bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevated glutamine/glutamate ratio in cerebrospinal fluid of first episode and drug naive schizophrenic patients
Authors: Hashimoto Kenji , Engberg Göran , Shimizu Eiji , Nordin Conny , Lindström Leif H , Iyo Masaomi 
Published: February 2005

Abstract
Background
Recent magnetic resonance spectroscopy (MRS) studies report that glutamine is altered in the brains of schizophrenic patients. There were also conflicting findings on glutamate in cerebrospinal fluid (CSF) of schizophrenic patients, and absent for glutamine. This study aims to clarify the question of glutamine and glutamate in CSF of first episode and drug naive schizophrenic patients.

Method
Levels of glutamine and glutamate in CSF of 25 first episode and drug-naive male schizophrenic patients and 17 age-matched male healthy controls were measured by a high performance liquid chromatography.

Results
The ratio (126.1 (median), 117.7 ± 27.4 (mean ± S.D.)) of glutamine to glutamate in the CSF of patients was significantly (z = -3.29, p = 0.001) higher than that (81.01 (median), 89.1 ± 22.5 (mean ± S.D.)) of normal controls although each level of glutamine and glutamate in patients was not different from that of normal controls.

Conclusion
Our data suggests that a disfunction in glutamate-glutamine cycle in the brain may play a role in the pathophysiology of schizophrenia.
Resection of small plexiform neurofibromas in neurofibromatosis type 1 children
Authors: Friedrich Reinhard E , Schmelzle Rainer , Hartmann Melanie , Fünsterer Carsten , Mautner Victor-F 
Published: February 2005

Abstract
Background
Plexiform neurofibromas (PNF) are benign tumors of the peripheral nerve which mostly develop in patients with neurofibromatosis type 1 (NF1). Surgical interventions are usually not applied to children with small tumors. These are rather restricted to debulking of larger tumors in adults that cause clinical complications or aesthetic disfigurement. In most cases, a total resection of PNF is not possible due to the network-like growth of the tumors.

Patients and methods
Early surgical intervention was carried out for 9 small PNFs in 7 NF1 children. Tumor resection was performed following the graphical delineation of the affected skin and according the MRI findings.

Results
Total resection was achieved for all 9 PNF without causing any neurological or organic deficit. Annual magnetic resonance tomography over a period of four years did not reveal any relapse of the tumors.

Conclusions
Early surgical intervention for small superficial PNFs in NF1 children have various advantages and may especially be considered a strategy to prevent progression.
Assessing post-traumatic stress disorder in South African adolescents: using the child and adolescent trauma survey (CATS) as a screening tool
Authors: Suliman S , Kaminer D , Seedat S , Stein DJ 
Published: February 2005

Abstract
Background
Several studies have demonstrated that South African children and adolescents are exposed to high levels of violent trauma with a significant proportion developing PTSD, however, limited resources make it difficult to accurately identify traumatized children.

Methods
A clinical interview (K-SADS-PL, selected modules) and self-report scale (CATS) were compared to determine if these different methods of assessment elicit similar information with regards to trauma exposure and post-traumatic stress disorder (PTSD) in adolescents. Youth (n = 58) from 2 schools in Cape Town, South Africa participated.

Results
91% of youth reported having been exposed to a traumatic event on self-report (CATS) and 38% reported symptoms severe enough to be classified as PTSD. On interview (K-SADS-PL), 86% reported exposure to a traumatic event and 19% were found to have PTSD. While there were significant differences in the rates of trauma exposure and PTSD on the K-SADS and CATS, a cut-off value of 15 on the CATS maximized both the number of true positives and true negatives with PTSD. The CATS also differentiated well between adolescents meeting DSM-IV PTSD symptom criteria from adolescents not meeting criteria.

