bluuebunny/crossref_metadata_2025 huggingface dataset:
Bio-Logic: Gene Expression and the Laws of Combinatorial Logic
Authors: Schilstra Maria J. , Nehaniv Chrystopher L.
Published: January 2008

At the heart of the development of fertilized eggs into fully formed organisms and the adaptation of cells to changed conditions are genetic regulatory networks (GRNs). In higher multicellular organisms, signal selection and multiplexing are performed at the cis-regulatory domains of genes, where combinations of transcription factors (TFs) regulate the rates at which the genes are transcribed into mRNA. To be able to act as activators or repressors of gene transcription, TFs must first bind to target sequences on the regulatory domains. Two TFs that act in concert may bind entirely independently of each other, but more often binding of the first one will alter the affinity of the other for its binding site. This article presents a systematic investigation into the effect of TF binding dependences on the predicted regulatory function of this bio-logic. Four extreme scenarios, commonly used to classify enzyme activation and inhibition patterns, for the binding of two TFs were explored: independent (the TFs bind without affecting each other's affinities), competitive (the TFs compete for the same binding site), ordered (the TFs bind in a compulsory order), and joint binding (the TFs either bind as a preformed complex, or binding of one is virtually impossible in the absence of the other). The conclusions are: (1) the laws of combinatorial logic hold only for systems with independently binding TFs; (2) systems formed according to the other scenarios can mimic the functions of their Boolean logical counterparts, but cannot be combined or decomposed in the same way; and (3) the continuously scaled output of systems consisting of competitively binding activators and repressors can be controlled more robustly than that of single TF or (quasi-)logical multi-TF systems.
Exploring the Operational Characteristics of Inference Algorithms for Transcriptional Networks by Means of Synthetic Data
Authors: Van Leemput Koenraad , Van den Bulcke Tim , Dhollander Thomas , De Moor Bart , Marchal Kathleen , van Remortel Piet
Published: January 2008

The development of structure-learning algorithms for gene regulatory networks depends heavily on the availability of synthetic data sets that contain both the original network and associated expression data. This article reports the application of SynTReN, an existing network generator that samples topologies from existing biological networks and uses Michaelis-Menten and Hill enzyme kinetics to simulate gene interactions. We illustrate the effects of different aspects of the expression data on the quality of the inferred network. The tested expression data parameters are network size, network topology, type and degree of noise, quantity of expression data, and interaction types between genes. This is done by applying three well-known inference algorithms to SynTReN data sets. The results show the power of synthetic data in revealing operational characteristics of inference algorithms that are unlikely to be discovered by means of biological microarray data only.
Low-level HIV-1 replication and the dynamics of the resting CD4+T cell reservoir for HIV-1 in the setting of HAART
Authors: Sedaghat Ahmad R , Siliciano Robert F , Wilke Claus O
Published: January 2008

Background

In the setting of highly active antiretroviral therapy (HAART), plasma levels of human immunodeficiency type-1 (HIV-1) rapidly decay to below the limit of detection of standard clinical assays. However, reactivation of remaining latently infected memory CD4+ T cells is a source of continued virus production, forcing patients to remain on HAART despite clinically undetectable viral loads. Unfortunately, the latent reservoir decays slowly, with a half-life of up to 44 months, making it the major known obstacle to the eradication of HIV-1 infection. However, the mechanism underlying the long half-life of the latent reservoir is unknown. The most likely potential mechanisms are low-level viral replication and the intrinsic stability of latently infected cells.

Methods

Here we use a mathematical model of T cell dynamics in the setting of HIV-1 infection to probe the decay characteristics of the latent reservoir upon initiation of HAART. We compare the behavior of this model to patient derived data in order to gain insight into the role of low-level viral replication in the setting of HAART.

Results

By comparing the behavior of our model to patient derived data, we find that the viral dynamics observed in patients on HAART could be consistent with low-level viral replication but that this replication would not significantly affect the decay rate of the latent reservoir. Rather than low-level replication, the intrinsic stability of latently infected cells and the rate at which they are reactivated primarily determine the observed reservoir decay rate according to the predictions of our model.

Conclusion

The intrinsic stability of the latent reservoir has important implications for efforts to eradicate HIV-1 infection and suggests that intensified HAART would not accelerate the decay of the latent reservoir.
COGNITIVE AND BEHAVIORAL ABILITIES OF CHILDREN WITH HIV INFECTION IN GREECE
Authors: Bertou Georgia , Thomaidis Loreta , Spoulou Vasiliki , Theodoridou Maria
Published: January 2008

OBJECTIVE: Our goal was to evaluate cognitive and behavioral abilities of HIV-positive children in Greece.

METHODS: The cognitive and behavioral abilities of 20 HIV-positive children (B and C status; 8 boys and 12 girls; aged 3–18 years [mean: 11.5 years]) who were vertically infected and were receiving antiretroviral treatment were assessed twice within a 7-year period. Clinical indices (CD4 lymphocyte and viral load counts) were monitored systematically. A detailed developmental assessment was performed for all children twice within a 7-year period. Cognitive abilities were assessed by using the Wechsler Intelligence Scale for Children III and Griffiths Mental Abilities Scales. Behavioral abilities were assessed by using the Strengths and Difficulties Questionnaire, which provides individual scores for anxiety, emotional tension, conduct, hyperactivity, and social relations with peers and provides an overall index of behavioral difficulties (IBD). Detailed neurologic examination and brain imaging were performed for all children.

