bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluoride exposure and dental fluorosis in Newburgh and Kingston, New York: policy implications
Authors: Kumar Jayanth V. , Swango Philip A.
Published: March 2007

Abstract– Objectives: This analysis was conducted to determine the changes in the effect of exposure to fluoridation and other sources of fluoride on dental fluorosis in children attending Newburgh and Kingston school districts in New York State. Methods: Data for this analysis were obtained from two surveys conducted in the 1986 and 1995 school years. Analyses were limited to 3500, 7–14‐year‐old lifelong residents of a fluoridated or a nonfluoridated community. Deans's classification and DMFS index were used for recording dental fluorosis and caries, respectively. A questionnaire was used to collect fluoride exposure data. Regression procedures were used to estimate the effect of fluoridation, fluoride supplements, and brushing before the age of 2 years on dental fluorosis. Results: Children examined in 1996 were at higher risk for both questionable and very mild to severe dental fluorosis if they received fluoride from water or daily tablet use, or started brushing before the age of 2 years. The increase in risk from 1986 to 1995 was greater for African‐American children. Conclusion: This analysis showed that the risk of developing dental fluorosis did not decline over time in these communities. Continuous exposure to water fluoridation had an observable effect on dental fluorosis. However, implementation of fluoridation in Newburgh Town did not result in an increase in dental fluorosis prevalence.
Understanding the intention of dentists to provide dental care to HIV+ and AIDS patients
Authors: Godin Gaston , Naccache Herminé , Brodeur Jean‐Marc , Alary Michel
Published: March 2007

Abstract– Objective: The aim of this study was to understand the intention of dentists to provide dental care to HIV+/AIDS patients. Methods: A representative sample of 791 dentists from the province of Quebec completed a questionnaire assessing their intention to provide dental care to individuals with HIV+/AIDS as well as their attitudes, perceived social norm, perceived behavioral control, perceived behavioral norm and personal normative belief regarding this behavior. Past experience with providing dental care (habit) to HIV+/AIDS patients, fear of AIDS and socio‐demographic characteristics were also assessed. Results: Overall, dentists have a strong intention to provide dental care to HIV+/AIDS patients. Nevertheless, 25% of the respondents expressed a low intention to provide dental care to these patients. The main factors explaining 71% of the variance in intention were perceived behavioral control (β= 0.52, P < 0.0001), personal normative belief (β= 0.33, P < 0.0001) and habit of treating HIV+/AIDS patients (β= 0.12, P < 0.0001). Conclusion: To improve the motivation of dentists to treat HIV+/AIDS patients, emphasis should be placed on increasing self‐efficacy to cope with the difficulties of providing dental care to HIV+/AIDS patients as well as on the importance of acting in agreement with the Dental Association's Code of Ethics.
The Ternary Rab27a–Myrip–Myosin VIIa Complex Regulates Melanosome Motility in the Retinal Pigment Epithelium
Authors: Lopes Vanda S. , Ramalho José S. , Owen Dylan M. , Karl Mike O. , Strauss Olaf , Futter Clare E. , Seabra Miguel C.
Published: March 2007

The retinal pigment epithelium (RPE) contains melanosomes similar to those found in the skin melanocytes, which undergo dramatic light‐dependent movements in fish and amphibians. In mammals, those movements are more subtle and appear to be regulated by the Rab27a GTPase and the unconventional myosin, Myosin VIIa (MyoVIIa). Here we address the hypothesis that a recently identified Rab27a‐ and MyoVIIa‐interacting protein, Myrip, promotes the formation of a functional tripartite complex. In heterologous cultured cells, all three proteins co‐immunoprecipitated following overexpression. Rab27a and Myrip localize to the peripheral membrane of RPE melanosomes as observed by immunofluorescence and immunoelectron microscopy. Melanosome dynamics were studied using live‐cell imaging of mouse RPE primary cultures. Wild‐type RPE melanosomes exhibited either stationary or slow movement interrupted by bursts of fast movement, with a peripheral directionality trend. Nocodazole treatment led to melanosome paralysis, suggesting that movement requires microtubule motors. Significant and similar alterations in melanosome dynamics were observed when any one of the three components of the complex was missing, as studied in ashen‐ (Rab27a defective) and shaker‐1 (MyoVIIa mutant)‐derived RPE cells, and in wild‐type RPE cells transduced with adenovirus carrying specific sequences to knockdown Myrip expression. We observed a significant increase in the number of motile melanosomes, exhibiting more frequent and prolonged bursts of fast movement, and inversion of directionality. Similar alterations were observed upon cytochalasin D treatment, suggesting that the Rab27a–Myrip–MyoVIIa complex regulates tethering of melanosomes onto actin filaments, a process that ensures melanosome movement towards the cell periphery.
Re‐Visiting Peruvian Grassroots Women's Organisations: Where Are They Now?
Authors: Jenkins Katy
Published: March 2007

