Atherosclerosis: analysis of the eNOS (T786C) gene polymorphism.

The coronary arteriosclerotic disease is the most common cardiovascular disease. Atherosclerosis affects large- and medium-sized arteries leading to severe thrombosis or artery stenosis that could evolve to myocardial infarction, ischemic stroke, ischemic injury of kidneys and intestines, and several other life-threatening clinical manifestations. Nitric oxide has been shown to be a promising therapeutic agent against cardiovascular diseases. The eNOS gene assumes several important functions, including regulation of vascular tone and regional blood flow, the suppression of vascular smooth muscle cell proliferation, and modulation of leukocyte-endothelium interactions. The T786C polymorphism is an important point mutation, where thymine is changed to cytosine. T786C significantly reduces the activity of the eNOS promoter gene. Two hundred and ninety-seven peripheral blood samples were collected from patients with the previous diagnosis of atherosclerotic disease based on clinical examination and confirmed by imaging methods. Results were compared using the chi-square test and the G-test. In the present study, the TC genotype was more frequent in both case and control groups with no statistically significant difference. Comparing the relation TC/TT and CC genotypes in the case and control groups, there was no statistically significant difference. No significant difference was found when genotypes were analyzed regarding gender and smoking. Our results suggest a strong tendency of the T allele, in single or double dose, to be associated with atherosclerosis that was not confirmed by the scientific data.

Analysis of p53 gene polymorphism (codon 72) in symptomatic patients with atherosclerosis.

Atherosclerosis is a multifactorial pathological disease that alters the morphology and function of arterial walls. The atheroma growth leads to vessel hardening and lumen narrowing, limiting the blood flow. The atheroma plaque can eventually break, expose highly thrombogenic material and lead to platelet activation and subsequent formation of a thrombus that may block blood flow in loco, or even leading to obstruction of other vessels with a smaller diameter. This process is one of the main determinants of the clinical manifestations of atherosclerosis, such as coronary artery disease, ischemic stroke, and peripheral arterial disease. Although the inflammatory theory about atherosclerosis is the most renowned one, observations point to common biological characteristics between cancer and atherosclerosis suggesting a possible association between p53 and atherosclerotic diseases. We collected peripheral blood samples from 200 individuals with clinical manifestations of atherosclerotic disease and 100 individuals without manisfestation of the disease to form the control group. DNA was subjected to molecular analysis (PCR) to identify the polymorphism of the p53 gene. We have not found any relationship between the polymorphism of the p53 gene and atherosclerosis in the population studied (P = 0.36). There was no relationship between atherosclerosis, polymorphism of p53 and the variables accounted: smoking habit (P = 0.72, 0.51 and 0.62 for smokers, non-smokers and former smokers respectively), alcohol consumption (P = 0.17 for individuals with drinking habits and 0.38 for those who do not consume alcohol beverage), systemic arterial hypertension (P = 0.60), diabetes mellitus (P = 0.34), and dyslipidemia (P = 0.89). Our population has a high rate of miscegenation and heterozygotes, and according to studies the arginine variant is more related to plaque formation because it induces apoptosis more frequently when compared to the proline variant. According to our results, there is no association between the polymorphism of the p53 gene, atherosclerosis and its risk factors in the population studied.

Molecular analysis of the GSTT1 gene polymorphism in patients with clinical manifestation of atherosclerosis.

Atherosclerosis is a chronic inflammatory disease formed by the accumulation of lipids in the innermost layer and large-caliber artery (tunica intima). This accumulation, along with platelet factors, stimulates the proliferation of muscle cells in this region. Over than 400 genes may be related to the pathology since they regulate endothelial function, coagulation, inflammation, metabolism of amino acids, lipids, and carbohydrates. Glutathione S-transferases (GST) are enzymes that catalyze the polymorphic detoxification of metabolites produced by oxidative stress within the cells, which is induced by reactive oxygen species. GSTs are one of the defense mechanisms against oxidative stress damage. Due to genetic, cultural, and environmental factors, the rate of atherosclerosis is higher; however, an early diagnosis is crucial for the prevention and treatment of several complications related to the disease. The present study aimed to analyze the frequency of GSTT1 genotypes regarding the presence or absence of the polymorphism in patients with clinical manifestation of atherosclerosis. We collected 200 samples of peripheral blood of patients with the previous diagnosis of atherosclerosis based on clinical examination and imaging, and 100 samples of peripheral blood to compose the control group of patients without clinical manifestation of atherosclerosis. The polymorphism was assessed by PCR and analyzed on the agarose gel stained with 2.0% ethidium bromide. The frequency of the GSTT1 gene polymorphism was compared using the chi-square test (P < 0.05) and the G-test. In the case group, we detected 85.5% of patients with the GSTT1 genotype present and 14.5% of patients with the null genotype. A significant difference was observed between groups (case vs control) for the presence of the GSTT1 polymorphism. According to the analysis of the variable alcohol consumption, we found that in the case group the presence of the GSTT1 gene was higher in individuals who reported not drinking alcohol. In this study, the presence of the GSTT1 gene polymorphism in male patients with atherosclerosis was 1.5 times higher when compared to female patients. Regarding the variable time of smoking, we found that this genotype was more frequent in smokers for both case and control groups.