RESULTS: HIV encephalopathy was evident in 3 children, and 5 of 20 children presented with coexisting diseases (2 neurofibromatosis encephalopathy, 1 brain aneurysm, and 2 autistic disorders). HIV-positive children with normal MRI findings and without signs of HIV encephalopathy scored within the normal range for their chronological age in all measures of general and specific domain cognitive abilities. Low IQ scores showed in 15 of 20 HIV-positive children in both assessments. Factors that were associated consistently with lower scores were positive MRI results, coexistence of an organic disease, maternal education, and gender. The IBD was raised in 7 children. In detail, 9 children had raised IBD scores in emotional tension, 6 seemed to have conduct disorders, 5 had hyperactivity, and 11 presented as having difficulties in social relations with their peers. Factors that were associated significantly and consistently with abnormal IBD scores were lower IQ, positive MRI findings, and coexistence of an organic disease.

CONCLUSIONS: Although the sample was small, the findings of our study support the idea that HIV infection places children at increased risk for poor cognitive and behavioral outcomes only if they experience a severe illness of advancing disease stage or a coexisting disease.
ASSOCIATION OF CYTOKINE-RELATED GENE EXPRESSION WITH DENGUE INFECTION SEVERITY
Authors: Waidab Woraman , Suphapeetiporn Kanya , Srichomthong Chalurmpon , Tongkobpetch Siraprapa , Pancharoen Chitsanu , Shotelersuk Vorasuk , Thisyakorn Usa
Published: January 2008

INTRODUCTION: Dengue is the most prevalent mosquito-borne viral disease and one of the most serious infectious diseases worldwide. Infection by any of the serotypes of dengue viruses (DEN-1–DEN-4) may result in different severities ranging from a relatively benign fever, called dengue fever (DF), to fatal dengue shock syndrome. The pathogenesis of dengue hemorrhagic fever (DHF) and dengue shock syndrome is thought to be mediated by various host factors. Previous reports have suggested an involvement of immunoresponse mediators as well as apoptosis-related molecules in the severity of dengue infection.

OBJECTIVE: Our aim was to elucidate the cellular gene responses to dengue viral infection at the transcriptional level and to correlate expression levels with disease activity and/or clinical manifestation.

METHODS: Expression levels of interleukin 8 (IL-8), IL-1β, matrix metalloproteinase 9 (MMP-9), and Fas in peripheral blood cells were assayed for 10 children with DF, 10 children with DHF, and 5 healthy controls by using real-time reverse-transcription quantitative polymerase chain reaction.

RESULTS: Expression levels of IL-8, IL-1β, MMP-9, and Fas were higher in children who developed DHF than in those with DF.

CONCLUSIONS: The messenger RNA expression levels of IL-8, IL-1β, MMP-9, and Fas were significantly elevated in children with DHF, which suggests that these mediators are involved in the pathogenesis. The messenger RNA expression level might serve as a predictor of dengue disease activity. Reverse-transcription polymerase chain reaction has a potential to be another rapid and useful tool in assessing disease severity, leading to a proper therapeutic plan.
TRADITIONAL PRACTICES AFFECTING CHILD HEALTH: A SUB-SAHARAN AFRICAN EXPERIENCE
Authors: Chapp-Jumbo Assumpta
Published: January 2008

INTRODUCTION: Culture includes the values of a people and affects nurturing of children as well as illness attribution. In spite of scientific discoveries, traditional practices that relate to health-seeking behaviors have persisted.

OBJECTIVE: The purpose of this work was to highlight the harmfulness and consequent negative effects of some of these practices on child health.

METHODS: A 1-year longitudinal study of children who attended the children's emergency and outpatient departments of a health institution in an urban area in Nigeria was carried out. Oral interviewing of the caregivers and physical inspection of the children was carried out for all patients. Treatment history, preferences for health care, and obvious traditional attempts at cure were evaluated.

RESULTS: There were 4484 hospital visits during which 2040 children were evaluated. The most common form of medical intervention at home before the visit was the use of herbal remedies (964 [47.25%]), scarifications that remained after blood-letting procedures (867 [42.5%]), and pastes applied on the anterior fontanel (24 [1.18%]). Other less common but more traumatic therapies were foot roasting (18 [0.88%]), heat treatment of extremities (6 [0.29%]), and application of special preparations orifices (0.88%).

CONCLUSIONS: The high use of traditional methods of treatment and the harmfulness of some of them calls for health providers in any environment to evaluate these practices to use the information obtained as tools for health education, thereby discouraging harmful treatments and encouraging the practice of useful ones.
CENTRAL OBESITY IS THE MAJOR RISK FACTOR FOR FAILURE OF OBESITY MANAGEMENT DURING CONSOLIDATION PHASE IN CHILDREN
Authors: El Taguri Adel , Dabbas-Tyan Myriam , Ricour Claude
Published: January 2008

INTRODUCTION: A proportion of obese children who are treated with a multidisciplinary approach with behavior modification and parental involvement show no response to the consolidation phase of treatment.

OBJECTIVE: Our goal was to identify possible risk factors that led to failure of obesity management in children who were attending an equipped, busy, specialized outpatient clinic.

METHODS: We performed a case-control study in which cases were those whose conditions failed to respond to current multidisciplinary management as judged by no decrease in BMI z score. Controls were those who responded to treatment (lower subsequent BMI z scores).

