Lack of association between vascular dementia and Chlamydia pneumoniae infection: a case-control study

Background

Chronic inflammation appears to play a role in the pathogenesis of vascular dementia. Given the association between Chlamydia pneumoniae and stroke, the possibility exists that previous exposure to C. pneumoniae may play a role in vascular dementia. The objective of this study was to determine if there was an association between serological evidence of C. pneumoniae infection or inflammatory markers with vascular dementia.

Methods

28 case-patients with vascular dementia at a geriatric clinic and 24 caregiver-controls were tested for C. pneumoniae IgG and IgA antibodies. The association between vascular dementia and C. pneumoniae titres as well as inflammatory markers was estimated by using both conditional logistic regression and stratified logistic regression.

Results

When matched cases were compared to controls, there was no significant difference in elevated C. pneumoniae specific IgG antibodies (titre ≥ 1:32), odds ratio [OR] 1.3 (95% confidence intervals [CI] 0.3 to 6.0), p = 0.71, or in elevated C. pneumoniae specific IgA antibodies (titre ≥ 1:16), OR 2.0 (95%CI 0.5 to 8.0), p = 0.33 indicative of past or persistent C. pneumoniae infection. Similarly, no difference in high IgG or IgA antibody levels (IgG titre ≥ 1:512 or IgA titre ≥ 1:64) between the two groups, indicative of recent C. pneumoniae infection, was found, OR 0.4 (95%CI 0.1 to 2.1), p = 0.27. For C-reactive protein (CRP), the mean difference between 18 matched pairs (case – control) was – 3.33 mg/L. There was no significant difference between cases and controls when comparing log transformed values, OR 0.03 (95%CI 0.00 to 2.89), p = 0.13 or comparing CRP values above or below the median, OR 0.8 (95%CI 0.2 to 3.4), p = 0.71. For fibrinogen, the mean difference between pairs (case – control) was -0.07 g/L. There was no statistical difference between cases and controls when comparing log transformed values, OR 0.6 (95%CI 0.0 to 31.2), p = 0.79 or between fibrinogen values above and below the median, OR = 0.5 (95%CI 0.1 to 2.0), p = 0.50.

Conclusion

We found no evidence for a significant association between C. pneumoniae infection, inflammatory markers such as CRP and fibrinogen, and vascular dementia.

     

Lack of association between SNP rs3914132 of the RELN gene and otosclerosis in India

Otosclerosis (MIM 166800) is primarily a metabolic bone disorder of the otic capsule, which leads to bony fixation of the stapedial footplate in the oval window; it is among the most common causes of acquired hearing loss. The etiology of this disease is largely unknown, although epidemiological studies suggest the involvement of both genetic and environmental factors. Recently, a reelin gene, SNP rs3914132, located in intron 2, was shown to be associated with otosclerosis in a European population. When we sequenced blood DNA samples of 85 individuals with otosclerosis and 85 controls, four SNPs of this gene: rs3914131 (P = 0.6463), rs3914132 (P = 0.1822), rs9641319 (P = 0.7371), and rs10227303 (P = 0.5669) were not significantly associated with this disease. In one familial case, a novel variant (C/T) at contig position 2923488 was found to be inherited by the proband and affected family members.     

Interactions of anthropometric indices,rs9939609 FTO gene polymorphism and breast cancer: A case-control study

Contradictory results were reported on the effect of fat mass- and obesity-associated (FTO) gene and anthropometric measurements on breast cancer (BC). This study aimed to assess the interactions between rs9939609 polymorphism of FTO gene, anthropometric indices and BC risk in Iranian women. This case-control study was performed on 540 women including 180 women with BC and 360 healthy women in Tehran, Iran. Physical activity and dietary intakes were assessed by validated questionnaires. Data on sociodemographic and pathologic factors of the participants as well as their blood samples were collected. The rs9939609 FTO gene polymorphism was genotyped using the tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). No significant association was found between BC and risk allele of FTO rs9939609 polymorphism after adjustments for the confounders. However, there was a significant association between rs9939609 polymorphism risk allele and BC risk in females with overweight, even after adjusting for age, family history of BC, abortion, BMI and the number of pregnancies (P < .05). The association was disappeared after further adjustments for lifestyle factors including smoking, alcohol consumption, calorie and macronutrients intake, and physical activity. The FTO gene polymorphism was associated with the risk of BC in overweight individuals. This association was influenced by environmental factors including diet, alcohol consumption and smoking. Future studies are required to confirm the association between the FTO gene and BC in overweight females and to identify the underlying mechanisms.     

