bluuebunny/crossref_metadata_2025 huggingface dataset:
The orientation of learner language use in peer work: teacher role, learner role and individual identity
Authors: Chavez Monika Maria
Published: March 2007

This study investigates the orientation of language-use practices during in-class peer work of second-year college learners of German in three different sections (classes) of a multi-section course, taught by three different teachers at a public American Midwestern research university. Qualitative analyses of recordings made over the course of an academic semester focused on differences among the three sections in terms of (1) the use of slang and profanity; (2) student dis/engagement with the task and each other; and (3) the use of the first language (English). Results show that the learners in the three course sections oriented themselves between norms established during teacher-led instruction, their institutional learner role and their individual identity. In sociocultural theoretical terms, the teacher proved a shadow participant in peer interaction and the notion of situated learning, as applied in Activity Theory, was expanded to account for the specific language-use conventions, situated in the respective classroom language speech community.
Some benefits of peer–peer interaction: 10-year-old children practising with a communication task
Authors: Pinter Annamaria
Published: March 2007

This paper explores peer–peer interactions of children using a spot-the-differences task in an EFL context in Hungary. The children were asked to practise with several sets of similar spot-the-differences tasks and the analysis focuses on the observable changes from the first to the last repetition. After the task performances were recorded, the children were invited to watch their first and last performances and comment on the changes they noticed in an interview. Both the analysis of their dialogues performing the tasks and their reflections clearly indicate that peer–peer interactions with this age group at a very low level of competence can bring various benefits and thus primary language teachers could consider introducing similar communication tasks with children with some confidence.
‘Them’ and ‘Us’
Authors: Young Robert J. C.
Published: March 2007

This article analyses the ways in which Richard Hoggart, in The Uses of Literacy, evokes the class nuances of the working-class culture of his childhood while deprecating the popular culture of his own day. It is argued that despite his judgemental attitude, his literary evocation of the contemporary popular culture that he dislikes leaps to life in a manner comparable to Joyce’s Ulysses and overpowers his arguments against it.
Organizational Commitment Profiles and Job Satisfaction among Greek Private and Public Sector Employees
Authors: Markovits Yannis , Davis Ann J. , van Dick Rolf
Published: March 2007

Recent research into organizational commitment has advocated a profiles-based approach. However, with the exception of Wasti, published findings are confined to North American samples. This article examines the relationships between organizational commitment profiles and job satisfaction in Greece. Greek organizations have rarely been the subject of detailed examination, so the study provides baseline information regarding levels of organizational commitment and job satisfaction in Greece. Both private sector ( N = 1119) and public sector ( N = 476) employees in Greece were surveyed, as this sectoral distinction is regularly associated with different patterns of job-related attitudes. The contrasts between Greek and Anglo-American values present a new challenge to the profiles approach. The results confirm the utility of the profiles approach to the study of organizational commitment. Affective organizational commitment was found to be most influential with respect to levels of intrinsic and extrinsic job satisfaction. This concurs with other studies of the behavioural outcomes of commitment.
Comparison of protein structures by growing neighborhood alignments
Authors: Bhattacharya Sourangshu , Bhattacharyya Chiranjib , Chandra Nagasuma R
Published: March 2007

Background

Design of protein structure comparison algorithm is an important research issue, having far reaching implications. In this article, we describe a protein structure comparison scheme, which is capable of detecting correct alignments even in difficult cases, e.g. non-topological similarities. The proposed method computes protein structure alignments by comparing, small substructures, called neighborhoods. Two different types of neighborhoods, sequence and structure, are defined, and two algorithms arising out of the scheme are detailed. A new method for computing equivalences having non-topological similarities from pairwise similarity score is described. A novel and fast technique for comparing sequence neighborhoods is also developed.

Results

The experimental results show that the current programs show better performance on Fischer and Novotny's benchmark datasets, than state of the art programs, e.g. DALI, CE and SSM. Our programs were also found to calculate correct alignments for proteins with huge amount of indels and internal repeats. Finally, the sequence neighborhood based program was used in extensive fold and non-topological similarity detection experiments. The accuracy of the fold detection experiments with the new measure of similarity was found to be similar or better than that of the standard algorithm CE.

Conclusion

A new scheme, resulting in two algorithms, have been developed, implemented and tested. The programs developed are accessible at http://mllab.csa.iisc.ernet.in/mp2/runprog.html.
Are patients with non-ST elevation myocardial infarction undertreated?
Authors: Rasoul Saman , Ottervanger Jan Paul , Dambrink Jan-Henk E , de Boer Menko-Jan , Hoorntje Jan CA , Gosselink AT Marcel , Zijlstra Felix , Suryapranata Harry , van't Hof Arnoud WJ
Published: March 2007

Background

The worse prognosis in patients without ST-elevation (non-STEMI) as compared to ST-elevation myocardial infarction (STEMI), may be due to treatment differences. We aimed to evaluate the differences in characteristics, treatment and outcome in patients with non-STEMI versus STEMI in an unselected patient population.

Methods

Individual patient data from all patients in our hospital with a discharge diagnosis of MI between Jan 2001 and Jan 2002 were evaluated. Follow-up data were obtained until December 2004. Patients were categorized according to the presenting electrocardiogram into non-STEMI or STEMI.

