Evaluation of genotoxicity and oxidative damage in painters exposed to low levels of toluene

Toluene is an organic solvent used in numerous processes and products, including industrial paints. Toluene neurotoxicity and reproductive toxicity are well recognized: however, its genotoxicity is still under discussion, and toluene is not classified as a carcinogenic solvent. Using the comet assay and the micronucleus test for detection of possible genotoxic effects of toluene, we monitored industrial painters from Rio Grande do Sul, Brazil. The putative involvement of oxidative stress in genetic damage and the influences of age, smoking, alcohol consumption, and exposure time were also assessed. Although all biomarkers of toluene exposure were below the biological exposure limits, painters presented significantly higher DNA damage (comet assay) than the control group; however, in the micronucleus assay, no significant difference was observed. Painters also showed alterations in hepatic enzymes and albumin levels, as well as oxidative damage, suggesting the involvement of oxidative stress. According to multiple linear regression analysis, blood toluene levels may account for the increased DNA damage in painters. In summary, this study showed that low levels of toluene exposure can cause genetic damage, and this is related to oxidative stress, age, and time of exposure. (C) 2012 Elsevier B.V. All rights reserved.

Ischemic heart disease and correlates in adults from Ribeirao Preto, Brazil

OBJECTIVE: To identify the prevalence of ischemic heart disease (IHD) and correlates in an adult population. METHODS: Cross-sectional population-based epidemiological study including a weighted sample of 2,471 adults of both sexes and with age 30 years or older residing in Ribeirao Preto, Southeastern Brazil, in 2007. The Rose Questionnaire was administered, and IHD prevalence was calculated with point estimates and 95% confidence intervals. To identify correlates (sociodemographic, cardiovascular risk factors, and those related to access to health services and to physical activity level), crude and adjusted prevalence ratios were estimated using Poisson regression. RESULTS: IHD prevalence was higher in females than males at all age strata. In the final model, the following variables were independently associated with IHD: work status (PR = 0.54 [0.37; 0.78]); family history of IHD (PR = 1.55 [1.12;2.13]); hypertension (PR = 1.70 [1.18;2.46]); self-reported health status (PR=2.15 [1.40;3.31]); smoking duration (third tertile) (PR=1.73 [1.08;2.76]); adjusted waist circumference (PR=1.79 [1.21;2.65]) and hypertriglyceridemia (PR=1.48 [1.05;2.10]). Linear trend test of PR across self-reported health status categories was statistically significant (p<0.05). CONCLUSIONS: A high prevalence of IHD was found, and the factors associated with the outcome are almost all modifiable and potentially influenced by public policy interventions.

Use of Demonstrably Effective Therapies in the Treatment of Acute Coronary Syndromes: Comparison between Different Brazilian Regions. Analysis of the Brazilian Registry on Acute Coronary Syndromes (BRACE)

Background: Little is known in our country about regional differences in the treatment of acute coronary disease. Objective: To analyze the behavior regarding the use of demonstrably effective regional therapies in acute coronary disease. Methods: A total of 71 hospitals were randomly selected, respecting the proportionality of the country in relation to geographic location, among other criteria. In the overall population was regionally analyzed the use of aspirin, clopidogrel, ACE inhibitors / AT1 blocker, beta-blockers and statins, separately and grouped by individual score ranging from 0 (no drug used) to 100 (all drugs used). In myocardial infarction with ST elevation (STEMI) regional differences were analyzed regarding the use of therapeutic recanalization (fibrinolytics and primary angioplasty). Results: In the overall population, within the first 24 hours of hospitalization, the mean score in the North-Northeast (70.5 +/- 22.1) was lower (p < 0.05) than in the Southeast (77.7 +/- 29.5), Midwest (82 +/- 22.1) and South (82.4 +/- 21) regions. At hospital discharge, the score of the North-Northeast region (61.4 +/- 32.9) was lower (p < 0.05) than in the Southeast (69.2 +/- 31.6), Midwest (65.3 +/- 33.6) and South (73.7 +/- 28.1) regions; additionally, the score of the Midwest was lower (p < 0.05) than the South region. In STEMI, the use of recanalization therapies was highest in the Southeast (75.4%, p = 0.001 compared to the rest of the country), and lowest in the North-Northeast (52.5%, p < 0.001 compared to the rest of the country). Conclusion: The use of demonstrably effective therapies in the treatment of acute coronary disease is much to be desired in the country, with important regional differences.

Endogenous testosterone increases leukocyte-endothelial cell interaction in spontaneously hypertensive rats

Aims: Inflammation may have an important role in the beginning and in the progress of cardiovascular diseases. Testosterone exerts important effects on vascular function, which is altered in arterial hypertension. Thus, the aim of this study was to evaluate the influence of endogenous testosterone on leukocyte behavior in post-capillary venules of the mesenteric bed of spontaneously hypertensive rats (SHR). Main methods: 18 week-old intact SHR, castrated SHR and normotensive rats (intact Wistar) were used. Blood pressure was measured by tail plethysmography and serum testosterone levels by ELISA. Leukocyte rolling, adhesion and migration were evaluated in vivo in situ by intravital microscopy. Key findings: Castration significantly reduced blood pressure and reversed the increased leukocyte rolling and adhesion observed in SHRs. Leukocyte counts and other hemodynamic parameters did not differ among groups. SHRs displayed increased protein expression of P-selectin and ICAM-1 in mesenteric venules when compared to intact Wistar. Castration of SHRs restored the protein expression of the cell adhesion molecules. Significance: The findings of the present study demonstrate the critical role of endogenous testosterone mediating the effects of hypertension increasing leukocyte-endothelial cell interaction. Increased expression of cell adhesion molecules contribute to the effects of endogenous testosterone promoting increased leukocyte rolling and adhesion in SHRs. (c) 2012 Elsevier Inc. All rights reserved.

