Genetic association between Notch4 polymorphisms and Alzheimer's disease in the Japanese population.

It is shown that Notch 4 plays important roles in the pathogenesis of Alzheimer's disease (AD). To investigate whether three single nucleotide polymorphisms (SNPs) of the Notch4 gene are associated with AD, the three SNPs were genotyped by a polymerase chain reaction-restriction fragment length polymorphism method for 243 AD patients and 130 age-matched controls. We also confirmed the linkage disequilibrium among these three SNPs of the gene using the EH program. The three SNPs did not seem to alter risk for AD. Our study suggests that SNPs studied are not associated with AD. The linkage disequilibrium of this locus indicates that there is genetic heterogeneity in the Notch4 gene. We could not confirm the previous synergetic associations of the 5' untranslated region (rs367398) C/C genotype in apolipoprotein E epsilon4 bearers in AD patients. Potential markers nearby the 5' untranslated region polymorphism might affect risk for AD.

Genetic association between USF 1 and USF 2 gene polymorphisms and Japanese Alzheimer's disease.

To investigate the effect of single nucleotide polymorphisms (SNPs) of the upstream stimulatory factor (USF) 1 and 2 genes on the onset of Alzheimer's disease (AD), a case-control study was performed. The SNPs were genotyped by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 236 AD patients and 120 age-matched controls of Japanese descent. We observed no significant association between the three SNPs of the USF 1 gene and AD in our Japanese participants. In addition, the SNPs studied did not affect plasma cholesterol levels in our AD cases. For the USF 2 gene, the two SNPs did not show significant association with onset of AD. Our study suggests that the three SNPs of the USF 1 gene and two SNPs of the USF 2 gene presented here are not associated with onset of AD.

Genetic association between Notch4 polymorphisms and Japanese schizophrenics.

The objective of this study was to investigate whether three single nucleotide polymorphisms of the Notch4 gene are associated with the onset of schizophrenia. To confirm the linkage disequilibrium among these three single nucleotide polymorphisms of the gene, the three single nucleotide polymorphisms were genotyped by a polymerase chain reaction-restriction-fragment length polymorphism method for all samples. The genotypic frequencies of each single nucleotide polymorphism in the schizophrenic were compared with respective controls using a chi method. To check linkage disequilibrium, the haplotype frequency program was utilized. No statistical association between the two single nucleotide polymorphisms of the Notch4 gene and schizophrenia was observed in our Japanese samples. Although one nonsynonymous single nucleotide polymorphism did show a weakly significant P-value, its allelic frequencies are not positive. Two of the single nucleotide polymorphisms showed strong linkage disequilibrium in our Japanese samples. The single nucleotide polymorphism between the other two single nucleotide polymorphisms showed a weaker linkage disequilibrium with the others. Our study suggests that the three single nucleotide polymorphisms are not associated with the onset of schizophrenia. The linkage disequilibrium of this locus indicates that there is genetic heterogeneity in the Notch4 gene. Linkage disequilibrium may differ among ethnic groups, and so a larger study should be performed in this region.

No genetic association between the myeloperoxidase gene -463 polymorphism and estrogen receptor-alpha gene polymorphisms and Japanese sporadic Alzheimer's disease.

Myeloperoxidase (MPO) presence has been demonstrated in microglia associated with senile plaques and contributes to Alzheimer's disease (AD) pathology through oxidation-induced damage. MPO activity is normally higher in women than in men. Additionally, a functional biallelic (G/A) polymorphism in the promoter region (-463) of the MPO gene has been associated with a gender-specific risk factor for AD, but reports of this association have been inconsistent. Furthermore, estrogen is known to enhance MPO activity in myeloid cells and increases the amount of MPO in plasma. Recently, estrogen replacement therapy has been reported to reduce the risk of developing AD and to help maintain cognitive function in patients with AD. In the current study, we analyzed the MPO -463 polymorphism and two estrogen receptor-alpha polymorphisms in 205 Japanese sporadic AD patients and 92 controls. The results suggest that there is no significant difference in the genotypic frequencies and allelic frequencies of the MPO -463 polymorphism and the estrogen receptor-alpha polymorphisms between the Japanese sporadic AD group and the control group.