Results

A total of 824 patients were discharged with a diagnosis of MI, 29% with non-STEMI and 71% with STEMI. Patients with non-STEMI were significantly older and had a higher cardiovascular risk profile. They underwent less frequently coronary angiography and revascularization and received less often clopidogrel and ACE-inhibitor on discharge. Long-term mortality was significantly higher in the non-STEMI patients as compared to STEMI patients, 20% vs. 12%, p = 0.006, respectively. However, multivariate analysis showed that age, diabetes, hypertension and no reperfusion therapy (but not non-STEMI presentation) were independent and significant predictors of long-term mortality.

Conclusion

In an unselected cohort of patients discharged with MI, there were significant differences in baseline characteristics, and (invasive) treatment between STEMI and non-STEMI. Long-term mortality was also different, but this was due to differences in baseline characteristics and treatment. More aggressive treatment may improve outcome in non-STEMI patients.
Generalist care managers for the treatment of depressed medicaid patients in North Carolina: A pilot study
Authors: Landis Suzanne E , Gaynes Bradley N , Morrissey Joseph P , Vinson Nina , Ellis Alan R , Domino Marisa E
Published: March 2007

Background

In most states, mental illness costs are an increasing share of Medicaid expenditures. Specialized depression care managers (CM) have consistently demonstrated improvements in patient outcomes relative to usual primary care (UC), but are costly and may not be fully utilized in smaller practices. A generalist care manager (GCM) could manage multiple chronic conditions and be more accepted and cost-effective than the specialist depression CM. We designed a pilot program to demonstrate the feasibility of training/deploying GCMs into primary care settings.

Methods

We randomized depressed adult Medicaid patients in 2 primary care practices in Western North Carolina to a GCM intervention or to UC. GCMs, already providing services in diabetes and asthma in both study arms, were further trained to provide depression services including self-management, decision support, use of information systems, and care management. The following data were analyzed: baseline, 3- and 6-month Patient Health Questionnaire (PHQ9) scores; baseline and 6-month Short Form (SF) 12 scores; Medicaid claims data; questionnaire on patients' perceptions of treatment; GCM case notes; physician and office staff time study; and physician and office staff focus group discussions.

Results

Forty-five patients were enrolled, the majority with preexisting depression. Both groups improved; the GCM group did not demonstrate better clinical and functional outcomes than the UC group. Patients in the GCM group were more likely to have prescriptions of correct dosing by chart data. GCMs most often addressed comorbid conditions (36%), then social issues (27%) and appointment reminders (14%). GCMs recorded an average of 46 interactions per patient in the GCM arm. Focus group data demonstrated that physicians valued using GCMs. A time study documented that staff required no more time interacting with GCMs, whereas physicians spent an average of 4 minutes more per week.

Conclusion

GCMs can be trained in care of depression and other chronic illnesses, are acceptable to practices and patients, and result in physicians prescribing guideline concordant care. GCMs appear to be a feasible intervention for community medical practices and to warrant a larger scale trial to test their appropriateness for Medicaid programs nationally.
2‐Methoxyestradiol Inhibits Superoxide Anion Generation while It Enhances Superoxide Dismutase Activity in Swine Granulosa Cells
Authors: BASINI GIUSEPPINA , SANTINI SUJEN ELEONORA , GRASSELLI FRANCESCA
Published: March 2007

Abstract:  2‐Methoxyestradiol (2‐ME) is an estradiol metabolite with antiangiogenic properties. It can be produced by granulosa cells and it is present in normal follicle at high concentrations. The identification of reactive oxygen species (ROS) role in the molecular pharmacology of 2‐ME is an active area of research. The objective of this article was therefore to evaluate the effect of 2‐ME on both superoxide anion (O2−) production and superoxide dismutase (SOD) activity in swine granulosa cells collected from follicles greater than 5 mm and treated for 48 h with 1 μM 2‐ME. 2‐ME inhibited (P < 0.001) O2− generation in swine granulosa cells, while it stimulated (P < 0.05) the SOD activity. We previously demonstrated that a stimulation of O2− generation triggers angiogenetic response in granulosa cells. Therefore, we argue that the inhibitory effect of 2‐ME on O2− could be responsible for its antiangiogenetic effect.
DNA Strand Breaks by Metal‐Induced Oxygen Radicals in Purified Salmonella typhimurium DNA
Authors: KEYHANI EZZATOLLAH , ABDI‐OSKOUEI FATEMEH , ATTAR FARNOOSH , KEYHANI JACQUELINE
Published: March 2007

Abstract:  Purified Salmonella typhimurium DNA was incubated for 1h at 37°C with various concentrations (10–100 μM) of transition metal ions (Fe2+, Fe3+, Cu2+, Ni2+, Cd2+), with various concentrations (0.1–100 mM) of H2O2, and with various concentrations of each transition metal ion in the presence of various concentrations of H2O2. Damage to DNA was assessed by electrophoresis of the reaction mixtures in 1% agarose gel. Breakage of the DNA strands would produce a series of DNA fragments resulting in a smear in the gel, while intact DNA produced a single band. Results showed that no damage to the DNA was detectable after incubation with either H2O2 alone or either of the metal ions alone. However, all of the metal ions investigated triggered DNA breakage in the presence of H2O2. The extent of breakage depended on the metal ion and on its concentration, as well as on the H2O2 concentration. Addition of either EDTA or catalase to the reaction mixture completely inhibited the DNA degradation, confirming the involvement of both the metal ion and the H2O2 in the breakage of DNA strands. Production of the hydroxyl radical when H2O2 and a metal ion were both present in the reaction mixture was evidenced by the thiobarbituric acid method. The most extensive damage was caused by Cu2+ followed, in decreasing order, by Fe2+, Fe3+, Ni2+, and Cd2+.
Control of Bioamine Metabolism by 5‐HT2Band α1DAutoreceptors through Reactive Oxygen Species and Tumor Necrosis Factor‐α Signaling in Neuronal Cells
Authors: SCHNEIDER BENOIT , PIETRI MATHÉA , MOUILLET‐RICHARD SOPHIE , ERMONVAL MYRIAM , MUTEL VINCENT , LAUNAY JEAN‐MARIE , KELLERMANN ODILE
Published: March 2007

