation of a cluster of five arginine residues in the amino terminus of capsid, though not interfering with its binding to mitochondria, abrogated its ability to block protein import into mitochondria. This is the first report of a viral protein that affects the import of proteins into mitochondria.
Associations between HLA Class I Alleles and Escape Mutations in the Hepatitis B Virus Core Gene in New Zealand-Resident Tongans
Authors: Abbott William G. H. , Tsai Peter , Leung Euphemia , Trevarton Alex , Ofanoa Malakai , Hornell John , Gane Edward J. , Munn Stephen R. , Rodrigo Allen G.
Published: October 2009

The full repertoire of hepatitis B virus (HBV) peptides that bind to the common HLA class I molecules found in areas with a high prevalence of chronic HBV infection has not been determined. This information may be useful for designing immunotherapies for chronic hepatitis B. We identified amino acid residues under positive selection pressure in the HBV core gene by phylogenetic analysis of cloned DNA sequences obtained from HBV DNA extracted from the sera of Tongan subjects with inactive, HBeAg-negative chronic HBV infections. The repertoires of positively selected sites in groups of subjects who were homozygous for either HLA-B*4001 (
n
= 10) or HLA-B*5602 (
n
= 7) were compared. We identified 13 amino acid sites under positive selection pressure. A significant association between an HLA class I allele and the presence of nonsynonymous mutations was found at five of these sites. HLA-B*4001 was associated with mutations at E77 (
P
= 0.05) and E113 (
P
= 0.002), and HLA-B*5602 was associated with mutations at S21 (
P
= 0.02). In addition, amino acid mutations at V13 (
P
= 0.03) and E14 (
P
= 0.01) were more common in the seven subjects with an HLA-A*02 allele. In summary, we have developed an assay that can identify associations between HLA class I alleles and HBV core gene amino acids that mutate in response to selection pressure. This is consistent with published evidence that CD8
+
T cells have a role in suppressing viral replication in inactive, HBeAg-negative chronic HBV infection. This assay may be useful for identifying the clinically significant HBV peptides that bind to common HLA class I molecules.
The role of the sports and exercise medicine physician in the National Health Service: a questionnaire-based survey
Authors: O’Halloran P , Brown V Tzortziou , Morgan K , Maffulli N , Perry M , Morrissey D
Published: October 2009

Objectives:

To investigate the opinions of general practitioners, orthopaedic surgeons, rheumatologists, sport and exercise medicine (SEM) registrars and public health consultants on training, caseload, the most appropriate setting and the position of SEM within the National Health Service (NHS) in the UK.

Method:

A cross-sectional questionnaire-based survey investigated the opinions of the above professionals from three primary care trusts and associated hospitals in London and Birmingham.

Results:

With a 50% response rate (n = 226), 93% (208/224) of participants felt that there was a role for SEM in the NHS. 56% (124/223) agreed that this role should be in both primary and secondary care. 64% (136/212) of participants felt that their practice would benefit from the input of a SEM physician and 95% (191/202) would consider referring patients to SEM services. 74% (165/222) agreed that SEM should have a public health role, and 63% (140/222) believed that these responsibilities should be evenly balanced with the treatment of sports injuries. Despite the emphasis on public health work from SEM policy makers, none of the SEM registrars selected public health as an important training area. 31% (44/140) of participants felt that a lack of education in the medical profession regarding SEM represented the greatest hindrance to its development in the NHS.

Conclusion:

Several areas of agreement were demonstrated across the specialties, many of which matched the views of policy makers. This study involved participants from a range of cognate disciplines and was the first to investigate this issue since SEM was recognised as a specialty in 2005.
Étude du polymorphisme intraclonal chez le Verticillium albo-atrum, forme à microsclérotes. II. Influence de l'âge des thalles sur leur descendance par microconidies
Authors: Boisson Claude , Lahlou Houria
Published: October 2009

Aging of thalli of two microsclerotial strains of Verticillium albo-atrum isolated from tomato and avocado in Morocco affected microconidia viability and the phenotype of regenerated thalli. The percentage of regeneration of microconidia harvested in thalli of increasing age was first high; it diminished to a minimum, then increased again reaching high values. The age of cultures for which these variations arose as well as the different values of percentage of regeneration were dependent on the isolate and on culture conditions. Microconidia from young cultures produced only wild thalli; microconidia from old cultures also regenerated stable morphological variants, which increased in number with the age of the culture. Variants were numerous only when the age of cultures was equal or higher than the age for which the percentage of regeneration was minimum; they probably arose from late forming microconidia on old thalli.
Ultrastructural aspects of conidiogenesis in the entomogenous hyphomycete Nomuraea rileyi
Authors: Pendland J. C. , Boucias D. G.
Published: October 2009

Conidia in Nomuraea rileyi are produced basipetally from a phialide apex. Production of primary and all successive conidia appears to be enteroblastic, and only the inner, newly formed wall layer of the phialide surrounds developing conidia. Conidium formation ceases as layers of inner wall material accumulate at the phialide apex. In some cases, a pluglike structure resembling a Woronin body may cause cessation of conidiogenesis. Conidia are delimited by formation of a double septum. Since one half of the septum forms the base of the "older" conidium and the other half forms the apex of the next conidium, separation of successive conidia is schizolytic. Plasmalemmasomes, lomasomes, and smooth endoplasmic reticulum are often seen in association with septa and walls of conidiogenous cells. Transverse fibrils may be observed in some walls. Extensive vacuolization is common in older cells. Glycogen is present in conidiogenous cells and in conidia, which become very electron dense as they mature. An extranuclear plaque, an ascomycetous characteristic, may be observed on the nuclear envelope.
Effect of Fusarium oxysporum f. sp. apii on seed germination in celery (Apium graveolens)
Authors: Orton T. J.
Published: October 2009

