bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eating disorders and aggressiveness among adolescents
Authors: Miotto P. , De Coppi M. , Frezza M. , Petretto D. R. , Masala C. , Preti A. 
Published: July 2003

Objective: To explore the links between propensity to aggression and eating disorders in a sample of school‐aged adolescents in a northeastern area of Italy.Method: In a mixed male–female sample of 1000 adolescents (10% of the district's population aged 15–19 years) we administered the Eating Attitudes Test, the Bulimic Investigatory Test of Edinburgh and the Body Attitudes Test, as measures of abnormal eating attitudes and behaviours, and the Aggression Questionnaire, as a measure of the propensity to aggression.Results: Females scored significantly higher than males at all eating disorders inventories (P < 0.0001). Males scored higher than females at the Aggression Questionnaire. In both genders, there was a positive correlation between scores at any of the eating disorders inventories and those at the Aggression Questionnaire (P < 0.0001).Conclusion: Overtly expressed aggression might have a negative impact on the course of eating disorders and on the compliance with treatment, also enhancing the risk of suicide.
Comorbidity of impulse control disorders in pathological gamblers
Authors: Grant J. E. , Kim S. W. 
Published: July 2003

Objective: To investigate the rate of impulse control disorders among pathological gamblers and examine the relationship of comorbidity to gambling severity.Method: Ninety‐six adult pathological gamblers [mean age: 46.7 ± 11.0 years; female: 44 (45.8%)] completed the following: Minnesota Impulsive Disorders Interview, Yale‐Brown Obsessive–Compulsive Scale Modified for Pathological Gambling, and Gambling Symptom Assessment Scale.Results: Twenty‐two subjects (22.9%) reported a comorbid impulse control disorder, most commonly compulsive sexual behaviour and compulsive buying. Subjects with comorbidity reported significantly greater intensity of urges (t = −2.021; df = 94; P = 0.046) and thoughts (t = −2.147; df = 42.3; P = 0.038) related to gambling, and greater interference (t = −3.913; df = 48.1; P < 0.001) and distress (t = −2.504; df = 52.7; P = 0.015) secondary to gambling urges and thoughts.Conclusion: Impulse control disorders appear common among pathological gamblers and are associated with more severe gambling symptoms.
Examination stress in Singapore primary schoolchildren: how compliance by subjects can impact on study results
Authors: Parker G. , Cai Y. , Tan S. , Dear K. , Henderson A. S. , Poh G. T. , Kwee G. C. 
Published: July 2003

Objective: Examinations are anecdotally viewed as extremely stressful to Singapore schoolchildren. We test this postulate by obtaining parental ratings of children's emotional stress levels longitudinally in a large representative sample of sixth (P6) and fifth (P5) class primary schoolchildren, respectively, exposed and unexposed to a streaming examination.Method: Children's stress levels were rated monthly by a parent for 10 months.Results: Analyses failed to find evidence of any differential stress impact across P6 and P5 comparison groups, apart from a subset of P6 children whose parents complied with every monthly survey.Conclusion: The streaming examination in the final year of primary school did not emerge as a general stressor to children, but achieved salience within a defined subset of children whose parents were highly study compliant. Study compliance may be a proxy variable of some import, and have wider relevance to other cohort studies and to intervention trials.
Total plasma l‐tryptophan, free l‐tryptophan and competing amino acid levels in a homicidal male adolescent with conduct disorder
Authors: Virkkunen M. , Ebeling H. , Moilanen I. , Tani P. , Pennanen S. , Liesivuori J. , Tiihonen J. 
Published: July 2003

Objective: Several studies have shown abnormal findings in human serotonin metabolism, such as increased total plasma l‐tryptophan and free l‐tryptophan levels among habitually violent antisocial offenders. It is not clear if these increased l‐tryptophan levels are associated with adult antisocial personality disorder (ASP) or history of substance abuse, or if these levels are already present in adolescent subjects with conduct disorder (CD).Method: Total plasma and free l‐tryptophan and competing amino acids (CAAs) were measured in a 15‐year‐old adolescent offender, who was convicted for two homicides, and in 10 healthy male controls of similar age and body mass index (BMI).Results: In the juvenile offender, plasma total l‐tryptophan/CAA was 84% and free l‐tryptophan/CAA 143% higher than average mean among controls.Conclusion: From this very aggressive boy with CD, findings of free l‐ and total l‐tryptophan/CAA values were similar to those of habitually violent adult ASP offenders. As severe CDs in adolescence tend to develop into adults with ASP, increased l‐tryptophan/CAA and free l‐tryptophan/CAA values may serve as early indicators for the development of habitually violent adult offenders.
A critical examination of the amenorrhea and weight criteria for diagnosing anorexia nervosa
Authors: Watson T. L. , Andersen A. E. 
Published: July 2003

