| 1. |
- Alaerts, Maaike, et al.
(författare)
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Lack of association of an insertion/deletion polymorphism in the G protein-coupled receptor 50 with bipolar disorder in a Northern Swedish population
- 2006
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Ingår i: Psychiatric Genetics. - : Lippincott Williams & Wilkins. - 0955-8829 .- 1473-5873. ; 16:6, s. 235-236
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Tidskriftsartikel (refereegranskat)abstract
- GPR50 is a G protein-coupled receptor, located on Xq28 and related to the melatonin receptor family. It is suggested as a functional and positional candidate gene for bipolar disorder (BP). Recently an insertion/deletion polymorphism in GPR50, Delta502-505, was found to be associated with BP in a Scottish association sample (P=0.007). When the analysis was restricted to female subjects, the association increased in significance (P=0.00023). We attempted to replicate this finding in a Northern Swedish association sample, but no significant association was detected (P=0.7, women only: P=0.65).
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| 2. |
- Hägg, Staffan, 1963-, et al.
(författare)
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High prevalence of the metabolic syndrome among a Swedish cohort of patients with schizophrenia
- 2006
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Ingår i: International Clinical Psychopharmacology. - London : Clinical Neuroscience Publishers. - 0268-1315 .- 1473-5857. ; 21:2, s. 93-98
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Tidskriftsartikel (refereegranskat)abstract
- Several cardiovascular risk factors have been linked to antipsychotic treatment and cardiovascular mortality is increased in these patients compared to the general population. The full metabolic syndrome (or its components) is associated with an increased risk of cardiovascular disorders. The prevalence of the metabolic syndrome was investigated using a cross-sectional study design in a cohort of 269 patients, aged 20-69 years, with schizophrenia living in Northern Sweden, and was defined according to the criteria of the National Cholesterol Education program. The prevalence of the metabolic syndrome was 34.6% (95% CI = 28.8-40.3) and highest (43%; 95% CI = 32-53) for participants aged 40-49 years. Clozapine treated subjects reached the highest prevalence of the metabolic syndrome (48%; 95% CI = 34-62). The prevalence was similar for men (32.8%; 95% CI = 25.8-39.8) and women (38.0%; 95% CI = 27.9-48.2). Men had a high prevalence of hypertension (49.2%; 95% CI = 41.7-56.6) and women had high prevalence of low high-density lipoprotein cholesterol (40.2%; 95% CI = 30.0-50.4) and abdominal obesity (75.0%; 95% CI = 66.0-84.0). Subjects with the metabolic syndrome had significantly higher mean body mass index (BMI) (P < 0.001), HbA1c (P = 0.002), and fasting serum insulin (P < 0.001) compared to non-metabolic syndrome subject. Subjects with the metabolic syndrome had also significantly more often a positive history of cardiovascular diseases compared to non-metabolic syndrome subjects (25.8% versus 12.5%; P = 0.01). Of all study subjects 36.8% were obese (BMI > 30). These results clearly show that the metabolic syndrome and its components are highly prevalent in patients with schizophrenia. Physicians treating patients with schizophrenia are recommended to monitor the components included in the metabolic syndrome.
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| 3. |
- Lind, Johanna, et al.
(författare)
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Parietal cortex activation predicts memory decline in apolipoprotein E-epsilon 4 carriers
- 2006
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Ingår i: NeuroReport. - Oxford : Rapid Communications of Oxford. - 0959-4965 .- 1473-558X. ; 17:16, s. 1683-1686
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Tidskriftsartikel (refereegranskat)abstract
- Apolipoprotein E-[varepsilon]4 is the main known genetic risk factor for Alzheimer's disease. Functional abnormalities in the parietal cortex have been reported for Alzheimer's disease patients and also for those at risk. Hence, a critical question is whether measurements of parietal cortex integrity may predict negative outcome among at-risk persons. We studied nondementedapolipoprotein E-[varepsilon]4 carriers and found a significant relationship between parietal blood-oxygen-level-dependent functional magnetic resonance imaging response during a word categorization task and subsequent episodic memory performance. Thus, the results show that parietal cortex alterations predict memory decline in nondemented apolipoprotein E-[varepsilon]4 carriers, and hence likely progression to Alzheimer's disease.
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| 4. |
- Lind, Johanna, et al.