Lack of association between psoriasis vulgaris and red cell acid phosphatase polymorphism

Summary Polymorphism of red cell acid phosphatase (ACP-1; E.C. 3.1.3.2.) has been studied using the Cellogel technique of Martin et al. (1975) in 102 patients with psoriasis and 102 healthy controls. In contrast to two previous reports, no anomalies in distribution of phenotypes were found in patients or in controls.Results were obtained during medical thesis work of G. M.     

Lack of association between the Val158Met catechol-O-methyltransferase gene polymorphism and methamphetamine dependence

OBJECTIVES: About 25,000 serious methamphetamine abusers live in the Czech Republic among the total population of 10 million. Dependence on methamphetamine is markedly related to the brain neurotransmitter dopamine, metabolised by catechol-O-methyltransferase enzyme. The main aim of the study was to ascertain whether the Val158Met catechol-O-methyltransferase gene polymorphism is associated with methamphetamine dependence in this Central European country. Methods: One hundred and twenty-three subjects dependent on methamphetamine (women N=44), parents of sixty-seven dependent individuals, and four hundred healthy controls (women N=250) were involved into the study. We performed a population-based as well as family-based genetic association studies. Results: We did not find any significant association between the Val158Met catechol-O-methyltransferase gene polymorphism and methamphetamine dependence using the population-based or family-based design (p=0.41-0.66; Chi-Square Test or UNPHASED program, Version 3.1.4, respectively). We found a trend toward a statistically significant difference between the Val allele carriers and Met/Met homozygotes in the frequence of psychotic symptoms induced by methamphetamine (more frequent in Val carriers; p=0.062; Chi-Square Test). Conclusion: Further research involving haplotype analysis and other dopamine-related genetic polymorphisms in large populations is needed. More attention should also be paid to possible role of the Val158Met catechol-O-methyl-transferase gene polymorphism in individual clinical subtypes of dependence on methamphetamine involving e.g. psychotic features or violence.     

Lack of association between miR-146a rs2910164 C/G locus and colorectal cancer: from a case–control study to a meta-analysis

Previous studies suggested that miR-146a rs2910164 (C/G) locus was predicted to influence the risk of cancer. However, the relationship of miR-146a rs2910164 locus with colorectal cancer (CRC) susceptibility was controversial. We recruited 1003 CRC patients and 1303 controls, and performed a case–control study to clarify the correlation of miR-146a rs2910164 locus with CRC risk. Subsequently, a comprehensive meta-analysis was conducted to verify our findings. In the case–control study, we suggested that miR-146a rs2910164 variants did not alter CRC risk (CG vs. CC: adjusted P=0.465; GG vs. CC: adjusted P=0.436, CG/GG vs. CC: adjusted P=0.387 and GG vs. CC/CG: adjusted P=0.589), even in subgroup analysis. Next, we conducted a pooled-analysis to identify the correlation of miR-146a rs2910164 locus with CRC risk. In this pooled-analysis, 7947 CRC cases and 12,168 controls were included. We found that miR-146a rs2910164 polymorphism did not influence the risk of CRC (G vs. C: P=0.537; GG vs. CC: P=0.517, CG/GG vs. CC: P=0.520 and GG vs. CC/CG: P=0.167). Our findings suggest that miR-146a rs2910164 C/G polymorphism is not correlated with the susceptibility of CRC. In the future, more case–control studies are needed to confirm our results.     