No genetic association between ATP binding cassette proteins and Japanese sporadic Alzheimer's disease.

The identification of the epsilon4 variant of apolipoprotein E as a genetic risk factor for late-onset Alzheimer's disease (AD) suggests that cholesterol may play a direct role in the pathogenesis of the disease. Recent studies have suggested that the ATP-binding cassette (ABC) protein G5 (ABCG5) may be involved in the regulation of intestinal cholesterol absorption. Furthermore, genetic variation of this locus may affect blood cholesterol concentrations. We therefore studied whether the ABCG5 C1950G (Gln640Glu) polymorphism affects the risk of AD. In addition, there was no difference in mean baseline cholesterol concentrations between individuals with the C/C genotype and carriers of the G allele. Recent studies have shown that genetic regions including the ABCA12 gene might also be associated with the risk of AD. The ABCA12 gene, located <1 Mb from the peak marker on chromosome 2q34, is also a member of the ABC transporter superfamily. In the current study, two common polymorphisms of the ABCA12 gene, rs952718 (T/G) and rs956133 (A/G), were analyzed in our subjects. These polymorphisms showed no association with the risk of AD. Furthermore, we observed weak linkage disequilibrium between these two single nucleotide polymorphisms. These results indicate that the common polymorphisms of the ABCG5 and ABCA12 genes investigated here are not associated with AD.

Influence of aging on the improvement of subjective sleep quality by atypical antipsychotic drugs in patients with schizophrenia: comparison of middle-aged and older adults.

OBJECTIVE: The authors investigated the influence of aging on the improvement of subjective sleep quality by atypical antipsychotic drugs in patients with schizophrenia. METHODS: Subjects were 86 inpatients (mean age: 61.4 years) who had been receiving treatment with conventional antipsychotic drugs and who met DSM-IV criteria for schizophrenia. Their antipsychotic medication was changed from conventional antipsychotics to one of four atypical antipsychotic drugs (olanzapine, perospirone, quetiapine, or risperidone). Patients were grouped by age (older or younger than 65 years). Subjective sleep quality and psychopathology were assessed twice: 1) at baseline, and 2) 8 weeks after switching to the atypical antipsychotic drugs. Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI), and the Positive and Negative Syndrome Scale (PANSS) was used to measure psychopathology. RESULTS: The proportion of the patients who experienced improved subjective sleep quality was significantly higher in the elderly than in the middle-aged group. Logistic-regression analysis revealed that the improvement in subjective sleep quality through administration of atypical antipsychotic drugs was predicted by increased age, daytime dysfunction, and longer sleep latency at baseline. CONCLUSION: These results demonstrate that atypical antipsychotic drugs are beneficial to the quality of sleep in elderly patients with schizophrenia.

Genetic association between matrix metalloproteinase MMP-9 and MMP-3 polymorphisms and Japanese sporadic Alzheimer's disease.

Recent studies suggested that matrix metalloproteinases (MMPs) might play an important role in the pathophysiology of Alzheimer's disease (AD). MMP-9 and MMP-3 are reported to degrade amyloid beta and have several functional polymorphisms associated with other common diseases. Four common polymorphisms in each of MMP-9 and MMP-3 were examined in AD cases and normal control individuals. Common polymorphisms of MMP-9, rs3918248, rs2664538, rs2250889 and rs2274756 showed no association with risk for AD. We observed strong linkage disequilibrium (LD) between rs2664538 and rs2250889 in our Japanese samples. The polymorphisms of MMP-3; 5A/6A insertion polymorphism in the promoter, rs3025079, rs520540 and rs679620 also did not influence risk for AD. LD of the 5A/6A polymorphism with rs679620 was relatively strong. These results suggest that the common polymorphisms of MMP-9 and MMP-3 investigated here are not associated with AD.

Effects of changing from typical to atypical antipsychotic drugs on subjective sleep quality in patients with schizophrenia in a Japanese population.