Abstract: Homeostasis of the central nervous system relies on the proper integration of cell‐signaling pathways recruited by a variety of neuronal and non‐neuronal factors, with the aim of tightly controlling neurotransmitter metabolism, storage, and transport. We took advantage of the 1C11 neuroectodermal cell line, endowed with the capacity to selectively differentiate into serotonergic (1C115–HT) or noradrenergic (1C11NE) neurons, to identify functional targets of serotonin (5‐hydroxytryptamine [5–HT]) and norepinephrine (NE) autoreceptors possibly involved in the control of neuronal functions. We demonstrate that 5‐HT2Band adreno α1Dreceptors are coupled to reactive oxygen species (ROS) production through NADPH oxidase activation in 1C115–HTand 1C11NEneuronal cells, respectively. In the signaling cascade linking 5–HT2Breceptors to NADPH oxidase, phospholipase A2‐mediated arachidonic acid production is required for ROS synthesis. ROS, in turn, act as second message signals and control the activation of TACE (TNF‐α converting enzyme), a member of a disintegrin and metalloproteinase family. 5–HT2Band α1Dreceptor stimulation triggers TACE‐dependent TNF‐α shedding in the surrounding milieu of 1C115–HTand 1C11NEcells. In these cells, shed TNF‐α triggers degradation of 5‐HT and NE into 5‐HIAA and MHPG, respectively. Finally, we observe that 5‐HT2Band α1Dreceptor couplings to the NADPH oxidase‐TACE cascade are strictly restricted to 1C11‐derived progenies that have implemented a complete neuronal phenotype. Altogether, our data indicate that couplings of 5‐HT2Band α1Dautoreceptors to ROS and TNF‐α signaling control neurotransmitter metabolism in 1C11‐derived neuronal cells. Eventually, we might explain the origin of oxidative stress and high level of TNF‐α in neurodegenerative diseases as a consequence of deviation of normal signaling pathways coupled to neurotransmitters.
Different Modulation of ER‐Mediated Transactivation by Xenobiotic Nuclear Receptors Depending on the Estrogen Response Elements and Estrogen Target Cell Types
Authors: MIN GYESIK
Published: March 2007

Abstract:  Recent studies demonstrated that constitutive androstane receptor (CAR) inhibits ER‐mediated transactivation of both endogenous and synthetic estrogen responsive promotor in Hep G2. Whereas steroid and xenobiotic receptor (SXR) but not peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) was also reported to repress estrogen receptor (ER) transactivation of the synthetic 4ERE in Hep G2, the effects of these xenobiotic nuclear receptors (XNRs) on the endogenous estrogen responsive promotor remain to be determined. Effects of CAR, SXR, and PPAR‐γ on ER transactivation were also examined in three different kinds of breast cancer cell lines. However, except in MCF‐7, studies were limited either in single dose response (MDA‐MB‐231) or with CAR only (MCF‐7‐K3). And there is presently no report on the effects of CAR, SXR, and PPAR‐γ on ER‐mediated transactivation in ovarian‐derived CHO‐S cells. Accordingly, this article further examined the effects of the endogenous vitellogenin B1 estrogen responsive promotor on the SXR‐ and PPAR‐γ‐modulated ER transactivation in Hep G2, and either dose‐dependent or single dose effects of SXR, PPAR‐γ, and CAR in two different breast cancer cell lines and the ovarian‐derived cell line respectively, on the ER‐mediated transactivation of the synthetic (4ERE)‐tk‐luciferase reporter. Consistent with the previous report, CAR significantly repressed ER‐mediated transactivation of the endogenous vitellogenin B1 promotor in Hep G2 cells. However, contrary to the effects on the synthetic promotor, PPAR‐γ potentiated whereas SXR did not have any effects on the ER transactivation of the vitellogenin promotor in Hep G2. In the breast cancer cell line of MDA‐MB‐231 in which endogenous ER is known not to be expressed, CAR modestly stimulated ER transactivation of the synthetic 4ERE in a low dose whereas both SXR and PPAR‐γ did not have any effects in all doses examined (20–500 ng). And in both CHO‐S and estrogen‐independent breast cancer cell line, MCF‐7‐K3, none of the three xenobiotic receptors significantly influenced the ER‐mediated 4ERE transactivation in all doses examined. XNRs modulate ER‐mediated transactivation depending on the estrogen response elements (EREs) and estrogen target cell types.
Effects of TK Promotor and Hepatocyte Nuclear Factor‐4 in CAR‐Mediated Transcriptional Activity of Phenobarbital Responsive Unit of CYP2B Gene in Monkey Kidney Epithelial‐Derived Cell Line COS‐7
Authors: MIN GYESIK
Published: March 2007