RESULTS: Of the 519 children, 416 (80.2%) had BMI z scores of >3. Management was successful in 85% of the patients. In bivariate analysis, risk factors were age of <4 years (odds ratio [OR]: 4.00 [95% confidence interval (CI): 1.08–14.70]), previous obesity management (OR: 2.18 [95% CI: 1.10–4.32]), triglyceridemia (OR: 2.01 [95% CI: 1.10–3.65]), and higher abdominal fat content as measured directly by dual-energy radiograph absorptiometry (OR: 1.09 [95% CI: 1.00–1.19]) or relative to thigh (waist/hip index) (OR: 2.67 [95% CI: 1.13–6.72]). Duration of obesity, the initial BMI z score, and gender were not predictive of treatment failure. In multivariate analysis, central obesity was the single-most important factor. In more hierarchical conceptual framework, factors retained were maternal obesity (OR: 2.44 [95% CI: 1.22–4.86]), previous management of obesity (OR: 2.21 [95% CI: 1.11–4.37]), and waist/hip index (OR: 3.35 [95% CI: 1.18–9.49]).

CONCLUSIONS: We propose a model in which centrally obese children with obese mothers who have high triglyceride levels are more likely to show resistance to reversal of the pathologic process of excess fat accumulation. Central obesity is a well known correlate of increased morbidity.
RECURRENT IDIOPATHIC THROMBOCYTOPENIC PURPURA IN CHILDHOOD
Authors: Vranou Maria , Pergantou Helen , Platokouki Helen , Kousiafes Dimitris , Avgeri Maria , Aronis Sophia
Published: January 2008

INTRODUCTION: Idiopathic thrombocytopenic purpura (ITP) is usually a benign disease that remits within weeks to years. The literature on recurrent ITP (rITP) is limited.

OBJECTIVE: The aim of this study was to retrospectively review patients with rITP who were followed up during the period of 1975–2004.

METHODS: We reviewed the outcome of 790 children with rITP

RESULTS: Among 790 children with ITP, 47 (5.2%) presented with >1 episode of thrombocytopenia. The median age of the children at onset of the disease was 55.9 ± 35.3 months and at final remission was 94.4 ± 58.9 months. The majority of patients (76.6%) had 1 recurrence, whereas the rest of them had >1 recurrence (up to 4); the total number of recurrences was 63. The interval between 2 episodes was <6 months in 25% of the episodes, 6 to 12 months in 29%, 12 to 24 months in 24%, 24 to 36 months in 8%, and >3 years in 14%. Almost half the patients demonstrated bleeding manifestations at diagnosis, whereas only a minority (5) showed bleeding symptoms during the first recurrence. Hemorrhages occurred at times of severe thrombocytopenia and were, in general, mild; however, 1 patient suffered intracranial hemorrhage. Of the episodes, 28.6% necessitated hospitalization and 17.5% required therapeutic intervention with corticosteroids or/and intravenous immunoglobulin. The long-term outcome of all patients was excellent, and none of them needed splenectomy.

CONCLUSIONS: rITP occurs mostly in young children, has a good outcome after >1 to 5 episodes, and a median age that ranges from months to years. The course is more often benign; however, life-threatening hemorrhage may occur in a severely thrombocytopenic patient.
Computed tomography reconstruction artifact suggesting cervical spine subluxation
Authors: Sciubba Daniel M. , Dorsi Michael J. , Kretzer Ryan , Belzberg Allan J.
Published: January 2008

✓Use of computed tomography (CT) imaging for evaluation of the cervical spine following blunt trauma is both an efficient and reliable method for detecting injury. As a result, many trauma centers and emergency departments rely exclusively on CT scans to acutely clear the cervical spine of injury. Although quite sensitive for detecting bone injury, CT may be associated with a low sensitivity for detecting herniated discs, injured soft tissue or ligaments, and dynamic instability. In addition, CT-generated artifact may obscure pathological findings. In this case report, we describe the course of a patient whose CT scan harbored CT-generated artifact that suggested traumatic subluxation of the cervical spine. Clinicians should be aware of such artifact and how to recognize it when basing clinical management on such studies.
Stereoselective Synthesis of Sugar Nucleotides Using Neighboring Group Participation
Authors: Timmons Shannon C. , Jakeman David L.
Published: January 2008

A straightforward, efficient method for the chemical synthesis of sugar nucleotides derived from D‐mannose and L‐fucose precursors is described. This synthetic strategy involves the coupling of acylated glycosyl bromides with nucleoside 5′‐diphosphates, which enables the exploitation of neighboring group participation to exclusively prepare diastereomerically pure sugar nucleotides of desired 1,2‐trans anomeric configuration. This is the first stereoselective direct coupling approach to sugar nucleotide synthesis. Following deprotection using triethylamine and purification via C18 reversed‐phase ion‐pair chromatography, UDP‐ and GDP‐α‐D‐mannose as well as UDP‐ and GDP‐β‐L‐fucose were obtained in good yield in only four synthetic steps from D‐mannose and L‐fucose. Curr. Protoc. Nucleic Acid Chem. 31:13.7.1‐13.7.16. © 2007 by John Wiley & Sons, Inc.
One‐Dimensional SDS Gel Electrophoresis of Proteins
Authors: Gallagher Sean R.
Published: January 2008