Polymorphism of the gene eNOS G894T (Glu298Asp) in symptomatic patients with aterosclerosis.

Atherosclerotic and its cardiovascular complications are responsible for 17.5 million deaths a year, according to the World Health Organization. There is consensus that atherosclerosis involves multiple pathogenic processes initiated by endothelial dysfunction, with inflammation and vascular proliferation determining alterations in the matrix, with consequent formation of the atheromatous plaque and its clinical implications. Risk factors such as hypertension, diabetes mellitus, dyslipidemia, and smoking are widely known. Currently, genotyping, which is not directly related to these factors, is not accepted to estimate the risk of cardiovascular diseases, but strong evidence indicates several polymorphic genes as factors of risk and progression leading to complications of the disease. Among the genes involved, eNOS (endothelial nitric oxide synthase gene), which is responsible for the production of endothelial nitric oxide (an important arterial vasodilator), when presented in polymorphic variation can determine production, malfunction, and predisposition to atherosclerosis. In the present study, we analyzed the G894T polymorphism of the eNOS gene in groups of individuals diagnosed with atherosclerosis and in a control group. We collected 200 blood samples from patients previously diagnosed with atherosclerosis and 100 samples formed the control group. The genotyping analysis for polymorphism of the eNOS gene was determined by PCR. We considered variables such as gender, smoking, smoking history, and alcohol consumption; statistical differences were found in the distribution of case and control groups (P = 0.0378) and in non-smoking patients (P = 0.0263). In the other associations, no statistically significant difference was found. In the population studied, the frequency of the heterozygous genotype (GT) was much higher than in the other populations (GG and TT) in both groups (case and control). The GG genotype showed greater susceptibility to atherosclerosis. Association of the GG genotype in non-smokers also showed greater susceptibility. Gender, alcohol consumption, smoking, and smoking history did not influence atherosclerosis.

GSTM1 polymorphism in patients with clinical manifestations of atherosclerosis.

Atherosclerosis is characterized by lesions, called atheroma or atheromatous plaques, in the inner layer of blood vessels, which block the vascular lumen and weaken the underlying tunica media. Several modifiable and non-modifiable risk factors for the development of atherosclerosis exist. The modifiable risk factors include hypertension, smoking, obesity, high LDL and low HDL cholesterol levels, sedentary lifestyle, and stress; the non-modifiable factors include diabetes mellitus, family history of hypertension and heart disease, thrombophilia, sex, age, and genetic factors. The association of polymorphisms in GST with coronary artery disease has been studied since the polymorphisms can affect enzyme activity and contribute to the onset of atherosclerosis. We analyzed polymorphisms in GSTM1 in individuals diagnosed with atherosclerosis as well as in healthy individuals (control group). The frequency of the GSTM1 present genotype in the atherosclerosis group was 1.2 times higher than that observed in the control group. We found no sex- or alcohol-consumption-dependent differences between the occurrences of the present and null genotypes. However, the GSTM1 present genotype occurred in 52.6% individuals with atherosclerosis who reported smoking 20 or more cigarettes per day and in 60% individuals who smoked 10 to 20 cigarettes per day (P = 0.0035). In addition, the GSTM1 present genotype was more frequent in individuals who reported being former smokers - 45.5% in individuals with atherosclerosis who smoked for more than 20 years and 50% each for individuals in the control group who smoked for less than 10 years or for 10 to 20 years, respectively (P = 0.0240).

Male idiopathic infertility and the TP53 polymorphism in codon 72.

Many environmental agents affect the development of male germ cells at different stages. Apoptosis is common during normal spermatogenesis; it plays an important role in controlling the number of germ cells and the disposal of defective stem cells to produce functional sperm. The presence of p53 in primary spermatocytes suggests that it plays a role in the prophase of meiosis. p53 is expressed in the testis in both spermatocytes and spermatogonia. This suggests that the p53 gene (TP53) is important for apoptosis regulation during spermatogenesis, and may be associated with male infertility. The main causes of male infertility are genetic, physical, and pathological abnormalities, intense and prolonged exercise, aging, drug use, and long periods of sexual abstinence. Approximately 20% of male infertility is idiopathic. The Trp53 gene is involved in meiosis in male rats and mice suggesting that the p53 plays a critical role in spermatogenesis. We investigated the association between the TP53 polymorphism in codon 72 and idiopathic male infertility in 208 semen samples: 106 showed abnormal semen analysis results and were from infertile men, and 102 were from fertile individuals (the control group). Changes in Trp53 expression are associated with the main phase regulating meiotic progression with a peak in the pachytene stage, and Trp53-deficient mice exhibit degenerative syndrome (giant cells). The genotypic and allelic frequencies were not significantly different among the groups in this study; the results suggest that the TP53 polymorphism in codon 72 is not associated with the pathogenesis of idiopathic male infertility or failure of spermatogenesis.