OBJECTIVE: To investigate the effects of the atypical antipsychotic drugs risperidone, olanzapine, quetiapine, and perospirone on the subjective quality of sleep in patients with schizophrenia. METHOD: Subjects were 92 inpatients (mean age = 59.9 years) who had been receiving treatment with conventional antipsychotic drugs and who met the DSM-IV criteria for schizophrenia. Subjects were randomly assigned to receive 1 of 4 atypical antipsychotic drugs (olanzapine, perospirone, quetiapine, and risperidone). Subjective sleep quality and psychopathology were assessed twice: at baseline and 8 weeks after switching. Data were collected from June 2001 to December 2001. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI), and psychopathology was measured by the Positive and Negative Syndrome Scale (PANSS). RESULTS: Subjective sleep quality as assessed by the PSQI was significantly improved with administration of olanzapine, risperidone, or quetiapine, but not with perospirone, in comparison with conventional antipsychotic drugs. Multiple regression analysis revealed that the improvement of sleep quality with administration of atypical antipsychotic drugs was predicted by poor sleep quality at baseline. In addition, improvement of sleep quality was significantly correlated with improvement of negative symptoms as assessed by the PANSS. CONCLUSION: These results demonstrated that atypical antipsychotic drugs improved subjective quality of sleep in patients with schizophrenia compared with conventional antipsychotic drugs, suggesting that the marked potency of serotonin-2 receptor blockade in atypical antipsychotic drugs may be involved in the mechanism of this improvement. These improvements were correlated with improvement of negative symptoms.

Effect of switching to atypical antipsychotics on memory in patients with chronic schizophrenia.

While the usefulness of atypical antipsychotics for improving cognitive function has been proven, the specific effects of these drugs are still unknown. The objective of this study was to investigate changes of the immediate memory and verbal working memory in patients with chronic schizophrenia after switching to one of four atypical antipsychotic agents and cessation of anticholinergic therapy. The subjects included 77 schizophrenic patients who were treated primarily with typical antipsychotics. Treatment was randomly switched to one of four atypical antipsychotics (olanzapine, perospirone, quetiapine, or risperidone) over a 4-week period, and then the drug was continued for another 4 weeks while the patient was taken off anticholinergics. The immediate memory, verbal working memory, and symptoms were evaluated. Significant improvement of immediate memory was only seen with olanzapine and risperidone. Improvement was also seen after switching to perospirone, but immediate memory worsened after treatment with this anticholinergic drug was discontinued. Deterioration was seen after switching to quetiapine, but immediate memory improved and reached the previous level after treatment with anticholinergic drugs was discontinued. Significant improvement of the verbal working memory was only seen during risperidone administration. The findings suggested that switching chronic schizophrenic patients to atypical antipsychotics can improve both the immediate memory and the verbal working memory when risperidone is used, while improvement of immediate memory can be expected with olanzapine. From the viewpoint of improving the memory, quetiapine should not be administered concomitantly with anticholinergic drugs, and caution should be exercised when discontinuing anticholinergic drugs during treatment with perospirone.

No genetic association between Fyn kinase gene polymorphisms (-93A/G, IVS10+37T/C and Ex12+894T/G) and Japanese sporadic Alzheimer's disease.

Several groups have reported that abnormal phosphorylation of tau by Fyn, a protein-tyrosine kinase, may play a role in the neuropathogenesis of Alzheimer's disease (AD). In the present study, three common Japanese polymorphisms of the Fyn gene (-93A/G in the 5'-flanking region, IVS10+37T/C in intron 10 and Ex12+894T/G in the 3'-untranslated region) were studied in 127 healthy controls and 182 sporadic AD cases using a polymerase chain reaction restriction fragment length polymorphism method. A comparison of the allelic and genotypic frequencies of these polymorphisms between controls and sporadic AD cases failed to show any significant difference. These results suggest that the Fyn polymorphisms (-93A/G, IVS10+37T/C and Ex12+894T/G) investigated here have no genetic association with sporadic AD.

No genetic association between tumour necrosis factor receptor II 196R polymorphism and Japanese sporadic Alzheimer's disease.