Abstract:  Previous studies reported that constitutive androstane receptor (CAR) does not transactivate phenobarbital responsive unit (PBRU)2C1luciferase reporter gene in COS cells in which endogenous CYP2B1 gene is not induced with PB. In order to understand molecular mechanism(s) whereby PBRU is transactivated, this article determined if the use of strong thymidine kinase (TK) promotor rather than the minimal CYP2C1 promotor, and hepatocyte nuclear factor‐4 (HNF‐4) can affect CAR‐mediated transactivation of PBRU in the monkey kidney epithelial‐derived COS‐7 cells. To examine CAR‐mediated transactivation, cultured COS‐7 cells were transfected with CAR expression plasmid, pEGFP‐mCAR1, and confirmed for high level of the protein expression. In COS‐7 cells, TK promotor induced CAR‐mediated PBRU transactivation in a dose‐dependent manner. Whereas expression of HNF‐4 slightly promoted PBRU transactivation with low amount of CAR transfected, it repressed PBRU transactivation in a dose‐dependent manner with high amount of CAR. Consistent with the previous reports in Hep G2 cells, CAR transactivated PBRU2C1luciferase in a dose‐dependent manner and this CAR‐mediated transactivation required functional NR‐1 and NF‐1 sites. However, HNF‐4 did not affect CAR‐mediated PBRU transactivation in Hep G2 cells. These results suggest that proximal promotor and a trans‐acting factor, HNF‐4, can affect CAR‐mediated transactivation of PBRU in COS‐7 cells.
Isolation and Characterization of the Rat SND p102 Gene Promoter
Authors: RODRÍGUEZ LORENA , BARTOLOMÉ NEREA , OCHOA BEGOÑA , MARTÍNEZ MARÍA J.
Published: March 2007

Abstract:  In this work, we report the isolation and characterization of a 1,688‐bp sequence corresponding to the promoter region of the rat endoplasmic reticulum (ER) cholesterol ester hydrolase gene, renamed as staphylococcal nuclease domain–containing protein of 102 kDa (SND p102) in GenBank database according to the structural properties and molecular weight of the protein. The transcription start site was located 216 bases upstream of the ATG start codon by RNA ligase mediated‐rapid amplification of cDNA ends (RLM‐RACE)
. Bioinformatic analysis of the isolated sequence revealed a lack of typical promoter TATA box and the presence of GC‐rich motifs and CCAAT boxes recognized by Sp 1 and nuclear factor‐Y among other putative binding sites for a number of transcription factors implicated in both basal and regulated processes
. Electrophoretic mobility shift and supershift assays using nuclear extracts from human (HepG2) and rat (McA‐RH7777) hepatoma cells demonstrated that nuclear factor‐Y (NF‐Y) transcription factor bound to the core sequences at (−257, −253), (−290, −286), and (−370, −366) upstream translation initiation site. The absence of TATA box and the location and reverse orientation of the CCAAT boxes in the promoter region strongly suggest a role for NF‐Y in the regulation of transcription of SND p102 gene.
c‐Jun and JunB Are Essential for Hypoglycemia‐Mediated VEGF Induction
Authors: TEXTOR BJÖRN , SATOR‐SCHMITT MELANIE , RICHTER KARL HARTMUT , ANGEL PETER , SCHORPP‐KISTNER MARINA
Published: March 2007

Abstract:  Physiological conditions like hypoxia or hypoglycemia trigger expression of VEGF, a key regulator of angiogenesis. To elucidate the molecular mechanism underlying the VEGF regulation of hypoglycemia, we investigated the role of AP‐1 transcription factor subunits c‐Jun and JunB. Using c‐jun−/− and junB−/− mouse embryonic fibroblasts, we demonstrate that both c‐Jun and JunB are required for the hypoglycemia‐mediated induction of VEGF expression. This process is independent of the master regulator of hypoxic stress HIF‐1, as HIF expression and stabilization are not affected by the loss of AP‐1 subunits. Analysis of signaling cascades regulating c‐Jun and/or JunB activity and/or transcription upon hypoglycemia by application of specific inhibitors of protein kinase C (PKC) or extracellular signal‐regulated kinase (ERK) signaling revealed that hypoglycemia‐mediated induction of c‐Jun is regulated via a PKCα‐dependent signaling pathway. In contrast, JunB is activated by the MAP kinase ERK for the AP‐1 subunits c–Jun and JunB to mediate VEGF regulaltion of hypoglycemia.
A New Method to Assess Drug Sensitivity on Breast Tumor Acute Slices Preparation
Authors: MESTRES PEDRO , MORGUET ANDREA , SCHMIDT WERNER , KOB AXEL , THEDINGA ELKE
Published: March 2007

Abstract:  A method for assessing tumor drug sensitivity is described that is based on preparation of tissue slices and use of silicon chips equipped with electrochemical sensors (multisensor array). The tumor slices (200–300 μM thick) are prepared after surgery and incubated in a medium for recovery after slicing. The advantage, compared to other preparations, is that the original three‐dimensional structure is retained. Multisensor arrays measure: (a) pericellular acidification (anaerobic metabolism) and (b) oxygen consumption (respiration). The innovative aspect is that such measurements can be made online, as opposed to using a large battery of endpoint tests on cell vitality and proliferation. Electron microscopy of slices serves to determine cell density and structure and induction of apoptosis/necrosis. Slices of more than 200 breast tumors were used. Metabolic activity was inhibited by sodium fluoride, which reduces glycolysis, and potassium cyanide, which inhibits respiration. These changes are thus reflected in the curves of acidification and oxygen consumption. In other experiments the cytostatic Taxol, an anticytoskeletal agent, was used showing dose and time‐dependent effects on acidification and oxygen consumption. In conclusion, the method presented here, is able to provide information on drug sensitivity of a tumor, which aids in designing individualized therapy and is used for drug screening.
Animal Model of Drug‐Resistant Tumor Progression
Authors: MIRONOVA NADEZDA , SHKLYAEVA OLGA , ANDREEVA EKATERINA , POPOVA NELLY , KALEDIN VASILYI , NIKOLIN VALERYI , VLASSOV VALENTIN , ZENKOVA MARINA
Published: March 2007