Background: Amenorrhea and weight loss to below 15% of ‘healthy’ weight are current diagnostic criteria for anorexia nervosa (AN). This study compares females who meet current International Statistical Classification of Diseases and Related Health Problems, tenth revision (ICD‐10) and Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM‐IV) criteria for AN with females who meet the essential psychopathology and significant self‐starvation, but lack either amenorrhea or weight loss below 85%.Method: This study retrospectively examined the medical charts of 588 consecutive admissions to an in‐patient treatment program. All diagnoses conformed to ICD‐10 and DSM‐IV.Results: Of 588 admissions, 297 females had some form of AN with 77.4% (230 of 297) meeting current criteria, while 22.6% (67 of 297) with core psychopathology and self‐starvation were classified as eating disorders not otherwise specified or ‘atypical’ because of some menstrual function or final weight above 85%. The groups showed few statistically significant differences on demographics, illness history, and treatment response, psychopathology, or bone density.Conclusion: Amenorrhea may not be a useful diagnostic criterion. Also, requiring below 85% of healthy weight may need generalization.
Gender differences in unipolar depression: an update of epidemiological findings and possible explanations
Authors: Kuehner C. 
Published: July 2003

Objective: To give an update on epidemiological findings on sex differences in the prevalence of unipolar depression and putative risk factors.Material and methods: Systematic review of the literature.Results: Recent epidemiological research yields additional evidence for a female preponderance in unipolar depression, holding true across different cultural settings. Current explanations include artefacts, genetic, hormonal, psychological and psychosocial risk factors. Rather consistently, intrapsychic and psychosocial gender role related risk factors have been identified which may contribute to the higher depression risk in women. Gender role aspects are also reflected in endocrine stress reactions and possibly influence associated neuropsychological processes.Conclusion: There is a need for more integrative models taking into account psychological, psychosocial, and macrosocial risk factors as well as their interactions, which also connect these factors with physiological and endocrine responses. Furthermore, it is conceivable that across the life span, as well as across cultural settings, individual risk factors will add with varying emphasis to the higher prevalence of depression in women.
How does elevated ozone impact soybean? A meta‐analysis of photosynthesis, growth and yield
Authors: MORGAN P. B. , AINSWORTH E.A. , LONG S. P. 
Published: July 2003

ABSTRACTSurface ozone concentrations ([O3]) during the growing season in much of the northern temperate zone reach mean peak daily concentrations of 60 p.p.b. Concentrations are predicted to continue to rise over much of the globe during the next 50 years. Although these low levels of ozone may not induce visible symptoms on most vegetation, they can result in substantial losses of production and reproductive output. Establishing the vulnerability of vegetation to rising background ozone is complicated by marked differences in findings between individual studies. Ozone effects are influenced by exposure dynamics, nutrient and moisture conditions, and the species and cultivars that are investigated. Meta‐analytic techniques provide an objective means to quantitatively summarize treatment responses. Soybean has been the subject of many studies of ozone effects. It is both the most widely planted dicotyledonous crop and a model for other C3 annual plants. Meta‐analytic techniques were used to quantitatively summarize the response of soybean to an average, chronic ozone exposure of 70 p.p.b., from 53 peer‐reviewed studies. At maturity, the average shoot biomass was decreased 34% and seed yield was 24% lower. Even in studies where [O3] was < 60 p.p.b., there was a significant decrease in biomass and seed production. At low [O3], decreased production corresponded to a decrease in leaf photosynthesis, but in higher [O3] the larger loss in production was associated with decreases in both leaf photosynthesis and leaf area. The impact of ozone increased with developmental stage, with little effect on vegetative growth and the greatest effect evident at completion of seed filling. Other stress treatments, including UV‐B and drought, did not alter the ozone response. Elevated carbon dioxide significantly decreased ozone‐induced losses, which may be explained by a significant decrease in stomatal conductance.
Expression of the ipomoelin gene from sweet potato is regulated by dephosphorylated proteins, calcium ion and ethylene
Authors: CHEN Y.‐C. , TSENG B.‐W. , HUANG Y.‐L. , LIU Y.‐C. , JENG S.‐T. 
Published: July 2003

