Cigarette smoking and antioxidant defences in packed red blood cells prior to storage.

BACKGROUND: Red blood cells from smoking donors can have more lesions from oxidative stress, decreasing the benefits of blood transfusion. We aimed to explore the effect of cigarette smoking on the oxidative status of packed red blood cells (PRBCs) prior to storage. MATERIALS AND METHODS: We compared serum vitamin C, plasmatic malondialdehyde (MDA), and non-protein thiol groups (GSH) levels in PRBCs, as well glutathione peroxidase (GPx) and glutathione s-transferase (GST) activity in PRBCs from smoking (n=36) and non-smoking (n=36) donors. We also correlated urinary cotinine levels with these parameters. RESULTS: Cigarette smoking was associated with decreased serum levels of vitamin C and GPx, and increased GST activity in PRBCs. We found negative correlations between cotinine, GPx activity and vitamin C levels, and a positive correlation between cotinine and GST activity. DISCUSSION: Cigarette smoking changed antioxidant defences of PRBCs prior to storage and these parameters are correlated with cotinine levels. Increased RBC antioxidants such as GST may reflect an exposure to oxidants during erythropoiesis. Because of the inability of mature RBCs to resynthesise antioxidants, PRBCs from smokers may have higher risk of storage lesions than those from non-smoker donors.

Toxic elements in packed red blood cells from smoker donors: a risk for paediatric transfusion?

BACKGROUND AND OBJECTIVES: Smokers currently have no defined restrictions for blood donation. However, cigarette smoke contains toxic substances such as carbon monoxide (CO) and trace elements that can affect the packed red blood cells (PRBCs) quality and safety of transfusion. This study evaluated the effects of smoking on the concentration of essential and trace elements and on carboxyhemoglobin (COHb) levels in PRBCs from smoker donors. MATERIALS AND METHODS: A matched case-control study was conducted to compare COHb levels, determined by the CO-oximetry method, and levels of trace (Cd, Pb, Cr, Ni, As and Hg) and essential (Ca, Mg, Cu, Fe, Mn, Mo, Se and Zn) elements evaluated by inductively coupled plasma mass spectrometry, in PRBCs from smoker (n = 36) and non-smoker (n = 36) donors at Hospital de Clínicas de Porto Alegre, Brazil. RESULTS: Mean COHb level was 14 times higher in the PRBCs obtained from smoker donors (5·9 [4·0-9·1] vs. 0·4 [0·2-0·8]%). Cadmium (1·0 [1·0-1·8] µg/l vs. undetectable) and lead (27 [21-36] vs. 19 [14-26] µg/l) levels were significantly higher in the PRBCs from smokers. Moreover, except for molybdenum, levels of all essential elements were lower in smoker PRBCs. CONCLUSION: The PRBCs donated by smokers contain toxic elements that are probably not safe for transfusion in children. Our results might support changes in the current guidelines of blood banks to improve the transfusion safety through inclusion of inquiry about smoking in the clinical screening, labelling and reserve PRBCs from smoker donors for adults or less critical recipients.

Clinical, Endocrine and Imaging Characteristics of Patients with Primary Hypophysitis.

Primary hypophysitis (PH) is a rare disease with a poorly-defined natural history. Our aim was to characterise patients with PH at presentation and during prolonged follow-up. Observational retrospective study of 22 patients was conducted from 3 centres. In 14 patients, PH was confirmed histologically and in the remaining 8 clinically, after excluding secondary causes of hypophysitis. All patients had hormonal and imaging investigations before any treatment. Median follow up was 48 months (25-75%: 3-60). There was a female predominance with a female/male ratio: 3.4:1. Eight out of 22 patients had another autoimmune disease. Headaches and gonadal dysfunction were the most common symptoms. Five patients presented with panhypopituitarism; 17 patients had anterior pituitary deficiency, and 7 had diabetes insipidus. At presentation, 9 patients were treated surgically, 5 received replacement hormonal treatment, and 8 high-dose glucocorticoids from whom 5 in association with other immunosuppressive agents. Six patients showed complete recovery of pituitary hormonal deficiencies while 6 showed a partial recovery during a 5-year follow-up period. No difference was found between patients treated with surgery and those treated medically. The overall relapse rate was 18%. PH can be manifested with a broad spectrum of clinical and hormonal disturbances. Long-term follow-up is required to define the natural history of the disease and response to treatment, since pituitary hormonal recovery or relapse may appear many years after initial diagnosis. We suggest that surgery and immunosuppressive therapy be reserved for exceptional cases.