Conclusions
Our results indicate that trauma exposure and PTSD are prevalent in South African youth and if appropriate cut-offs are used, self-report scales may be useful screening tools for PTSD.
Weight, Weight Gain, and Survival After Breast Cancer Diagnosis
Authors: Kroenke Candyce H. , Chen Wendy Y. , Rosner Bernard , Holmes Michelle D. 
Published: February 2005

Purpose To determine whether weight prior to diagnosis and weight gain after diagnosis are predictive of breast cancer survival. Methods Patients included 5,204 Nurses' Health Study participants diagnosed with incident, invasive, nonmetastatic breast cancer between 1976 and 2000; 860 total deaths, 533 breast cancer deaths, and 681 recurrences (defined as secondary lung, brain, bone, or liver cancer, and death from breast cancer) accrued to 2002. We computed the change in body mass index (BMI) from before to the first BMI reported ≥ 12 months after the date of diagnosis. Cox proportional hazards models were used to evaluate associations of categories of BMI before diagnosis and of BMI change with time to event. We stratified by smoking, menopausal status, and breast cancer–related variables. Results In multivariate-adjusted analyses, weight before diagnosis was positively associated with breast cancer recurrence and death, but this was apparent only in never smokers. Similarly, among never-smoking women, those who gained between 0.5 and 2.0 kg/m2 (median gain, 6.0 lb; relative risk [RR], 1.35; 95% CI, 0.93 to 1.95) or more than 2.0 kg/m2 (median gain, 17.0 lb; RR, 1.64; 95% CI, 1.07 to 2.51) after diagnosis had an elevated risk of breast cancer death during follow-up (median, 9 years), compared with women who maintained their weight (test for linear trend, P = .03). Associations with weight were stronger in premenopausal than in postmenopausal women. Similar findings were noted for breast cancer recurrence and all-cause mortality. Conclusion Weight and weight gain were related to higher rates of breast cancer recurrence and mortality, but associations were most apparent in never-smoking women.
Meta-Analysis to Evaluate the Role of Interferon in Follicular Lymphoma
Authors: Rohatiner A.Z.S. , Gregory W.M. , Peterson B. , Borden E. , Solal-Celigny P. , Hagenbeek A. , Fisher R.I. , Unterhalt M. , Arranz R. , Chisesi T. , Aviles A. , Lister T.A. 
Published: February 2005

Purpose To determine whether interferon (IFN) -α2, when given with or following chemotherapy, influences response rate, remission duration, and survival in newly diagnosed patients with follicular lymphoma. Patients and Methods Ten phase III studies evaluating the role of IFN-α2 in 1,922 newly diagnosed patients with follicular lymphoma were analyzed. Updated individual patient data were used to perform meta-analyses for response, survival, and remission duration. Results The addition of IFN-α2 to initial chemotherapy did not significantly influence response rate. An overall meta-analysis for survival showed a significant difference in favor of IFN-α2, but also showed significant heterogeneity between studies. Further analyses were carried out in order to explain this heterogeneity, and to define the circumstances in which IFN-α2 prolonged survival. The survival advantage was seen when IFN-α2 was given: (1) in conjunction with relatively intensive initial chemotherapy (2P = .00005), (2) at a dose ≥ 5 million units (2P = .000002), (3) at a cumulative dose ≥ 36 million units per month (2P = .000008), and (4) with chemotherapy rather than as maintenance therapy (P = .004). With regard to remission duration, there was also a significant difference in favor of IFN-α2, irrespective of the intensity of chemotherapy used, IFN dose, or whether IFN was given as a maintenance strategy or with chemotherapy. Conclusion When given in the context of relatively intensive initial chemotherapy, and at a dose ≥ 5 million units (≥ 36 × 106 units per month), IFN-α2 prolongs survival and remission duration in patients with follicular lymphoma.
Quantification of Carbamylated LDL in Human Sera by a New Sandwich ELISA
Authors: Apostolov Eugene O , Shah Sudhir V , Ok Ercan , Basnakian Alexei G 
Published: February 2005

AbstractBackground: We previously suggested that increased carbamylated LDL (cLDL), a product of nonenzymatic modification of LDL in human serum by urea-derived cyanate, may cause cardiovascular complications in patients with chronic renal insufficiency. An assay for precise measurement of cLDL in serum was not previously available.Methods: Polyclonal antibodies against human cLDL and nonmodified, native LDL (nLDL) were raised in rabbits and extensively purified by affinity chromatography. New sandwich ELISAs to measure cLDL and nLDL with use of these antibodies were developed. Serum concentrations of cLDL and nLDL were measured by the sandwich ELISAs in 41 patients with end-stage renal disease (ESRD) and 40 healthy controls.Results: Both assays showed satisfactory reproducibility, linearity, and recovery. The assays could detect 2.7 mg/L cLDL with a linear detection range of 5–1000 mg/L and 5 mg/L nLDL with a linear detection range of 50–1000 mg/L. These measurements showed that patients with ESRD have significantly increased serum cLDL [281.5 (46.9) mg/L compared with 86.1 (29.7) mg/L in a control group; P &lt;0.001]. There was no significant difference in nLDL concentrations between the groups.Conclusions: These assays are a potentially valuable tool for cardiovascular research in renal patients and healthy individuals. The cLDL concentration appears to be the highest among all previously described modified LDL isoforms in both controls and ESRD patients.
Comparative approach of the solubility of protactinium oxy/hydroxides
Authors: Tarapcik P. , Fourest B. , Giffaut E. 
Published: February 2005