(författare)
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Reduced functional brain activity response in cognitively intact apolipoprotein E ε4 carriers
- 2006
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Ingår i: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 129:5, s. 1240-1248
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Tidskriftsartikel (refereegranskat)abstract
- The apolipoprotein E epsilon4 (APOE epsilon4) is the main known genetic risk factor for Alzheimer's disease. Genetic assessments in combination with other diagnostic tools, such as neuroimaging, have the potential to facilitate early diagnosis. In this large-scale functional MRI (fMRI) study, we have contrasted 30 APOE epsilon4 carriers (age range: 49-74 years; 19 females), of which 10 were homozygous for the epsilon4 allele, and 30 non-carriers with regard to brain activity during a semantic categorization task. Test groups were closely matched for sex, age and education. Critically, both groups were cognitively intact and thus symptom-free of Alzheimer's disease. APOE epsilon4 carriers showed reduced task-related responses in the left inferior parietal cortex, and bilaterally in the anterior cingulate region. A dose-related response was observed in the parietal area such that diminution was most pronounced in homozygous compared with heterozygous carriers. In addition, contrasts of processing novel versus familiar items revealed an abnormal response in the right hippocampus in the APOE epsilon4 group, mainly expressed as diminished sensitivity to the relative novelty of stimuli. Collectively, these findings indicate that genetic risk translates into reduced functional brain activity, in regions pertinent to Alzheimer's disease, well before alterations can be detected at the behavioural level.
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| 5. |
- Lind, Johanna, et al.
(författare)
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Reduced hippocampal volume in non-demented carriers fo the apolipoprotein E ε4 : Relation to chronological age and recognition memory
- 2006
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 396:1, s. 23-27
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Tidskriftsartikel (refereegranskat)abstract
- Apolipoprotein E ε4 (APOE ε4) is the main known genetic risk factor for Alzheimer's disease (AD). Some previous studies have reported structural brain changes as well as cognitive deficits in non-demented APOE ε4 carriers, but the pattern of results is inconsistent and studies with larger sample sizes have been called for. Here we compared hippocampal volume and recognition–memory performance between AD-symptom-free carriers (N = 30) and non-carriers (N = 30) of the APOE ε4 (age range: 49–79 years). We observed reduced right hippocampal volume in APOE ε4 carriers, and found that the difference was most pronounced before the age of 65. Further, the APOE ε4 carriers made significantly more false alarms in the recognition–memory test, and the number of false alarms correlated significantly with right hippocampus volume. These results indicate that relatively young individuals at genetic risk for AD have smaller hippocampal volume and lower performance on hippocampal-dependent cognitive tasks. A question for the future is whether smaller hippocampal volume represents early-onset hippocampal volume reduction or an inherent trait.
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| 6. |
- Nilsson, Lars-Göran, et al.
(författare)
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The influence of APOE status on episodic and semantic memory : data from a population-based study
- 2006
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Ingår i: Neuropsychology. - Washington : American Psychological Association. - 0894-4105 .- 1931-1559. ; 20:6, s. 645-57
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Tidskriftsartikel (refereegranskat)abstract
- In a prospective cohort study, the authors demonstrated a more pronounced epsilon4-related deficit for participants 70 years of age and older in tasks assessing episodic recall. Apolipoprotein E (APOE) and age interacted for episodic memory tasks, whereas the interaction for semantic memory tasks was between APOE and test wave. Heterozygotes of epsilon4 between middle-age and young-old participants performed at a higher level than noncarriers of this allele in recall tasks. A dose effect was found such that carriers of 2 epsilon4 alleles failed more profoundly in acquiring and recollecting episodic information than carriers of 1 epsilon4 allele, who in turn failed more than carriers of non-epsilon4 alleles. The pattern of findings observed for older epsilon4 carriers suggests that these individuals have particular difficulty when the executive task demands are high. Several factors (e.g., smaller hippocampal volumes, less effective neural repair mechanisms) may account for these findings. On the basis of the data obtained, the authors argue that analyses of the effect of specific genes in cognition should be accompanied by assessment of performance at a specific level, with due attention to the individual's age.
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| 7. |
- Persson, Jonas, 1971-, et al.
(författare)
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Altered brain white matter integrity in healthy carriers of the APOE epsilon4 allele : A risk for AD?
- 2006
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Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 66, s. 1029-1033
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Previous research has shown that polymorphisms of apolipoprotein E (APOE) represent genetic risk factors for dementia and for cognitive impairment in the elderly. The neural mechanisms by which these genetic variations influence behavioral performance or clinical severity are not well understood.METHODS: The authors used diffusion tensor imaging to investigate ultrastructural properties in brain white matter to detect pathologic processes that modify tissue integrity. Sixty participants were included in the study of which 30 were homozygous for the APOE epsilon3 allele, 10 were homozygous for the APOE epsilon4 allele, and 20 had the APOE epsilon34 allele combination. All individuals were non-demented, and the groups were matched on demographic variables and cognitive performance.RESULTS: The results showed a decline in fractional anisotropy, a marker for white matter integrity, in the posterior corpus callosum of epsilon4 carriers compared to non-carriers. Additional sites of altered white matter integrity included the medial temporal lobe.CONCLUSIONS: Although the mechanism underlying vulnerability of white matter tracts in APOE epsilon4 carriers is still unknown, these findings suggest that increased genetic risk for developing Alzheimer disease is associated with changes in microscopic white matter integrity well before the onset of dementia.
