bluuebunny/crossref_metadata_2025 huggingface dataset:
Can I Trust You to Trust Me?
Authors: Ferrin Donald L. , Bligh Michelle C. , Kohles Jeffrey C.
Published: August 2007

Drawing on the diverse literatures of game theory, negotiation, interpersonal trust, and interorganizational relationships, the authors develop a theoretical model of the relationships among trust, monitoring, and cooperation in interpersonal and intergroup interactions. They use the concept of isomorphism as a basis for developing this theory, observing that although the constructs may differ in structure across levels, they may still have similar functions. They also argue that a more explicit distinction between own and other's trust, own and other's monitoring, and own and other's cooperation is critical for better understanding the relationships among trust, monitoring, and cooperation. By making this distinction between own and other and by drawing on four distinct literatures, the authors provide greater precision in how trust, monitoring, and cooperation are defined, and they provide a more comprehensive and variegated view of the relationships among the constructs through the development of specific research propositions. They conclude with potential contributions of the model for future research and practice.
Histone H2B as a functionally important plasminogen receptor on macrophages
Authors: Das Riku , Burke Tim , Plow Edward F.
Published: August 2007

Plasminogen (Plg) facilitates inflammatory cell recruitment, a function that depends upon its binding to Plg receptors (Plg-Rs). However, the Plg-Rs that are critical for cell migration are not well defined. Three previously characterized Plg-Rs (α-enolase, annexin 2, and p11) and a recently identified Plg-R (histone H2B [H2B]) were assessed for their contribution to Plg binding and function on macrophages. Two murine macrophage cell lines (RAW 264.7 and J774A.1) and mouse peritoneal macrophages induced by thioglycollate were analyzed. All 4 Plg-Rs were present on the surface of these cells and showed enhanced expression on the thioglycollate-induced macrophages compared with peripheral blood monocytes. Using blocking Fab fragments to each Plg-R, H2B supported approximately 50% of the Plg binding capacity, whereas the other Plg-Rs contributed less than 25%. Anti-H2B Fab also demonstrated a major role of this Plg-R in plasmin generation and matrix invasion. When mice were treated intravenously with anti-H2B Fab, peritoneal macrophage recruitment in response to thioglycollate was reduced by approximately 45% at 24, 48, and 72 hours, with no effect on blood monocyte levels. Taken together, these data suggest that multiple Plg-Rs do contribute to Plg binding to macrophages, and among these, H2B plays a very prominent and functionally important role.
Treatment with GITR agonistic antibody corrects adaptive immune dysfunction in sepsis
Authors: Scumpia Philip O. , Delano Matthew J. , Kelly-Scumpia Kindra M. , Weinstein Jason S. , Wynn James L. , Winfield Robert D. , Xia Changqing , Chung Chun Shiang , Ayala Alfred , Atkinson Mark A. , Reeves Westley H. , Clare-Salzler Michael J. , Moldawer Lyle L.
Published: August 2007

Apoptosis of CD4+ T cells and TH2 polarization are hallmarks of sepsis-induced immunoparalysis. In this study, we characterized sepsis-induced adaptive immune dysfunction and examined whether improving T-cell effector function can improve outcome to sepsis. We found that septic mice produced less antigen-specific T-cell–dependent IgM and IgG2a antibodies than sham-treated mice. As early as 24 hours after sepsis, CD4+ T cells proliferated poorly to T-cell receptor stimulation, despite normal responses to phorbol myristate acetate and ionomycin, and possessed decreased levels of CD3ζ. Five days following immunization, CD4+ T cells from septic mice displayed decreased antigen-specific proliferation and production of IL-2 and IFN-γ but showed no difference in IL-4, IL-5, or IL-10 production. Treatment of mice with anti-GITR agonistic antibody restored CD4+ T-cell proliferation, increased TH1 and TH2 cytokine production, partially prevented CD3ζ down-regulation, decreased bacteremia, and increased sepsis survival. Depletion of CD4+ T cells but not CD25+ regulatory T cells eliminated the survival benefit of anti-GITR treatment. These results indicate that CD4+ T-cell dysfunction is a key component of sepsis and that improving T-cell effector function may be protective against sepsis-associated immunoparalysis.
Effects of systemic steroids in patients with severe community-acquired pneumonia
Authors: Garcia-Vidal C. , Calbo E. , Pascual V. , Ferrer C. , Quintana S. , Garau J.
Published: August 2007

The benefit of systemic steroids as adjunctive treatment in patients with severe community-acquired pneumonia (CAP) remains unclear. The present study aimed to evaluate the impact of corticosteroid treatment on mortality in patients with severe CAP.

A retrospective, observational study of a cohort of patients hospitalised with severe CAP, classes IV and V of the Prognostic Severity Index score, was carried out. Information on epidemiological, clinical and laboratory data, and 30-day mortality was collected from medical charts.

Of the 308 patients evaluated, 238 (77%) were treated with standard antimicrobial therapy and 70 (23%) received both antibiotics and systemic steroids. Clinical characteristics were similar between steroid and nonsteroid groups, except in the prevalence of male sex and the presence of chronic obstructive pulmonary disease. Systemic steroids were independently associated with a decreased mortality (odds ratio 0.287; 95% confidence interval 0.113–0.732), while severity of CAP (2.923; 1.262–6.770) was the only independent factor associated with increased mortality.

Mortality decreased in the patients with severe CAP who received simultaneous administration of systemic steroids along with antibiotic treatment.