Electrophoresis is used to separate complex mixtures of proteins (e.g., from cells, subcellular fractions, column fractions, or immunoprecipitates), to investigate subunit compositions, and to verify homogeneity of protein samples. It can also serve to purify proteins for use in further applications. In polyacrylamide gel electrophoresis, proteins migrate in response to an electrical field through pores in a polyacrylamide gel matrix; pore size decreases with increasing acrylamide concentration. The combination of pore size and protein charge, size, and shape determines the migration rate of the protein. In this unit, the standard Laemmli method is described for discontinuous gel electrophoresis under denaturing conditions, that is, in the presence of sodium dodecyl sulfate (SDS). Both full‐size and minigel formats are detailed. Several modifications are provided for specific applications. For separation of peptides and small proteins, the standard buffers are replaced with either a Tris‐tricine buffer system or a modified Tris buffer in the absence of urea. Continuous SDS‐PAGE is a simplified method in which the same buffer is used for both the gel and the electrode solutions and the stacking gel is omitted. Other protocols cover the preparation and use of ultrathin gels and gradient gels, and the simultaneous preparation of multiple gels. Curr. Protoc. Cell Biol. 37:6.1.1‐6.1.38. © 2007 by John Wiley & Sons, Inc.
Using the iHOP Information Resource to Mine the Biomedical Literature on Genes, Proteins, and Chemical Compounds
Authors: Hoffmann Robert
Published: January 2008

The iHOP (Information Hyperlinked over Proteins) resource employs sophisticated text‐mining methods to assist researchers in their quest for information on specific genes and proteins, their physical interactions and regulatory relationships, their relevance in pathologies, and their interactions with chemical compounds. iHOP parses thousands of PubMed documents every day and collects information specific to thousands of different biological molecules. Rather than providing long lists of entire abstracts upon keyword searches, iHOP selectively retrieves information that is specific to genes and proteins, and summarizes their interactions and functions. In iHOP, with genes and proteins acting as hyperlinks between sentences and abstracts, a large part of the PubMed knowledgebase becomes a giant navigable information network. Curr. Protoc. Bioinform. 20:1.16.1‐1.16.16. © 2007 by John Wiley & Sons, Inc.
Synthesis and characterization of starch piperinic ester and its self‐assembly of nanospheres
Authors: Han Jingfen , Borjihan Gereltu , Bai Ruke , Chen Xuesi , Jing Xiabin
Published: January 2008

A novel amphiphilic starch piperinic ester (SPE) has been synthesized by coupling a carboxyl group on the piperic acid and a hydroxyl group on the starch backbone. The synthetic process includes three steps. Firstly, piperic acid was obtained by hydrolyzing piperine that was extracted from seeds of Piper longum L (a kind of traditional Mongolian medicine). Then, piperic acid was reacted with carbonyl diimidazole (CDI) under N2 at 70°C for 4 h to form an activated piperic acid. Finally, starch piperinic ester was obtained by the reaction of the activated piperic acid with water‐soluble starch at 80°C under N2 for 24 h. The product was characterized by FTIR, NMR. It was found that the starch piperinic ester could easily form stable micelles in aqueous solution, and the spherical morphology of micelle was observed by ESEM. The results of DLS analysis proved that the micelle size depends on the composition of the amphiphilic polymer. Our results demonstrate that SPE has great potential in the drug controlled release delivery. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Surface and bulk properties of poly(ether urethane)s/fluorinated phosphatidylcholine polyurethanes blends
Authors: Zhang Xiaoqing , Jiang Xia , Li Jiehua , Tan Hong , Zhong Yinping , Fu Qiang
Published: January 2008

As a part of long‐term project aimed at biomembrane mimicking polyurethanes (PU) with excellent biocompatibility and good mechanical properties, in this work, we report the surface and bulk properties of two series blends of fluorinated phosphatidylcholine polyurethanes (FPCPU) with poly(ether urethane)s (PEU). The blend films were prepared by solution mixing, and the surface and bulk properties were investigated by contact angle measurement, XPS, DSC, and Instron. Our results demonstrated that the surface with high percentage of phosphorus, fluorine, and nitrogen content could be achieved by blending FPCPU with PEU, because of the migration of FPCPU to the surface, resulting in a decreased water contact angle and increased hystersis. The blend films showed a reversible rearrangement of surface structure according to the change of environment from dry state to hydrated state. DSC result suggested that FPCPU could be phase miscible with PEU well in a broad composition region (as the content of FPCPU is less than 50 wt %). The blends showed an increased tensile strength and elongation at break compared with FPCPU, and increased modulus compared with PEU. Combined with the improved mechanical properties and much reduced price, together with the excellent blood compatibility, it can be expected these materials may play important roles in future medical application. © 2008 Wiley Periodicals, Inc. JAppl Polym Sci, 2008
Factors determining the pattern of a hydrogen‐bonding network in the diastereomeric salts of 1‐arylethylamines with enantiopure P‐chiral acids
Authors: Kobayashi Yuka , Handa Hiroaki , Maeda Jin , Saigo Kazuhiko
Published: January 2008