While women's organising in Latin America was the subject of significant academic attention throughout the 1980s and early 1990s, there has been little more recent discussion of the ongoing role of low income women in urban community development. This article therefore re‐visits women's long‐term voluntary work in order to explore how their endeavours have been conceptualised over time, tracing the trajectory of women's popular organising in Peru. The discussion begins with understandings of women's popular organising as part of an ‘alternative development’ paradigm, before exploring more recent mainstream considerations of women's organisations as a source of social capital. This overview is complemented by a recent case study of a group of women health promoters in Lima, which emphasises the continued resilience and dedication of grassroots women activists, despite their recent low profile in the international development arena.
The Sensitivity of California Water Resources to Climate Change Scenarios1
Authors: Vicuna Sebastian , Maurer Edwin P. , Joyce Brian , Dracup John A. , Purkey David
Published: March 2007

Abstract:  Using the latest available General Circulation Model (GCM) results we present an assessment of climate change impacts on California hydrology and water resources. The approach considers the output of two GCMs, the PCM and the HadCM3, run under two different greenhouse gas (GHG) emission scenarios: the high emission A1fi and the low emission B1. The GCM output was statistically downscaled and used in the Variable Infiltration Capacity (VIC) macroscale distributed hydrologic model to derive inflows to major reservoirs in the California Central Valley. Historical inflows used as inputs to the water resources model CalSim II were modified to represent the climate change perturbed conditions for water supply deliveries, reliability, reservoir storage and changes to variables of environmental concern. Our results show greater negative impacts to California hydrology and water resources than previous assessments of climate change impacts in the region. These impacts, which translate into smaller streamflows, lower reservoir storage and decreased water supply deliveries and reliability, will be especially pronounced later in the 21st Century and south of the San Francisco bay Delta. The importance of considering how climate change impacts vary for different temporal, spatial, and institutional conditions in addition to the average impacts is also demonstrated.
Developing a Standardized Water Quality Index for Evaluating Surface Water Quality1
Authors: Kaurish Fredrick W. , Younos Tamim
Published: March 2007

Abstract:  There is a significant need for a science‐based approach to interpret water‐monitoring data and to facilitate the rapid transfer of information to water resource managers and the general public. The water quality Index (WQI) is defined as a single numeric score that describes the surface water quality condition at a particular time and location. The objective of this paper is to describe the WQI concept and the approach for developing an ecoregion‐specific standardized WQI that meets the needs described above. The premise of the proposed WQI is based on categorizing scientifically documented aquatic life responses to changes in instream water chemistry. The method uses an aggregated procedure that matches the entire range of standardized probable biological responses to standardized narrative water quality evaluation categories and standardized rank score categories. The calculation of WQI and decision‐making process are performed within an Excel spreadsheet software program. The article includes examples of the proposed WQI applications that could enhance effective water resource management and facilitate timely communication of water quality conditions to water resource managers and the general public.
Understanding, Excusing, Forgiving
Authors: PETTIGROVE GLEN
Published: March 2007

This paper explores the relation between understanding and forgiving. A number of people have argued against the old adage that to understand is to forgive, for in many instances understanding leads to excusing rather than forgiving. Nonetheless, there is an interesting connection to be found between forgiving and understanding. I identify three ways in which understanding can lead to forgiveness of unexcused wrongdoing: It can do so by changing our interpretation of the actor, by changing our interpretation of the action, and by engaging self‐love.
What the Disjunctivist is Right About
Authors: MILLAR ALAN
Published: March 2007

There is a traditional conception of sensory experience on which the experiences one has looking at, say, a cat could be had by someone merely hallucinating a cat. Disjunctivists take issue with this conception on the grounds that it does not enable us to understand how perceptual knowledge is possible. In particular, they think, it does not explain how it can be that experiences gained in perception enable us to be in ‘cognitive contact’ with objects and facts. I develop this challenge to the traditional conception and then show that it is possible to accommodate an adequate account of cognitive contact in keeping with the traditional conception. One upshot of the discussion is that experiences do not bear the explanatory burden placed upon them by disjunctivists.
Stability Analysis of Complex Multibody Systems
Authors: Bauchau Olivier A. , Wang Jielong
Published: March 2007

The linearized stability analysis of dynamical systems modeled using finite element-based multibody formulations is addressed in this paper. The use of classical methods for stability analysis of these systems, such as the characteristic exponent method or Floquet theory, results in computationally prohibitive costs. Since comprehensive multibody models are “virtual prototypes” of actual systems, the applicability to numerical models of the stability analysis tools that are used in experimental settings is investigated in this work. Various experimental tools for stability analysis are reviewed. It is proved that Prony’s method, generally regarded as a curve-fitting method, is equivalent, and sometimes identical, to Floquet theory and to the partial Floquet method. This observation gives Prony’s method a sound theoretical footing, and considerably improves the robustness of its predictions when applied to comprehensive models of complex multibody systems. Numerical and experimental applications are presented to demonstrate the efficiency of the proposed procedure.
Research Advances in the Dynamic Stability Behavior of Plates and Shells: 1987–2005—Part I: Conservative Systems
Authors: Sahu S. K. , Datta P. K.
Published: March 2007

