bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical activity of poor urban women in Cali, Colombia: A comparison of working and not working women
Authors: Dufour D.L. , Reina J.C. , Spurr G.B.
Published: June 2003

We have previously presented evidence that the physical activity level (PAL) and total energy expenditure (per kg body weight) of poor urban women who “work” (engage in income‐earning activities) is similar to those who do not “work” (but do tend to household and childcare responsibilities) (Spurr et al. [1996] Am J Clin Nutr 63:870–878; [1997] Med Sci Sports Exerc 29:1255–1262). These findings were unexpected and raised questions regarding the actual types of activities engaged in by the two groups. In this article we address those questions by comparing the time allocation of the two groups. Time allocation during waking hours (14.2 ± 1.1 hours/day) was recorded in minute‐by‐minute diaries by trained observers for two consecutive days for 52 working women and 28 not‐working women. The working women were engaged in predominately informal sector economic activities, such as street vending, childcare, and domestic service, in addition to their own household and childcare responsibilities. The activities of the not‐working women were largely restricted to household and childcare responsibilities. The working women tended to spend less time in resting activities and TV‐watching and more time in travel and miscellaneous work activities, but other between‐group differences were not significant. We conclude that the time allocation of working women is similar to that of not‐working women because 1) many of the activities engaged in are the same or similar, and 2) some working women are only engaged in income‐earning activities for limited time periods. Am. J. Hum. Biol. 15:490–497, 2003. © 2003 Wiley‐Liss, Inc.
Reduced rate of fat oxidation: A metabolic pathway to obesity in the developing nations
Authors: Frisancho A. Roberto
Published: June 2003

The purpose of this article is to document the metabolic and environmental factors associated with the increased frequency of obesity in the developing nations. While the prevalence of obesity in the developed countries is caused by the increased consumption of calorie‐dense foods, in the developing nations, because obesity coexists with undernutrition, additional factors are necessary to account for it. The evidence suggests that an important contributing factor for obesity in the developing nations is a reduced fat oxidation and increased metabolism of carbohydrate that has been brought about by the chronic undernutrition experienced during prenatal and postnatal growth. This shift toward a preferential metabolic use of carbohydrate rather than of fat results in an increased deposition of body fat. This tendency, along with the general decrease of energy expenditure in physical activity associated with urbanization, and the culturally mediated acceptance of fatness leads to obesity among populations from the developing nations. A joint effect of these factors is that in the developing nations obesity is associated with short stature resulting from developmental undernutrition, while in the developed countries obesity is associated with tall stature. It is hoped that future research will address the mechanisms whereby undernutrition increases the tendency toward obesity. Understanding how to modify fat oxidation could affect our ability to prevent weight gain among undernourished populations of the developing nations. Therefore, future research on the interaction of undernutrition and the development of obesity is of prime importance for anthropology concerned with the origins of human variability. Am. J. Hum. Biol. 15:522–532, 2003. © 2003 Wiley‐Liss, Inc.
DNA stability and schizophrenia in twins
Authors: Nguyen Giang H. , Bouchard Joseph , Boselli Monica G. , Tolstoi Linda G. , Keith Louis , Baldwin Clinton , Nguyen Nam C. , Schultz Mark , Herrera Victoria L.M. , Smith Cassandra L.
Published: June 2003

The goal of these experiments was to understand DNA changes relevant to schizophrenia. This work compared DNA of monozygotic (MZ) twins surrounding (CAG)n repeating sequences, and characterized the relationship between fragile sites and schizophrenia. Twelve twin‐pairs, previously classified as MZ and 18 unrelated sib‐pairs, from seven families were studied. Eight twin‐pairs were affected by schizophrenia, four concordantly and four discordantly. DNA comparisons were made using profiles of electrophoretic size fractionations of PCR amplified (CAG)n containing genomic fragments. These profiles were generated by a new method, developed by us, called targeted genomic differential display (TGDD). Surprisingly, the number of peak profile differences in MZ twin‐pairs discordant for schizophrenia was greater than the concordantly ill twins and the well twins and, in some cases, overlapped the range of sib‐pairs. These results might mean that some twins were not MZ but it was not possible to definitively test these samples for zygosity. Alternatively, the results might be explained as an increased mutation rate (or genomic instability) around (CAG)n sites in individuals afflicted with schizophrenia. Also, we uncovered an association of schizophrenia (i.e., a linkage of chromosomal abnormalities and gene localizations) with fragile sites spread throughout the genome (χ2, P = 0.001). Furthermore, it appears that an increasing number of genes linked to schizophrenia are associated with (CAG)n sequences. Fragile sites and (CAG)n repeat sequences are known to be unstable. We speculate the association of genomic instability with schizophrenia accounts for seemingly disparate biological and environmental factors that influence disease occurrence. © 2003 Wiley‐Liss, Inc.
Association between depressed mood in the elderly and a 5‐HTR2A gene variant
Authors: Jansson M. , Gatz M. , Berg S. , Johansson B. , Malmberg B. , McClearn G.E. , Schalling M. , Pedersen N.L.
Published: June 2003