ABSTRACTA wound‐inducible cDNA, ipomoelin (IPO) was isolated from the subtraction library of sweet potato (Ipomoea batatas cv. Tainung 57) and used as a molecular probe to investigate the transduction pathway of wounding signal within plant cells. Following mechanical wounding of the leaves of sweet potato, IPO mRNA accumulation peaked at 6 h and then continuously declined. However, IPO gene expression in the apical unwounded leaves began at 6 h after wounding and continued for a further 10 h. Besides mechanical wounding, methyl jasmonate (MeJA) was identified as a signal transducer leading to the accumulation of IPO mRNA. Treatment with salicylic acid reduced the production of IPO mRNA, further supporting the involvement of the octadecanoid pathway in the signal transduction of wounding in sweet potato. In addition, ethylene was involved in the signal pathway and induced the expression of the IPO gene. Furthermore, the application of okadaic acid, a protein phosphatase inhibitor, blocked the accumulation of IPO mRNA induced by MeJA or ethylene, indicating that activation of the IPO gene by both MeJA and ethylene was via dephosphorylated proteins. The presence of a calcium ion chelator or channel blockers also inhibited the expression of the IPO gene after wounding. However, investigation by confocal scanning microscopy further pointed out that mechanical wounding rather than the application of MeJA induced the accumulation of the calcium ion. These results may indicate that the calcium ion is also involved in the activation of IPO mRNA. In addition, wounding signals the accumulation of calcium ion first and then stimulates the biosynthesis of MeJA in sweet potato. Hence, the reaction sequence of signal transducers, including the calcium ion, MeJA and protein kinase/phosphatase, in the wounding signalling pathway of sweet potato is suggested in this report.
Expression and regulation of the crucial plant‐like ferredoxin of cyanobacteria
Authors: Mazouni Khalil , Domain Francis , Chauvat Franck , Cassier‐Chauvat Corinne 
Published: July 2003

SummaryThe Synechocystis fedI gene (petF, ssl0020) was found to be strongly expressed under the negative control of H2O2 or heavy metals, and the positive control of light fluence (regulation dependent on active photosynthesis) or carbon availability [under the control of NdhR, the regulator of the ndh3 operon encoding NAD(P)H dehydrogenase subunits]. The basic and constitutive promoter (BP) of fedI extending from −62 to +25 (relative to the transcription start point) is weakly active, presumably because it harbours a long (30 bp) spacer between the two crucial motifs: the −10 box (5′‐TAgtAT‐3′, −13 to −8) and the ‘−35’ box (5′‐TTGctA‐3′, −49 to −44). BP strength is strongly enhanced by the two upstream regions, −113 to −82 and −151 to −114, mediating the 30‐fold constitutive stimulation and the fourfold light activation respectively. Three well‐conserved transcriptional elements were characterized for the first time, namely the −19 box (5′‐TTTT‐3′) that is essential to transcription, and the two twice repeated elements that are both critical to light induction: the TTGyCA‐3′ box (−35 to −30, and −125 to −120) and the 5′‐ATTTyA‐3′ box (−55 to −50, and −134 to −129). That two of these light induction motifs (5′‐TTGtCA‐3′, −35 to −30; 5′‐ATTTcA‐3′, −55 to −50) occur in the constitutive BP promoter indicate that in the fedI gene light activation and transcription per se are closely interacting. Interestingly, the fedI gene from marine strains was found to lack the three transcriptional elements presently described, as well as the 5′‐AGGA‐3′ Shine–Dalgarno sequence, which are all conserved among the fedI from non‐marine strains.
Microcin E492 antibacterial activity: evidence for a TonB‐dependent inner membrane permeabilization on Escherichia coli
Authors: Destoumieux‐Garzón Delphine , Thomas Xavier , Santamaria Mónica , Goulard Christophe , Barthélémy Michel , Boscher Bénédicte , Bessin Yannick , Molle Gérard , Pons Anne‐Marie , Letellier Lucienne , Peduzzi Jean , Rebuffat Sylvie 
Published: July 2003