Lack of association between TLR4 rs4986790 polymorphism and risk of cardiovascular disease in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with increased cardiovascular (CV) mortality. Toll-like receptor-4 (TLR4) activates the innate immune response via NF-kB pathway and mitogen-activated protein kinase signaling, leading to expression of proinflammatory cytokines and chemokines. The G allele of TLR4 rs4986790 (+896A>G, Asp299Gly) gene polymorphism has been implicated in reduction of risk of atherosclerosis. In this study, 1481 RA patients fulfilling the 1987 American College of Rheumatology (ACR) criteria were genotyped for the rs4986790 TLR4 variant to determine the influence of this variant in the risk of CV events in these patients. Also, HLA-DRB1 status was determined using molecular based methods. Moreover, potential influence of rs4986790 variant in the development of subclinical atherosclerosis was assessed in a subgroup of RA patients with no history of CV events by the measurement of surrogate markers of subclinical atherosclerosis. No statistically significant differences in allele or genotype frequencies for the rs4986790 variant between RA patients who experienced CV events or not were found. Likewise, no significant association between this gene variant and any of the surrogate markers of subclinical atherosclerosis was found. In summary, results in our study do not support the hypothesis that the rs4986790 (+896A>G, Asp299Gly) TLR4 variant may influence predisposition for subclinical atherosclerosis and clinically evident CV disease in RA patients.     

Angiotensin-converting-enzyme gene polymorphism and heart failure: a case-control study.

Heart failure (HF) is the final outcome of virtually all cardiovascular diseases and is a major and increasingly serious public health problem. The renin-angiotensin system plays an important role in the pathogenesis of cardiovascular disease. Insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) has attracted significant attention; it has been extensively investigated in a spectrum of cardiovascular phenotypes because of its correlation with serum ACE activity. There is controversy regarding the association of ACE I/D polymorphism with cardiovascular disease. The aim of this study was to investigate whether ACE genotype is associated with HF by comparing cases and controls. The study sample consisted of 229 cases with HF due to coronary heart disease or idiopathic dilated cardiomyopathy and 230 controls recruited from the general population. The ACE I/D genotype was identified using a polymerase chain reaction assay. No evidence was found to support an association between ACE genotype and HF.     

PSCA gene variants (rs2294008 and rs2978974) confer increased susceptibility of gallbladder carcinoma in females

Background and aim

PSCA is a tissue specific tumor suppressor or oncogene which has been found to be associated with several human tumors including gallbladder cancer. It is considered to be involved in the cell-proliferation inhibition and/or cell-death induction activity. Therefore, we aimed to investigate the role of PSCA gene polymorphisms in gallbladder cancer risk in North Indian population.

Methodology

A total of 405 gallbladder cancer patients and 247 healthy controls were included in the case–control study for risk prediction. We examined the association of two functional SNPs, rs2294008 and rs2978974 in PSCA gene by genotyping using Taqman allelic discrimination assays. Statistical analysis was done using SPSS software, version 17. Linkage disequilibrium and haplotype analysis was done with the help of SNPstats software. FDR test was used to correct for multiple comparisons.

Results

No significant associations of rs2294008 and rs2978974 genetic variants of the PSCA gene were found with GBC risk at allele, genotype or haplotype levels. Stratifying the subjects on the basis of gallstone also did not show any significant result. However, on gender stratification, we found a significant association of T_rs2294008-G_rs2978974 haplotype with higher risk of GBC in females (FDR Pcorr = 0.021, OR = 1.6). In contrary, T_rs2294008-A _rs2978974 haplotype conferred significant lower risk in males (FDR Pcorr = 0.013; OR = 0.25).

Conclusions

These findings suggest that PSCA genetic variants may have a significant effect on GBC susceptibility in a gender specific manner.     

The effects of FTO gene rs9939609 polymorphism on the association between breast cancer and dietary intake

Breast cancer (BC) is the leading cause of cancer‐related deaths in females worldwide and is related to genetic and environmental factors. Dietary components may strongly influence the risk of BC. A possible association was also reported between the fat mass and obesity‐associated (FTO) single‐nucleotide polymorphisms (SNPs) and BC. This study aimed to investigate the impact of FTO rs9939609 polymorphism on the association between BC and dietary intake. This study was conducted on 180 women with BC as the case group and 360 healthy women as the control group. The dietary intakes were assessed by a valid 168‐item food frequency questionnaire (FFQ). The FTO gene was genotyped for rs9939609 polymorphism. After adjusting the confounding variables, there was no significant association between dietary intake and BC in individuals without risk allele. A positive association between dietary intake of omega‐6 fatty acids and BC was found only in individuals with risk allele of FTO gene (OR: 1.31, 95% CI: 1.08–1.60, p: 0.006). FTO gene risk allele may influence the effect of diet on breast cancer risk. Further studies are needed to assess the possible effects of the FTO genotype on the association between BC risk and dietary components.     