Occult hepatitis B virus infection among blood donors from the Brazilian Amazon: implications for transfusion policy.

BACKGROUND: Brazil requires the performance of both a test for hepatitis B surface antigen (HBsAg) and a test for antibodies to the core of hepatitis B for blood donor screening. Blood centres in regions of high HBV endemicity struggle to maintain adequate stocks in face of the high discard rates due to anti-HBc reactivity. We evaluated the potential infectivity of donations positive for anti-HBc in search of a rational approach for the handling of these collections. STUDY DESIGN AND METHODS: We tested anti-HBc reactive blood donations from the state of Amazonas for the presence of HBV DNA and for titres of anti-HBs. The study population consists of village-based donors from the interior of Amazonas state. RESULTS: Among 3600 donations, 799 were anti-HBc reactive (22·2%). We were able to perform real-time PCR for the HBV S gene on specimens from 291 of these donors. Eight of these samples were negative for HBsAg and positive for HBV DNA and were defined as occult B virus infections (2·7%). Six of those eight specimens had anti-HBs titres above 100 mIU/ml, indicating the concomitant presence of the virus with high antibody titres. CONCLUSION: A small proportion of anti-HBc reactive donors carry HBV DNA and anti-HBs testing is not useful for predicting viremia on them. This finding indicates the possibility of HBV transmission from asymptomatic donors, especially in areas of high HBV prevalence. Sensitive HBV DNA nucleic acid testing may provide another level of safety, allowing eventual use of anti-HBc reactive units in critical situations.

Efeito da aplicação de hCG ou GnRH sobre a concentração sérica de progesterona e eficiência reprodutiva em porcas / Effect of injection of hCG or GnRH on progesterone serum concentration and reproductive efficiency of sows

Avaliou-se o efeito da aplicação de diferentes hormônios no quinto dia após a primeira inseminação sobre a concentração sérica de progesterona e sobre as características reprodutivas, em 103 porcas entre o terceirro e sexto parto. As matrizes foram divididas em: grupo-controle (n=35), não tratado, grupo GnRH (n=34), animais submetidos à aplicação intramuscular (IM) de 50mcg de um análogo-GnRH no quinto dia após a primeira inseminação, e grupo hCG (n=34), animais submetidos à aplicação IM de 500UI de hCG no quinto dia após a primeira inseminação. A aplicação dos hormônios não influenciou as características reprodutivas taxa de parto, número total de nascidos, número de nascidos vivos e peso da leitegada (P>0,05). Cinco animais de cada grupo foram submetidos a coletas de sangue da veia cava nos dias 3, 5, 8, 12, 21 e 28 após a primeira inseminação para avaliação da concentração sérica de progesterona (ng/ml), utilizando a técnica de radioimunoensaio. Não houve diferença significativa quanto à concentração sérica de progesterona entre os grupos

Efeito do fracionamento da ração diária sobre a concentração sérica de progesterona em porcas gestantes / Effect of fractionating daily food intake on serum progesterone concentration in pregnant sows

Avaliou-se a influência do fracionamento da alimentação diária nos primeiros 30 dias de gestação de porcas sobre a concentração sérica de progesterona (ng/ml) no 3º, 5º, 8º, 12º, 21º e 28º dias pós-cobrição, utilizando-se a técnica de radioimunoensaio, a partir de amostras de sangue coletadas da veia cava em 15 matrizes entre o terceiro e o sexto parto. As fêmeas foram distribuídas em três grupos de cinco animais: o grupo 1 recebeu apenas um trato diário de dois quilos de ração, o grupo 2 recebeu dois tratos diários de um quilo de ração cada, e o grupo 3, três tratos diários de 670 gramas de ração até 30 dias de gestação. O fracionamento da quantidade de ração fornecida diariamente não alterou a concentração sérica de progesterona até o 28º dia de gestação nas matrizes suínas pluríparas

A eletrocardiografia dinamica (sistema Holter) em clinica medica. / Dynamic electrocardiography (Holter system) in internal medicine

A E.C.D. e um metodo nao invasivo, usado amplamente em cardiologia, no estudo das arritmias. A eficiencia do metodo, o colocou em primeiro plano no estudo da epidemiologia da morte subita. Neste artigo, os autores analisam o seu uso, as suas indicacoes na cardiologia e na clinica medica