Severity of community-acquired pneumonia remains the most important risk factor associated with increased mortality.
Anti-inflammatory effects of high-dose inhaled fluticasoneversusoral prednisone in asthma exacerbations
Authors: Belda J. , Margarit G. , Martínez C. , Bellido-Casado J. , Casan P. , Torrejón M. , Brufal M. , Rodríguez-Jerez F. , Sanchis J.
Published: August 2007

The objective of the present study was to investigate the kinetics of high doses of inhaled steroid fluticasone in comparison with oral steroid prednisone on plasma protein leakage and bronchial eosinophilia in adults with moderate asthma exacerbations.

The study design was a randomised, double-blind, placebo-controlled prospective trial. In total, 45 patients treated at the emergency department for moderate asthma exacerbations were recruited and 39 were assigned to receive fluticasone and placebo of prednisone (19 patients), or prednisone and placebo of fluticasone (20 patients). Medication was administered to all patientsviaa metered-dose inhaler and spacer (16 puffs; 4,000 μg·day−1or placebo) plus one pill (prednisone 30 mg·day−1or placebo). Spirometry and induced sputum for differential cell counts, albumin and α2-macroglobulin levels and blood eosinophils, interleukin-5 and granulocyte-macrophage colony-stimulating factor levels were obtained before treatment and at 2, 6 and 24 h after treatment.

Symptoms clearly improved after 24 h in both groups. No differences were seen between groups in peak expiratory flow or forced expiratory flow in one second, which improved progressively but then decayed slightly after 24 h. Eosinophil counts in sputum also improved over time in both groups. The effect was faster with fluticasone than with prednisone, but was partially lost at 24 h. However, plasma proteins in sputum and eosinophil count in blood both decreased until 24 h, with no significant differences between groups. There was no correlation between eosinophil counts and plasmatic protein levels.

In conclusion, both treatments improved symptoms, airway obstruction and inflammation, and plasma protein leakage at 24 h. Prednisone reduced blood eosinophil counts, while fluticasone reduced airway eosinophil counts, suggesting that the anti-inflammatory performance of fluticasone is exerted locally.
Clinical and operational value of the extensively drug-resistant tuberculosis definition
Authors: Migliori G. B. , Besozzi G. , Girardi E. , Kliiman K. , Lange C. , Toungoussova O. S. , Ferrara G. , Cirillo D. M. , Gori A. , Matteelli A. , Spanevello A. , Codecasa L. R. , Raviglione M. C.
Published: August 2007

Currently, no information is available on the effect of resistance/susceptibility to first-line drugs different from isoniazid and rifampicin in determining the outcome of extensively drug-resistant tuberculosis (XDR-TB) patients, and whether being XDR-TB is a more accurate indicator of poor clinical outcome than being resistant to all first-line anti-tuberculosis (TB) drugs.

To investigate this issue, a large series of multidrug-resistant TB (MDR-TB) and XDR-TB cases diagnosed in Estonia, Germany, Italy and the Russian Federation during the period 1999–2006 were analysed. Drug-susceptibility testing for first- and second-line anti-TB drugs, quality assurance and treatment delivery was performed according to World Health Organization recommendations in all study sites.

Out of 4,583 culture-positive TB cases analysed, 361 (7.9%) were MDR and 64 (1.4%) were XDR. XDR-TB cases had a relative risk (RR) of 1.58 to have an unfavourable outcome compared with MDR-TB cases resistant to all first-line drugs (isoniazid, rifampicin ethambutol, streptomycin and, when tested, pyrazinamide), and an RR of 2.61 compared with “other” MDR-TB cases (those susceptible to at least one first-line anti-TB drug among ethambutol, pyrazinamide and streptomycin, regardless of resistance to the second-line drugs not defining XDR-TB).

The emergence of extensively drug-resistant tuberculosis confirms that problems in tuberculosis management are still present in Europe. While waiting for new tools which will facilitate management of extensively drug-resistant tuberculosis, accessibility to quality diagnostic and treatment services should be urgently ensured and adequate public health policies should be rapidly implemented to prevent further development of drug resistance.
Effects of Maternal Levels of Thyroid Hormone (TH) on the Hypothalamus-Pituitary-Thyroid Set Point: Studies in TH Receptor β Knockout Mice
Authors: Alonso Manuela , Goodwin Charles , Liao XiaoHui , Page David , Refetoff Samuel , Weiss Roy E.
Published: August 2007

A level of thyroid hormone (TH) in agreement with the tissue requirements is essential for vertebrate embryogenesis and fetal maturation. In this study we evaluate the immediate and long-term effects of incongruent intrauterine TH levels between mother and fetus using the TH receptor (TR) β−/− knockout mouse as a model. We took advantage of the fact that the TRβ−/− females have elevated serum TH but are not thyrotoxic due to resistance to TH. We used crosses between heterozygotes with wild-type phenotype (TRβ+/−) males and TRβ−/− females, with a hyperiodothyroninemic (high T4 and T3 levels) intrauterine environment (TH congruent with the TRβ−/− fetus and excessive for the TRβ+/− fetus), and reciprocal crosses between TRβ−/− males and TRβ+/− females, providing a euiodothyroninemic intrauterine environment. We found that TRβ−/− dams had reduced litter sizes and pups with lower birth weight but preserved the mendelian TRβ−/− to TRβ+/− ratio at birth, indicating that the incongruous TH levels did not decrease intrauterine survival of a specific genotype. The results of studies in newborns demonstrate that TRβ+/− pups born to TRβ−/− dams have persistent suppression of serum TSH without a peak. On the other hand, TRβ−/− pups born to TRβ+/− dams have lower serum TSH at birth and a tendency to peak higher, compared with TRβ−/− pups born to TRβ−/− dams. The studies in the adult progeny demonstrate that TRβ+/− mice born to TRβ−/− dams and, thus, exposed to higher intrauterine TH levels, have greater resistance to TH at the level of the pituitary when stimulated with TRH. On the other hand, TRβ−/− mice born to TRβ+/− dams and, thus, deprived of TH in uterine life, were more sensitive to TH when similarly stimulated with TRH. Thus, TH exposure in utero has an effect on the regulatory set point of the hypothalamus-pituitary-thyroid axis, which can be seen early in life and persists into adulthood.
Progesterone, But Not Estrogen, Stimulates Vessel Maturation in the Mouse Endometrium
Authors: Girling Jane E. , Lederman Fiona L. , Walter Lisa M. , Rogers Peter A. W.
Published: August 2007