This paper reviews most of the recent research done in the field of dynamic stability/dynamic instability/parametric excitation/parametric resonance characteristics of structures with special attention to parametric excitation of plate and shell structures. The solution of dynamic stability problems involves derivation of the equation of motion, discretization, and determination of dynamic instability regions of the structures. The purpose of this study is to review most of the recent research on dynamic stability in terms of the geometry (plates, cylindrical, spherical, and conical shells), type of loading (uniaxial uniform, patch, point loading …), boundary conditions (SSSS, SCSC, CCCC …), method of analysis (exact, finite strip, finite difference, finite element, differential quadrature, and experimental …), method of determination of dynamic instability regions (Lyapunovian, perturbation, and Floquet’s methods), order of theory being applied (thin, thick, three-dimensional, nonlinear …), shell theory used (Sanders’, Love’s and Donnell’s), materials of structures (homogeneous, bimodulus, composite, FGM …), and the various complicating effects such as geometrical discontinuity, elastic support, added mass, fluid structure interactions, nonconservative loading and twisting, etc. The important effects on dynamic stability of structures under periodic loading have been identified and influences of various important parameters are discussed. A review of the subject for nonconservative systems in detail will be presented in Part 2. This review paper cites 156 references.
Phagocytosis of poly(L-lysine)-graft-poly (ethylene glycol) coated microspheres by antigen presenting cells: Impact of grafting ratio and poly (ethylene glycol) chain length on cellular recognition
Authors: Wattendorf Uta , Koch Mirabai C. , Walter Elke , Vörös Janos , Textor Marcus , Merkle Hans P.
Published: March 2007

Microparticulate carrier systems have significant potential for antigen delivery. The authors studied how microspheres coated with the polycationic copolymer poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) can be protected against unspecific phagocytosis by antigen presenting cells, a prerequisite for selective targeting of phagocytic receptors. For this aim the authors explored the influence of PLL-g-PEG architecture on recognition of coated microspheres by antigen presenting cells with regard to both grafting ratio and molecular weight of the grafted PEG chains. Carboxylated polystyrene microspheres (5 μm) were coated with a small library of PLL-g-PEG polymers with PLL backbones of 20 kDa, grafting ratios from 2 to 20, and PEG side chains of 1–5 kDa. The coated microspheres were characterized by their ζ-potential and resistance to IgG adsorption. Phagocytosis of these microspheres by human monocyte derived dendritic cells (DCs) and macrophages (MΦ) was quantified by phase contrast microscopy and by analysis of the cells’ side scattering in a flow cytometer. Generally, increasing grafting ratios impaired the protein resistance of coated microspheres, leading to higher phagocytosis rates. For DC, long PEG chains of 5 kDa decreased the phagocytosis of coated microspheres even in the case of considerable IgG adsorption. In addition, preferential adsorption of dysopsonins is discussed as another factor for decreased phagocytosis rates. For comparison, the authors studied the cellular adhesion of DC and Mζ to PLL-g-PEG coated microscopy slides. Remarkably, DC and Mζ were found to adhere to relatively protein-resistant PLL-g-PEG adlayers, whereas phagocytosis of microspheres coated with the same copolymers was inefficient. Overall, PLL(20)-[3.5]-PEG(2) was identified as the optimal copolymer to ensure resistance to both phagocytosis and cell adhesion. Finally, the authors studied coatings made from binary mixtures of PLL-g-PEG type copolymers that led to microspheres with combined properties. This enables future studies on cell targeting with ligand modified copolymers.
Enhancement of poly(ethylene glycol) mucoadsorption by biomimetic end group functionalization
Authors: Catron Nathaniel D. , Lee Haeshin , Messersmith Phillip B.
Published: March 2007

Poly(ethylene glycol) (PEG) is widely used in the pharmaceutical, biotechnology, and medical device industries. Although PEG is a biocompatible polymer that has enjoyed widespread use in drug delivery technology, it is not considered adhesive toward mucosal tissue. Here the authors describe a simple approach to enhancing mucoadsorption of PEG polymers through end group functionalization with the amino acid 3,4-dihydroxyphenyl-l-alanine (DOPA). Using a variety of surface analytical techniques, the authors show that a four-armed poly(ethylene glycol) polymer functionalized with a single DOPA residue at the terminus of each arm (PEG-(DOPA)4 adsorbed strongly to surface immobilized mucin. Successful mucoadsorption of PEG-(DOPA)4 across several pH values ranging from 4.5 to 8.5 was demonstrated, and control experiments with unfunctionalized four-arm PEG demonstrated that mucoadsorption of PEG-(DOPA)4 is due largely to the presence of DOPA end groups. This conclusion was confirmed with single molecule atomic force microscopy experiments that revealed a surprisingly strong interaction force of 371±93 pN between DOPA and adsorbed mucin. Direct comparisons with known mucoadhesive polymers revealed that PEG-(DOPA)4 was equal to or more adsorptive to immobilized mucin than these existing mucoadhesive polymers. In addition to demonstrating significant enhancement of mucoadhesive properties of PEG by DOPA functionalization, this study also introduced a new simple approach for rapid screening of mucoadhesive polymers.
Benzamidine-based coatings: Implication of inhibitor structure on the inhibition of coagulation enzymes in solution and in vitro hemocompatibility assessment
Authors: Gouzy Marie-Françoise , Sperling Claudia , Salchert Katrin , Pompe Tilo , Rauwolf Cordula , Werner Carsten
Published: March 2007