Abstract:  Experimental animal model of tumor progression based on mice lymphosarcoma (LS) and resistant lymphosarcoma (RLS) has been developed
. LS tumor displays high sensitivity to cyclophosphamide, which is widely used in anticancer therapy. RLS tumor was derived from LS by passaging in mice receiving low concentration of cyclophosphamide (20 mg/kg) and display resistance to cyclophosphamide (up to dose 150 mg/kg).
The primary cultures of LS and RLS tumors display different expression levels of the genes related to apoptosis and multiple drug‐resistant phenotype: in RLS tumor high levels of mdr1b and bcl‐2 genes and low level of p53 gene expression were found. A total of 10% of cells in RLS primary culture display multiple drug‐resistant phenotype and survive even at high dose of cytostatics. Cultivation of RLS primary culture in the presence of increasing vinblastine concentrations gives RLS40 cell culture, which exhibits high levels of mdr1a/1b genes expression as compared to RLS and 20‐fold increase of resistance to cytostatics. Drug‐resistant RLS40 cells were transplanted into CBA mice and sensitivity of the tumors to anticancer drugs was tested
. RLS40 tumors were resistant to a number of cytostatics used in anticancer therapy (cyclophosphamide, cysplatin, vinblastine, rubomycinum). Thus, RLS40 tumor can be used as model, which corresponds to tumor status observed in patients after one or several courses of chemotherapy and can be useful for testing conventional therapy alone or together with newly developed gene‐targeted therapeutics.
Preparation and Characterization of Recombinant Chicken Growth Hormone (chGH) and Its Putative Antagonist chGH G119R Mutein
Authors: PACZOSKA‐ELIASIEWICZ HELENA E. , SALOMON GILI , REICHER SHAY , GUSSAKOWSKY EUGENE E. , HRABIA ANNA , GERTLER ARIEH
Published: March 2007

Abstract:  Synthetic cDNA of chicken GH (chGH) and its G119R mutein was synthesized after being optimized for expression in E. coli. The respective cDNAs were inserted into expression vector, expressed and found almost entirely in the insoluble inclusion bodies (IBs). The IBs were isolated, the proteins solubilized in 4.5 M urea, at pH 11.3 in presence of cysteine, refolded, and purified to homogeneity by anion‐exchange chromatography on Q‐Sepharose. The overall yields were 400 to 500 mg from 5 L of fermentation. Both proteins were > 98% pure, as evidenced by SDS‐PAGE, and contained at least 95% monomers, as documented by gel‐filtration chromatography under non‐denaturing conditions. Circular dichroism analysis revealed that both proteins have identical secondary structure characteristic of cytokines, namely > 50% of alpha helix content. Chicken GH was capable of forming a 1:2 complex with recombinant oGH receptor extracellular domain, but its affinity, as determined by RRA, was 11‐fold lower than that of ovine GH (oGH). Correspondingly, its bioactivity, assessed using FDC‐P1 3B9 cells stably transfected with rabbit GHR, was 30–40‐fold lower, whereas chGH G119R mutant did not bind to oGHR‐ECD and was devoid of any biological activity in FDC‐P1 3B9 cells. However, in binding experiments that were carried out using chicken liver membranes, both oGH and chGH showed similar IC50 values in competition with 125I‐oGH, while the IC50 of G119R mutein was 10‐fold higher. These results emphasize the importance of species specificity and indicate the possibility of antagonistic activity of chGH G119R.
Equilibrium Conditions in Laser-Desorbed Plumes: Thermodynamic Properties of α-Cyano-4-Hydroxycinnamic Acid and Protonation of Amino Acids
Authors: Kinsel Gary R. , Yao Daqing , Yassin Faten H. , Marynick Dennis S.
Published: March 2007

The equilibrium nature of a plume of laser desorbed material is explored through the application of a simple equilibrium model to the ion signals observed in 355 nm laser desorption/ionization mass spectra of mixtures of the MALDI matrix α-cyano-4-hydroxycinnamic acid (αCHCA) with the amino acids glycine, alanine, valine, isoleucine, and phenylalanine. In these studies it is found that there are systematic and predictable increases in the relative yield of protonated amino acid with increases in amino acid gas-phase basicity. In addition, the thermodynamic values extracted from the equilibrium plot are shown to be in good agreement with values obtained from computational investigation of plausible αCHCA proton donor species. These results are supportive of a picture wherein the laser-desorbed material is viewed as a dense plume in which facile charge transfer occurs leading, ultimately, to a thermodynamically equilibrated distribution of proton donor and proton acceptor species.
Gas-Phase Ionization/Desolvation Processes and Their Effect on Protein Charge State Distribution under Matrix-Assisted Laser Desorption/Ionization Conditions
Authors: Alves Sandra , Fournier Françoise , Afonso Carlos , Wind Franck , Tabet Jean-Claude
Published: March 2007