AbstractThe hydrolysis constants and the solubility products of the oxide/hydroxides of Pa(IV) and Pa(V) have been first reviewed and re-evaluated through the application of three comparative methods: the simple Hard Sphere Electrostatic model (HSE), the Brown and Wanner Theory (BWT) and the Correlation between Solubility and Complex stability constants of a metal ion (CSC). The latter method is the most empirical one, but it gives coherent results, in agreement with the few published experimental values, for all the possible aqua species of protactinium (Pa4+, Pa5+, PaO2+and PaO3+). The selected thermodynamic data have then been used to predict the protactinium solubility in non complexing media of various pH and redox potential.
Prognosticating the humic complexation for redox sensitive actinides through analogy, using the charge neutralisation model
Authors: Reiller Pascal 
Published: February 2005

AbstractThe complexation of redox sensitive elements by humic acid (HA), described through the charge neutralisation model (CNM), has been reviewed in order to have a comprehensive scope. The data acquired in HUMICS program on thorium(IV), and data available in the literature, were reinterpreted according to the CNM, and adapted to uranium(IV), neptunium(IV) and plutonium(IV) through analogy in order to draw a boundary prediction. Otherwise, available data obtained in the framework of the CNM were used, or adapted if necessary, for other redox states when the analogy is justified,i.e.Am3+-Cm3+for Pu3+, NpO2+for PuO2+and UO22+for PuO22+.The obtained speciation diagrams indicate that, when (HA)=100 mg/L, redox sensitive actinides should be reduced to their +IV state whenEh≤650 mV/SHE for plutonium,Eh≤100 mV/SHE for neptunium andEh≤-20 mV/SHE for U. Plutonium could be present as mixtures of plutonium(III) and (IV) depending on the pH value in reducing ground waters -150 ≤Eh(mV/SHE) ≤ 150. The known reduction of neptunium(V) to neptunium(IV) in Gorleben ground waters seems also well represented, so is the stability of uranium(VI) in humic solution whenEh≥ 100 mV/SHE. Conversely, the known association of plutonium(VI) in marine systems is not satisfactorily represented, so does is the uranium behaviour under reducing conditions. Experiments under well-controlled conditions are still needed to ascertain the plutonium and uranium comportment in the presence of humic acid.
Sorption and transport behavior of radionuclides in the proposed low-level radioactive waste disposal facility at the Hanford site, Washington
Authors: Um Wooyong , Serne R. Jeffrey 
Published: February 2005

AbstractA series of batch sorption and column experiments was conducted to investigate sorption and transport behavior of99Tc,129I,79Se, and90Sr on and through borehole sediments collected from the proposed low-level radioactive waste disposal facility at the Hanford Site (200 East Area). Batch sorption experiments were conducted on Hanford sediment using uncontaminated Hanford groundwater and simulated glass leachates spiked with individual radionuclides. Strongest sorption occurred for90Sr, while79Se sorption was intermediate, and129I and99Tc showed the least sorption affinities on Hanford sediment among these radionuclides studied. The results of column experiments that measured transport behavior of these radionuclides through Hanford sediment were similar to the mobility that can be calculated from the batch sorption results, that is high mobility for99Tc and129I compared to the intermediate and strong retardation for79Se and90Sr, respectively. These contaminant sorption data on sediments from below the proposed disposal facility, especially the tests using simulated glass leachate, corroborate values obtained for sediments collected in the past from near by locations and for generic solutions such as regional groundwater. These new data should provide more technical defensibility for past performance assessment predictions that did not use site-specific sediments and leachates. Further, the new data will be incorporated into future performance assessment activities that will update and improve past predictions.
A Genetic and Molecular Characterization of Two Proximal Heterochromatic Genes on Chromosome 3 of Drosophila melanogaster
Authors: Schulze Sandra R , Sinclair Donald A R , Fitzpatrick Kathleen A , Honda Barry M 
Published: February 2005