The aim of this study was to investigate any possible association between depressed mood in the elderly and two candidate SNPs in the serotonin system: one in the 5‐HTR2A gene promotor (−1438 G/A) and one in the 5‐HT transporter gene (−925 C/A). DNA from a population‐based Swedish twin sample (N = 1,592; mean age = 73) was genotyped using Pryosequencing™. An association was found between the 5‐HTR2A gene promotor polymorphism and depressed mood (OR: 1.5, CI: 1.1–2.1) for the A/A genotype in the total sample. When the sample was analyzed by gender, a significant association (OR: 2.4, CI: 1.4–4.4) was found for males and the A/A genotype, but not for females. The 5‐HT transporter gene was not associated with depressed mood in this elderly population. These results suggest that there might be different genetic mechanisms for males and females contributing to the development of depressed mood in the elderly. © 2003 Wiley‐Liss, Inc.
Beta‐1‐adrenergic receptor gene in major depression: Influence on antidepressant treatment response
Authors: Zill Peter , Baghai Thomas C. , Engel Rolf , Zwanzger Peter , Schüle Cornelius , Minov Christo , Behrens Stefanie , Bottlender Ronald , Jäger Markus , Rupprecht Rainer , Möller Hans‐Jürgen , Ackenheil Manfred , Bondy Brigitta
Published: June 2003

Noradrenergic dysfunction has been implicated in the development of affective disorders. β‐adrenergic receptors (βARs) mediate the response to norephinephrine, are coupled to the cAMP signaling cascade, supposed to be altered in their density and/or sensitivity in depression, and down regulated in several brain regions after long term treatment with different but not all antidepressants. A recently identified functional polymorphism in the β1‐adrenergic receptor (G1165C) leading to the amino acid variation Gly389Arg was associated with an enhanced coupling to the stimulatory Gs‐protein and increased adenylyl cyclase activation, disturbances which are often observed in affective disorders. Therefore, we investigated whether this β1AR polymorphism is associated with major depression or with the response to antidepressant treatment in a sample of 259 patients compared to 206 healthy controls. Although we could not detect an association between the β1AR polymorphism and major depression we found a tendency for a relation between CC homozygosity and a better and even faster response to antidepressant treatment in those patients, which were treated with antidepressants affecting directly or indirectly the β1AR system (tricyclic antidepressants, noradrenergic and serotonergic specific agents, selective noradrenaline reuptake inhibitors) determined by the HAMD and CGI score (P = 0.05). However, after correction for multiple testing (Bonferroni) these results did not remain significant. Nevertheless, these findings suggest that the presence of the C allele might be an indicator for antidepressant treatment response. © 2003 Wiley‐Liss, Inc.
Is the α‐2A adrenergic receptor gene (ADRA2A) associated with attention‐deficit/hyperactivity disorder?
Authors: Roman Tatiana , Schmitz Marcelo , Polanczyk Guilherme V. , Eizirik Mariana , Rohde Luis A. , Hutz Mara H.
Published: June 2003

Attention‐Deficit/Hyperactivity Disorder (ADHD) is a complex childhood‐onset psychiatric disorder characterized by marked symptoms of inattention, hyperactivity, and impulsivity. The role of genetic factors in its etiology is strongly supported by family, adoption, and twin studies. Although most of the molecular studies have investigated the dopamine D4 receptor gene (DRD4) and the dopamine transporter gene (DAT1) genes in its etiology, pharmacological and brain imaging evidences seem to indicate that genes of the adrenergic system could also be attractive for association studies. We investigated a sample of 96 Brazilian ADHD children and adolescents and their parents for the ADRA2A MspI polymorphism. Although no association with either MspI allele was observed through the haplotype relative risk (HRR) analysis, effects of the ADRA2A gene on inattention and combined (inattention + hyperactivity/impulsivity) symptom scores were detected (U = 222.5, z = 2.19, P = 0.03; and U = 208.5, z = 2.32, P = 0.02, respectively). Our results suggest that the ADRA2A gene might have a small effect on ADHD susceptibility or that this gene might modulate the severity of the disorder. They are also consistent with the noradrenergic theories of ADHD, suggesting a role for the α2A adrenergic receptors in the disorder. © 2003 Wiley‐Liss, Inc.
Aggressive behavior in schizophrenia is associated with the low enzyme activity COMT polymorphism: A replication study
Authors: Strous Rael D. , Nolan Karen A. , Lapidus Raya , Diaz Libna , Saito Takuya , Lachman Herbert M.
Published: June 2003

We have previously reported that increased aggressive behavior in schizophrenic patients may be associated with a polymorphism at codon 158 of the catecholO‐methyltransferase (COMT) gene that encodes a low enzyme activity variant. The finding has been replicated by one group, but not others. The discordant findings could be due to statistical errors or methodological issues in the assessment of aggressive/violent behavior. Consequently, additional studies are needed. Patients with schizophrenia (SZ) were assessed for violent behavior using the Lifetime History of Aggression (LHA) scale, an 11‐item questionnaire that includes Aggression, Self‐Directed Aggression, and Consequences/Antisocial Behavior subscales. DNA was genotyped for the COMT 158 polymorphism, as well as a functional polymorphism in the monoamine oxidase A (MAOA) gene promoter. Similar to our previously reported findings, a statistically significant association was found between aggressive behavior in SZ and the COMT 158 polymorphism; mean LHA scores were higher in subjects homozygous for 158Met, the low enzyme activity COMT variant (F(2,105) = 5.616,P = 0.005). Analysis of the major LHA subscales revealed that the association with 158Met was due to high scores on the Aggression, and Self‐Directed Aggression subscales, but not the Consequences/Antisocial Behavior subscale. No significant association was detected for theMAOAgene alone. Our findings provide further support thatCOMTis a modifying gene that plays a role in determining interindividual variability in the proclivity for outward and self‐directed aggressive behavior found in some schizophrenic patients. © 2003 Wiley‐Liss, Inc.
Initial genome‐wide scan for linkage with schizophrenia in the Japanese schizophrenia sib‐pair linkage group (JSSLG) families
Authors: Arinami T. ,   Japanese Schizophrenia Sib‐Pair Linkage Group (JSSLG)
Published: June 2003