The CD40 gene polymorphism rs1883832 is associated with risk of acute coronary syndrome in a Chinese case-control study

Numerous reports in the past few years have demonstrated that atherosclerosis is a lipid-driven, chronic inflammatory disease of the vessel. Recent studies have indicated that the immune mediator CD40-CD40L (CD40 ligand), which is expressed on several inflammatory cells within human atherosclerotic lesions, has roles in atherogenesis. A functional polymorphism (-1C>T, rs1883832) in the 5' untranslated region of TNFRSF5 gene has been reported to affect CD40 expression and be associated with several chronic inflammatory and autoimmune diseases. The aim of the present study was to validate the potential coronary artery disease susceptibility marker in a Chinese case-control study. A total of 160 patients with acute coronary syndrome (ACS) and 180 control subjects were used to genotype and identify this single-nucleotide polymorphism by polymerase chain reaction-restriction fragment length polymorphism and sequencing, respectively. Peripheral blood mononuclear cells were isolated and incubated with interferon-γ with or without pretreatment of fluvastatin, followed by measurement of CD40 expression using flow cytometry. In addition, soluble CD40L was determined by ELISA as another biomarker of coronary artery disease. The distribution of the rs1883832 genotypes (CC, CT, and TT) was 33.1%, 54.4%, and 12.5% in the ACS group and 22.8%, 53.3%, and 23.9% in controls, respectively. The frequency of the C allele was significantly higher among ACS patients compared with controls (60.3% vs. 49.4%, odds ratio=1.554, 95% confidence intervals: 1.146-2.107, p<0.05). ACS patients showed a significant increase of CD40 and sCD40L coexpression compared with controls (p<0.05). Cell culture experiments showed that CC carriers presented significantly higher CD40 expression levels than CT and TT subjects (p<0.05). Additionally, fluvastatin suppressed CD40 expression in all three genotypes. These data suggest that the single-nucleotide polymorphism of CD40 gene is associated with susceptibility to ACS in Chinese population, and the polymorphism may influence the CD40 production. These expand the understanding of inflammatory mechanisms during atherogenesis.     

Lack of association between methylenetetrahydrofolate reductase gene A1298C polymorphism and breast cancer susceptibility

Published data on the association between methylenetetrahydrofolate reductase gene (MTHFR) A1298C polymorphism and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, and Web of Science were searched. Crude ORs with 95% CIs were used to assess the strength of association between the MTHFR A1298C polymorphism and breast cancer risk. The pooled ORs were performed for co-dominant model (AC vs. AA, CC vs. AA), dominant model (CC+AC vs. AA), and recessive model (CC vs. AC+AA), respectively. A total of 26 studies including 12,244 cases and 15,873 controls were involved in this meta-analysis. Overall, no significant associations were found between MTHFR A1298C polymorphism and breast cancer risk when all studies pooled into the meta-analysis (AC vs. AA: OR=0.99, 95% CI 0.94-1.05; CC vs. AA: OR 0.99, 95% CI 0.90-1.09; dominant model: OR=0.99, 95% CI 0.95-1.04; and recessive model: OR=0.98, 95% CI 0.90-1.08). In the subgroup analysis by ethnicity or study design, still no significant associations were found for all comparison models. In conclusion, this meta-analysis suggests that the MTHFR A1298C polymorphism may be not associated with breast cancer development. However, large sample and representative population-based studies with homogeneous breast cancer patients and well matched controls are warranted to confirm this finding.     

Dynamic and adaptive cancer stem cell population admixture in colorectal neoplasia

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