Abstract
Heterochromatin comprises a transcriptionally repressive chromosome compartment in the eukaryotic nucleus; this is exemplified by the silencing effect it has on euchromatic genes that have been relocated nearby, a phenomenon known as position-effect variegation (PEV), first demonstrated in Drosophila melanogaster. However, the expression of essential heterochromatic genes within these apparently repressive regions of the genome presents a paradox, an understanding of which could provide key insights into the effects of chromatin structure on gene expression. To date, very few of these resident heterochromatic genes have been characterized to any extent, and their expression and regulation remain poorly understood. Here we report the cloning and characterization of two proximal heterochromatic genes in D. melanogaster, located deep within the centric heterochromatin of the left arm of chromosome 3. One of these genes, RpL15, is uncharacteristically small, is highly expressed, and encodes an essential ribosomal protein. Its expression appears to be compromised in a genetic background deficient for heterochromatin protein 1 (HP1), a protein associated with gene silencing in these regions. The second gene in this study, Dbp80, is very large and also appears to show a transcriptional dependence upon HP1; however, it does not correspond to any known lethal complementation group and is likely to be a nonessential gene.
Flexibility in a Gene Network Affecting a Simple Behavior in Drosophila melanogaster
Authors: van Swinderen Bruno , Greenspan Ralph J 
Published: February 2005

Abstract
Gene interactions are emerging as central to understanding the realization of any phenotype. To probe the flexibility of interactions in a defined gene network, we isolated a set of 16 interacting genes in Drosophila, on the basis of their alteration of a quantitative behavioral phenotype—the loss of coordination in a temperature-sensitive allele of Syntaxin1A. The interactions inter se of this set of genes were then assayed in the presence and in the absence of the original Syntaxin1A mutation to ask whether the relationships among the 16 genes remain stable or differ after a change in genetic context. The pattern of epistatic interactions that occurs within this set of variants is dramatically altered in the two different genetic contexts. The results imply considerable flexibility in the network interactions of genes.
Evolution of Recombination Due to Random Drift
Authors: Barton N H , Otto Sarah P 
Published: February 2005

Abstract
In finite populations subject to selection, genetic drift generates negative linkage disequilibrium, on average, even if selection acts independently (i.e., multiplicatively) upon all loci. Negative disequilibrium reduces the variance in fitness and hence, by Fisher's (1930) fundamental theorem, slows the rate of increase in mean fitness. Modifiers that increase recombination eliminate the negative disequilibria that impede selection and consequently increase in frequency by “hitchhiking.” Thus, stochastic fluctuations in linkage disequilibrium in finite populations favor the evolution of increased rates of recombination, even in the absence of epistatic interactions among loci and even when disequilibrium is initially absent. The method developed within this article allows us to quantify the strength of selection acting on a modifier allele that increases recombination in a finite population. The analysis indicates that stochastically generated linkage disequilibria do select for increased recombination, a result that is confirmed by Monte Carlo simulations. Selection for a modifier that increases recombination is highest when linkage among loci is tight, when beneficial alleles rise from low to high frequency, and when the population size is small.
Roles of RAD6 Epistasis Group Members in Spontaneous Polζ-Dependent Translesion Synthesis in Saccharomyces cerevisiae
Authors: Minesinger Brenda K , Jinks-Robertson Sue 
Published: February 2005

Abstract
DNA lesions that arise during normal cellular metabolism can block the progress of replicative DNA polymerases, leading to cell cycle arrest and, in higher eukaryotes, apoptosis. Alternatively, such blocking lesions can be temporarily tolerated using either a recombination- or a translesion synthesis-based bypass mechanism. In Saccharomyces cerevisiae, members of the RAD6 epistasis group are key players in the regulation of lesion bypass by the translesion DNA polymerase Polζ. In this study, changes in the reversion rate and spectrum of the lys2ΔA746 −1 frameshift allele have been used to evaluate how the loss of members of the RAD6 epistasis group affects Polζ-dependent mutagenesis in response to spontaneous damage. Our data are consistent with a model in which Polζ-dependent mutagenesis relies on the presence of either Rad5 or Rad18, which promote two distinct error-prone pathways that partially overlap with respect to lesion specificity. The smallest subunit of Polδ, Pol32, is also required for Polζ-dependent spontaneous mutagenesis, suggesting a cooperative role between Polδ and Polζ for the bypass of spontaneous lesions. A third error-free pathway relies on the presence of Mms2, but may not require PCNA.
Persistence and Loss of Meiotic Recombination Hotspots
Authors: Pineda-Krch Mario , Redfield Rosemary J 
Published: February 2005