The charge state distribution of proteins was studied as a function of experimental conditions, to improve the understanding of the matrix-assisted laser desorption/ionization (MALDI) mechanisms. The relative abundances of the multiply-charged ions appear to be a function of the matrix chosen, the laser fluence and the matrix-to-analyte molar ratio. A correlation is found between the matrix proton affinity and the yield of singly- versus multiply-charged ions. These results are in good agreement with a model in which gas-phase intracluster reactions play a significant role in analyte ion formation. A new model for endothermic desolvation processes in ultraviolet/MALDI is presented and discussed. It is based upon the existence of highly-charged precursor clusters and, complementary to the ion survivor model of Karas et al., assumes that two energy-dependent processes exist: (i) a soft desolvation involving consecutive losses of neutral matrix molecules, leading to a multiply-charged analyte and (ii) hard desolvation leading to a low charge state analyte, by consecutive losses of charged matrix molecules. These desolvations pathways are discussed in terms of kinetically limited processes. The efficiency of the two competitive desolvation processes seems related to the internal energy carried away by clusters during ablation.
Personality and religious values among adolescents: A three‐wave longitudinal analysis
Authors: Heaven Patrick C. L. , Ciarrochi Joseph
Published: March 2007

Using three waves of data, we assessed the relationships between endorsement of religious values, some of the major personality dimensions, and social and emotional well‐being amongst teenagers. Participants were 784 high school students at Time 1 (382 males and 394 females; 8 did not indicate their gender) and 563 provided data at each of Time 1, Time 2 and Time 3. We examined the impact of changes in (Eysenckian) psychoticism and conscientiousness from Time 1 to Time 2 on religious values assessed at Time 3. Both personality and personality change predicted religious values and the specific effects depended on gender. Participants higher in hope, joviality, psychological acceptance and mindfulness also tended to be higher in religious values. The implications of these results for adolescent well‐being and resilience are discussed.
The practitioner‐researcher divide revisited: Strategic‐level bridges and the roles of IWO psychologists
Authors: Anderson Neil
Published: March 2007

This paper responds to, and extends, the debate between Gelade, Wall, Symon and Hodgkinson in JOOP. In concluding that JOOP is fulfilling its remit for robust information exchange between research and practice, four lines of argument are proposed that (i) the Principle of Scientific Replication warrants full details of study methods being routinely published, (ii) any divide is reflective of a perfectly natural distance between the two wings of the discipline and is not necessarily harmful as long as sufficient bridging mechanisms exist, (iii) several strategic‐level bridging mechanisms do exist but need to be better utilized and (iv) as JOOP will be unable to be all things to all readers, its most suitable niche remains as a scientific outlet for pragmatic research in IWO psychology internationally.
Classical Genetic and Quantitative Trait Loci Analyses of Heterosis in a Maize Hybrid Between Two Elite Inbred Lines
Authors: Frascaroli Elisabetta , Canè Maria Angela , Landi Pierangelo , Pea Giorgio , Gianfranceschi Luca , Villa Marzio , Morgante Michele , Pè Mario Enrico
Published: March 2007

The exploitation of heterosis is one of the most outstanding advancements in plant breeding, although its genetic basis is not well understood yet. This research was conducted on the materials arising from the maize single cross B73 × H99 to study heterosis by procedures of classical genetic and quantitative trait loci (QTL) analyses. Materials were the basic generations, the derived 142 recombinant inbred lines (RILs), and the three testcross populations obtained by crossing the 142 RILs to each parent and their F1. For seedling weight (SW), number of kernels per plant (NK), and grain yield (GY), heterosis was >100% and the average degree of dominance was >1. Epistasis was significant for SW and NK but not for GY. Several QTL were identified and in most cases they were in the additive–dominance range for traits with low heterosis and mostly in the dominance–overdominance range for plant height (PH), SW, NK, and GY. Only a few QTL with digenic epistasis were identified. The importance of dominance effects was confirmed by highly significant correlations between heterozygosity level and phenotypic performance, especially for GY. Some chromosome regions presented overlaps of overdominant QTL for SW, PH, NK, and GY, suggesting pleiotropic effects on overall plant vigor.
Experimental Estimate of the Abundance and Effects of Nearly Neutral Mutations in the RNA Virus ϕ6
Authors: Burch Christina L , Guyader Sebastien , Samarov Daniel , Shen Haipeng
Published: March 2007

Although the frequency and effects of neutral and nearly neutral mutations are critical to evolutionary patterns and processes governed by genetic drift, the small effects of such mutations make them difficult to study empirically. Here we present the results of a mutation-accumulation experiment designed to assess the frequencies of deleterious mutations with undetectable effects. We promoted the accumulation of spontaneous mutations by subjecting independent lineages of the RNA virus ϕ6 to repeated population bottlenecks of a single individual. We measured fitness following every bottleneck to obtain a complete picture of the timing and effects of the accumulated mutations with detectable effects and sequenced complete genomes to determine the number of mutations that were undetected by the fitness assays. To estimate the effects of the undetected mutations, we implemented a likelihood model developed for quantitative trait locus (QTL) data (Otto and Jones 2000) to estimate the number and effects of the undetected mutations from the measured number and effects of the detected mutations. Using this method we estimated a deleterious mutation rate of U = 0.03 and a gamma effects distribution with mean $\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\bar{s}}{=}0.093\) \end{document}$ and coefficient of variation = 0.204. Although our estimates of U and $\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\bar{s}}\) \end{document}$ fall within the range of recent mutation rate and effect estimates in eukaryotes, the fraction of mutations with detectable effects on laboratory fitness (39%) appears to be far higher in ϕ6 than in eukaryotes.
The Caenorhabditis elegans Rad17 Homolog HPR-17 Is Required for Telomere Replication
Authors: Boerckel Julie , Walker Dana , Ahmed Shawn
Published: March 2007