To determine if there are common genes that contribute to the susceptibility for schizophrenia, first‐stage genome‐wide scan was carried out by genotyping 417 short‐tandem repeat (STR) markers in 338 individuals from 130 families with 148 affected sib‐pairs identified at 16 sites nationwide in Japan. Data was from the Japanese Schizophrenia Sib‐pair Linkage Group (JSSLG), which is a multi‐site collaborative study group established to create a national resource for genetic studies of schizophrenia in Japan. All subjects were Japanese, and the probands and their siblings had schizophrenia. Multipoint non‐parametric linkage analysis and exclusion mapping were performed with GENEHUNTER software. Simulation studies suggested that in the absence of linkage we could expect one multipoint maximum LOD score (MLS) of 1.9 per genome scan. An MLS of 3.7 would be expected only once in every 20 genome scans and thus corresponds to a genome‐wide significance of 0.05. No loci in the initial screen fulfilled the criteria for significant or suggestive evidence for linkage. Ten chromosomes (1, 2, 3, 4, 5, 8, 9, 14, 17, and 20) had at least one region with a nominal P value < 0.05. Susceptibility genes with λs of 3 and 2 were excluded from 98 and 70% of the genome, respectively. Our results suggest that common genes that contribute significantly to susceptibility for schizophrenia are unlikely to exist in the Japanese population. © 2003 Wiley‐Liss, Inc.
Relationship between catechol‐O‐methyltransferase polymorphism and treatment‐resistant schizophrenia
Authors: Inada Toshiya , Nakamura Ataru , Iijima Yoshimi
Published: June 2003

Catechol‐O‐methyltransferase (COMT) plays a crucial role in the regulation of central dopaminergic systems. We examined the allelic association of a functional polymorphism of the COMT gene with the clinical manifestations and the response to antipsychotics of 100 schizophrenic patients and 201 healthy controls from the general Japanese population. No statistically significant difference was observed in the allele and genotype frequencies between the schizophrenic patients and the healthy controls. The daily neuroleptic dosage that patients received during their maintenance therapy was significantly higher in patients with the L/L genotype than in the other patients (P < 0.05). The present results suggest that the presence of the COMT genotype does not help in evaluating the susceptibility to the development of schizophrenia, but that it may help in the estimation of treatment‐resistant features of schizophrenia. © 2003 Wiley‐Liss, Inc.
Apolipoprotein E Pittsburgh variant is not associated with the risk of late‐onset Alzheimer's disease in a Spanish population
Authors: Baron M. , Jimenez‐Escrig A. , Orensanz L. , Simon J. , Perez‐Tur J.
Published: June 2003

The objective of this study was to assess whether the APOEPittsburghvariant (APOE*4P) is associated to Alzheimer's disease (AD) in a population from Madrid (Spain). APOE*4P variant is caused by an exonic mutation which results in the substitution of proline‐28 for leucine‐28, only present in APOE*4 alleles. A study in a US population associated this APOE variant with an increased risk for AD, about five times higher than the risk attributed to APOE*4 carriers overall. One hundred and seventeen cases of late‐onset AD and 121 matched control subjects from Madrid (Spain) were included. We studied the APOE polymorphism and the APOE*4P occurrence, by PCR and restriction analysis, and plasma lipids levels using standard protocols. As expected, APOE*4 was significantly overrepresented in AD cases. The APOE*4P mutation was observed in heterozygous state in four subjects, two AD (1.71%) and two controls (1.65%). APOE*4P did not confer higher risk for AD, globally (odds ratio 0.14; 95% confidence interval (CI) 0.02–1.12) or respect to APOE*4 carriers (odds ratio 0.14; 95% CI 0.02–1.24). There were no differences in plasma lipids levels among genotype groups. The mutation frequency in controls was higher in our sample than in the US one (1.65 and 0.18%, respectively; Fisher testP = 0.049). Our results suggest that this variant is not so uncommon in our population and is not directly related to AD, contrary to what has been proposed for other populations. © 2003 Wiley‐Liss, Inc.
Etiology of the comorbidity between RD and ADHD: Exploration of the non‐random mating hypothesis
Authors: Friedman Melanie C. , Chhabildas Nomita , Budhiraja Nisha , Willcutt Erik G. , Pennington Bruce F.
Published: June 2003

The present research sought to test the validity of the non‐random mating hypothesis in a community sample in order to determine whether it contributes significantly to the comorbidity between attention‐deficit/hyperactivity disorder (ADHD) and reading disability (RD) and to test whether the two disorders segregate independently. Data were gathered from 394 twin participants of the Colorado Learning Disabilities Research Center (CLDRC) and their biological parents. Parents were asked to complete retrospective questionnaires regarding their own ADHD and RD symptomatology as children, as well as rate their children on DSM‐IV ADHD symptomatology before age 12. Twin RD was assessed by a composite score consisting of several reading measures. Chi‐square and correlational analyses assessed the presence of non‐random mating, as well as whether the two disorders were transmitted independently. Non‐random mating between those with ADHD and those with RD did not significantly contribute to the comorbidity of the two disorders. Furthermore, there was some evidence that these two disorders did not segregate independently in this sample. These results are consistent with recent evidence that ADHD and RD are often comorbid because of significant genetic overlap. There was little evidence to support that non‐random mating also contributes to this comorbidity in the present sample. © 2003 Wiley‐Liss, Inc.
Family‐based association study of markers on chromosome 22 in schizophrenia using African‐American, European‐American, and Chinese families
Authors: Takahashi Sakae , Cui Yu‐hu , Kojima Takuya , Han Yong‐hua , Zhou Ru‐lum , Kamioka Masashi , Yu Shun‐ying , Matsuura Masato , Matsushima Eisuyke , Wilcox Marsha , Arinami Tadao , Shen Yu‐cun , Faraone Stephen V. , Tsuang Ming T.
Published: June 2003