The effects of Fusarium oxysporum f. sp. apii on celery seed germination were investigated with the hope of developing a germ-plasm screening procedure with seeds. Seeds of celery lines known to exhibit a range of disease responses to the pathogen as whole plants were inoculated with two different virulence types and in two ways: (1) spore–mycelial suspensions in potato dextrose broth (PDB), and (2) spore–mycelial suspensions in sterile H2O. Inoculum in PDB retarded germination in all celery lines and the relative degree of this retardation was congruent with virulence of the pathogen and, in general, relative retardation of germination was also in agreement with whole-plant disease response. Inoculum in H2O stimulated germination and the degree of stimulation also appeared related to degree of whole-plant disease response. Extracts from disease lesions incited by F. oxysporum f. sp. apii on celery exerted a dose-dependent inhibition of germination but filtrates from 14-day-old cultures in PDB had no significant effect.
An undescribed species of Inocybe from mine wastes in Ontario
Authors: Malloch David
Published: October 2009

An undescribed species of Inocybe, I. immigrans sp. nov., has been encountered several times on mine wastes in north-eastern and east-central Ontario. It is characterized by large smooth basidiospores, a dark entirely cystidiate bulbous stipe, and a brown scaly pileus. It is thought to be ectomycorrhizal and has been collected in association with Betula papyrifera, Populus balsamifera, and Salix spp.
Niche differentiation between two rhizomatous plant species: Typha latifolia and Typha angustifolia
Authors: Grace James B. , Wetzel Robert G.
Published: October 2009

Morphological characteristics and biomass allocation were examined for two species of Typha in a small pond. Typha latifolia differed from T. angustifolia in having shorter leaf height, wider leaves, greater leaf surface area, greater allocation to leaves, greater number of smaller rhizomes, greater allocation to vegetative reproduction, smaller allocation to sexual reproduction, and fewer number of flowering plants. For both species, those plants growing in deeper water had taller leaves, a greater allocation to leaves, and a decreased allocation to sexual and vegetative reproduction. Previous studies of these populations have demonstrated that these two species are segregated according to water depth with T. latifolia being competitively superior in shallow water (less than 15 cm) but T. angustifolia having the potential to grow in deeper water than T. latifolia. Results from this study indicate that T. latifolia is competitively superior in shallow water because of its greater leaf surface area but that T. angustifolia's tall, narrow leaves and large rhizome storage permit it to grow in deeper water than T. latifolia. The greater amount of sexual reproduction in T. angustifolia is correlated with its more restricted distribution and fugitive nature.
Slope recession in the Onefour Badlands, Alberta, Canada: an initial appraisal of contrasted moisture regimes
Authors: Barendregt R. W. , Ongley E. D.
Published: October 2009

The initial 2 years (1975–1977) of a 10 year program of slope process measurement in the Onefour Badlands of Alberta, Canada, has encompassed two highly contrasted moisture regimes with measurable differences to process–response mechanisms. The Onefour Badlands are one of several distinctive and recurring dryland erosional landform elements which together are responsible for large sediment yields in Southeastern Alberta. Somewhat unique among temperate semiarid lands, the study area undergoes limited snowmelt runoff effects during the spring months which, together with typical temperate semiarid runoff processes, produces an extensive contemporary pedimented (glacis) surface.With a 48 year average precipitation of 32 cm, the 46 cm in the first year caused an average scarp retreat of 8.6 mm but with little erosion of the glacis surfaces. During the second drier year (20 cm), the scarps retreated only an average 3.7 mm. There was, however, active sheet erosion of the glacis surfaces during the second year which amounted to an average 7.0 mm. Observations of debris accumulation, runoff mechanisms, and measured profile changes suggest that glacis surfaces operate as transport slopes during wet years when there is significantly increased scarp erosion. During drier years when there appears to be much less scarp erosion, the glacis surfaces become a sediment source.
Skeleton Lake, Ontario—evidence for a Paleozoic impact crater
Authors: Waddington E. D. , Dence M. R.
Published: October 2009

Skeleton Lake, Ontario (lat. 45°15′N, long. 70°27′W), contains an approximately circular depression, 3.6 km in diameter and 65 m maximum depth, which appears to truncate the regional geological and physiographic trends of the local Precambrian gneisses and migmatites. Outcrops of breccia are present on the northern lake shore, and erratics of Ordovician limestone, evidently scoured from the lake bottom by glaciation, occur along the south shore. Aeromagnetic data indicate a field of low uniform magnetic intensity across the lake, in contrast to the variable regional magnetic pattern. A detailed gravity survey has revealed a circular gravity anomaly of −3.3 ± 0.7 mGal (−33 ± 7 μm∙s−2) over the depression. The anomaly has been modelled by bowl-shaped distributions of low density brecciated rocks. These observations suggest that the Skeleton Lake depression is the eroded remnant of an impact crater of Paleozoic age which has been preserved by a covering of Ordovician sediments until recently exhumed.