The human endometrium undergoes regular periods of growth and regression, including concomitant changes in the vasculature, and is one of the few adult tissues where significant angiogenesis and vascular maturation occurs on a routine, physiological basis. The aim of this study was to investigate the effects of estrogen and progesterone on endometrial vascular maturation in mice. Endometrial tissues were collected from early pregnant mice (d 1–4) and ovariectomized mice given a single 17β-estradiol (100 ng) injection 24 h before dissection (short-term estrogen regime) or three consecutive daily injections of progesterone (1 mg) with/without estrogen priming (progesterone regime). Experiments were then repeated with the inclusion of mice treated concurrently with progesterone and either RU486 or a vascular endothelial growth factor-A antiserum. Proliferating vascular mural cells (PVMC) were observed on d 3–4 of pregnancy, corresponding with an increase in circulating progesterone. A significant increase in PVMC and α-smooth muscle actin (labels mural cells) coverage of vessel profiles were observed in mice treated with progesterone in comparison to controls; no significant change was noted in mice treated with estrogen or with vascular endothelial growth factor antiserum. RU486 treatment did not inhibit the progesterone-induced increases in PVMC and mural cell coverage, although progesterone-induced changes in endothelial and epithelial cell proliferation were inhibited. These results show that progesterone, but not estrogen, stimulates vessel maturation in the mouse endometrium. The work illustrates the relevancy of the mouse model for understanding endometrial vascular remodeling during the menstrual cycle and in response to the clinically important progesterone receptor antagonist RU486.
Unique Helical Triangle Molecular Geometry Induced by Dipole–Dipole Interactions
Authors: Ishikawa Takahito , Morita Tomoyuki , Kimura Shunsaku
Published: August 2007

Novel helix-peptide wheels, in which three helices were connected by using a template, were prepared, and the dipole–dipole interactions among the helices were studied in relation to the formation of a planar triangle structure containing three helices. The helical segments had a 310-helix structure. 13C spin-lattice relaxation time (T1) measurements showed that the helical segments had restricted mobility. Deuterium exchange rates of amide protons were accelerated in the helix-peptide wheels compared to the respective linear helix peptides, suggesting that there is torsion on the cylindrical shape. Therefore, the predominant structure of the helix-peptide wheels is a planar triangle in solution. Further, the triangle structure was successfully transferred onto a gold substrate.
Bond Resonance Energy as an Indicator of Local Aromaticity
Authors: Aihara Jun-ichi , Ishida Toshimasa , Kanno Hideaki
Published: August 2007

By definition, bond resonance energy (BRE) represents the contribution of a given π-bond to aromaticity. The minimum BRE in a π-system is an excellent measure of kinetic stability. It was found that the BRE for a peripheral π-bond correlated not only to the harmonic oscillator model of aromaticity (HOMA) index for a ring, to which the π-bond belongs, but also to the corresponding bond-order index of aromaticity (BOIA) for local aromaticity. Thus, the BRE for a peripheral π-bond can be used as an energetic indicator of local aromaticity at least for polycyclic aromatic hydrocarbons (PAHs).
Micellization Behaviour of AOT in the Presence of Sodium Citrate
Authors: Umlong Iohborlang Mylliem , Dey Jahar , Chanda Snigdha , Ismail Kochi
Published: August 2007

Critical micelle concentration (cmc) values of dioctyl sulfosuccinate (AOT) in aqueous trisodium citrate (NaCit) solution were determined as functions of electrolyte concentration and temperature by using surface tension and EMF methods. Values of surface excess, counter ion binding constant (β), surface area, and standard free energies of micellization and adsorption of AOT were evaluated. Using fluorescence-quenching method, aggregation number and polarity index of AOT were also determined. A sudden increase in the value of β from almost 0.4 to 0.8, associated with a sudden increase in the aggregation number and decrease in the polarity index, was observed with a NaCit concentration of about 0.007 mol kg−1, which is considered to be due to change in the micellar shape of AOT. The present study confirms the special counter ion binding behaviour of AOT as an additional special feature of AOT.
Application of Rank Annihilation Factor Analysis to the Determination of the Stability Constant of the Complex XL and Rate Constants for the Reaction of X and XL with the Reagent Z Using Kinetic Profiles
Authors: Afkhami Abbas , Khalafi Lida
Published: August 2007