Several studies suggest that loci at chromosome 22q11.2‐q13 might be linked to susceptibility to schizophrenia. Here we performed family‐based association studies on chromosome 22q using 12 DNA microsatellite markers in African‐American, European‐American, and Chinese pedigrees. The marker D22S683 showed significant linkage and association with schizophrenia in not only the European‐American sample but also in a combined sample (European‐American and Chinese samples). Notably, D22S683 is located nearby and between D22S278 and D22S283, which have shown linkage and association to schizophrenia in prior reports. However, we found no significant association for the African‐American sample. In conclusion, our data provide further support for the idea that the region around D22S683 contains a susceptibility gene for schizophrenia. © 2003 Wiley‐Liss, Inc.
Mutation screening of the Homer gene family and association analysis in schizophrenia
Authors: Norton N. , Williams H.J. , Williams N.M. , Spurlock G. , Zammit S. , Jones G. , Jones S. , Owen R. , O'Donovan M.C. , Owen M.J.
Published: June 2003

Homer proteins are a group of proteins that regulate group 1 metabotropic glutamate receptor function. As altered glutamate function has been implicated in many neuro psychiatric disorders, particularly schizophrenia, we have screened all three known Homer genes for sequence variation for use under the candidate gene association paradigm. We found seven SNPs, including three in exons. Of these, none was non‐synonymous. Allele frequencies of all the detected SNPs were estimated in DNA pools of 368 schizophrenics and 368 controls. Only one (Homer 1 IVS4 + 18A > G) was associated with schizophrenia in this sample, a finding confirmed by individual genotyping (P = 0.01). However, in our extended sample of 680 cases and 671 controls, the evidence for association diminished (P = 0.05). Our results suggest it is unlikely that sequence variants in the Homer genes contribute to the aetiology of schizophrenia, but the variants we identified are plausible candidates for other neuropsychiatric phenotypes. © 2003 Wiley‐Liss, Inc.
NURR1 promoter polymorphisms: Parkinson's disease, schizophrenia, and personality traits
Authors: Carmine Andrea , Buervenich Silvia , Galter Dagmar , Jönsson Erik G. , Sedvall Göran C. , Farde Lars , Gustavsson J. Petter , Bergman Hans , Chowdari Kodavali V. , Nimgaonkar Vishwajit L. , Anvret Maria , Sydow Olof , Olson Lars
Published: June 2003

We have previously identified mutations in exon three in NURR1 (NR4A2) in two patients with schizophrenia (SZ) and one patient with bipolar disease with psychotic symptoms. In the present study we analyzed the promoter region of NURR1 and identified five polymorphic sites: three were found to be in strong linkage disequilibrium with a previously identified polymorphic site in the sixth intron. One polymorphism of this haplotype and the two other independent polymorphisms were investigated for their possible association with SZ and Parkinson's disease (PD) by comparing their frequencies in a Swedish material consisting of 134 subjects with SZ and 207 matched controls and 108 subjects with PD and 125 matched controls. Exon 1 was also investigated in our Parkinson and control material but no variances were found. The distributions of the two most informative polymorphisms in the promoter were investigated in an American material as well consisting of 141 subjects with SZ and 139 matched controls. Furthermore, the identified markers were screened for association with putative endophenotypes of SZ in the Swedish material. The distribution of sequence variants among the Swedish controls matched for SZ was investigated with regard to personality. No significant genotype or allelic association of the three sequence variants with SZ or PD was found. Several comparisons regarding endophenotypes or personality indicated association at the 5% confidence level, although correction for multiple testing rendered none of these findings significant. We conclude that the identified polymorphic sites in the human NURR1 are unlikely to be involved in conferring susceptibility for SZ or PD in our patient material. © 2003 Wiley‐Liss, Inc.
Haplotypes at the OPRM1 locus are associated with susceptibility to substance dependence in European‐Americans
Authors: Luo Xingguang , Kranzler Henry R. , Zhao Hongyu , Gelernter Joel
Published: June 2003

Our objective was to investigate the relationship between the gene encoding the μ‐opioid receptor (OPRM1) and susceptibility to substance dependence in European‐American (EA) and African‐American (AA) subjects. Eight single nucleotide polymorphisms (SNPs) at the OPRM1 locus, i.e., −2044C/A, −1793T/A, −1699insT, −1469T/C, −1320A/G, −111C/T, +17C/T (Ala6Val), and +118A/G (Asn40Asp) were genotyped in 676 subjects: 318 EA subjects and 124 AA subjects with substance dependence, and 179 EA normal controls, and 55 AA normal controls. Affection status was defined by each unique combination of alcohol, cocaine, and opioid dependence and analysis of association examined in relation to the possible combinations. We used a newly implemented permutation method to evaluate statistical significance. In EAs, a significant difference in haplotype frequency distributions was found between controls and “alcohol + opioid” dependent patients (P = 0.0036). This finding is also supported by logistic regression analysis and a simulation method. The frequencies of allele −2044A and haplotypes including −2044A are higher in these patients than in controls. In AAs, no allele, haplotype, or genotype frequencies were significantly different between cases and controls. There were highly significant differences in the allele, haplotype, and genotype frequencies between EA and AA controls. Four of the variants [−1793T/A, −1699insT, −1320A/G, and −111C/T] are in virtually complete linkage disequilibrium (LD) to compose a sequence pattern, which does not associate with any of the seven categories of substance dependence. In EAs, allele −2044A and haplotypes that include −2044A are the susceptibility allele and haplotypes for substance dependence. These findings suggest that OPRM1 may play a role in the pathophysiology of substance dependence and this role is population‐ and diagnosis‐specific. © 2003 Wiley‐Liss, Inc.
Monoamine oxidase B polymorphism, cigarette smoking and risk of Parkinson's disease: A study in an Asian population
Authors: Tan E.K. , Chai A. , Lum S.Y. , Shen H. , Tan C. , Teoh M.L. , Yih Y. , Wong M.C. , Zhao Y.
Published: June 2003