In order to clarify factor(s) determining the pattern of a hydrogen‐bonding network in the diastereomeric salts of 1‐arylethylamines (1) with enantiopure P‐chiral acids, three kinds of enantiopure P‐chiral alkylphenylphosphinothioic acids (3) were synthesized, and their chiral recognition abilities for racemic 1 were examined. The characteristics of the diastereomeric salt crystals of 1 with 3 were then studied on the basis of their X‐ray crystallographic analyses. Statistical analysis on the molecular conformations observed in the diastereomeric salts with 3 as well as those with P‐chiral O‐alkyl arylphosphonothioic acids (2), which have a chemical structure similar to that of 3, and molecular orbital calculations for 2 and 3 in a gas phase revealed that the torsion angle between the aromatic plane and the PO(alkoxy in 2) or PC(alkyl in 3) plays an important role in determining the pattern of a hydrogen‐bonding network in the diastereomeric salts, either a closed globular cluster or an infinite 21 column type. The calculations also indicated that there is a hydrogen‐bonding‐like interaction between the ammonium hydrogen atom of 1‐arylethylammonium cations and the PO(alkoxy) oxygen atom of phosphonothioate anions in the clusters. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
High‐frequency stimuli preferentially release large dense‐core vesicles located in the proximity of nonspecialized zones of the presynaptic membrane in sympathetic ganglia
Authors: Cifuentes F. , Montoya M. , Morales M.A.
Published: January 2008

We characterized the effect of a brief high‐frequency stimulus on the number, distribution, and optical density of large dense‐core vesicles (LDCVs) in the nerve terminals of the rat superior cervical ganglia. From 4.21 ± 0.37 LDCVs/bouton detected in control nerve terminals, a stimulus of 40 Hz for 1 min released 41% of LDCVs, decreasing their number to 2.48 ± 0.14 LDCVs/bouton (p = 0.0009). In control ganglia, most dense vesicles were located close to the plasma membrane (at ≤100 nm); in contrast, in stimulated ganglia they were broadly distributed with respect to the active zone. The mean distance of LDCVs to membrane and active zones was 95 ± 8 nm and 473 ± 15 nm, respectively. The analysis of the core density showed that both groups had a similar asymmetric distribution with the same average. Stimulation preferentially released those vesicles located ≤100 nm from the plasma membrane that had no apparent relationship with the active zone. After the stimulus, the average distances of LDCVs to the plasma membrane and active zone did not change, suggesting that the stimulus also caused the relocation of inner LDCVs. Interestingly, optical density analysis showed that the released vesicles had low range densities, and suggested that LDCVs release their entire content. We conclude that LDCV exocytosis mainly involves those vesicles located ≤100 nm from the plasma membrane and occurs in regions of synaptic boutons presumed to be nonspecialized. These results agree with the characteristics of the classical model that proposes full content release. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.
Selenium Heterocycles: Reactions of SeX4 (X = Cl, Br) with the Enamine Form of β‐Diketiminato Ligands
Authors: Gushwa Audra F. , Richards Anne F.
Published: January 2008

Treatment of SeX4 (X = Cl, Br) with either MesnacnacLi(nacnac = [{N(Ar)C(Me)}2CH]–, Ar = Mes = C6H2Me3‐2,4,6) or DmpnacnacLi (Ar = Dmp = C6H3Me2‐2,6) affords four new SeII six‐membered heterocycles, [MesnacnacHCl2SeCl] (2), [MesnacnacH2Se]+Br– (3), [DmpnacnacH2Cl3Se]+Cl– (4), and [MesnacnacH2(O)Br2Se] (5). All have been characterized in the solid state by X‐ray crystallography. Each of the four complexes is proposed to have formed from the initial reaction of SeX4 with the C–C double bond that results from the enamine form of the ligand, giving rise to an Se–C single bond. Subsequent nucleophilic attack by either the more distant nitrogen atom or the remaining C–C double bond of the enamine form results in the Se heterocycle. In complexes 2, 4, and 5 varying degrees of halogenation of the newly formed heterocycles was observed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Epigenetic changes and nontargeted radiation effects—Is there a link?
Authors: Kovalchuk Olga , Baulch Janet E.
Published: January 2008

It is now well accepted that the effects of ionizing radiation (IR) exposure can be noticed far beyond the borders of the directly irradiated tissue. IR can affect neighboring cells in the proximity, giving rise to a bystander effect. IR effects can also span several generations and influence the progeny of exposed parents, leading to transgeneration effects. Bystander and transgeneration IR effects are linked to the phenomenon of the IR‐induced genome instability that manifests itself as chromosome aberrations, gene mutations, late cell death, and aneuploidy. While the occurrence of the abovementioned phenomena is well documented, the exact mechanisms that lead to their development have still to be delineated. Evidence suggests that the IR‐induced genome instability, bystander, and transgeneration effects may be epigenetically mediated. The epigenetic changes encompass DNA methylation, histone modification, and RNA‐associated silencing. Recent studies demonstrated that IR exposure alters epigenetic parameters in the directly exposed tissues and in the distant bystander tissues. Transgeneration radiation effects were also proposed to be of an epigenetic nature. We will discuss the role of the epigenetic mechanisms in radiation responses, bystander effects, and transgeneration effects. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Endogenous sex hormones and the risk of prostate cancer: A prospective study
Authors: Weiss Jocelyn M. , Huang Wen‐Yi , Rinaldi Sabina , Fears Thomas R. , Chatterjee Nilanjan , Hsing Ann W. , Crawford E. David , Andriole Gerald L. , Kaaks Rudolf , Hayes Richard B.
Published: January 2008