A simple procedure for the kinetic spectrophotometric determination of the formation constant of 1:1 (XL) complexes (or adducts) using rank annihilation factor analysis (RAFA) is proposed. The method was based on the effect of the concentration of L (or X) on the reaction of X (or L) with a reagent (Z). The rate constants for the reactions of X (or L) and XL with Z were also determined. In order to perform RAFA, concentration profiles were calculated by optimizing the value of formation constant. The rank of the original data matrix was reduced by one by annihilating the information of X (or L). The best estimation of rate constant of complex XL reduced the rank of the system to zero (noise level). The performance of the method was evaluated using synthetic data as well as experimental data, and good results were obtained. The spectrophotometric data for the study of the effect of β-cyclodextrin (β-CD) on the oxidation reaction of some catechol derivatives with iodate at pH 3.60 was used as an example. The difference in the rate of the oxidation reaction of catechol derivatives with iodate at pH 3.60 in the presence of different concentrations of β-CD was monitored.
Heterometal Assembly in Dendritic Polyphenylazomethines
Authors: Takanashi Kensaku , Fujii Atsunobu , Nakajima Reina , Chiba Hiroshi , Higuchi Masayoshi , Einaga Yasuaki , Yamamoto Kimihisa
Published: August 2007

Fine-controlled metal–organic hybridization is strongly desired for advanced nano-materials. Dendrimers are highly branched organic macromolecules with successive layers or “generations” of branch units surrounding a central core. Metal–organic hybrid versions have also been produced by trapping metal ions or metal clusters within the voids of dendrimers. Here, we report a technique to form a dendritic organic structure, which includes various metals, with fine control over the number and location of the metal salts through a radial stepwise complexation. FeCl3, GaCl3, VCl3, and SnCl2 were decorated on a phenylazomethine dendrimer with 4th generations at the first, second, third, and forth layers, respectively. These stepwise complexation and heterometal assembling were also supported by TEM observation, 57Fe Mössbauer spectroscopy, XPS measurement, and NMR spectroscopy.
Anodic Oxidation of Catechols in the Presence of 1,3-Indandione. A Green Electrosynthetic Approach to New Catechol Derivatives
Authors: Raoof Jahan-Bakhsh , Kiani Abolfazl , Ojani Reza , Khalilzadeh Mohammad A
Published: August 2007

Efficient carbon–carbon bond-forming reaction at the 5- and 6-positions of catechol skeleton was achieved through anodic oxidation of catechol, 3-methylcatechol, and 4-methylcatechol in the presence of 1,3-indandione as a nucleophile. The electrochemical synthesis was carried out in aqueous solution, which is a green solvent, using cyclic voltammetry and controlled-current coulometry techniques. The results indicate that the electrogenerated benzoquinone from the electrooxidation of the corresponding catechol participates in a Michael addition reaction with 1,3-indandione. The mechanism of anodic oxidation was deduced from voltammetric and spectroscopic data. The galavanostatic electrochemical synthesis of compounds 2a, 2b, and 2c was successfully performed in an undivided cell in good yield. The products were characterized by 1H NMR, 13C NMR, DEPT, FT-IR, and mass spectrometry.
Improved Preparative Method for 1,2-Diaryl-3,4-diphosphinidenecyclobutenes and Its Application to the Studies of 1,2-Bis(arylthienyl)-3,4-diphosphinidenecyclobutenes
Authors: Toyota Kozo , Horikawa Keiko , Jensen Rader S , Omori Kouhei , Kawasaki Subaru , Ito Shigekazu , Yoshifuji Masaaki , Morita Noboru
Published: August 2007

Sterically protected 1,2-diaryl-3,4-diphosphinidenecyclobutenes were prepared from 3-aryl-2-bromo-1-(2,4,6-tri-t-butylphenyl)-3-(trimethylsiloxy)-1-phosphapropene using t-butyllithium and 1,2-dibromoethane, and the properties of the products, such as 1,2-di(2,2′-bithienyl-5-yl)-3,4-diphosphinidenecyclobutene, were studied. This method is an excellent method for preparing these compounds.
Basis Set and Electron Correlation Effects on Lithium Carbenoid Dimerization Energies
Authors: Pratt Lawrence M , Phan Diep Huong Tran , Tran Phuong Thao Thi , Nguyen Ngan Van
Published: August 2007

A systematic investigation was performed to determine which levels of theory are required to obtain accurate geometries and dimerization energies for lithium carbenoids. Dimerization free energies of six lithium carbenoids were calculated in the gas phase at the B3LYP and MP2 levels with several different basis sets and at the CCSD(T) level with the aug-cc-pvdz basis set. It was found that the calculated thermal corrections to the dimerization free energy, obtained from frequency calculation, were relatively independent of the basis set for basis sets larger than 6-31+G(d) and that smaller basis sets often generated qualitatively correct results. The dimerization free energies were usually overestimated by small basis sets compared to those using polarization and diffuse functions, whereas only modest gains were obtained by using basis sets larger than 6-31+G(d). The B3LYP DFT method generated geometries consistent with the MP2 and CCSD methods for halomethyllithium carbenoids, but not always for 1-halovinyllithium carbenoids. The B3LYP calculations also severely underestimated the dimerization free energies for the halovinyllithium carbenoids, compared to the MP2, and coupled cluster methods.
Molecular Mechanism for Antidiabetic Activity of [meso-Tetrakis(4-sulfonatophenyl)porphyrinato]oxovanadium(IV) (VO(tpps)) Complex. Studies on Akt Phosphorylation and GLUT4 Translocation in 3T3-L1 Adipocytes
Authors: Basuki Wanny , Hiromura Makoto , Sakurai Hiromu
Published: August 2007