SummaryThe mechanism of action of microcin E492 (MccE492) was investigated for the first time in live bacteria. MccE492 was expressed and purified to homogeneity through an optimized large‐scale procedure. Highly purified MccE492 showed potent antibacterial activity at minimal inhibitory concentrations in the range of 0.02–1.2 µM. The microcin bactericidal spectrum of activity was found to be restricted to Enterobacteriaceae and specifically directed against Escherichia and Salmonella species. Isogenic bacteria that possessed mutations in membrane proteins, particularly of the TonB–ExbB–ExbD complex, were assayed. The microcin bactericidal activity was shown to be TonB‐ and energy‐dependent, supporting the hypothesis that the mechanism of action is receptor mediated. In addition, MccE492 depolarized and permeabilized the E. coli cytoplasmic membrane. The membrane depolarization was TonB dependent. From this study, we propose that MccE492 is recognized by iron‐siderophore receptors, including FepA, which promote its import across the outer membrane via a TonB‐ and energy‐dependent pathway. MccE492 then inserts into the inner membrane, whereupon the potential becomes destabilized by pore formation. Because cytoplasmic membrane permeabilization of MccE492 occurs beneath the threshold of the bactericidal concentration and does not result in cell lysis, the cytoplasmic membrane is not hypothesized to be the sole target of MccE492.
The pair of arginine codons AGA AGG close to the initiation codon of the lambda int gene inhibits cell growth and protein synthesis by accumulating peptidyl‐tRNAArg4
Authors: Olivares‐Trejo José J. , Bueno‐Martínez José G. , Guarneros Gabriel , Hernández‐Sánchez Javier 
Published: July 2003

SummaryTo analyse the mechanism by which rare codons near the initiation codon inhibit cell growth and protein synthesis, we used the bacteriophage lambda int gene or early codon substitution derivatives. The lambda int gene has a high frequency of rare ATA, AGA and AGG codons; two of them (AGA AGG) located at positions 3 and 4 of the int open reading frame (ORF). Escherichia coli pth (rap) cells, which are defective in peptidyl‐tRNA hydrolase (Pth) activity, are more susceptible to the inhibitory effects of int expression as compared with wild‐type cells. Cell growth and Int protein synthesis were enhanced by overexpression of Pth and tRNAArg4 cognate to AGG and AGA but not of tRNAIle2a specific for ATA. The increase of Int protein synthesis also takes place when the rare arginine codons AGA and AGG at positions 3 and 4 are changed to common arginine CGT or lysine AAA codons but not to rare isoleucine ATA codons. In addition, overexpression of int in Pth defective cells provokes accumulation of peptidyl‐tRNAArg4 in the soluble fraction. Therefore, cell growth and Int synthesis inhibition may be due to ribosome stalling and premature release of peptidyl‐tRNAArg4 from the ribosome at the rare arginine codons of the first tandem, which leads to cell starvation for the specific tRNA.
Phosphatidylethanolamine and phosphatidylglycerol are segregated into different domains in bacterial membrane. A study with pyrene‐labelled phospholipids
Authors: Vanounou Sharon , Parola Abraham H. , Fishov Itzhak 
Published: July 2003

SummaryTo detect and characterize membrane domains that have been proposed to exist in bacteria, two kinds of pyrene‐labelled phospholipids, 2‐pyrene‐decanoyl‐phosphatidylethanolamine (PY‐PE) and 2‐pyrene‐decanoyl‐phosphatidylglycerol (PY‐PG) were inserted into Escherichia coli or Bacillus subtilis membrane. The excimerization rate coefficient, calculated from the excimer‐to‐monomer ratio dependencies on the probe concentration, was two times higher for PY‐PE than for PY‐PG at 37°C. This was ascribed to different local concentrations rather than to differences in mobility. The extent of mixing between the two fluorescent phospholipids, estimated by formation of their heteroexcimer, was found very low both in E. coli and B. subtilis, in contrast to model membranes. In addition, these two pyrene derivatives exhibited different temperature phase transitions and different detergent extractability, indicating that the surroundings of these phospholipids in bacterial membrane differ in organization and order. Inhibition of protein synthesis, leading to condensation of nucleoid and presumably to dissipation of membrane domains, indeed resulted in increased formation of heteroexcimers, broadening of phase transitions and equal detergent extractability of both probes. It is proposed that in bacterial membranes these phospholipids are segregated into distinct domains that differ in composition, proteo–lipid interaction and degree of order; the proteo‐lipid domain being enriched by PE.
The Aspergillus nidulans metR gene encodes a bZIP protein which activates transcription of sulphur metabolism genes
Authors: Natorff Renata , Sieńko Marzena , Brzywczy Jerzy , Paszewski Andrzej 
Published: July 2003