Sex steroid hormones influence prostate development and maintenance through their roles in prostate cellular proliferation, differentiation and apoptosis. Although suspected to be involved in prostate carcinogenesis, an association between circulating androgens and prostate cancer has not been clearly established in epidemiologic studies. We conducted a nested case‐control study with prospectively collected samples in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, to examine associations of prostate cancer with androstenedione (Δ4‐A), testosterone (T), sex hormone‐binding globulin (SHBG) and 3α‐androstanediol glucuronide (3α‐diolG). A total of 727 incident Caucasian prostate cancer cases (age ≥ 65 years, N = 396) and 889 matched controls were selected for this analysis. Overall, prostate cancer risks were unrelated to serum T, estimated free and bioavailable T, and SHBG; however, risks increased with increasing T:SHBG ratio (ptrend = 0.01), mostly related to risk in older men (≥65 years, ptrend = 0.001), particularly for aggressive disease [highest versus lowest quartile: odds ratio (OR) 2.76, 95% confidence interval (CI) 1.50–5.09]. No clear patterns were noted for Δ4‐A and 3α‐diolG. In summary, our large prospective study did not show convincing evidence of a relationship between serum sex hormones and prostate cancer. T:SHBG ratio was related to risk in this older population of men, but the significance of this ratio in steroidal biology is unclear. © 2008 Wiley‐Liss, Inc.
On‐farm remediation and fertility enhancement of cadmium‐contaminated silt loam by electrokinetic treatment process in Taiwan
Authors: Chang Po‐Wen , Tan Yih‐Chi , Wang I‐Sen
Published: January 2008

The purpose of this research was a large‐scale project, of an on‐farm remediation of cadmium‐contaminated silty loam by an electrokinetic treatment process in Taiwan. The electrokinetic (EK) treatment process is a useful remedial technology, particularly for soil with low permeability. This pilot test farm implements EK technology to remove heavy metal Cd from the silty loam in rice paddies, and evaluates the removal efficiency of the Cd, as well as soil fertility enhancement during the EK treatment process. A citric acid–surfactant mixture was used as the treatment solution, applied under an electrical current, to improve the removal of the Cd, while simultaneously enhancing the fertility of the silty farm soil. The test results revealed that the EK process gained a Cd removal efficiency of 76.6%; in addition, the contents of organic matter, total nitrogen, Bray‐1 phosphorus, and exchangeable potassium and magnesium were relatively elevated after 92 days of treatment duration. This study concluded that the on‐farm EK treatment technology would be capable of mitigating soil contaminated with not only heavy metals, but also organic compounds in the future. Copyright © 2008 John Wiley & Sons, Ltd.
Chromosome damage in workers in cigarette manufacturing industry
Authors: Milić Mirta , Kašuba Vilena , Oreščanin Višnja , Želježić Davor , Kopjar Nevenka , Rozgaj Ružica
Published: January 2008

To investigate whether occupational exposure to tobacco dust is genotoxic, a group of employees in a tobacco factory was tested for structural chromosome aberrations (CA), cytokinesis‐block micronucleus assay (CBMN) and sister chromatid exchanges (SCE) that are well established as indicators of early biological effects. The study group consisted of 40 tobacco workers and an equal number of matched controls. The results obtained in the exposed group showed a significant increase in chromosome aberrations (R = 0.26), micronucleus frequency (R = 0.56) and in sister chromatid exchanges (R = 0.75), which was additionally influenced by smoking. A significant increase in high frequency cells (HFC) in the exposed group was also observed. Like the SCE frequency, the HFC frequency increased significantly in smokers of the control and exposed smokers. The study indicates that occupational exposure to tobacco dust induces genome damage. A higher risk was observed in women. The micronucleus frequency and sister chromatid exchange tests seem to be more reliable indicators of genome damage than chromosome aberrations in monitoring chronically exposed subjects. Copyright © 2008 John Wiley & Sons, Ltd.
S1P‐lyase independent clearance of extracellular sphingosine 1‐phosphate after dephosphorylation and cellular uptake
Authors: Peest Ulrike , Sensken Sven‐Christian , Andréani Paul , Hänel Petra , Van Veldhoven Paul P. , Gräler Markus H.
Published: January 2008

Sphingosine 1‐phosphate (S1P) is the natural ligand for a specific family of G protein‐coupled receptors (‐Rs). The type 1 S1P‐R (S1P1) is important for lymphocyte egress, and blood‐borne S1P as the natural ligand for S1P1 is involved in the maintenance of lymphocyte circulation. This report reveals that extracellular S1P was cleared by all tested primary cells and cell lines with exponential progression. Clearance of S1P, but not sphingosine (Sph) was inhibited with the protein phosphatase inhibitor sodium orthovanadate. Fluorescence microscopy and flow cytometry using fluorescently labeled S1P and Sph showed a major cellular uptake of Sph, but not S1P. HPLC‐analyses with C17‐Sph demonstrated that cellular Sph accumulation was transient in tested cell lines, but enduring in mouse splenocytes. Sub cellular fractionation resulted in dephosphorylation of S1P to Sph by nuclear, membrane, and cytosolic fractions. Degradation of Sph however only occurred in combined membrane and cytosolic fractions. Inhibitors for Sph kinases 1/2, ceramide synthase, and S1P‐lyase, as well as S1P‐lyase deficiency did not block clearance of extracellular S1P. In vivo experiments revealed a transient increase in plasma S1P levels after single intravenous injection into C57BL/6 mice. This exogenously added S1P was cleared within 15–30 min in contrast to ex vivo incubation of whole blood which required more than 8 h for comparable clearance from plasma. Our data thus show that extracellular S1P is dephosphorylated and subsequently converted by cells, which appears to be important for clearance of the signaling molecule S1P in the local tissue environment after infections or injuries. J. Cell. Biochem. 104: 756–772, 2008. © 2008 Wiley‐Liss, Inc.
Breeding upland rice for drought resistance
Authors: Bernier Jérôme , Atlin Gary N , Serraj Rachid , Kumar Arvind , Spaner Dean
Published: January 2008