A [meso-tetrakis(4-sulfonatophenyl)porphyrinato]oxovanadium(IV) (VO(tpps)), has been found to have an antidiabetic activity and thus to be effective for treating diabetic animal models. High hypoglycemic effects have been observed not only in streptozotocin (STZ)-induced type 1 diabetic mice but also type 2 diabetic KKAy mice by oral administration of the complex. However, the molecular mechanism for the activities has not yet been examined. The aim of this study was to investigate the molecular mechanism of VO(tpps) in 3T3-L1 adipocytes with respect to insulin signaling pathway. Addition of VO(tpps) was found to phosphorylate the insulin receptor β (IRβ) subunit, insulin receptor substrate 1 (IRS1) and protein kinase B (PKB)/Akt in 3T3-L1 adipocytes, in which all phosphorylations were time dependent. The VO(tpps)-induced Akt phosphorylation was suppressed by a PI3K inhibitor, wortmannin. VO(tpps) also stimulated GLUT4 protein translocation to the plasma membrane. Based on these results, we conclude that VO(tpps) exhibits both insulinomimetic and antidiabetic activities via tyrosine phosphorylations of IRβ and IRS1, which activate the downstream Akt phosphorylation through PI3K, and this signaling cascade finally causes GLUT4 translocation from the cytosol to the plasma membrane.
Effective Suppression of Hydrogen Poisoning from a Ru-Based Catalyst in a Ag–Pd Membrane Reactor
Authors: Saito Makoto , Itoh Masahiro , Iwamoto Jun , Machida Ken-ichi
Published: August 2007

Ammonia synthesis was performed using a hydrogen-permeable membrane reactor with a Ru/(MgO–CeO2) catalyst (Mg:Ce = 50:50 in molar ratio; Ru loading = 5 wt %). The catalytic activity with permeated hydrogen (atomic hydrogen) was 1.6 times higher than those of with non-permeated hydrogen (molecular hydrogen). Temperature-programmed reaction experiments, which were conducted by flowing hydrogen onto the catalysts, revealed that the ceria component of the MgO–CeO2 support became much more reductive by hybridization with magnesia. The partially reduced ceria promoted the dissociative adsorption of molecular nitrogen by donating the electrons of Ce3+ ions to Ru metal particles. Furthermore, hydrogen poisoning of the Ru metal catalysts was suppressed by supplying atomic hydrogen through a Ag–Pd hydrogen-permeable membrane under well-controlled conditions to accelerate the catalytic reaction.
Identification of 8 Foodborne Pathogens by Multicolor Combinational Probe Coding Technology in a Single Real-Time PCR
Authors: Huang Qiuying , Hu Qinghua , Li Qingge
Published: August 2007

Background: Real-time PCR assays have been widely used for detecting foodborne pathogens but have been much less frequently applied in species identification, mainly because of the low number of species they can distinguish in 1 reaction. The present study used a new probe coding/labeling strategy, termed multicolor combinational probe coding (MCPC), to increase the number of targets that can be distinguished in a single real-time PCR for rapid and reliable species identification.

Methods: With MCPC, 8 pairs of species-specific tagged primers, 1 pair of universal primers, and 8 unilabeled or mix-labeled molecular beacon probes were included in a single reaction tube. Real-time PCR was performed, and the identity of each of the 8 pathogens was determined by amplification profile comparison. The method was validated via blind assessment of 118 bacterial strains, including clinical isolates and isolates from food products.

Results: The blind test with 118 samples gave no false-positive or -negative results for the target genes. The template DNA suitable for MCPC analysis was simply prepared by heating lysis, and the total PCR analysis was finished within 2.5 h, excluding template preparation.

Conclusions: MCPC is suitable for rapid and reliable identification of foodborne pathogens at the species level.
Pseudoxanthoma Elasticum: Genetic Variations in Antioxidant Genes Are Risk Factors for Early Disease Onset
Authors: Zarbock Ralf , Hendig Doris , Szliska Christiane , Kleesiek Knut , Götting Christian
Published: August 2007

Background: Pseudoxanthoma elasticum (PXE) is a rare hereditary disorder characterized by progressive calcification and fragmentation of elastic fibers in connective tissues. PXE is caused by mutations in the ABCC6 gene, which encodes the membrane transporter multidrug resistance–associated protein 6. Chronic oxidative stress was recently suggested to play a crucial role in the pathogenesis of the disease. Our aim was to investigate the association of PXE with genetic variation in genes coding for antioxidant enzymes.

Methods: We used restriction fragment length polymorphism and allele-specific PCR analyses to evaluate the distribution of single-nucleotide polymorphisms in the genes encoding catalase (CAT), superoxide dismutase 2 (SOD2), and glutathione peroxidase 1 (GPX1) in DNA samples from 117 German PXE patients and 117 healthy age- and sex-matched control individuals.

Results: The investigated genetic variants had previously been shown to affect the activities of these antioxidant enzymes. We found a correlation between genotype and age of disease onset for polymorphisms in CAT (c.−262C>T), SOD2 (c.47C>T), and GPX1 (c.593C>T). Furthermore, the age of disease onset was inversely correlated with the number of mutated alleles, indicating a cumulative effect on the time of disease onset [mean (SD) age of 40.9 (13.6) years, 32.4 (16.3) years, and 25.7 (15.9) years for carriers of 0, 1–2, and >2 mutated alleles, respectively; P = 0.03].