Cigarette smoking is associated with reduced monoamine oxidase B (MAO B) activity. Polymorphisms of the MAO B gene may modify the relationship between smoking and Parkinson's Disease (PD). We examined the association of MAO B intron 13 G/A polymorphism and risk of PD, and the modulation of the polymorphism on smoking and PD in an Asian study population in Singapore. Two hundred and thirty PD patients (mean age 66.0 ± 9.4 years, 63% men) and 241 age, gender, and race matched controls (mean age 64 ± 9.2 years, 58.9% males) were studied. The frequency of G and A alleles in PD and controls was; 66/315 (21.0%) vs. 73/340 (21.5%) and 249/315 (79.0%) vs. 267/340 (78.5%). For women, the genotype frequency in PD and controls was; GG: 7/85 (8.2%) vs. 8/99 (8.1%); GA: 25/85 (29.4%) vs. 27/99 (27.3%); AA: 53/85 (62.4%) vs. 64/99 (64.6%). For men, allele frequency in PD and controls was; A: 118/145 (81.4%) vs. 112/142 (78.9%) and G: 27/145 (18.6%) vs. 30/142 (21.1%). The allele and genotype frequencies were not significantly different between young and late onset PD. The frequency of “ever” smokers in PD and controls was 31/230 (13.5%) vs. 52/241 (21.6%), P = 0.02. A stepwise logistic regression analysis did not reveal any interaction of smoking and the G allele and risk of PD. The MAO B G/A genotype frequency in our Asian population was quite different from Caucasians suggesting that ethnicity specific effects need to be considered in evaluating gene‐environmental interaction. © 2003 Wiley‐Liss, Inc.
Association between Val108/158met polymorphism of theCOMTgene and schizophrenia
Authors: Wonodi Ikwunga , Stine O. Colin , Mitchell Braxton D. , Buchanan Robert W. , Thaker Gunvant K.
Published: June 2003

Schizophrenia is a complex disorder with a multifactorial polygenic inheritance with several genes conferring susceptibility at many genetic locations, each with a small effect. An attractive candidate gene for schizophrenia is the catechol‐O‐methyltransferase (COMT) gene, which is a modulator of dorsolateral prefrontal cortical function. A missense G to A mutation in this gene that results in a substitution of Methionine (Met) for Valine (Val) at codon 108/158 (Val108/158Met) has recently been identified in association to schizophrenia. We compared allele frequencies of the variant Val allele between 96 schizophrenia cases and 80 normal controls. We selected controls from a similar pool to cases in ethnicity and gender. The frequency of the Val allele was significantly higher in schizophrenia cases compared to controls (0.620 vs. 0.506;P = 0.043). Calculation of the population attributable risk suggests that the Val allele accounts for as much as 23% of schizophrenia in this population (range: 3–38%). These results provide support for a role of this variant in the etiopathophysiology of schizophrenia. © 2003 Wiley‐Liss, Inc.
Genome wide scan using homozygosity mapping and linkage analyses of a single pedigree with affective disorder suggests oligogenic inheritance
Authors: Ewald Henrik , Kruse Torben A. , Mors Ole
Published: June 2003

The present study reports results from a genome scan on a family with bipolar affective disorder in which the parents are first cousins and four of the offsprings and one grandchild have affective disorder. The study searched for risk loci for affective disorder by searching for homozygous segments or more complex inherited loci using parametric and non‐parametric multipoint linkage analysis. In addition dominant, multipoint, affecteds‐only linkage analyses were performed as a supplement to previous analyses. On chromosomes 2q31.3, 10, 12q24, and 21q22.3 evidence for a risk locus was obtained by parametric and/or non‐parametric linkage analyses and by haplotype sharing. As other studies have found significant or suggestive linkage to bipolar disorder in these chromosome regions this suggests that an oligogenic mode of inheritance is possible in this family involving at least some of the loci. Finally, the work discusses whether homozygosity mapping using parametric and non‐parametric linkage analyses may be of value for complex diseases including rare subphenotypes of such disorders. © 2003 Wiley‐Liss, Inc.
Association of mitochondrial complex I subunit gene NDUFV2 at 18p11 with bipolar disorder
Authors: Washizuka Shinsuke , Kakiuchi Chihiro , Mori Kanako , Kunugi Hiroshi , Tajima Osamu , Akiyama Tsuyoshi , Nanko Shinichiro , Kato Tadafumi
Published: June 2003