Recent studies have reported that acute effects of tumour necrosis factor (TNF), a pro-inflammatory cytokine, are limited by binding to a soluble receptor, TNF receptor II, and the G allele at position 196 in exon 6 of the TNF receptor II gene (TNFRII 196R) has been associated with auto-immune diseases. Since complex interactions among cytokines have been suggested around senile plaques in Alzheimer's disease, TNF might be associated with ageing and the pathophysiology of Alzheimer's disease. We examined the TNFRII 196R polymorphism in 243 Japanese sporadic Alzheimer's disease cases and 106 control cases using a polymerase chain reaction-restriction fragment length polymorphism method. Allelic frequencies with TNFRII 196R T/G polymorphism were 28.3% and 27.4% in the control and Alzheimer's disease groups, respectively. The results showed no genetic association between TNFRII 196R polymorphism and Alzheimer's disease. The TNFRII 196R G allele does not appear to be associated with Alzheimer's disease susceptibility in a Japanese population.

Effect of IL-6 polymorphism on risk of Alzheimer disease: genotype-phenotype association study in Japanese cases.

Interleukin-6 (IL-6), an inflammatory cytokine might be involved in the pathophysiology of Alzheimer disease (AD); several studies have reported that the "C allele of IL-6 variable number of tandem repeat polymorphism" (IL-6vntr) delayed initial onset of AD and also decreased its risk per se. Another polymorphism, G/C allele of IL-6 gene promoter region (IL-6prom), is also a candidate because it has an influence on the regulation of plasma IL-6 concentration. We examined these IL-6 polymorphisms in 128 Japanese AD cases and 83 control cases using a PCR-RFLP method. The results showed the frequency of the IL-6prom G allele was significantly increased in AD, although IL-6vntr polymorphism was not. Plasma IL-6 concentration of the AD cases was also significantly higher than that of the control cases. Moreover, the IL-6prom G allele-positive AD patients showed a tendency to have higher IL-6 concentration in the AD group. These findings suggest that the IL-6prom G allele which may affect plasma IL-6 concentration might be a risk factor for sporadic AD in Japanese.

The effect of IL4 +33C/T polymorphism on risk of Japanese sporadic Alzheimer's disease.

Interleukin-4 (IL4) is an anti-inflammatory cytokine that may play a role in the inflammation pathology observed surrounding senile plaques, and may also associate with Alzheimer's disease (AD) pathogenesis. Recently, it has been reported that a single nucleotide polymorphism in the IL4 gene promoter region, IL4 +33C/T polymorphism, associates with its phenotype. It was thought that the IL4 +33C/T polymorphism causing high IL4 production may reduce the risk for AD. In the present study, therefore, we investigated this mutation in 108 healthy controls and in 178 sporadic AD cases by the polymerase chain reaction restriction fragment length polymorphism method in a Japanese AD population. Allelic frequencies with +33C/T polymorphism in the gene were 35.6 and 32.6% in the control and AD groups, respectively. Our results failed to demonstrate an association between this polymorphism and Japanese sporadic AD. We also tested whether the IL4 functional variants were regulated by this polymorphism in a portion of the subjects (16 AD cases and 13 control cases). We could not find any relationship between the IL4 +33C/T polymorphism and plasma IL4 concentration.

Effect of risperidone on sleep in schizophrenia: a comparison with haloperidol.

The aim of the present study is to determine the effect of the atypical antipsychotic drug, risperidone on sleep measures in patients with schizophrenia by polysomnography. Sleep measures were compared in five schizophrenic patients who were receiving risperidone alone and five schizophrenic patients who were receiving haloperidol alone. There were no differences between these two groups in their demographic characteristics or doses of antipsychotic medication. The slow wave sleep period was significantly longer in the risperidone-treated group than in the haloperidol-treated group. There were, however, no other significant differences in sleep variables between these groups. This difference in the effect on sleep between risperidone and haloperidol may be due to their differential actions on serotonin (5-HT2) receptors. Risperidone, which is known to be a serotonin-dopamine antagonist, has the potential to improve the quality of sleep in schizophrenic patients.