Conclusion: Our findings demonstrate that increased oxidative stress due to activity-affecting polymorphisms in genes encoding antioxidant enzymes leads to earlier PXE onset.
Native eelgrass (Zostera marina L.) survival and growth adjacent to non-native oysters (Crassostrea gigas Thunberg) in the Strait of Georgia, British Columbia
Authors: Kelly Jennifer R. , Volpe John P.
Published: August 2007

We investigated effects of the introduced Pacific oyster (Crassostrea gigas) on native eelgrass (Zostera marina) health on Cortes Island, British Columbia, Canada. Oysters physically alter their environment by increasing habitat complexity and altering water flow, and possibly by causing sulphide to accumulate in the sediment. Sulphide is toxic to eelgrass, and the current decline of eelgrass around Cortes Island may be a consequence of oyster population growth. While oysters and eelgrass coexist at a regional scale, eelgrass is typically absent directly seaward of oyster beds (the “below-oyster zone”) on Cortes Island. In a controlled experiment, we transplanted eelgrass plugs to below-oyster plots to determine whether this habitat is suitable for eelgrass growth. Shoot and leaf number were significantly greater over time in eelgrass-bed transplants than in below-oyster transplants. These results indicate that the below-oyster zone is unsuitable for eelgrass growth; if a causal link exists between oyster presence in the high intertidal zone and eelgrass absence directly seaward, then expansion of feral and farmed oyster beds will result in further eelgrass loss on Cortes Island.
Heavy metal biomonitoring by seaweeds on the Delmarva Peninsula, east coast of the USA
Authors: Chaudhuri Anish , Mitra Madhumi , Havrilla Christopher , Waguespack Yan , Schwarz Jurgen
Published: August 2007

Metal pollution in aquatic ecosystems can pose a major environmental concern impacting various life-forms. The usefulness of seaweeds as biomonitors or indicators of metals in the coastal bays of the Delmarva Peninsula is highlighted in this study, conducted in early spring 2006. Lack of any preexisting data on metal loads in Delmarva seaweeds and in the ambient medium (water and sediments) led to this pilot study for preliminary investigations on the ecological health of these coastal bays. The seaweed species collected from three different sites of the Delmarva Peninsula were: phaeophytes Fucus vesiculosus, and Fucus distichus, chlorophytes Ulva lactuca, and Enteromorpha intestinalis, and rhodophyte Gracilaria tikvahiae. The sampled seaweeds, seawater, and sediments were subsequently analyzed for chromium, manganese, cobalt, nickel, copper, lead, arsenic, and zinc. The results showed high concentrations of Mn, and low concentrations of Cu in almost all the species. Bioconcentration factors (BCFs) in Ulva lactuca and Fucus vesiculosus, across sites, were similar (though the orders of magnitude varied) for Cu, Zn, and Ni. Calculation of metal pollution index (MPI) and Tomlinson pollution load index (PLI) showed that all three sites had low contamination with the metals investigated.
Morphological and genetic variation in Egregia menziesii over a latitudinal gradient
Authors: Henkel Sarah K. , Hofmann Gretchen E. , Whitmer Allison C.
Published: August 2007

This study characterized morphological variation in the kelp, Egregia menziesii, over a large geographic scale. Marked differences in rachis and lateral blade morphology were observed, suggesting local adaptation to the variable conditions of wave exposure and upwelling found across the study area. Observations of rachis type at different developmental stages indicated differential survivorship of smooth versus papillated individuals at sites with differing wave exposure. Variations in Egregia morphology have long been recognized and were previously used for discriminating species within the genus; thus, we tested the hypothesis that the different morphological forms reflect genetically distinct populations. Nucleotide sequences of the ITS regions did not reveal genetic structure among three, morphologically distinct populations providing little evidence for speciation in Egregia.
Kinetics and thermodynamics of uranium(VI) sorption on hydrous silica
Authors: Pathak P. N. , Choppin Gregory R.
Published: August 2007

Sorption of uranyl ion, UO22+, on SiO2·xH2O (silica gel) has been investigated as a function of time, amount of silica gel (0.10–0.60g), uranium concentration (5.00×10−5–1.00×−3M), ionic strength (0.20–1.40M NaClO4), pH (∼2.0–6.0), and temperature (283–333K). Based on kinetic data, the diffusion coefficient of UO22+ion was calculated to be 6.83(±0.22)×10−12m2s−1under particle diffusion-controlled conditions. The rate of sorption of uranyl ion on silica gel was determined to be 8.56(±0.50)×10−2min−1at 298K, pH 1.82±0.05 and 0.20M NaClO4. The uranyl sorption data on silica gel followed the Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherms. Uranyl sorption (11.48±0.03 (0.20M NaClO4) to 34.81±0.20 (1.40M NaClO4) at pH 2.79±0.03 using 0.10g silica gel. The sorption decreased in the presence of 1.00×10−3M fluoride and oxalate ions; while the presence of carbonate anion showed negligible change in uranyl sorption profile in the pH range of 2 to 6 at 0.20M NaClO4. Temperature variation experiments showed that the sorption of uranium on silica gel had an endothermic enthalpy, which became more spontaneous at elevated temperatures.
Genetically Manipulated Human Embryonic Stem Cell-Derived Dendritic Cells with Immune Regulatory Function
Authors: Senju Satoru , Suemori Hirofumi , Zembutsu Hitoshi , Uemura Yasushi , Hirata Shinya , Fukuma Daiki , Matsuyoshi Hidetake , Shimomura Manami , Haruta Miwa , Fukushima Satoshi , Matsunaga Yusuke , Katagiri Toyomasa , Nakamura Yusuke , Furuya Masataka , Nakatsuji Norio , Nishimura Yasuharu
Published: August 2007

Genetically manipulated dendritic cells (DC) are considered to be a promising means for antigen-specific immune therapy. This study reports the generation, characterization, and genetic modification of DC derived from human embryonic stem (ES) cells. The human ES cell-derived DC (ES-DC) expressed surface molecules typically expressed by DC and had the capacities to stimulate allogeneic T lymphocytes and to process and present protein antigen in the context of histocompatibility leukocyte antigen (HLA) class II molecule. Genetic modification of human ES-DC can be accomplished without the use of viral vectors, by the introduction of expression vector plasmids into undifferentiated ES cells by electroporation and subsequent induction of differentiation of the transfectant ES cell clones to ES-DC. ES-DC introduced with invariant chain-based antigen-presenting vectors by this procedure stimulated HLA-DR-restricted antigen-specific T cells in the absence of exogenous antigen. Forced expression of programmed death-1-ligand-1 in ES-DC resulted in the reduction of the proliferative response of allogeneic T cells cocultured with the ES-DC. Generation and genetic modification of ES-DC from nonhuman primate (cynomolgus monkey) ES cells was also achieved by the currently established method. ES-DC technology is therefore considered to be a novel means for immune therapy.

