The study of mitochondrial ATP6, ND3 and COX3 gene nucleotide variations in Iranian patients with atherosclerosis by PCR-SSCP

Background and aims: Atherosclerosis is a complex arterial disease that is caused due to the interaction of genetic and environmental factors. Mutations in the mitochondrial genome have probably a direct effect on increased oxidative stress and thereby cause progression of the disease. The aim of the current study was to identify the possible nucleotide changes in the mitochondrial ATP6, ND3 and COX3 genes in Iranian patients with atherosclerosis. Methods: In this case-control study, DNA was extracted from peripheral blood of 90 patients with atherosclerosis and 95 healthy individuals by standard method. The regions of the mitochondrial genome including ATP6, ND3 and COX3 genes were studied by PCR-SSCP; and banding shift specimens were sequenced to determine the exact nucleotide changes. The obtained data were analyzed using the Fisher's exact test and GraphPad prism software. Results: The results of SSCP and DNA sequencing lead to the detection of three nucleotide changes in ATP6 gene including a synonymous polymorphism at position m.9034 G>A, and an SNP at position m.9055 G>A, in which alanine is converted to tyrosine and synonymous hetroplasmic variant at m. 9162C>T. Also, it was found three homoplasmic nucleotide variations including synonymous m.9602A>G, m.9899T>C related to histidine amino acid and homoplasmic variant m.9929C>A that resulted in changing of tyrosine to stop codon. Conclusion:. Since it has been proven, m.9055G>A variant increases the risk of developing breast cancer, and on the other hand, this polymorphism has also been reported in the Caucasian population of Parkinson's; Therefore, it can be said that the combination of this mutation with other predisposing factors increases the severity of coronary heart disease. Investigating other mitochondrial genes could be regarded important in order to find the the relationship between nucleotide changes of mitochondrial genes cardiovascular diseases

Novel and heteroplasmic mutations in mitochondrial tRNA genes in Brugada syndrome

  Background: Brugada syndrome (BrS) is a rare cardiac arrhythmia characterized by sudden death associated with electrocardiogram patterns characterized by incomplete right bundle-branch block and ST-segment elevations in the anterior precordial leads. This syndrome predominantly is seen in younger males with structurally normal hearts. Mitochondrial variants particularly mt-tRNA mutations, are hot spots that lead to cardiological disorders. Previous studies have shown that mutations in mitochondrial tRNA genes play an important causal or modifying role in BrS. The present study aims to evaluate the involvement of mitochondrial tRNA genes in arrhythmogenic BrS. Methods: In this study, 40 Iranian patients were investigated for the presence of the mutations in 6 mitochondrial tRNA genes (tRNA Ile, Met, Gln, Asn, Ala and Trp) by PCR-SSCP analysis. Results: There were 4 mutations in tRNA genes, that for first time, were found in BrS patients and these mutations were not in controls. Three of them were heteroplasmic and located in tRNAGln (T4377A) and tRNAMet (G4407A and C4456T) which were assessed as pathogenic mutations. A homo­plasmic variant (5580T > C) in tRNATrp gene was located within the junction region between tRNATrp and tRNAAla genes. This mutation may disturb the processing of mt-tRNATrp. Conclusions: The results of this study suggest that mutations in mitochondrial tRNA genes might lead to deficiencies in translational process of critical proteins of the respiratory chain and potentially lead to BrS in Iranian subjects. (Cardiol J 2018; 25, 1: 113–119

Mitochondrial mutations in protein coding genes of respiratory chain including complexes IV, V, and MT-TRNA genes are associated risk factors for congenital heart disease

Most studies aiming at unraveling the molecular events associated with cardiac congenital heart disease (CHD) have focused on the effect of mutations occurring in the nuclear genome. In recent years, a significant role has been attributed to mitochondria for correct heart development and maturation of cardiomyocytes. Moreover, numerous heart defects have been associated with nucleotide variations occurring in the mitochondrial genome, affecting mitochondrial functions and cardiac energy metabolism, including genes encoding for subunits of res-piratory chain complexes. Therefore, mutations in the mitochondrial genome may be a major cause of heart dis-ease, including CHD, and their identification and characterization can shed light on pathological mechanisms occurring during heart development. Here, we have analyzed mitochondrial genetic variants in previously re-ported mutational genome hotspots and the flanking regions of mt-ND1, mt-ND2, mt-COXI, mt-COXII, mt-ATPase8, mt-ATPase6, mt-COXIII, and mt-tRNAs (Ile, Gln, Met, Trp, Ala, Asn, Cys, Tyr, Ser, Asp, and Lys) en-coding genes by polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) in 200 pa-tients with CHD, undergoing cardiac surgery. A total of 23 mitochondrial variations (5 missense mutations, 8 synonymous variations, and 10 nucleotide changes in tRNA encoding genes) were identified and included 16 novel variants. Additionally, we showed that intracellular ATP was significantly reduced (P=0.002) in CHD pa-tients compared with healthy controls, suggesting that the mutations have an impact on mitochondrial energy production. Functional and structural alterations caused by the mitochondrial nucleotide variations in the gene products were studied in-silico and predicted to convey a predisposing risk factor for CHD. Further studies are necessary to better understand the mechanisms by which the alterations identified in the present study contribute to the development of CHD in patients.info:eu-repo/semantics/publishedVersio