N-acetylcysteine Plus Deferoxamine Improves Cardiac Function in Wistar Rats After Non-reperfused Acute Myocardial Infarction.

The antioxidant N-acetycysteine can turn into a prooxidant molecule in presence of iron ions. Thus, our goal was to test if the association of N-acetylcysteine (NAC) and an iron chelator (deferoxamine--DFX) in a rodent model of acute myocardial infarction (AMI) improves cardiac function. Male Wistar rats were subjected to a SHAM surgery or AMI. The animals were randomized: vehicle, NAC (25 mg/kg for 28 days), DFX (40 mg/kg for 7 days), or NAC plus DFX (NAC plus DFX, respectively). Animals were killed 28 days after the AMI. Animals treated with NAC/DFX showed an increase in left ventricular ejection fraction at 28 days when compared with vehicle group (45.2 ± 10.9 % vs. 34.7 ± 8.7 %, p = 0.03). Antioxidant effect of NAC/DFX treatment decreased 4-hydroxynonenal when compared to AMI group (p = 0.06). In conclusion, we showed beneficial effect of NAC/DFX association in improving left ventricle function in an experimental AMI.

An analysis of the global expression of microRNAs in an experimental model of physiological left ventricular hypertrophy.

BACKGROUND: MicroRNAs (miRs) are a class of small non-coding RNAs that regulate gene expression. Studies of transgenic mouse models have indicated that deregulation of a single miR can induce pathological cardiac hypertrophy and cardiac failure. The roles of miRs in the genesis of physiological left ventricular hypertrophy (LVH), however, are not well understood. OBJECTIVE: To evaluate the global miR expression in an experimental model of exercise-induced LVH. METHODS: Male Balb/c mice were divided into sedentary (SED) and exercise (EXE) groups. Voluntary exercise was performed on an odometer-monitored metal wheels for 35 days. Various tests were performed after 7 and 35 days of training, including a transthoracic echocardiography, a maximal exercise test, a miR microarray (miRBase v.16) and qRT-PCR analysis. RESULTS: The ratio between the left ventricular weight and body weight was increased by 7% in the EXE group at day 7 (p<0.01) and by 11% at day 35 of training (p<0.001). After 7 days of training, the microarray identified 35 miRs that were differentially expressed between the two groups: 20 were up-regulated and 15 were down-regulated in the EXE group compared with the SED group (p = 0.01). At day 35 of training, 25 miRs were differentially expressed: 15 were up-regulated and 10 were decreased in the EXE animals compared with the SED animals (p<0.01). The qRT-PCR analysis demonstrated an increase in miR-150 levels after 35 days and a decrease in miR-26b, miR-27a and miR-143 after 7 days of voluntary exercise. CONCLUSIONS: We have identified new miRs that can modulate physiological cardiac hypertrophy, particularly miR-26b, -150, -27a and -143. Our data also indicate that previously established regulatory gene pathways involved in pathological LVH are not changed in physiological LVH.

Transcoronary gradient of plasma microRNA 423-5p in heart failure: evidence of altered myocardial expression.

CONTEXT: Elevated plasmatic microRNAs (miRs) are observed in heart failure (HF). However, the cardiac origin of these miRs remains unclear. OBJECTIVE: We calculated transcoronary gradients of miR-29b, miR-133a and miR-423-5p in 17 outpatients with stable systolic HF and in controls without structural cardiac disease. MATERIALS AND METHODS: MicroRNAs were measured by quantitative real-time polymerase chain reaction. RESULTS: Positive transcoronary miR gradients were observed in patients with HF but not in controls (p = 0.03). B-type natriuretic peptide (BNP) moderately correlated with the transcoronary gradients of miR-133a and miR-423-5p. DISCUSSION AND CONCLUSIONS: The difference in transcoronary gradients between HF outpatients and controls suggests that miR-423-5p has a cardiac origin. The positive correlation between miR-423-5p and BNP transcoronary gradients supports this hypothesis.

Association study of polymorphisms in the receptor for advanced glycation end-products (RAGE) gene with susceptibility and prognosis of heart failure.