Disclosure of potential conflicts of interest is found at the end of this article.
Donor-Derived Human Bone Marrow Cells Contribute to Solid Organ Cancers Developing After Bone Marrow Transplantation
Authors: Avital Itzhak , Moreira Andre L. , Klimstra David S. , Leversha Margaret , Papadopoulos Esperanza B. , Brennan Murray , Downey Robert J.
Published: August 2007

Bone marrow-derived stem cells have been shown to participate in solid organ repair after tissue injury. Animal models suggest that epithelial malignancies may arise as aberrant stem cell differentiation during tissue repair. We hypothesized that if bone marrow stem cells participate in human neoplasia, then solid organ cancers developing after allogeneic bone marrow transplantation (ABMT) might include malignant cells of donor origin. We identified four male patients who developed solid organ cancers (lung adenocarcinoma, laryngeal squamous cell carcinoma, glioblastoma, and Kaposi sarcoma) after myeloablation, total body irradiation, and ABMT from female donors. Donor-derived malignant cells comprised 2.5%–6% of the tumor cellularity The presence of donor-derived malignant cells in solid organ cancers suggests that human bone marrow-derived stem cells have a role in solid organ cancer's carcinogenesis. However, the nature of this role is yet to be defined.

Disclosure of potential conflicts of interest is found at the end of this article.
Concise Review: Human Umbilical Cord Stroma with Regard to the Source of Fetus-Derived Stem Cells
Authors: Can Alp , Karahuseyinoglu Sercin
Published: August 2007

Human umbilical cord (UC) has been a tissue of increasing interest in recent years. Many groups have shown the stem cell potency of stromal cells isolated from the human UC mesenchymal tissue, namely, Wharton's jelly. Since UC is a postnatal organ discarded after birth, the collection of cells does not require an invasive procedure with ethical concerns. Stromal cells, as the dominant cells of this fetus-derived tissue, possess multipotent properties between embryonic stem cells and adult stem cells. They bear a relatively higher proliferation rate and self-renewal capacity. Although they share common surface markers with bone marrow-derived MSCs, they also express certain embryonic stem cell markers, albeit in low levels. Without any spontaneous differentiation, they can be successfully differentiated into mature adipocytes, osteoblasts, chondrocytes, skeletal myocytes, cardiomyocytes, neurons, and endothelial cells. While causing no immunorejection reaction, they effectively function in vivo as dopaminergic neurons, myocytes, and endothelial cells. Given these characteristics, particularly the plasticity and developmental flexibility, UC stromal cells are now considered an alternative source of stem cells and deserve to be examined in long-term clinical trials. This review first aims to document the published findings so far regarding the nature of human UC stroma with special emphasis on the spatial distribution and functional structure of stromal cells and matrix, which serves as a niche for residing cells, and, secondly, to assess the in vitro and in vivo experiments in which differential stem cell potencies were evaluated.

Disclosure of potential conflicts of interest is found at the end of this article.
In vitro analysis of hGH secretion in the presence of mutations of amino acids involved in zinc binding
Authors: Iliev Daniel I , Wittekindt Nicola E , Ranke Michael B , Binder Gerhard
Published: August 2007

Zinc (Zn2+) binding by human GH through amino acid residues His18, His21, and Glu174 has been described as a prerequisite for GH dimerization and storage in secretory granules. Our aim was to investigate in vitro whether disturbed Zn2+ binding of mutant GH inhibits wild-type GH (wtGH) secretion and contributes to the pathogenetic mechanisms involved in dominantly transmitted isolated GH deficiency type II. Seven expression vectors harboring mutated human GH cDNAs were constructed in which nucleotide triplets encoding histidine or glutamine at positions 18, 21, and 174 were mutated to triplets encoding alanine: H18A, H21A, G174A, H18A–G174A, H21A–G174A, H18A–H21A, and H18A–H21A–G174A. These vectors were transiently cotransfected with a vector encoding wtGH or were singly transfected into rat pituitary GH4C1 cells. Plasmids encoding β -galactosidase were cotransfected. 48h after transfection, GH in media and cell extracts was measured using a GH-specific RIA, and results were normalized for transfection efficiency by means of β -galactosidase activity. In comparison with the control transfection (wtGH/wtGH set at 100%), GH secretion remained unaffected when coexpressing wtGH and any of the GH mutants in which Zn2+ binding was partially or completely prevented. When these mutants were singly expressed, the amount of GH in both media and cell extracts was decreased by about 50% when compared with cells expressing only wtGH. Our in vitro data do not support the hypothesis of disturbed Zn2+ binding as a major pathogenetic mechanism in dominantly transmitted GH deficiency.
Laboratory Validation of Soil Phosphorus Storage Capacity Predictions for Use in Risk Assessment
Authors: Chrysostome M. , Nair V. D. , Harris W. G. , Rhue R. D.
Published: August 2007