Subunits of the Rad9/Rad1/Hus1 (9-1-1) proliferating cell nuclear antigen (PNCA)-like sliding clamp are required for DNA damage responses and telomerase-mediated telomere replication in the nematode Caenorhabditis elegans. PCNA sliding clamps are loaded onto DNA by a replication factor C (RFC) clamp loader. The C. elegans Rad17 RFC clamp loader homolog, hpr-17, functions in the same pathway as the 9-1-1 complex with regard to both the DNA damage response and telomerase-mediated telomere elongation. Thus, hpr-17 defines an RFC-like complex that facilitates telomerase activity in vivo in C. elegans.
Distinguishing the type I and type II isozymes of hexokinase: the need for a reexamination of past practice.
Authors: Wilson J E
Published: March 2007

The type I and type II isozymes of hexokinase coexist in insulin-sensitive tissues, such as cardiac and skeletal muscle and adipose tissue. Based on an early report that the purified type I isozyme was stable at 45 degrees C whereas the purified type II isozyme was not, investigators in a number of studies have used heat lability as a criterion for distinguishing these isozymes in crude tissue extracts or subcellular fractions; that is, activity lost after incubation at 45 degrees C was believed to be type II while remaining activity was considered type I. This extrapolation is dangerous because thermal lability can be markedly affected by the solvent environment, including the presence or absence of other proteins. In the present study, the rate of thermal inactivation of the type I isozyme has been shown to vary by at least an order of magnitude in soluble and particulate fractions prepared from rat heart and brain. Thus, the use of thermal stability as a general criterion for identifying the type I isozyme is invalid, and conclusions based on thermal inactivation as a means for distinguishing the type I and type II isozymes need to be reconsidered.
Interorgan signaling between adipose tissue metabolism and skeletal muscle uncoupling protein homologs: is there a role for circulating free fatty acids?
Authors: Samec S , Seydoux J , Dulloo A G
Published: March 2007

Uncoupling proteins 3 and 2 (UCP3 and UCP2) are two newly cloned genes that have been implicated in the regulation of lipids as fuel substrate in skeletal muscle on the basis that their mRNA expressions are upregulated during starvation (when fat stores are being rapidly mobilized) and downregulated during the early phase of refeeding (when fat stores are being rapidly replenished). To test the hypothesis that circulating free fatty acids (FFAs) may have a physiological role as an interorgan signal linking these dynamic changes in the fat stores to skeletal muscle expression of UCP3 and UCP2, the mRNA levels of these UCP homologs were examined in fed and fasted rats treated with the antilipolytic agent nicotinic acid. In 46-h fasted rats, we observed a threefold increase in serum FFA levels and increases in UCP3 and UCP2 mRNA levels that were more marked in the gastrocnemius and tibialis anterior muscles (predominantly fast-twitch fibers) than in the soleus muscle (predominantly slow-twitch fibers). Treatment with nicotinic acid blunted the fasting-induced increase in serum FFA levels and prevented the increase in mRNA levels of UCP3 and UCP2 in the soleus muscle, but had little or no effect on the elevated mRNA levels of these UCP homologs in the gastrocnemius and tibialis anterior muscles. Furthermore, treatment of ad libitum-fed animals with nicotinic acid resulted in a twofold reduction in serum FFA levels (i.e., by a magnitude similar to that observed during early refeeding) and significant reductions in UCP3 and UCP2 mRNA levels in the soleus muscle, but not in the gastrocnemius or tibialis anterior muscles. These results revealed a muscle-type dependency in the way UCP2 and UCP3 gene expression in skeletal muscle is regulated, and suggest that the hypothesis that circulating FFAs function as an interorgan signal between fat stores and skeletal muscle UCP3 and UCP2 gene expression is adequate only for slow-twitch (oxidative) muscles. Consequently, a signal(s) other than circulating FFAs must be implicated in the link between dynamic changes in body fat stores and UCP expression in predominantly fast-twitch (glycolytic/oxidative-glycolytic) muscles, which constitute the major fiber type of the total skeletal muscle mass and which have high susceptibility to developing insulin resistance and impairment in substrate utilization in metabolic diseases.
Transcribing pancreas.
Authors: Edlund H
Published: March 2007

For approximately 30-35 years, our insight into some of the fundamental aspects of pancreas development has been based mainly on two independent studies performed in the 1960s by Golosow and Grobstein and Wessells and Cohen. By performing classical embryological experiments, these two reports described the morphogenesis of the pancreas and the epitheliomesenchymal interactions that are required for proper pancreas development. In the 1970s, the groups of LeDourain and associates and Rutter and associates showed, importantly, that despite their similarities with neurons, the pancreatic endocrine cells, like the exocrine and ductual cells, were of an endodermal origin. Then during the 1980s, studies pioneered by Rutter, but also performed by many other groups, were focused on the transcriptional regulation of endocrine and exocrine genes. This eventually lead to the cloning of various transcription factors. By using a genetic approach to study the function of these transcription factors, new insights into pancreas development have now emerged that, on a molecular level, are beginning to explain some of the earlier observations. This review discusses our current knowledge of the mechanisms by which the various pancreatic cell types are generated.
Differential regulation of amino acid exchange and protein dynamics across splanchnic and skeletal muscle beds by insulin in healthy human subjects.
Authors: Meek S E , Persson M , Ford G C , Nair K S
Published: March 2007