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| 8. |
- Van Den Bogaert, Ann, et al.
(författare)
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Association of brain-specific tryptophan hydroxylase, TPH2, with unipolar and bipolar disorder in a Northern Swedish, isolated population
- 2006
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Ingår i: Archives of General Psychiatry. - : American Medical Association. - 0003-990X .- 1538-3636. ; 63:10, s. 1103-1110
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Tryptophan hydroxylase is the rate-limiting enzyme in the serotonin (5-HT) biosynthetic pathway responsible for the regulation of serotonin levels. Tryptophan hydroxylase 2 (TPH2) was found to be solely expressed in the brain and therefore considered an important susceptibility gene in psychiatric disorders.OBJECTIVE: To determine the role of the brain-specific TPH2 gene in unipolar (UP) disorder and bipolar (BP) disorder in a northern Swedish, isolated population.DESIGN: HapMap-based haplotype-tagging single nucleotide polymorphism (htSNP) patient-control association study.SETTING: A northern Swedish, isolated population.PARTICIPANTS: One hundred thirty-five unrelated patients with UP disorder, 182 unrelated patients with BP disorder, and 364 unrelated control individuals.RESULTS: Significant allelic association was identified in our UP disorder association sample for an htSNP located in the 5' promoter region (rs11178997; P = .001). Haplotype analysis supported this significant result by the presence of a protective factor on hapblock 2 (P(specific) = .002). In the BP disorder association sample, single-marker association identified a significant htSNP in the upstream regulatory region (rs4131348; P = .004). Moreover, haplotype analysis in the BP disorder sample showed that the same htSNPs from hapblock 2 associated with UP disorder were also significantly associated with BP disorder (P(specific) = .002).CONCLUSIONS: Haplotype-based analysis of TPH2 in patients with UP and BP disorder and controls from northern Swedish descent provides preliminary evidence for protective association in both disorders and thus supports a central role for TPH2 in the pathogenesis of affective disorders.
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| 9. |
- Van Den Bogaert, Ann, et al.
(författare)
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No allelic association or interaction of three known functional polymorphisms with bipolar disorder in a northern Swedish isolated population
- 2006
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Ingår i: Psychiatric Genetics. - : Lippincott Williams & Wilkins. - 0955-8829 .- 1473-5873. ; 16:5, s. 209-212
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Tidskriftsartikel (refereegranskat)abstract
- Most genetic association studies in bipolar disorder have focussed on genes involved in major neurotransmitter systems or brain development. Functional polymorphisms in the serotonin transporter (5-HTTLPR), catechol-O-methyltransferase (Val158Met) and dopamine D3 receptor (Ser9Gly) genes have all been associated with bipolar disorder. We aimed at investigating whether these functional variants contribute to the genetic etiology of bipolar disorder in a northern Swedish isolated population. Moreover, we wanted to gain information about the synergistic contribution of these functional variants. Neither of these functional polymorphisms was associated with bipolar disorder in the northern Swedish patient-control sample nor did we find evidence of gene-gene interaction. Together, our data suggest that these functional variants are not involved in the etiology of bipolar disorder in the northern Swedish population nor did gene-gene interaction analysis support a central role of these variants in bipolar disorder.
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| 10. |
- van West, Dirk, et al.
(författare)
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Glucocorticoid receptor gene-based SNP analysis in patients with recurrent major depression
- 2006
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Ingår i: Neuropsychopharmacology. - : Nature Publishing Group. - 0893-133X .- 1740-634X. ; 31:3, s. 620-627
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Tidskriftsartikel (refereegranskat)abstract
- Dysregulation of the hypothalamic-pituitary-adrenal axis, one of the stress-response systems, is one of the key neurobiological features of major depression (MDD). Data supporting the notion that glucocorticoid-mediated feedback inhibition is impaired in MDD come from a multitude of studies demonstrating nonsuppression of cortisol secretion following administration of the synthetic glucocorticoid dexamethasone. We examined whether genetic variations in the glucocorticoid receptor gene (Nuclear Receptor Subfamily 3, Group C, Member 1; NR3C1) could be associated with increased susceptibility for MDD using a whole gene-based association analysis of single nucleotide polymorphisms (SNPs). Four SNPs were identified in NR3C1 and genotyped in two well-diagnosed samples of patients with MDD ascertained in Belgium and northern Sweden, and matched control samples. In total, 314 MDD patients and 354 control individuals were included in the study. In the Belgian sample, we observed significant allele (p=0.02) and genotype (p=0.02) association with an SNP in the promoter region (NR3C1-1); in the Swedish sample, we observed significant allele (p=0.02) and genotype (p=0.02) association with the R23K SNP. The haplotype association studies showed modest evidence for an involvement of the 5' region of the NR3C1 gene in the genetic vulnerability for MDD. This study suggests that polymorphisms in the 5' region of the NR3C1 gene may play a role in the genetic vulnerability for MDD.
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