Synthetic inhibitors of trypsin-like serine proteases were covalently immobilized to polymeric materials to passivate coagulation enzymes during blood contact. The inhibitory potency of a structurally simple and larger, more complex amidine derivatives was assessed against thrombin and factor Xa. After adsorption of serum albumin, the polymer films decorated with either one of the inhibitors were found to scavenge thrombin—with a higher affinity in the case of the larger inhibitor—but not factor Xa. Both inhibitor-containing coatings showed a significantly reduced thrombogenicity, coagulation activation, as well as complement activation when incubated with freshly drawn human whole blood in vitro. The authors conclude that the introduced principle offers a promising approach for hemocompatible materials for short term applications. Even rather simple inhibitors can be successfully employed for that purpose.
Evolution of Resistant M414T Mutants among Hepatitis C Virus Replicon Cells Treated with Polymerase Inhibitor A-782759
Authors: Lu Liangjun , Mo Hongmei , Pilot-Matias Tami J. , Molla Akhteruzzaman
Published: March 2007

Treatment of hepatitis C virus (HCV) replicon cells with any single specific anti-HCV inhibitor in vitro leads to a rapid selection of resistant mutants. However, the source and the kinetic evolution of these resistant mutants during treatment are poorly understood. In this study we developed allele-specific real-time PCR assays for quantitative detection of the M414T mutant that was selected by a number of benzothiadiazine HCV polymerase inhibitors. Low levels of preexisting M414T mutants were detected in both 1b-con1 (0.22%) and 1b-N (0.18%) subgenomic replicon cell lines, as well as in 6 of 15 HCV RNA isolated from the sera of treatment-naive HCV-infected patients ranging from 0.11 to 0.60%. The proportion of M414T mutants in replicons rapidly increased in a dose-dependent manner upon treatment with benzothiadiazine inhibitor A-782759. After 4 days of treatment, 2.5, 26, or 60% of the replicon population contained M414T mutants with the use of A-782759 at 1×, 10×, or 100× its 50% effective concentration, respectively. In addition, the short 4-day treatment resulted in significant changes in inhibitor susceptibility in the replicon cells. Our results indicated that the resistant mutant preexisted as a minor population in replicon cells and that the mutant was selected within days of treatment with the inhibitor. The findings from this study suggested that early application of combination therapy of an HCV-specific inhibitor with interferon-based regimens or other classes of available inhibitors will be necessary to avoid quick viral rebound or treatment failure.
Lack of Effect of DX-619, a Novel Des-Fluoro(6)-Quinolone, on Glomerular Filtration Rate Measured by Serum Clearance of Cold Iohexol
Authors: Sarapa Nenad , Wickremasingha Prachi , Ge NanXiang , Weitzman Richard , Fuellhart Merynda , Yen Cindy , Lloyd-Parks Julia
Published: March 2007

DX-619 is a novel des-fluoro(6)-quinolone with activity against a broad range of bacterial strains, including methicillin-resistantStaphylococcus aureus. The effects of DX-619 on the glomerular filtration rate (GFR) were evaluated because drug-related increases in serum creatinine levels were observed in studies with healthy volunteers. Forty-one healthy subjects were randomized to receive intravenous DX-619 at 800 mg or placebo once daily for 4 days, and the GFR was directly measured by determination of the clearance of a bolus iohexol injection in 33 subjects who completed the study per protocol. DX-619 was noninferior to placebo for the GFR on the basis of a criterion for a clinically significant difference of −12 ml/min/1.73 m2. The mean GFRs on day 4 were 101.1 ± 14.2 ml/min/1.73 m2and 100.2 ± 15.6 ml/min/1.73 m2for the volunteers receiving placebo and DX-619, respectively. On day 4 the mean serum creatinine concentration for volunteers receiving DX-619 increased by 30 to 40%, with a corresponding decrease in mean creatinine clearance. Both parameters normalized within 7 days after the cessation of DX-619 treatment. Nonclinical studies suggest that DX-619 increases the serum creatinine concentration by inhibiting excretory tubular transporters. In conclusion, DX-619 administered intravenously at 800 mg once a day for 4 days did not affect the GFR in healthy volunteers. Glomerular toxicity is not expected to present a risk to patients receiving DX-619 in clinical trials, but monitoring of the renal function, with an emphasis on the serum creatinine concentration, is still warranted.
Broad-Spectrum Antiviral Activity of Small Interfering RNA Targeting the Conserved RNA Termini of Lassa Virus
Authors: Müller Stefanie , Günther Stephan
Published: March 2007

Small interfering RNAs targeting the conserved RNA termini upstream of NP and L gene were found to reduce reporter gene expression from Lassa virus replicon and Lassa virus mRNA expression construct and to inhibit replication of different Lassa virus strains, lymphocytic choriomeningitis virus, and Mopeia virus in cell culture.
In Vitro Activities of Miltefosine and Two Novel Antifungal Biscationic Salts against a Panel of 77 Dermatophytes
Authors: Tong Zhongsheng , Widmer Fred , Sorrell Tania C. , Guse Zofia , Jolliffe Katrina A. , Halliday Catriona , Lee Ok Cha , Kong Fanrong , Wright Lesley C. , Chen Sharon C. A.
Published: March 2007

The susceptibilities of 77 dermatophytes to miltefosine (MI), 1,12-bis(4-pentylpyridinium)dodecane (PYR), 1,12-bis(tributylammonium)dodecane (AM), itraconazole (ITC), terbinafine (TRB), and butenafine (BTF) were compared. Geometric mean MICs of TRB, BTF, ITC, MI, PYR, and AM were 0.039, 0.059, 1.718, 0.671, 6.006, and 4.771 μg/ml, respectively. MI was more active than ITC (
P
< 0.001).
Assessment and Continued Validation of the Malaria SYBR Green I-Based Fluorescence Assay for Use in Malaria Drug Screening
Authors: Johnson Jacob D. , Dennull Richard A. , Gerena Lucia , Lopez-Sanchez Miriam , Roncal Norma E. , Waters Norman C.
Published: March 2007

Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against
Plasmodium falciparum
strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and ∼0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z′ range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [
3
H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (
r
2
≥ 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
Candida albicans
Iff11, a Secreted Protein Required for Cell Wall Structure and Virulence
Authors: Bates Steven , de la Rosa José M. , MacCallum Donna M. , Brown Alistair J. P. , Gow Neil A. R. , Odds Frank C.
Published: March 2007

The
Candida albicans
cell wall is the immediate point of contact with the host and is implicated in the host-fungal interaction and virulence. To date, a number of cell wall proteins have been identified and associated with virulence. Analysis of the
C. albicans
genome has identified the
IFF
gene family as encoding the largest family of cell wall-related proteins. This family is also conserved in a range of other
Candida
species. Iff11 differs from other family members in lacking a GPI anchor, and we have demonstrated it to be O glycosylated and secreted in
C. albicans
. A null mutant lacking
IFF11
was hypersensitive to cell wall-damaging agents, suggesting a role in cell wall organization. In a murine model of systemic infection the null mutant was highly attenuated in virulence, and survival-standardized infections suggest it is required to establish an infection. This work provides the first evidence of the importance of this gene family in the host-fungal interaction and virulence.
PERFORMANCE EVALUATION OF IMPUTATION METHODS FOR INCOMPLETE DATASETS
Authors: YENDURI SUMANTH , IYENGAR S. S.
Published: March 2007

In this study, we compare the performance of four different imputation strategies ranging from the commonly used Listwise Deletion to model based approaches such as the Maximum Likelihood on enhancing completeness in incomplete software project data sets. We evaluate the impact of each of these methods by implementing them on six different real-time software project data sets which are classified into different categories based on their inherent properties. The reliability of the constructed data sets using these techniques are further tested by building prediction models using stepwise regression. The experimental results are noted and the findings are finally discussed.
GEOMETRIC CONSTRUCTION OF MODULAR FUNCTORS FROM CONFORMAL FIELD THEORY
Authors: ANDERSEN JØRGEN ELLEGAARD , UENO KENJI
Published: March 2007

We give a geometric construct of a modular functor for any simple Lie-algebra and any level by twisting the constructions in [16, 19] by a certain fractional power of the abelian theory first considered in [13] and further studied in [2].
Role of FoxO1 in FFA-induced oxidative stress in adipocytes
Authors: Subauste Angela R. , Burant Charles F.
Published: March 2007

Reactive oxygen species (ROS) production has recently been established as an essential contributor in the pathogenesis of obesity-associated insulin resistance. The FoxO1 pathway plays a role not only in nutrient sensing but also in regulating ROS production. We exposed adipocytes to free fatty acids (FFA) and demonstrated that FoxO1 protein levels decrease in a dose-dependent manner. The FoxO1 downregulation correlated with an increase in the production of ROS and a proinflammatory adipokine pattern characterized by a decrease in adiponectin and an increase in IL-6, plasminogen activator inhibitor-1, and monocyte chemotactic protein-1 mRNA expression levels. Similarly, a decrease in FoxO1 protein levels was seen in adipocytes of db/ db mice compared with controls. Treatment with the sirtuin agonist resveratrol, which translocates FoxO1 to the nucleus, increased FoxO1 protein levels in adipocytes exposed to FFA. This correlated with a decrease in the generation of ROS and a partial reversal of the proinflammatory adipokine pattern. Together these results indicate that the insulin-resistant adipocyte produced by the exposure to a high concentration of fatty acids is characterized by decreased levels of FoxO1. These data also suggest that modulation of the Sirt1/FoxO1 pathway is a potentially useful therapeutic target for the obesity-induced dysfunctional adipocyte.
Uterine TRPV6 expression during the estrous cycle and pregnancy in a mouse model
Authors: Lee Geun-Shik , Jeung Eui-Bae
Published: March 2007

Maintenance of uterine calcium balance is crucial for physiological functioning, including smooth muscle contraction and embryo implantation. Although calbindins were previously thought to act as important uterine calcium-processing genes for female reproductive function, they were not enough to attest the roles of calcium ions in the reproductive organs. Previously, we reported that rat transient receptor potential cation channel, subfamily V, member 6 ( TRPV6) was expressed and regulated by hormones in the uterus. In the present study, we observed uterine TRPV6 expression in a mouse model to clarify the mutual roles of these two calcium-processing genes in female reproductive organs. We investigated uterine TRPV6 mRNA expression during the estrous cycle and pregnancy, as well as its regulation by the steroid hormones estrogen (E2) and progesterone (P4) in mice. Uterine TRPV6 mRNA levels increased at estrus and fluctuated in the uterus, placenta, and fetal membrane during pregnancy. Uterine TRPV6 mRNA increased in mid- and late pregnancy, and its expression was strongly induced in midpregnancy in the labyrinth and spongy zones of the placenta, and in the fetal membrane. E2 (17β-estradiol) was found to regulate uterine TRPV6 expression in the luminal and glandular epitheliums. In addition, we determined that ERα tightly regulated uterine TRPV6 transcription. Together, these results suggest that for uterine function in normal pregnancy, TRPV6 is regulated by E2 via an ERα-dependent pathway.
Metformin and exercise reduce muscle FAT/CD36 and lipid accumulation and blunt the progression of high-fat diet-induced hyperglycemia
Authors: Smith Angela C. , Mullen Kerry L. , Junkin Kathryn A. , Nickerson Jennifer , Chabowski Adrian , Bonen Arend , Dyck David J.
Published: March 2007