Linkage of bipolar disorder with 18p11 has been replicated by several investigators. A nuclear‐encoded mitochondrial complex I subunit gene, NDUFV2, is one of the candidate genes in this locus, since the possible pathophysiological significance of mitochondrial dysfunction in bipolar disorder has been suggested. The objective of our study was to clarify the association between the NDUFV2 gene and bipolar disorder. We performed the real‐time quantitative reverse transcription polymerase chain reaction (RT‐PCR) for NDUFV2 mRNA expression in lymphoblastoid cell lines derived from patients with bipolar disorder and healthy controls. We also screened novel polymorphisms using denaturing high performance liquid chromatography (D‐HPLC) and PCR‐direct sequencing method. Detected five single nucleotide polymorphisms (SNPs) were genotyped. A decrease of the expression level of NDUFV2 gene was found in patients with bipolar I disorder compared with controls (P = 0.006). We also found that the haplotype frequencies of the four polymorphisms in the upstream region of NDUFV2 were significantly different between bipolar disorders and controls (P = 0.0001). Our findings suggest that polymorphisms of the NDUFV2 gene may be one of the genetic risk factors for bipolar disorder. © 2003 Wiley‐Liss, Inc.
Association analysis of MAOA and COMT with neuroticism assessed by peers
Authors: Eley Thalia C. , Tahir Eda , Angleitner Alois , Harriss Kaveri , McClay Joseph , Plomin Robert , Riemann Rainer , Spinath Frank , Craig Ian
Published: June 2003

There are several reported associations between depressive disorders, panic disorder, and obsessive–compulsive disorder (OCD) and a variety of polymorphisms in the monoamine oxidase A (MAOA) gene. Associations have also been reported between the catechol‐O‐methyltransferase (COMT) gene and both OCD and bipolar depression. However, the role of these markers has not been explored for the personality trait of neuroticism (N), a normally distributed quantitative trait, which is highly genetically correlated with anxiety and depression and may be a vulnerability to either type of disorder. We explored the possible role of MAOA, COMT, and their interaction on N using a selected extremes design. From a sample of 2,085 individuals, each assessed for N by two independent peers rather than using self‐report questionnaires, we selected 57 individuals from the top 10% of scores, and 62 individuals from the bottom 10%. Using selected extreme low subjects as the controls, rather than an unselected control group gives roughly twice the power of a standard case‐control design. We typed a functional variable number tandem repeat (VNTR) in the MAOA gene promoter, and a functional polymorphism in the coding region of the COMT gene. Two novel alleles in the MAOA VNTR were identified on the basis of their size, and their structure examined by sequencing analysis. We found weak evidence for association with COMT genotype, when the females and males were considered separately, and for MAOA genotype in males only. There was no significant interaction between COMT and MAOA. © 2003 Wiley‐Liss, Inc.
Detailed analysis of PRODH and PsPRODH reveals no association with schizophrenia
Authors: Williams H.J. , Williams N. , Spurlock G. , Norton N. , Zammit S. , Kirov G. , Owen M.J. , O'Donovan M.C.
Published: June 2003

People with deletion of the chromosome 22q11 region associated with velo cardio‐facial syndrome (VCFS) have a remarkably high risk of developing schizophrenia. Recently, the gene proline dehydrogenase (PRODH) which maps to 22q11 and is also an excellent functional candidate gene for psychosis, has been reported to show genetic association with schizophrenia. We have screened all the exons and adjacent intronic sequences of PRODH for the presence of sequence variation in 14 DSM IV schizophrenic subjects. Similarly, we also screened all putative exons of a sequence that is similar to proline dehydrogenase (PsPRODH) and which also maps within the deleted region. A total of nine single nucleotide polymorphisms (SNPs) were identified in PRODH, eight of which were exonic, while in PsPRODH, five SNPs were identified, one of which was in a putative exon. All samples were tested for association in a pooled sample of 368 DSM IV diagnosed schizophrenic subjects and 368 matched controls. None of the variants identified in PRODH gave even modest evidence for allelic association (P < 0.1). In PsPRODH, two variants (−3864G > A and 226G > A) gave P values < 0.1. These were individually genotyped in the same subjects that had been used to construct the pools. Although a trend for association was confirmed, neither showed evidence for association at the P ≤ 0.05 level. These results do not suggest that PRODH or PsPRODH contribute to the aetiology of schizophrenia, and that the putative schizophrenia susceptibility gene in 22q11 remains unknown. © 2003 Wiley‐Liss, Inc.
Anwendung und Grenzen kristallographischer Daten im strukturbezogenen Liganden‐ und Wirkstoff‐Design
Authors: Davis Andrew M. , Teague Simon J. , Kleywegt Gerard J.
Published: June 2003

Strukturbezogenes Design konzentriert sich auf die Optimierung der Ligandenaffinität, aber ein erfolgreiches Wirkstoff‐Design erfordert auch die Optimierung anderer Eigenschaften. Die Informationen zur Protein‐Ligand‐Struktur stammen meist aus der Kristallstrukturanalyse. Unsicherheiten, die während der Entwicklung eines Atommodells aus der experimentell erhaltenen Elektronendichte eingeführt werden, lassen sich manchmal nur eingeschränkt beurteilen. Ungenauigkeiten im Atommodell können aber erhebliche Konsequenzen haben, wenn das Modell anschließend als Grundlage für manuelles Design, Docking‐ und Scoring‐Rechnungen und virtuelles Screening dient. Manche Ansätze im strukturbezogenen Design nutzen inzwischen das Durchmustern von Substanzbibliotheken mit NMR‐spektroskopischen und röntgenographischen Methoden, um kleine polare Template zu identifizieren und anschließend zu optimieren. Nach diesen leitstrukturähnlichen Verbindungen wird auch mit dem moderneren Hochdurchsatz‐Screening gesucht.
Influence of molecular structure of star S‐SBR on its properties
Authors: Zhao S. , Zhang X. , Jin G.
Published: June 2003

