A method for improving the efficiency of DNA extraction from clotted blood samples.

BACKGROUND: The efficient and rapid extraction of high-quality genomic DNA from clotted blood samples, which normally have a low yield and poor quality, is an important factor in genomic research. The objective of this study was to develop a simple and safe technique for dispersing the blood clots by the ball bearing metal shots. Normally, such clot samples may not have an acceptable yield by conventional DNA extraction methods. Also, in the present study, we have further investigated to improve salting-out DNA extraction methods. METHODS: Initially, 500 µL phosphate-buffered saline (PBS) (1×) and two ball bearing metal shots were added to each tube of the clotted blood sample and then were gently rotated in an electric laboratory rotator for 1 hour at room temperature (18-25°C). Genomic DNA was then extracted from samples using a modified salting-out method and a modified QIAamp® DNA Blood Midi Kit and was compared with QIAamp® DNA Blood Midi Kit as a control. An assessment of the concentration and quality of the extracted DNA was performed using the UV-visible spectrophotometer. The isolated DNA proved amenable to PCR amplification and gel electrophoresis. RESULTS: The yield and purity of DNA obtained by these three methods were significantly different (P < 0.001), with a higher yield in the modified salting-out method. CONCLUSIONS: Our proposed modified salting-out method is simple and efficient for the isolation of DNA from old blood clot samples. It is both easy to use and is of low cost in routine laboratory tasks.

Association of heat shock protein70-2 (HSP70-2) gene polymorphism with obesity.

BACKGROUND: Obesity is a major risk factor of chronic-diseases, including cardiovascular-diseases (CVD). Increasing evidence is showing the association of heat-shock protein (HSP) with type-2 diabetes and CVD; however, there is little data on the relationship between the genetic-polymorphisms of HSP70-2 with obesity. AIM: The present study has investigated the association between 1267HSP70-2 genetic polymorphism and obesity in an Iranian population with 317 subjects. SUBJECTS AND METHODS: Anthropometric parameters and biochemical measurements were measured in all the samples, while genotypes were determined using PCR-RFLP. Univariate/multivariate analyses were conducted to explore the relationship between the genetic-polymorphisms and obesity. RESULTS: The data showed a significant association between 1267HSP70-2 polymorphism in obese subjects, compared to the non-obese group. Moreover, it was observed that this polymorphism was associated with obesity in the CAD + group, which had a high BMI compared to non-obese controls. CONCLUSION: The 1267HSP70-2 polymorphism is associated with obesity in an Iranian population, supporting a possible potential genetic link between obesity and cardiovascular diseases.

High Prevalence of Y Chromosome Partial Microdeletions in Overweight Men.

BACKGROUND: Microdeletions of the Y chromosome are one of the most frequent genetic causes of spermatogenic failure in infertile men. But their role in gaining weight is unclear. The present study investigated the possible association of these partial microdeletions and obesity. METHODS: In a case-control study, 180 males were selected. The prevalence of microdeletions was assessed using PCR in AZFc area of Y chromosome and statistical analysis was done using the Fisher exact test and Pearson correlation. RESULTS: In our study, inverse relationship was observed between body mass index and testosterone level (p-value: 0.005). Fisher exact tests showed that there was a significant association between gr/gr mutation and BMI (p-value: 0.044). CONCLUSION: Our study revealed that Y chromosome microdeletions are more common in obese men. Furthermore, microdeletions such as gr/gr, which were observed in normal men, could cause decreased testosterone level. So, they may contribute to gaining weight.

Association of heat shock protein70-2 (HSP70-2) gene polymorphism with coronary artery disease in an Iranian population.

BACKGROUND: Coronary artery disease (CAD) is an inflammatory process and a major cause of mortality and morbidity. The (heat shock protein70-2) HSP70-2 gene is reported to be associated with coronary artery disease possibly by affecting the regulation of pro-inflammatory cytokines such as TNF-α. The association between CAD and the HSP70-2 gene +1267A>G polymorphism has been studied in some populations but there are no data about this association in the Iranian population. AIM: We have investigated the association between the HSP70-2 gene +1267A>G polymorphism and angiographically defined CAD within an Iranian population. METHODS: We determined the presence of the HSP70-2 gene +1267A>G polymorphism in 628 patients with CAD and 307 healthy individuals using PCR-RFLP. Of the patients, 433 (68%) had >50% stenosis (CAD+) and the remaining 195 patients had <50% stenosis (CAD-), based on coronary angiography. Angiogram positive patients were subdivided into three groups: those with single (n=113), double (n=134), and triple vessels (n=186) disease. RESULTS: A significant higher frequency of AG+GG genotypes (G allele carriers) was observed in angiogram positive and angiogram negative groups compared to controls in a dominant analysis model of the HSP70-2 gene +1267A>G position (51.2 vs. 43.2, P=0.002, OR=1.37) (51.0 vs. 43.2, P=0.01, OR=1.37). The allele frequency of the HSP70-2 G was also significantly higher in angiogram positive and angiogram negative groups compared to the control group (51.2 vs. 43.2, P=0.002, OR=1.37) (51.0 vs. 43.2, P=0.01, OR=1.37). CONCLUSION: These results suggest that HSP70-2 +1267 polymorphism may influence the risk of CAD in Iranian population, however further studies are needed to clarify the role of other HSP70-2 gene polymorphisms in the pathogenesis of the CAD.