Derangements in skeletal muscle fatty acid (FA) metabolism associated with insulin resistance in obesity appear to involve decreased FA oxidation and increased accumulation of lipids such as ceramides and diacylglycerol (DAG). We investigated potential lipid-related mechanisms of metformin (Met) and/or exercise for blunting the progression of hyperglycemia/hyperinsulinemia and skeletal muscle insulin resistance in female Zucker diabetic fatty rats (ZDF), a high-fat (HF) diet-induced model of diabetes. Lean and ZDF rats consumed control or HF diet (48 kcal %fat) alone or with Met (500 mg/kg), with treadmill exercise, or with both exercise and Met interventions for 8 wk. HF-fed ZDF rats developed hyperglycemia (mean: 24.4 ± 2.1 mM), impairments in muscle insulin-stimulated glucose transport, increases in the FA transporter FAT/CD36, and increases in total ceramide and DAG content. The development of hyperglycemia was significantly attenuated with all interventions, as was skeletal muscle FAT/CD36 abundance and ceramide and DAG content. Interestingly, improvements in insulin-stimulated glucose transport and increased GLUT4 transporter expression in isolated muscle were seen only in conditions that included exercise training. Reduced FA oxidation and increased triacylglycerol synthesis in isolated muscle were observed with all ZDF rats compared with lean rats ( P < 0.01) and were unaltered by therapeutic intervention. However, exercise did induce modest increases in peroxisome proliferator-activated receptor-γ coactivator-1α, citrate synthase, and β-hydroxyacyl-CoA dehydrogenase activity. Thus reduction of skeletal muscle FAT/CD36 and content of ceramide and DAG may be important mechanisms by which exercise training blunts the progression of diet-induced insulin resistance in skeletal muscle.
Molecular basis of sex and reproductive status in breeding zebrafish
Authors: Santos E. M. , Workman V. L. , Paull G. C. , Filby A. L. , Van Look K. J. W. , Kille P. , Tyler C. R.
Published: March 2007

The zebrafish ( Danio rerio) is used extensively as a model species for studies on vertebrate development and for assessing chemical effects on reproduction. Despite this, the molecular mechanisms controlling zebrafish reproduction are poorly understood. We analyzed the transcriptomic profiles of the gonads of individual zebrafish, using a 17k oligonucleotide microarray, to define the molecular basis of sex and reproductive status in sexually mature fish. The gonadal transcriptome differed substantially between sexes. Among the genes overexpressed in females, 11 biological processes were overrepresented including mitochondrion organization and biogenesis, and cell growth and/or maintenance. Among the genes overexpressed in males, six biological processes were overrepresented including protein biosynthesis and protein metabolism. Analysis of the expression of gene families known to be involved in reproduction identified a number of genes differentially expressed between ovaries and testes including a number of sox genes and genes belonging to the insulin-like growth factor and the activin-inhibin pathways. Real-time quantitative PCR confirmed the expression profiles for nine of the most differentially expressed genes and indicated that many transcripts are likely to be switched off in one of the sexes in the gonads of adult fish. Significant differences were seen between the gonad transcriptomes of individual reproductively active females reflecting their stage of maturation, whereas the testis transcriptomes were remarkably similar between individuals. In summary, we have identified molecular processes associated with (gonadal) sex specificity in breeding zebrafish and established a strong relationship between individual ovarian transcriptomes and reproductive status in females.
Genetic and Epigenetic Regulation of the Human Prostacyclin Synthase Promoter in Lung Cancer Cell Lines
Authors: Stearman Robert S. , Grady Michael C. , Nana-Sinkam Patrick , Varella-Garcia Marileila , Geraci Mark W.
Published: March 2007

The importance of the arachidonic acid pathway has been established in colon and lung cancers, as well as in inflammatory diseases. In these diseases, prostacyclin I2 (PGI2) and prostaglandin E2 (PGE2) are thought to have antagonistic activities, with PGI2 exerting anti-inflammatory and antiproliferative activities, whereas PGE2 is proinflammatory and antiapoptotic. In human lung cancer, prostacyclin synthase (PGIS) and PGI2 are down-regulated, whereas PGE2 synthase (PGES) and PGE2 are up-regulated. Murine carcinogenesis models of human lung cancer reciprocate the relationship between PGIS and PGES expression. PGIS-overexpressing transgenic mice are protected from carcinogen- and tobacco smoke–induced lung tumor formation, suggesting that PGI2 may play a role in chemoprevention. We investigated several potential mechanisms for the down-regulation of PGIS in human lung cancer. Using transcription reporter assays, we show that single nucleotide polymorphisms in the PGIS promoter can affect transcriptional activity. In addition, PGIS expression in several human lung cancer cell lines is silenced by CpG methylation, and we have mapped these sites across the variable number of tandem repeats (VNTR) sequence in the promoter, as well as CpGs within exon 1 and the first intron. Finally, using fluorescence in situ hybridization, we show that human lung cancer cell lines and lung cancer tissues do not have a loss of the PGIS genomic region but multiple copies. These results show that an individual's PGIS promoter haplotype can play an important role in the predisposition for lung cancer and CpG methylation provides an epigenetic mechanism for the down-regulated PGIS expression. (Mol Cancer Res 2007;5(3):295–308)
Protease-Activated Receptor-1 (hPar1), A Survival Factor Eliciting Tumor Progression
Authors: Salah Zaidoun , Maoz Myriam , Pokroy Elisheva , Lotem Michal , Bar-Shavit Rachel , Uziely Beatrice
Published: March 2007