Star S‐SBR can be produced in one step by a kind of new anion polymerization technology in which modified naphthalene lithium acted as the initiator and SnCl4 acted as the coupling agent. The influence of the molecular structure of star S‐SBR on its mechanical and dynamic properties was studied. The results showed that Star S‐SBR, with styrene (St) content of 20–25% and vinyl (Bv) content of 45%, and molecular weight for one arm (MW/arm) of 8 ten thousand, has good mechanical properties, low rolling resistance and high wet grip. The end of the S‐SBR molecular chain was coupled by a coupling agent, which resulted in low internal friction loss. The bound rubber content of star S‐SBR‐carbon black compound was larger than that of linear S‐SBR compound. Experiments showed that the Sn—C key in star S‐SBR broke easily under shear action and formed a free group, and the free group bonded immediately with the active group on the surface of a carbon black particle. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2311–2315, 2003
Effects of thermal ageing treatment and antioxidants on the positive temperature coefficient characteristics of carbon black/polyethylene conductive composites
Authors: Seok Park Jong , Hyun Kang Phil , Chang Nho Young , Hack Suh Dong
Published: June 2003

Polyethylene (PE)‐filled with carbon black (CB) is a prototypical composite that displays resistance switching. These materials can exhibit either a positive temperature coefficient (PTC) or negative temperature coefficient (NTC). The CB‐filled semicrystalline polymer composites ideally need antioxidants, which stabilize the composites against thermooxidative degradation, because they should be resistant to the severe conditions of high temperature. The characterization of PTC materials is affected by the crystallinity of the polymer, and the crystallinity of the polymer is changed with thermal ageing treatment. Thermal ageing of PTC samples was conducted in an oven in the range 50–140°C, in air. The composites, containing 0.5–3% (by weight) Irganox 1076 (Ciba‐Geigy), were irradiated under nitrogen at room temperature with different doses of gamma rays from a 60Co source. The resulting composites were analyzed by differential scanning calorimetry, gel fractionation, X‐ray diffraction, and dynamic mechanical analysis. The conductivity of the composites depended on the amounts of antioxidants and the duration of the thermal ageing treatment. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2316–2322, 2003
Preparation of polyethylene–clay nanocomposites directly from Na+ montmorillonite by a melt intercalation method
Authors: Wang Shaofeng , Hu Yuan , Tang Yong , Wang Zhengzhou , Chen Zuyao , Fan Weicheng
Published: June 2003

Polyethylene (PE)/clay nanocomposites were prepared directly from Na+ montmorillonite by a melt intercalation technique, using hexadecyl trimethyl ammonium bromide (C16) as a reactive compatibilizer. Three other polymer–clay nanocomposites were also prepared by this new technique. Their structures were characterized by X‐ray diffraction and transmission electron microscopy. The mechanism of this new method was studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2583–2585, 2003
Enzyme‐catalyzed hydrolysis of poly(ethylene terephthalate) cyclic trimer
Authors: Hooker Jacob , Hinks David , Montero Gerardo , Icherenska Magdelena
Published: June 2003

Oligoesters present in poly(ethylene terephthalate) fibers are commonly extracted from the fiber during processing, such as aqueous‐based dyeing. Aqueous, insoluble oligoesters, particularly cyclic trimers that precipitate on processing machinery and on the fiber surface are difficult to remove under benign conditions. Reported is a new method for the efficient removal of cyclic trimer by enzyme‐catalyzed hydrolysis. Almost complete hydrolysis of trimer was accomplished at pH 8 and 60°C. Effects of time, agitation, surfactant, and enzyme and trimer concentrations on the efficiency of hydrolysis are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2545–2552, 2003
Synthesis and asymmetric nanofiltration membrane performance of heterogeneously sulfonated aromatic polyimides
Authors: Kim In‐Chul , Lee Kew‐Ho , Tak Tae‐Moon
Published: June 2003

Soluble sulfonated polyimides (PI) were heterogeneously synthesized by reacting soluble PIs with sulfur trioxide and dichloromethane solvent. The sulfonated PIs were soluble in polar solvents like N‐methyl‐2‐pyrrolidone (NMP) and N,N'‐dimethylformamide. The sulfonated PIs were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, differential scanning calorimetry, thermogravimetric analysis, triangular phase diagram, and back titration. Asymmetric nanofiltration membranes were prepared by the phase inversion method from the casting solution containing NMP and diethyleneglycol dimethylether (DGDE). Introducing DGDE as an additive in the casting solution decreased pore size. The rejection rates of organic molecules and salts were investigated. The observed salt rejection of the membrane was of the order R(Na2SO4) > R(NaCl) > R(CaCl2). The membrane morphology was investigated by scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2483–2489, 2003
Microhardness of ternary blends of polyolefins with recycled polymer components
Authors: Berdjane K. , Berdjane Z. , Rueda D.R. , Bénachour D. , Baltá‐Calleja F.J.
Published: June 2003