Upland rice, produced by smallholder farmers, is the lowest‐yielding rice production system. Drought stress is the most severe abiotic constraint in upland rice. Improving productivity of rice in the upland ecosystem is essential to meet rice food security needs of impoverished upland communities. Breeding drought‐resistant upland rice is therefore an increasingly important goal. Numerous secondary characters have been suggested to help plant breeders in their selections. Most of these traits are not used in selection, as they are not practical for selection purposes, exhibit low heritability, or are not highly correlated with grain yield. The use of managed drought stress, where drought stress can be imposed at specific periods, has been shown to increase the heritability of yield under stress to values similar to those obtained for yield in well‐watered conditions. It has now been demonstrated that drought‐tolerant upland rice can be bred by directly selecting for yield in stress environments. The use of molecular markers to perform selection may eventually provide plant breeders with more efficient selection methods. To date, many quantitative trait loci (QTL) for drought resistance have been identified in rice, but few are suitable for use in marker‐assisted selection. However, large‐effect drought resistance QTL have now been identified and may enable effective use of marker‐assisted selection for drought resistance. Copyright © 2008 Society of Chemical Industry
Identification of the unknown diffusion coefficient in a quasi‐linear parabolic equation by semigroup approach with mixed boundary conditions
Authors: Ozbilge Ebru
Published: January 2008

In this article, a semigroup approach is presented for the mathematical analysis of the inverse coefficient problems of identifying the unknown diffusion coefficient k(u(x, t)) in the quasi‐linear parabolic equation ut(x, t)=(k(u(x, t))ux(x, t))x, with Dirichlet boundary conditions ux(0, t)=ψ0, u(1, t)=ψ1. The main purpose of this work is to analyze the distinguishability of the input–output mappings Φ[·] : 𝒦→C1[0, T], Ψ[·] : 𝒦→C1[0, T] using semigroup theory. In this article, it is shown that if the null space of semigroups T(t) and S(t) consists of only a zero function, then the input–output mappings Φ[·] and Ψ[·] have the distinguishability property. Copyright © 2008 John Wiley & Sons, Ltd.
Existence and uniqueness for a mathematical model in superfluidity
Authors: Berti V. , Fabrizio M.
Published: January 2008

In this paper we propose a model to study superfluidity by considering as state variables the order parameter, describing the concentration of the superfluid phase, the velocity of the superfluid and the absolute temperature. We assume that the order parameter satisfies a Ginzburg–Landau equation and that the velocity is decomposed as the sum of a normal and a superfluid component. The heat equation provides the evolution equation for the temperature. We prove that this model is consistent with the principles of thermodynamics. Well‐posedness of the resulting initial and boundary value problem is shown. Copyright © 2008 John Wiley & Sons, Ltd.
An assessment of the archaeological applicability of faunal ageing methods based on dental wear
Authors: Twiss K. C.
Published: January 2008

Mortality profiles are central to our reconstructions of past animal hunting and herding strategies. This article considers five different ageing methods based on the progressive wear of hypsodont herbivore teeth. The Quadratic Crown Height Method and the Linear Crown Height Method are based on tooth crown height. The Grant and both Payne methods are based on occlusal wear patterns. Statistical correlations and mortality profiles constructed using caprine teeth from the Anatolian Neolithic site of Çatalhöyük are used to assess the archaeological utility of each method. All of the methods are affected by uncertainties about inter‐ and intrapopulation variation in rates of wear, and by issues surrounding the degree of fragmentation in an assemblage. The crown height methods are biased against younger age classes. The occlusal wear‐based methods suffer less from inherent age‐related biases, but have significant and potentially biasing problems related to fragmentation. The degree of fragmentation in an assemblage determines which method is most appropriate for use. Comparisons of dental wear‐based mortality profiles across assemblages or sites should be treated with considerable caution, unless the same method was used on all assemblages. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization and plant expression of a glyphosate‐tolerant enolpyruvylshikimate phosphate synthase
Authors: Vande Berg Brian J , Hammer Philip E , Chun Betty L , Schouten Laura C , Carr Brian , Guo Rong , Peters Cheryl , Hinson Todd K , Beilinson Vadim , Shekita Amy , Deter Rebekah , Chen Zhixian , Samoylov Vladimir , Bryant Charles T , Stauffer Maria E , Eberle Timothy , Moellenbeck Dan J , Carozzi Nadine B , Koziel Mike G , Duck Nicholas B
Published: January 2008

BACKGROUND: Glyphosate tolerance is a dominant trait in modern biotech crops.

RESULTS: A gene encoding a glyphosate‐tolerant EPSP synthase (aroA1398) from bacterial strain ATX1398 was cloned and characterized. The protein is initiated at a GTG translational start codon to produce a protein that provides robust glyphosate resistance in Escherichia coli (Mig) Cast & Chalm. The aroA1398 protein was expressed and purified from E. coli, and key kinetic values were determined (Ki = 161 µM; Km(PEP) = 11.3 µM; kcat = 28.3 s−1). The full‐length enzyme is 800‐fold more resistant to glyphosate than the maize EPSP synthase while retaining high affinity for the substrate phosphoenol pyruvate. To evaluate further the potential of aroA1398, transgenic maize events expressing the aroA1398 protein were generated. T0 plants were screened for tolerance to glyphosate sprays at 1.3× commercial spray rates, and T1 plants were selected that completely resisted glyphosate sprays at 1×, 2× and 4× recommended spray rates in field trials.