To define the mechanism of insulin's anticatabolic action, the effects of three different dosages of insulin (0.25, 0.5, and 1.0 mU x kg(-1) x min(-1)) versus saline on protein dynamics across splanchnic and skeletal muscle (leg) beds were determined using stable isotopes of phenylalanine, tyrosine, and leucine in 24 healthy subjects. After an overnight fast, protein breakdown in muscle exceeded protein synthesis, causing a net release of amino acids from muscle bed, while in the splanchnic bed protein synthesis exceeded protein breakdown, resulting in a net uptake of these amino acids. Insulin decreased (P < 0.003) muscle protein breakdown in a dose-dependent manner with no effect on muscle protein synthesis, thus decreasing the net amino acid release from the muscle bed. In contrast, insulin decreased protein synthesis (P < 0.03) in the splanchnic region with no effect on protein breakdown, thereby decreasing the net uptake of the amino acids. In addition, insulin also decreased (P < 0.001) leucine nitrogen flux substantially more than leucine carbon flux, indicating increased leucine transamination (an important biochemical process for nitrogen transfer between amino acids and across the organs), in a dose-dependent manner, with the magnitude of effect being greater on skeletal muscle than on the splanchnic bed. In conclusion, muscle is in a catabolic state in human subjects after an overnight fast and provides amino acids for synthesis of essential proteins in the splanchnic bed. Insulin achieves amino acid balance across splanchnic and skeletal muscle beds through its differential effects on protein dynamics in these tissue beds.
Regulation of glutamine:fructose-6-phosphate amidotransferase by cAMP-dependent protein kinase.
Authors: Zhou J , Huynh Q K , Hoffman R T , Crook E D , Daniels M C , Gulve E A , McClain D A
Published: March 2007

Glutamine:fructose-6-phosphate amidotransferase (GFA) is the rate-limiting enzyme in hexosamine biosynthesis, an important pathway for cellular glucose sensing. Human GFA has two potential sites for phosphorylation by cAMP-dependent protein kinase A (PKA). To test whether GFA activity is regulated by cAMP-dependent phosphorylation, rat aortic smooth muscle cells were treated in vivo with cAMP-elevating agents, 10 micromol/l forskolin, 1 mmol/l 8-Br-cAMP, or 3-isobutyl-1-methylxanthine. All treatments resulted in rapid and significant increases (2- to 2.4-fold) in GFA activity assayed in cytosolic extracts. Maximal effects of forskolin were observed at 10 micromol/l and 60 min. Preincubation of cells with cycloheximide did not abolish the effect of forskolin. Incubation of cytosolic extracts at 37 degrees C for 10 min in a buffer without phosphatase inhibitors led to a 79% decrease of GFA activity. This loss of activity was inhibited by the addition of phosphatase inhibitors (5 mmol/l sodium orthovanadate, 50 mmol/l sodium fluoride, or 5 mmol/l EDTA, but not 100 nmol/l okadaic acid), suggesting that GFA undergoes rapid dephosphorylation by endogenous phosphatases. Purified GFA is phosphorylated in vitro by purified PKA, resulting in a 1.7-fold increase in GFA activity. Treatment of GFA with purified protein kinase C had no effect. We conclude that GFA activity may be modulated by cAMP-dependent phosphorylation.
Differential protection in two transgenic lines of NOD/Lt mice hyperexpressing the autoantigen GAD65 in pancreatic beta-cells.
Authors: Bridgett M , Cetkovic-Cvrlje M , O'Rourke R , Shi Y , Narayanswami S , Lambert J , Ramiya V , Baekkeskov S , Leiter E H
Published: March 2007

Although expressed at very low levels in islets of NOD mice, GAD65 is a candidate islet autoantigen. Two transgenic lines of NOD/Lt mice expressing high levels of human GAD65 from a rat insulin promoter were generated. Transgenes were integrated on proximal chromosome 15 of the A line and on the Y chromosome of the Y line. Transgenic A-line mice were obligate hemizygotes, since homozygous expression resulted in developmental lethality. A twofold higher level of hGAD65 transcripts in A-line islets from young donors was associated with higher GAD protein and enzyme activity levels. Y-line males developed diabetes at a similar rate and incidence as standard NOD/Lt males. In contrast, A-line mice of both sexes exhibited a markedly lowered incidence of diabetes. Insulitis, present in both transgenic lines, developed more slowly in A-line mice and correlated with a reduction in the ratio of gamma-interferon to interleukin-10 transcripts. Splenic leukocytes from young A-line donors transferred diabetes into NOD-scid recipients at a retarded rate compared with those from nontransgenic donors. Further, nontransgenic NOD T-cells transferred diabetes more slowly in NOD-scid recipients that were congenic for A-line transgenes as compared with standard NOD-scid recipients. Primed T-cell responses and spontaneous humoral reactivity to GAD65 failed to distinguish transgenic from nontransgenic mice. Quantitative differences in expression level or insertional mutagenesis are possible mechanisms of protection in the A line.