Comparative study of albumin 5% solution with Ringer's lactate for substitute blood loss of intra-operation on the integrity of the patient's coagulation system, renal function and electrolytes after surgery; a double-blind clinical trial study

Introduction: The type of fluid replace sufficient volume loss during surgery is crucial for normal renal functioning. Objectives: The aim of this study was to compare the effect of albumin 5% infusion versus Ringer's lactate solution on substitution of intraoperative bleeding on the status of the patient's hemodynamic and coagulation system after surgery. Patients and Methods: This clinical trial study was performed on 80 patients with non-emergency surgery with the possibility of intraoperative bleeding. Bleeding replacement was performed in the control group with Ringer's lactate serum and in the case group was replaced with 5% albumin. Patients' coagulation status (prothrombin time [PT] and relative thromboplastin time and international normalized ratio; INR), electrolyte concentrations (sodium, potassium, and calcium), renal activity tests (serum urea and creatinine) were performed before and at 6, 12, and 24 hours after anesthesia. Results: The results of the study showed no significant difference between the two groups regarding renal parameters, electrolytes (sodium, potassium and calcium) in all stages of the study. Additionally, PT and partial thromboplastin time (PPT) at 6, 12, and 24 hours post-operation in albumin receiving group was less than that of the Ringer's lactate group (P < 0.01). Additionally, 12 and 24 hours after operation, the INR was significantly less in the albumin group compared to Ringer's lactate serum receiver (P < 0.05). Conclusion: This study showed that the administration of albumin solution in comparison with Ringer's lactate for replacement of intraoperative bleeding reduces the risk of bleeding after surgery due to less coagulation disorder. Keywords:Albumin; Ringer's lactate; Prothrombin time (PT); Partial thromboplastin time; International normalized rati

Novel Point Mutations in the NKX2.5 Gene in Pediatric Patients with Non-Familial Congenital Heart Disease

Background and objective: Congenital heart disease (CHD) is the most common birth abnormality in the structure or function of the heart that affects approximately 1% of all newborns. Despite its prevalence and clinical importance, the etiology of CHD remains mainly unknown. Somatic and germline mutations in cardiac specific transcription factor genes have been identified as the factors responsible for various forms of CHD, particularly ventricular septal defects (VSDs), tetralogy of Fallot (TOF), and atrial septal defects (ASDs). p. NKX2.5 is a homeodomain protein that controls many of the physiological processes in cardiac development including specification and proliferation of cardiac precursors. The aim of our study was to evaluate the NKX2.5 gene mutations in sporadic pediatric patients with clinical diagnosis of congenital heart malformations. Materials and methods: In this study, we investigated mutations of the NKX2.5 gene&rsquo;s coding region in 105 Iranian pediatric patients with non-familial CHD by polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) and direct sequencing. Results: We observed a total of four mutations, of which, two were novel DNA sequence variants in the coding region of exon 1 (c. 95 A &gt; T and c. 93 A &gt; T) and two others were previously reported as single-nucleotide polymorphisms (SNPs), namely rs72554028 (c. 2357 G &gt; A) and rs3729753 (c. 606 G &gt; C) in exon 2. Further, observed mutations are completely absent in normal healthy individuals (n = 92). Conclusion: These results suggest that NKX2.5 mutations are highly rare in CHD patients. However, in silico analysis proves that c.95 A &gt; T missense mutation in NKX2.5 gene is probably pathogenic and may be contributing to the risk of sporadic CHD in the Iranian population

Apolipoprotein E Gene Polymorphism in Iranian Coronary Atherosclerosis Patients Candidate for Coronary Artery Bypass Graft