Although ample evidence point to the central involvement of protease activated receptor-1 (PAR1) in tumor progression, little is known about the fate of the tumor when hPar1 is being silenced. We observed that hPar1 antisense clones exhibit low PAR1 levels, attenuated cell proliferation and invasion in vitro, and tumor formation in vivo. These clones showed noticeably reduced paxillin phosphorylation compared with the parental A375SM cells, whereas no change in the integrin levels was noticed. Antisense clones injected into the mice resulted in very few and only occasional small tumors, whereas advanced and vascularized tumors were observed in A375SM cells. The antisense-derived tumor sections expressed active caspase-3, increased terminal deoxynucleotidyl transferase–mediated nick-end labeling staining, and a markedly reduced proliferating cell nuclear antigen level compared with A375SM cell–derived tissue sections. Likewise, ablation of the hPar1 gene in a tetracycline-inducible hPar1 system leads to apoptosis in immature blood vessels, whereas mature vessels were unaffected. The activation of PAR1-induced pAkt/protein kinase B abrogated serum-deprived BimEL induction and also markedly inhibited Bax levels. On the other hand, small interfering RNA silencing of the hPar1 gene induced the expression of BimEL, a direct substrate of Akt/protein kinase B and also induced expression of active caspase-9 and caspase-3. These results altogether identify PAR1 as a survival factor that protects cells from undergoing apoptosis. We conclude that whereas PAR1 gene expression correlates with tumor progression, its neutralization effectively initiates an apoptotic pathway leading at least in part to significantly reduced tumor formation. (Mol Cancer Res 2007;5(3):229–40)
Altered Expression of Apoptosis-Related Genes in Osteocytes Exposed to High-Dose Steroid Hormones and Hypoxic Stress
Authors: Tsuji Muneharu , Ikeda Hitoshi , Ishizu Akihiro , Miyatake Yukiko , Hayase Hiroko , Yoshiki Takashi
Published: March 2007

Objective: High-dose steroid hormones cause necrosis of the femoral head. Since steroid hormones function as blood coagulants, we hypothesized that ischemic hypoxia induced by steroid hormones is critical for apoptosis which occurs before necrosis of osteocytes. Methods: We performed an analysis of gene expression in the process of leading osteocytes to apoptosis, using a mouse cell line. Cultured osteocytes were loaded with hypoxic stress with or without exposure to steroid hormones, and the gene expression under these conditions was investigated using a cDNA array and real-time quantitative RT-PCR. Results: The proapoptotic p53 gene was downregulated under a hypoxic (1% O2) condition without exposure to steroid hormones. On the other hand, the expression of antiapoptotic Bcl-2 gene was increased by exposure to high-dose steroid hormones under a normoxic condition (20% O2). Interestingly, both proapoptotic (p53 and Bax) and antiapoptotic (Bcl-2 and MDM2)genes were downregulated in osteocytes treated with high-dose steroid hormones in the hypoxic environment. Conclusions: These findings suggest that osteocytes exposed to high-dose steroid hormones appear to be more sensitive to apoptosis in the hypoxic environment than those without exposure to steroid hormones. This concept helps to understand the pathogenesis of idiopathic necrosis of the bone.
Causes and Consequences of Increased Arterial Stiffness in Chronic Kidney Disease Patients
Authors: Gusbeth-Tatomir Paul , Covic Adrian
Published: March 2007

Cardiovascular (CV) morbidity and mortality is greatly enhanced in patients with chronic kidney disease, compared to the non-renal population. One key element of this high CV burden appears to be arterial stiffness, as an expression of premature vascular aging. Increased arterial stiffness in renal patients may be a consequence of vascular calcification, chronic volume overload, inflammation, endothelial dysfunction, oxidative stress and several other factors. The authors review briefly the main pathophysiological mechanisms leading to reduced arterial compliance. Increased arterial stiffness has significant clinical consequences: isolated systolic hypertension, left ventricular hypertrophy (and failure), and reduced myocardial perfusion. Better knowledge of the mechanisms of arterial functional and morphologic alteration may help in developing more refined therapeutic strategies aimed to reduce the high CV burden in chronic kidney disease. The potential therapeutic interventions – mainly the use of certain antihypertensive drugs and reduction of vascular calcification – are finally discussed.
Endogenous Erythropoietin Levels and Anemia in Long-Term Renal Transplant Recipients
Authors: Zadražil Josef , Horák Pavel , Horčička Vladko , Zahálková Jana , Štrébl Pavel , Hrubý Miroslav
Published: March 2007