SummaryThe identification, isolation and characterization of a new Aspergillus nidulans positive‐acting gene metR, which encodes a transcriptional activator of sulphur metabolism, is reported. metR mutants are tight auxotrophs requiring methionine or homocysteine for growth. Mutations in the metR gene are epistatic to mutations in the negative‐acting sulphur regulatory scon genes. The metR coding sequence is interrupted by a single intron of 492 bp which is unusually long for fungi. Aspergillus nidulans METR is a member of bZIP family of DNA‐binding proteins. The bZIP domains of METR and the Neurospora crassa CYS3 transcriptional activator of sulphur genes are highly similar. Although Neurospora cys‐3 gene does not substitute for the metR function, a chimeric metR gene with a cys‐3 bZIP domain is able to transform the ΔmetR mutant to methionine prototrophy. This indicates that METR recognizes the same regulatory sequence as CYS3. The metR gene is not essential, as deletion mutants are viable and have similar phenotype as point mutants. In contrast to the Neurospora cys‐3, transcription of the metR gene was found to be regulated neither by METR protein nor by sulphur source. Transcription of metR gene is derepressed in the sconB2 mutant. Transcription of genes encoding sulphate permease, homocysteine synthase, cysteine synthase, ATP‐sulphurylase, and sulphur controller –sconB is strongly regulated by the metR gene product and depends on the character of the metR mutation and sulphur supplementation.
Biphasic intracellular expression of Staphylococcus aureus virulence factors and evidence for Agr‐mediated diffusion sensing
Authors: Shompole Sankale , Henon Kim T. , Liou Linda E. , Dziewanowska Katarzyna , Bohach Gregory A. , Bayles Kenneth W. 
Published: July 2003

Summary Staphylococcus aureus invades a variety of mammalian cells and escapes from the endosome to multiply in the cytoplasm. We had previously hypothesized that the molecular events leading to escape of S. aureus from the endosome involved the Agr virulence factor regulatory system. In this report we demonstrate that temporal changes in intracellular activation of the Agr regulon correlates with expression of membrane active toxins. Also, the initial expression of Agr by even small numbers of staphylococci resulted in the permeabilization of the endosomal membrane and the eventual escape of bacteria into the cytoplasm by 3 h post invasion. After Agr downregulation, a second peak of expression coincided with increased permeability of the host cell membrane. In contrast to the parental strain, an Agr‐mutant was unable to escape into the cytoplasm and was observed in intact endosomes as late as 5 h post invasion. These data provide evidence that staphylococcal virulence factor production during invasion of host cells is mediated by an Agr‐dependent process that is most accurately described in the context of diffusion sensing.
Distant cis‐active sequences and sialic acid control the expression of fimB in Escherichia coli K‐12
Authors: El‐Labany Sammia , Sohanpal Baljinder K. , Lahooti Maryam , Akerman Robert , Blomfield Ian C. 
Published: July 2003

SummaryThe phase variation of type 1 fimbriation in Escherichia coli is controlled by the inversion of a 314 bp element of DNA, determined by FimB (switching in both directions) or FimE (switching from the ON‐to‐OFF orientation predominantly), and influenced by auxiliary factors IHF, Lrp and H‐NS. The fimB gene is separated from the divergently transcribed yjhATS operon by a large (1.4 kbp) intergenic region of unknown function. Here, we show that fimB expression is regulated by multiple cis‐active sequences that lie far upstream (>600 bp) of the transcription start sites for the recombinase gene. Two regions characterized further (regions 1 and 2) show sequence identity, and each coincides with a methylation‐protected Dam (5′‐GATC) site. Regions 1 and 2 apparently control fimB expression by an antirepression mechanism that involves additional sequences proximal to yjhA. Region 1 encompasses a 27 bp DNA sequence conserved upstream of genes known (nanAT ) or suspected (yjhBC) to be involved in sialic acid metabolism, and we show that FimB expression and recombination are suppressed by N‐acetylneuraminic acid. We propose that E. coli recognizes the amino sugars as a harbinger of potential host defence activation, and suppresses the expression of type 1 fimbriae in response.