Objective(s): Apolipoprotein E genotype (APOE) polymorphism affects lipid levels and coronary artery disease (CAD) risk. The aim of this study was to study the association of the Apolipoprotein E genotypes with coronary artery disease in the Iranian population.   Materials and Methods: The Apolipoprotein E genotype in DNA samples extracted from 66 CAD+ patients and 61 control subjects by restricting enzyme digestion of amplified exon 4 APOE gene was determined. Results : The ε3 allele was found at similar frequency in control subjects (88.5%) and atherosclerosis patients (83.3%) (P=0.314). Our results showed that the frequency of the ɛ3/ɛ3 and ε3/ε4 genotypes increased in three-vessel-disease patients and the frequency of ɛ2/ɛ2 genotype increased in one-vessel-disease patients. Conclusion : ɛ3/ɛ3 and ɛ3/ɛ4 genotypes are suggested to be predisposing factors, which, in combination with environmental factors, may trigger the degree of luminal narrowing. The possible mechanisms remain elusive and require further studies

Polymorphisms in NOS3, MTHFR, APOB and TNF-α genes and risk of coronary atherosclerotic lesions in Iranian patients

Background: Atherosclerosis is a complex multifocal arterial disease involving interactions between multiple genetic and environmental factors. Objectives: In the present study, we investigated the possible association between NOS3 (rs1799983), MTHFR (rs1801133), APOB (rs5742904) and TNF-α (rs361525) polymorphisms and the risk of coronary atherosclerotic lesions in Iranian patients. Patients and Methods: In the case-control study, 108 patients with coronary atherosclerosis disease and 95 control subjects with no family history of cardiovascular disease were enrolled. Genotypes for NOS3, MTHFR, APOB and TNF-α polymorphisms were identified using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Results: We specifically detected the NOS3 TT genotype in 12 patients (11.11%) and did not find the same genotype in any of the controls. The frequencies of T allele in patients and the controls were 24% and 17.8%, respectively. The prevalence of the MTHFR TT genotype was 16.7% in patients and 2.2% in control groups. The prevalence of the APOB-100 (R350 0Q) mutation in this patient population was 0%. The frequency of the A allele in the TNF-α gene was 11.1% and 11% in patients and controls, respectively, and the AA genotype was undetected. Conclusions: Our results show a significant association of NOS3 and MTHFR gene polymorphisms with coronary atherosclerotic lesions. Therefore, these variants might influence the risk of coronary artery disease, specifically in the Iranian population

Selective laser melted stainless steel CX : role of built orientation on microstructure and micro-mechanical properties

In this work, the effect of built direction on the small-scale mechanical properties and microstructure of a novel maraging stainless steel (SS-CX) manufactured through the selective laser melting (SLM) process was studied. Advanced electron microscopy and nanoindentation techniques were utilized to evaluate retained austenite fraction and micro-mechanical properties, respectively. Different thermal histories caused by the change of the built direction resulted in microstructures with different volume fractions of retained austenite and grain morphology. Furthermore, the slower cooling rates in the vertically built sample was found to result in the formation of large elongated grains and lower hardness values during the nanoindentation experiments

Adenosine Preconditioning versus Ischemic Preconditioning in Patients undergoing Off-Pump Coronary Artery Bypass (OPCAB)

Background: During off-pump coronary artery bypass (OPCAB), the heart is subjected to ischemic and reperfusion injury. Preconditioning is a mechanism that permits the heart to tolerate myocardial ischemia. The aim of this study was to compare the effects of Adenosine preconditioning with ischemic preconditioning on the global ejection fraction (EF) in patients undergoing OPCAB. Methods: In this single-blind, randomized controlled trial, sixty patients undergoing OPCAB were allocated into three equally-numbered groups through simple randomization: Adenosine group, ischemic group, and control group. The patients in the Adenosine group received an infusion of Adenosine. In the ischemic group, ischemic preconditioning was induced by the temporary occlusion of the left anterior descending coronary artery twice for a 2-minute period, followed by 3-minute reperfusion before bypass grafting of the first coronary vessel. The control group received an intravenous infusion of 0.9% saline. Blood samples at different times were sent for the measurement of creatine kinase isoenzyme MB (CK-MB) and cardiac troponin I (cTnI). We also recorded electrocardiographic indices and clinical parameters, including postoperative use of inotropic drugs and preoperative and postoperative EF. Results: History of myocardial infarction, hyperlipidemia, diabetes mellitus, kidney disease, preoperative arrhythmias, and utilization of postoperative inotrope was the same between the three groups. The incidence of postoperative arrhythmias was not significant between the three groups. Also, there were no significant differences in preoperative and postoperative EF and the serum levels of enzymes (cTnI and CK-MB) between the groups. Conclusion: Based on the findings of this study, there was no significant difference in the postoperative EF between the groups. Although the incidence of arrhythmias was higher in the ischemic preconditioning group than in the other groups, the difference between the groups did not constitute statistical significance