Background/Aim: Although anemia is a common complication after renal transplantation (RT), data concerning endogenous erythropoietin (EPO) levels in long-term RT recipients are rare. The goal of this study was to evaluate the prevalence of anemia within 6 months to 5 years after RT and to assess the relationship between the serum concentrations of endogenous EPO, graft function and grade of improvement of anemia. Methods: 140 patients who had undergone RT were included in the group: 89 males (63.6%) and 51 females (36.4%), with an average age 46.8 ± 12.8 years. The serum concentrations of EPO and creatinine (Cr) were tested in all the individuals and the values of the red blood component of blood count, serum ferritin (SF), plasma iron concentration, plasma total iron-binding capacity (TIBC), transferrin saturation (TS), folic acid and vitamin B12 levels in the serum were determined. A statistical analysis of the results was performed using the correlation analysis, Mann-Whitney U test and Duncan’s multiple range test. Results: Normal blood count values were found in 91 patients (65%), and a mild grade of anemia with a mean hemoglobin (Hb) 114.4 ± 11.9 g/l was observed in 45 patients (32.1%), and 4 patients (2.9%) fulfilled the diagnostic criteria for post-transplantation erythrocytosis. Individuals with normal Hb values had a mean EPO serum concentration of 39.3 ± 12.3 mU/ml (median 37.2) and the mean Cr was 133.8 ± 36.9 µmol/l (median 122). Patients with anemia (Hb <120 g/l in females, Hb <130 g/l in males) had a mean EPO value of 47.0 ± 26.6 mU/ml (median 36.0) and a mean Cr of 203.8 ± 108.9 µmol/l (median 181). The difference in the Cr values was statistically significant (p < 0.0001), while the difference between the EPO concentrations was not significant. No relation of EPO serum concentration with regard to graft function was found in the analysis. A lack of storage iron (SF <10 µg/l in females, SF <22 µg/l in males) was found in 16 patients (11.4%), and a lack of functional iron (TS <20%) was found in 27 patients (19.3%). Conclusions: Theprevalence of anemia in patients after transplantation was 32.1%. The most common cause of anemia is insufficient graft function development. The achieved values of the red component of blood count have no relation to the endogenous EPO serum concentrations.
Interleukin-6, C-Reactive Protein and Biochemical Parameters during Prolonged Intermittent Fasting
Authors: Aksungar Fehime B. , Topkaya Aynur E. , Akyildiz Mahmut
Published: March 2007

Background: It is well known that nutritional habits, sleeping patterns and meal frequency have profound effects on maintaining human health. Ramadan is a religious month for Islam, during which Muslims do not eat and drink during the daylight hours. The duration of restricted food and beverage intake is approximately 12 h/day for 1 month, which makes Ramadan a model of prolonged intermittent fasting. Methods: In order to evaluate the effects of long-lasting modifications of food intake on inflammatory markers and biochemical parameters 40 healthy volunteers of normal weight [20 females aged between 20 and 38 years, 20 males aged between 23 and 39 years, body mass index (BMI) <25 kg/m2] who fasted during Ramadan and another 28 healthy age- and BMI-matched volunteers (14 males, 14 females) who did not fast participated in the study. Venous blood samples were taken 1 week before Ramadan, during the last week of Ramadan and 3 weeks after Ramadan. Serum interleukin-6 (IL-6), C-reactive protein (CRP), homocysteine, vitamin B12, folate, total cholesterol (TC), triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) levels were measured. Results: No significant changes were observed in serum total cholesterol, triglycerides and LDL levels. TC/HDL ratio (HDL risk factor) was decreased during and after Ramadan in both genders in the fasting group while there were no changes in the nonfasting group. IL-6 (p < 0.001), CRP (p < 0.001) and homocysteine (p < 0.01) levels were significantly low during Ramadan in the fasting subjects of both genders when compared to basal values (1 week before Ramadan). Conclusion: Our results demonstrate that prolonged intermittent fasting in a model like Ramadan has some positive effects on the inflammatory status of the body and on the risk factors for cardiovascular diseases such as homocysteine, CRP and TC/HDL ratio.
Frequency of Mutated Allele CYP2D6*4 in the Turkish Population
Authors: Koseler Aylin , Ilcol Yesim Ozarda , Ulus Ismail H.
Published: March 2007

The frequency of functionally important mutations and alleles of the gene coding for CYP2D6 shows wide ethnic variations. The present study aimed to determine the most common mutated allele CYP2D6*4 gene in a Turkish population of 100 unrelated subjects, by using real-time PCR with fluorescent probe. CYP2D6*4 allele was not detected in 62 subjects (62%). Among the remaining 38 subjects (38%), 4 (4%) were carriers of two *4 alleles, being homozygous for CYP2D6 and genotyped as CYP2D6*4/*4. 34 subjects (34%) were carriers of one *4 allele, being heterozygous for CYP2D6*4. The frequency of allele *4 was 0.21. These data indicate that 4% of the Turkish individuals living in the city of Bursa are carriers of two nonfunctional mutated alleles *4, being homozygous for CYP2D6*4. It is clinically important to be able to identify those individuals who are likely to have altered pharmacokinetics for CYP2D6 substrates in order to avoid adverse drug reactions.