Soil P concentrations in agricultural soils have increased over the years, increasing concerns about eutrophication of surface waters. Sandy soils are particularly prone to P leaching due to limited P retention capacity. This study tested the validity of a measure of soil P storage capacity (SPSC) for sandy soils amended with dairy and poultry manure by evaluation of SPSC response to P gain or loss under controlled laboratory conditions. Forty soil samples representing A, E, and Bt horizons were collected from two dairy and two poultry operations within the Suwannee River Basin. Soils were packed into 1.5‐cm‐diameter columns and 0.05 M KCl solution was passed through the column using unsaturated flow at pore water velocities of approximately 1 cm d−1 Then the soils were leached with known quantities of P. Several P addition and leaching cycles followed and the whole experiment lasted approximately 30 mo. Phosphorus in the leachate was measured after each P addition. The P saturation ratio (PSR) was calculated from oxalate P, Al, and Fe extracts analyzed before and after the study. The SPSC of the soils was calculated based on a threshold PSR of 0.15 for the oxalate solutions. Changes in SPSC due to repeated P additions corresponded to predicted values calculated from P loading amounts, taking into consideration the P concentration before additional P loading. Results support the validity of SPSC as a means of estimating P loading rates that pose low environmental risk for specific sandy soils.
Integrated Management of Inorganic and Organic Nitrogen and Efficiency in Potato Systems
Authors: Nyiraneza Judith , Snapp Sieglinde
Published: August 2007

A potato (Solanum tuberosumL.) experiment from 2002 to 2004 examined fallow or winter rye (Secale cerealeL.) (average residues ∼1 Mg ha−1) cover crop systems with a split‐plot design of 0 or 5.6 Mg ha−1poultry manure. A 75‐L container experiment used field trial soil to evaluate N dynamics in the presence and absence of N fertilizer. Organic N source (manure, cover crop residues, or both) availability was used to adjust fertilizer rate downward to provide an estimated 224 kg N ha−1for all treatments. Plant growth, N uptake, and tuber yield were monitored, along with soil organic N status and light‐fraction organic matter. In the field, the integrated treatment (179 kg N ha−1fertilizer + manure) consistently increased tuber yield and N uptake efficiency by 20% compared with the unamended conventional management (224 kg N ha−1fertilizer). Similarly, tuber yield and N uptake in the integrated treatments of the container experiment were 14 to 33% higher than the fertilized, unamended treatment. In the absence of fertilizer, rye cover crop and manure enhanced tuber yield 40 to 210% compared with unamended plants. The release of N from diverse sources was in apparent synchrony with plant demand, as indicated by monitoring of NO3–N dynamics and the presence of light‐fraction N. Although manure application was associated with higher N input, subsoil NO3–N in manured and unmanured treatments averaged 6.7 and 7.9 mg kg−1, respectively. High productivity and N efficiency were associated with integrating organic and inorganic N sources, which represents an environmentally and agronomically sound management strategy.
Substrate‐Induced Respiration for Phosphorus‐Enriched and Oligotrophic Peat Soils in an Everglades Wetland
Authors: Wright Alan L. , Reddy K. R.
Published: August 2007

Nutrient enrichment may alter patterns of heterotrophic microbial activity (HMA) in wetland soils and influence organic matter decomposition dynamics. The response of the heterotrophic microbial community to C substrates (alcohols, amides, amino acids, aromatics, plant residues, and polysaccharides) was measured as CO2 and CH4 production in detritus and soil (0–10 cm) collected from P‐enriched and oligotrophic areas of Water Conservation Area 2a (WCA‐2a) of the Everglades. The wetland was characterized by decreasing P levels from peripheral to interior, oligotrophic areas. Denitrification and SO4 reduction appeared to be the primary metabolic pathways at the P‐enriched site, whereas the contribution of methanogenesis to organic matter decomposition was greater in the oligotrophic interior of the wetland. Methane production averaged 38 and 48% of the total CO2 + CH4 production for P‐enriched and oligotrophic detritus, respectively. Basal CO2 production of detritus was 36% higher at the P‐enriched than the oligotrophic site, but CH4 production was 43% greater at the oligotrophic site. All C substrates enhanced CO2 and CH4 production, indicating that labile organic C may be limiting in this wetland, and the types of C substrates used by the heterotrophic microbial community varied between P‐enriched and oligotrophic sites. Substrate‐induced respiration was 71 and 48% greater at the P‐enriched than the oligotrophic site for detritus and soil, respectively. Nutrient loading, particularly P, promoted the development of a N‐limited system near the periphery of the wetland, while the oligotrophic interior was characterized by P‐limited conditions. Continued nutrient loading into oligotrophic areas of WCA‐2a may enhance HMA and stimulate organic matter decomposition and nutrient regeneration, and further contribute to undesirable changes to the Everglades ecosystem.
A photo, a suggestion, a false memory
Authors: Strange Deryn , Hayne Harlene , Garry Maryanne
Published: August 2007

We examined the effect of photographs on children's memories for events that did and did not happen. Over three interviews, 10‐year olds saw three true photos and one false photo. Half the children saw a doctored photo of themselves and other family members in a hot air balloon, while the remaining half saw only the hot air balloon. At each interview, children reported what they could remember about each event, rated their confidence that the events really happened and rated how much they could remember. Children who saw the photo showing themselves in the balloon developed more false memories than those who saw only the balloon, but when children in either condition developed false memories, they were equally confident that the event was real. These data highlight a potential problem with the use of photographs as tools in therapy. Copyright © 2007 John Wiley & Sons, Ltd.