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Background:Diabetic retinopathy (DR) is a sight-threatening microvascular complication of diabetes in which the vascular endothelium is damaged due to oxidative stress and inflammation, and vitreous VEGF concentration becomes elevated. The aim of the present study was to assess the association of DR with genetic variations of the MnSOD, a major antioxidant enzyme, and VEGF, an important mediator of neovascularisation, in northern Iran. Methods: 70 patients with DR and 70 healthy control subjects matched for age and sex was recruited for this study. PCR-based RFLP assay was used to determine the genotypes of MnSODA16V and VEGF+405 C/G polymorphisms. Results and Conclusions:A higher frequency of the AV genotype (71.43%) of the MnSODA16V polymorphism was found in the patients compared with controls which had a 8.33-fold increase in risk of DR (OR= 8.33, 95% CI= 2.56-27.13, P= 0.0004). The frequency of GG, GC, and CC genotypes of VEGF +405 C/G polymorphism in controls were 42.86%, 45.71% and 11.43%, respectively, while in DR patients were 18.57%, 48.57%, and 32.86%, respectively.The +405C allele was considered as a high risk factor of DR (OR= 2.55, 95% CI= 1.57-4.14, P= 0.0001). In conclusion, It is suggested that the MnSODA16V and the VEGF+405 C/G polymorphisms may be associated with the risk of DR in northern Iran.

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Objective: In peripheral blood polymorphonuclear and mononuclear cells Nitric Oxide (NO) could be synthesized by an enzyme called inducible NO synthase (iNOS). iNOS gene (NOS2A) is located on chromosome 17 at position 17q11.2-q12. NO is released during inflammatory responses. In the present studies the frequency of NOS2A gene polymorphisms and their effects on NO production were investigated in the Peripheral Blood polymorphonuclear and mononuclear cells of normal individuals. Materials and Methods: In this study the frequency of NOS2A gene polymorphisms at positions -1659 C/T and +150 C/T of 232 normal subjects were investigated using PCR-Allele specific and PCR-RFLP methods, respectively. To study the effect of -1659 C/T and +150 C/T polymorphisms on NO production, polymorphonuclear and mononuclear cells of peripheral blood of 92 normal subjects were isolated and then stimulated by E.coli culture supernatants (ATCC 25922) for induction of iNOS enzyme and NO production. After 24h, the level of NO production in the culture supernatant were measured by Griess reaction. Polymorphisms as mentioned above were also studied in these normal cases. Results: The results showed no significant difference in the level of NO production of various genotypes in the polymorphonuclear and mononuclear cells of peripheral blood of normal subjects. Conclusion: Our results indicated no significant correlation between NOS2A genotypes and NO production. No significant difference was observed between Gambia and China normal population and normal subjects of this study in NOS2A -1659 C/T and +150 C/T polymorphisms. In Iran these differences are due to the genetic and ethnic differences among the studied populations, which indicates the importance of NOS2A polymorphism in the NO production, suggesting further studies in other ethnic groups.

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Background: To evaluate the relationship between COVID-19 and IL-6 polymorphism, a meta- analysis was conducted on seven studies, comprising 2265 controls and 1686 cases.
Materials & Methods: The literature on IL-6 polymorphism and its correlation with COVID-19 severity was extensively reviewed, covering research up to August 2023. Various databases including Google Scholar, PubMed, and Embase were utilized for literature search. Data analysis was performed using Cochrane Rob Tool 2 and Review Manager 5 software.
Findings: In this meta-analysis, none of the models showed a correlation between IL-6 polymorphism and COVID-19, including the allelic (G vs C, OR: 1.01, 95% CI: 0.63–1.64, p= .22, I2=91%), homozygote (GG vs. CC, OR: 1.08, 95% CI: 0.41–2.83, p= .87, I2=79%),
heterozygote (GC vs. CC, OR: 0.78, 95% CI: 0.34–1.78, p= .55, I2=73%), dominant (GG + GC vs CC, OR: 0.79, 95% CI: 0.32–1.95, p= .61, I2=81%), and recessive (OR: 1.26, 95% CI:
0.51–3.10, p= .61, I2=81%) models. Notably, funnel plot analysis revealed no indication of publication bias.
Conclusion: The findings of this meta-analysis indicated no significant correlation between IL-6 polymorphism and COVID-19 severity, suggesting insufficient data to establish a link between IL-6 (rs1800795) and more severe COVID-19 cases.

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A case-control study was designed to investigate the association between the risk of colorectal cancer and genetic variation in four single-nucleotide polymorphism (SNPs) within genes involved in folate metabolism: C677T and A1298C of methylenetetrahydrofolate reductase (MTHFR), A66G of methionine synthase reductase (MTRR), and A2756G of methionine synthase (MTR). Genomic DNA was extracted from peripheral blood of 80 patients with newly diagnosed colorectal cancer and 100 non-cancer controls. The statistical analysis was done by logistic regression. The results showed that the MTR and MTRR SNPs were significantly associated with an increased risk of colorectal cancer (p<0.01). Moreover, no significant association was found between MTHFR C677T and MTHFR A1298C polymorphisms and the risk of colorectal cancer. These findings suggest that the MTRR A66G and MTR A2756G polymorphisms might be some genetic risks factor for colorectal cancer in the studied population.