BACKGROUND: Functional polymorphisms in the receptor for advanced glycation end-products (RAGE) gene have been implicated in several vascular diseases. However, to date, no study investigated the association of RAGE polymorphisms with heart failure (HF). OBJECTIVE: In this study we tested the hypothesis that the 63-bp insertion/deletion, the -374T>A (rs1800624) and the -429T>C (rs1800625) polymorphisms in the RAGE gene might be associated with susceptibility to HF and could predict all-cause mortality in Brazilian outpatients with left ventricular systolic dysfunction. METHODS: A total of 273 consecutive HF patients (196 Caucasian- and 77 African-Brazilians) and 334 healthy blood donors (260 Caucasian- and 74 African-Brazilians) were enrolled in a tertiary care university hospital. Genotyping of RAGE polymorphisms was done by polymerase chain reaction (PCR) or PCR followed by enzyme restriction analysis. RESULTS: The allele, genotype and haplotype frequencies of -374T>A and -429T>C polymorphisms were not significantly different between HF patients and healthy blood donors in both ethnic groups. However, among African-Brazilians, the frequency of carriership of the del allele was lower in HF patients than in blood donors (2.6% vs 12.2%, respectively, p=0.008). Patients were followed-up for a median of 38 months and the survival analysis did not reveal a consistent association between RAGE polymorphisms and all-cause death in both ethnic groups. CONCLUSION: The -374T>A and -429T>C polymorphisms in the RAGE gene were not associated with the susceptibility and prognosis of HF. Notwithstanding, the 63-bp ins/del polymorphism might be involved in the susceptibility to HF in African-Brazilians.

Polymorphisms of endothelial nitric oxide synthase gene in systolic heart failure: an haplotype analysis.

BACKGROUND: Endothelial nitric oxide synthase (eNOS) gene polymorphisms have been associated with the pathogenesis of cardiovascular diseases, but few studies have evaluated the role of eNOS haplotypes on the risk and prognosis of heart failure (HF). This prospective study was designed to analyze the impact of three eNOS polymorphisms (T-786C, VNTR4a/b and Glu298Asp) and their haplotypes on the susceptibility and clinical outcomes in HF outpatients with systolic dysfunction. METHODS AND RESULTS: We conducted a case-control and a cohort study in which 316 HF patients and 360 healthy controls were recruited from a tertiary care university hospital. DNA was extracted from peripheral blood and eNOS polymorphisms were detected by PCR or PCR-RFLP. Patients were predominantly men, had a mean left ventricular ejection fraction of 31% and were followed-up for a median of 41months; there were 96 deaths, including 58 HF-related deaths. Genotype distribution of the eNOS T-786C, VNTR 4a/b and Glu298Asp was similar between HF patients and controls. Haplotype frequencies differed between HF patients and controls only in African-Brazilians (p=0.043). African-Brazilian patients that carried the haplotype -786C/4b/Asp298 had a better prognosis than patients that carried other haplotypes (log rank p value=0.016 for all-cause mortality). In a Cox proportional hazard model adjusted for clinical variables of risk, the -786C/4b/Asp298 haplotype remained as an independent genetic predictor of survival (adjusted HR=0.11; 95% CI=0.01-0.83; p=0.03). CONCLUSIONS: The -786C/4b/Asp298 eNOS haplotype had a significant impact on HF susceptibility and prognosis, particularly in African-Brazilian patients.

Polymorphisms of matrix metalloproteinases in systolic heart failure: role on disease susceptibility, phenotypic characteristics, and prognosis.

BACKGROUND: The role of matrix metalloproteinases (MMPs) polymorphisms on heart failure (HF) susceptibility, phenotypic characteristics, and prognosis has been poorly explored. METHODS AND RESULTS: We studied 313 HF patients with left ventricular systolic dysfunction and 367 healthy control subjects. Genotyping of MMP-1 (-1607 1G/2G), MMP-3 (-1171 5A/6A), and MMP-9 (-1562 C/T) polymorphisms was performed by polymerase chain reaction. Allelic and genotypic frequencies of MMP-1, -3, and -9 were similar in HF patients and controls. MMP1 2G allele carriers were positively associated to ischemic etiology and history of myocardial infarction (all P values <.05). Patients were followed-up for a median of 40 months and 58 HF-related deaths occurred during this period. HF-related survival was significantly better in MMP1 2G allele carriers (71% versus 42% for 1G/1G patients, P = .002) and in MMP-3 6A allele carriers (70% versus 61% for 5A/5A patients, P = .064), particularly in non-ischemic patients (P = .039). MMP1 2G allele was independently associated to HF survival after adjustment for several other predictors of risk (hazard ratio 0.47, 95% confidence interval 0.27 to 0.82; P = .008). CONCLUSIONS: MMP-1, -3, and -9 polymorphisms were not associated to HF susceptibility. However, MMP1 2G allele carriers were related to a higher prevalence of ischemic etiology among patients with systolic HF and better HF-related prognosis.