CONCLUSION: These data suggest that aroA1398 is a suitable candidate for conferring glyphosate tolerance in transgenic crop plants. Copyright © 2008 Society of Chemical Industry
Toxicity and sublethal effects of an insecticidal soap on Aphidius colemani (Hymenoptera: Braconidae)
Authors: Tremblay Éléonore , Bélanger André , Brosseau Marcel , Boivin Guy
Published: January 2008

BACKGROUND: The effects of an insecticidal soap on the survival, fitness and behaviour of an aphid parasitoid wasp, Aphidius colemani (Viereck), were studied in the laboratory. The LC50 (soap concentration causing 50% mortality 24 h after treatment) was determined. The survival of parasitoid larvae (% adult emergence), fitness (tibia length of adults) and number of eggs produced per female parasitoid that survived in third‐ and fourth‐instar aphids treated with insecticidal soap LC50 were also assessed. The LC50 for third‐ and fourth‐instar aphids was determined to be 3.25 g L−1. Acceptance by female parasitoids of aphids that survived their LC50 was also tested.

RESULTS: The soap concentration causing 100% mortality in adult wasps 24 h after treatment was 17.5 g L−1. The LC50 was 2.75 g L−1. Soap did not have any effect on the survival of parasitoid immatures or on the fitness or number of eggs produced per female parasitoid. Wasps that were in contact with treated aphids did not oviposit as much in them as in untreated aphids, indicating that female parasitoids detected aphids treated with insecticidal soap.

CONCLUSION: These data suggest that aphid parasitoids released following treatment with insecticidal soap are likely to accept a lower proportion of the surviving aphids. Biological control programmes could be ameliorated by soap applications if the latter were made 1 day before the release of wasps in the greenhouse. Copyright © 2008 Society of Chemical Industry
The Relationship Between Online Game Addiction and Aggression, Self-Control and Narcissistic Personality Traits
Authors: Kim Eun Joo , Namkoong Kee , Ku Taeyun , Kim Se Joo
Published: January 2008

Objectives.

This study aimed to explore the relationship between online game addiction and aggression, self-control, and narcissistic personality traits, which are known as the psychological characteristics linked to “at-risk” populations for online game addiction.

Method.

A total of 1471 online game users (males 82.7%, females 17.3%, mean age 21.30 ± 4.96) participated in this study and were asked to complete several self-report measures using an online response method. Questionnaires included demographic information and game use-related characteristics of the samples, the online game addiction scale (modified from Young's Internet addiction scale), the Buss–Perry aggression questionnaire, a self-control scale, and the narcissistic personality disorder scale.

Results.

Our results indicated that aggression and narcissistic personality traits are positively correlated with online game addiction, whereas self-control is negatively correlated with online game addiction (p< 0.001). In addition, a multiple regression analysis revealed that the extent of online game addiction could be predicted based on the person's narcissistic personality traits, aggression, self-control, interpersonal relationship, and occupation. However, only 20% of the variance in behavioral consequences was explained with the model.

Conclusion.

An interesting profile has emerged from the results of this study, suggesting that certain psychological characteristics such as aggression, self-control, and narcissistic personality traits may predispose some individuals to become addicted to online games. This result will deepen our understanding of the “at-risk” population for online game addiction and provide basic information that can contribute to developing a prevention program for people who are addicted to online games.
Dietary soya saponins increase gut permeability and play a key role in the onset of soyabean-induced enteritis in Atlantic salmon (Salmo salar L.)
Authors: Knudsen David , Jutfelt Fredrik , Sundh Henrik , Sundell Kristina , Koppe Wolfgang , Frøkiær Hanne
Published: January 2008

Saponins are naturally occurring amphiphilic molecules and have been associated with many biological activities. The aim of the present study was to investigate whether soya saponins trigger the onset of soyabean-induced enteritis in Atlantic salmon (Salmo salar L.), and to examine if dietary soya saponins increase the epithelial permeability of the distal intestine in Atlantic salmon. Seven experimental diets containing different levels of soya saponins were fed to seawater-adapted Atlantic salmon for 53 d. The diets included a fishmeal-based control diet, two fishmeal-based diets with different levels of added soya saponins, one diet containing 25 % lupin kernel meal, two diets based on 25 % lupin kernel meal with different levels of added soya saponins, and one diet containing 25 % defatted soyabean meal. The effect on intestinal morphology, intestinal epithelial permeability and faecal DM content was examined. Fish fed 25 % defatted soyabean meal displayed severe enteritis, whereas fish fed 25 % lupin kernel meal had normal intestinal morphology. The combination of soya saponins and fishmeal did not induce morphological changes but fish fed soya saponins in combination with lupin kernel meal displayed significant enteritis. Increased epithelial permeability was observed in fish fed 25 % defatted soyabean meal and in fish fed soya saponin concentrate independent of the protein source in the feed. The study demonstrates that soya saponins, in combination with one or several unidentified components present in legumes, induce an inflammatory reaction in the distal intestine of Atlantic salmon. Soya saponins increase the intestinal epithelial permeability but do not, per se, induce enteritis.