Microhardness tests, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) measurements were performed on melt‐pressed films of multicomponent blends based on low‐density polyethylene (LDPE), linear LDPE (LLDPE), high‐density polyethylene (HDPE), and polypropylene (PP), and their recycled homologues. Some of the PE blends also contained ethylene‐propylene‐diene monomer (EPDM) as compatibilizer. In all cases, the variation of microhardness as a function of content of the recycled component follows the additivity law of components. Thus, the range of hardness values of polyolefin blends can be controlled by choice of both components and their relative content in the blend. The hardness of the components increases from LDPE, to LLDPE, to HDPE, to PP and increases from 20 to 84 MPa. For recycled components, the hardness values are reduced by ∼15%. According to DSC results, all the blends are immiscible. Results are discussed in terms of the levels of crystallinity reached for the different blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2046–2050, 2003
Probe selection and description in IGC: A nontrivial factor
Authors: Schreiber H. P.
Published: June 2003

Inverse gas chromatography (IGC) has found many uses in the characterization of polymer surfaces and their interaction capabilities. The IGC method relies on the selection of vapors with which to probe polymer surfaces. Problems attached to the volatile phase in IGC are considered. One of these is the temperature dependence of the probe molecule dimensions. Experimental work shows that correcting for this temperature dependence is recommended when IGC work is carried out at temperatures removed from the ambient by more than 30°C. A second problem area is a possible variation in the orientation of adsorbed probe molecules. The variable orientation of linear alkane probe molecules on a polystyrene substrate is demonstrated, as is an orientational degree of freedom when diols of varying chain lengths are adsorbed on polymeric as well as on inorganic substrates. A conclusion reached from the experiments of this work is that acid–base parameters generated by the IGC method have relative but not necessarily absolute significance. Further, the orientation of polar probe molecules is dependent on the force field generated by the underlying substrate, which may be characterized by its total surface free energy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2323–2330, 2003
Effect of various additives on pore size of polysulfone membrane by phase‐inversion process
Authors: Kim In‐Chul , Lee Kew‐Ho
Published: June 2003

The phase‐inversion process was used to prepare integrally skinned asymmetric polysulfone (PSf) membranes with different pore sizes. Membranes were prepared from a casting solution of PSf; N‐methyl‐2‐pyrrolidone (NMP) as solvent; and 1,4‐dioxane, diethylene glycol dimethyl ether (DGDE), acetone, and γ‐butyrolactone (GBL) as additives by immersing them in water as a coagulant. The effect of the additives on membrane performance and structure was investigated. The low miscibility of 1,4‐dioxane, DGDE, and acetone with the coagulant resulted in reduced membrane pore size. However, by using GBL as additive pore size of the membrane was slightly increased because of its higher miscibility with the coagulant than NMP. Changing the amount of additives in the casting solution could control the molecular‐weight cutoff values of asymmetric membranes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2562–2566, 2003
Toughening of trifunctional epoxy using an epoxy‐functionalized hyperbranched polymer
Authors: Ratna D. , Varley R. , Simon G. P.
Published: June 2003

Chemorheology of curing as well as the phase separation behavior of an epoxy‐functionalized hyperbranched polymer (HBP)‐modified triglycidyl p‐amino phenol (TGAP) epoxy mixtures has been studied by several techniques. There was little change in gel time as a result of addition of HBP up to 10% of HBP, even though the HBP reacts at a slower rate with amine hardeners compared to the TGAP alone. The thermal and dynamic viscoelastic behavior of the modified matrices have been examined and compared with the unmodified TGAP matrix. Finally, impact properties have been discussed in terms of the morphological behavior for a TGAP matrix modified with various amounts of HBP. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2339–2345, 2003
Study on 1‐4 cycloaddition reaction. I. Synthesis and optimization of new adduct using Diels–Alder reaction
Authors: Mazroua Azza M. , Youssif M. A.
Published: June 2003

The present investigation has been achieved in accordance with the Diels–Alder reaction (1,4 cycloaddition) to produce a new halogenated bicyclic adduct. ortho‐Bromoallylbenzoate is a new dienophile that was prepared in a pure form, and its structure was confirmed. The Diels–Alder syntheses of hexachlorocyclopentadiene and the new dienophile were studied to determine the optimum condensation reaction conditions under a temperature range of 90–160°C, reaction times of 1–8 h, and molar diene/dienophile ratios from 1:1 to 5:1 as a consequence. The optimum conditions reached were a temperature of 140°C, an initial diene/dienophile molar ratio of 3:1, and a duration time of 6 h. The maximum stoichometric yield under these optimum conditions (82.5%) was obtained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2331–2338, 2003
High‐resolution thermogravimetry/coupled mass spectrometry analysis of flame‐retardant rubber
Authors: Gupta Y. N. , Chakraborty Amitabh , Pandey G. D. , Setua D. K.
Published: June 2003

A bromobutyl rubber composition containing a variety of conventional flame retardants, such as Saytex (decabromodiphenyl oxide), Sb2O3, chlorinated paraffin wax, and polychloroprene rubber, was prepared and used to coat nylon 6 fabric in a laboratory‐coating device. An attempt was made to evaluate the decomposition profile, the evolved gases, and the kinetics of the decomposition process at a dynamic heating rate with high‐resolution thermogravimetric analysis (HR‐TGA). HR‐TGA was used with mass spectrometry for evolved gas analysis (EGA). The HR‐TGA results were compared with results from conventional thermogravimetric analysis (TGA) at a constant heating rate; the former offered sharp transitions, an economic timescale, and an accurate activation energy. The resolution optimization for stability analysis and the effect of its variation on the kinetic parameters offered better results for HR‐TGA than conventional TGA. A lifetime and temperature relationship was evaluated in HR‐TGA with Toop's method, and it was observed that the shelf life decreased sharply with temperature. The effluents HBr, HCl, Br ·, and Cl ·, generated between 210 and 496°C during EGA, were correlated with the thermal stability and fire‐retardancy behavior of the material. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2051–2057, 2003