Abstract
The contradiction between the long-term persistence of the chromosomal hotspots that initiate meiotic recombination and the self-destructive mechanism by which they act strongly suggests that our understanding of recombination is incomplete. This “hotspot paradox” has been reinforced by the finding that biased gene conversion also removes active hotspots from human sperm. To investigate the requirements for hotspot persistence, we developed a detailed computer simulation model of their activity and its evolutionary consequences. With this model, unopposed hotspot activity could drive strong hotspots from 50% representation to extinction within 70 generations. Although the crossing over that hotspots cause can increase population fitness, this benefit was always too small to slow the loss of hotspots. Hotspots could not be maintained by plausible rates of de novo mutation, nor by crossover interference, which alters the frequency and/or spacing of crossovers. Competition among hotspots for activity-limiting factors also did not prevent their extinction, although the rate of hotspot loss was slowed. Key factors were the probability that the initiating hotspot allele is destroyed and the nonmeiotic contributions hotspots make to fitness. Experimental investigation of these deserves high priority, because until the paradox is resolved all components of the mechanism are open to doubt.
Bacterial Persistence
Authors: Kussell Edo , Kishony Roy , Balaban Nathalie Q , Leibler Stanislas 
Published: February 2005

Abstract
The persistence phenotype is an epigenetic trait exhibited by a subpopulation of bacteria, characterized by slow growth coupled with an ability to survive antibiotic treatment. The phenotype is acquired via a spontaneous, reversible switch between normal and persister cells. These observations suggest that clonal bacterial populations may use persister cells, whose slow division rate under growth conditions leads to lower population fitness, as an “insurance policy” against antibiotic encounters. We present a model of Escherichia coli persistence, and using experimentally derived parameters for both wild type and a mutant strain (hipQ) with markedly different switching rates, we show how fitness loss due to slow persister growth pays off as a risk-reducing strategy. We demonstrate that wild-type persistence is suited for environments in which antibiotic stress is a rare event. The optimal rate of switching between normal and persister cells is found to depend strongly on the frequency of environmental changes and only weakly on the selective pressures of any given environment. In contrast to typical examples of adaptations to features of a single environment, persistence appears to constitute an adaptation that is tuned to the distribution of environmental change.
In Vivo Bipartite Interaction Between the Hsp40 Sis1 and Hsp70 in Saccharomyces cerevisiae
Authors: Aron Rebecca , Lopez Nelson , Walter William , Craig Elizabeth A , Johnson Jill 
Published: February 2005

AbstractThe essential Hsp40, Sis1, is a J-protein cochaperone for the Ssa class of Hsp70's of Saccharomyces cerevisiae. Sis1 is required for the maintenance of the prion [RNQ+], as Sis1 lacking its 55-amino-acid glycine-rich region (G/F) does not maintain [RNQ+]. We report that overexpression of Sis1ΔG/F in an otherwise wild-type strain had a negative effect on both cell growth and [RNQ+] maintenance, while overexpression of wild-type Sis1 did not. Overexpression of the related Hsp40 Ydj1 lacking its G/F region did not cause inhibition of growth, indicating that this dominant effect of Sis1ΔG/F is not a characteristic shared by all Hsp40's. Analysis of small deletions within the SIS1 G/F region indicated that the observed dominant effects were caused by the absence of sequences known to be important for Sis1's unique cellular functions. These inhibitory effects of Sis1ΔG/F were obviated by alterations in the N-terminal J-domain of Sis1 that affect interaction with Ssa's ATPase domain. In addition, a genetic screen designed to isolate additional mutations that relieved these inhibitory effects identified two residues in Sis1's carboxy-terminal domain. These alterations disrupted the interaction of Sis1 with the 10-kD carboxy-terminal regulatory domain of Ssa1, indicating that Sis1 has a bipartite interaction with Ssa in vivo.