Left cardiac sympathetic denervation for treatment of symptomatic systolic heart failure patients: a pilot study

To evaluate the feasibility, safety, and potential beneficial effects of left cardiac sympathetic denervation (LCSD) in systolic heart failure (HF) patients. In this prospective, randomized pilot study, inclusion criteria were New York Heart Association (NYHA) functional class II or III, left ventricular ejection fraction (LVEF) 40, sinus rhythm, and resting heart rate 65 b.p.m., despite optimal medical therapy (MT). Fifteen patients were randomly assigned either to MT alone or MT plus LCSD. The primary endpoint was safety, measured by mortality in the first month of follow-up and morbidity according to pre-specified criteria. Secondary endpoints were exercise capacity, quality of life, LVEF, muscle sympathetic nerve activity (MSNA), brain natriuretic peptide (BNP) levels and 24 h Holter mean heart rate before and after 6 months. We studied clinical effects in long-term follow-up. Ten patients underwent LCSD. There were no adverse events attributable to surgery. In the LCSD group, LVEF improved from 25 6.6 to 33 5.2 (P 0.03); 6 min walking distance improved from 167 35 to 198 47 m (P 0.02). Minnesota Living with Heart Failure Questionnaire (MLWHFQ) score physical dimension changed from 21 5 to 15 7 (P 0.06). The remaining analysed variables were unchanged. During 848 549 days of follow-up, in the MT group, three patients either died or underwent cardiac transplantation (CT), while in the LCSD group six were alive without CT. LCSD was feasible and seemed to be safe in systolic HF patients. Its beneficial effects warrant the development of a larger randomized trial. Trail registration: NCT01224899.

Impaired blood-brain/spinal cord barrier in ALS patients

Vascular pathology, including blood-brain/spinal cord barrier (BBB/BSCB) alterations, has recently been recognized as a key factor possibly aggravating motor neuron damage, identifying a neurovascular disease signature for ALS. However, BBB/BSCB competence in sporadic ALS (SALS) is still undetermined. In this study, BBB/BSCB integrity in postmortem gray and white matter of medulla and spinal cord tissue from SALS patients and controls was investigated. Major findings include (1) endothelial cell damage and pericyte degeneration, (2) severe intra- and extracellular edema, (3) reduced CD31 and CD105 expressions in endothelium, (4) significant accumulation of perivascular collagen IV, and fibrin deposits (5) significantly increased microvascular density in lumbar spinal cord, (6) IgG microvascular leakage, (7) reduced tight junction and adhesion protein expressions. Microvascular barrier abnormalities determined in gray and white matter of the medulla, cervical, and lumbar spinal cord of SALS patients are novel findings. Pervasive barrier damage discovered in ALS may have implications for disease pathogenesis and progression, as well as for uncovering novel therapeutic targets. (C) 2012 Elsevier B.V. All rights reserved.

Quantitative coronary arterial stenosis assessment by multidetector CT and invasive coronary angiography for identifying patients with myocardial perfusion abnormalities

Semi-quantitative stenosis assessment by coronary CT angiography only modestly predicts stress-induced myocardial perfusion abnormalities. The performance of quantitative CT angiography (QCTA) for identifying patients with myocardial perfusion defects remains unclear. CorE-64 is a multicenter, international study to assess the accuracy of 64-slice QCTA for detecting a parts per thousand yen50% coronary arterial stenoses by quantitative coronary angiography (QCA). Patients referred for cardiac catheterization with suspected or known coronary artery disease were enrolled. Area under the receiver-operating-characteristic curve (AUC) was used to evaluate the diagnostic accuracy of the most severe coronary artery stenosis in a subset of 63 patients assessed by QCTA and QCA for detecting myocardial perfusion abnormalities on exercise or pharmacologic stress SPECT. Diagnostic accuracy of QCTA for identifying patients with myocardial perfusion abnormalities by SPECT revealed an AUC of 0.71, compared to 0.72 by QCA (P = .75). AUC did not improve after excluding studies with fixed myocardial perfusion abnormalities and total coronary arterial occlusions. Optimal stenosis threshold for QCTA was 43% yielding a sensitivity of 0.81 and specificity of 0.50, respectively, compared to 0.75 and 0.69 by QCA at a threshold of 59%. Sensitivity and specificity of QCTA to identify patients with both obstructive lesions and myocardial perfusion defects were 0.94 and 0.77, respectively. Coronary artery stenosis assessment by QCTA or QCA only modestly predicts the presence and the absence of myocardial perfusion abnormalities by SPECT. Confounding variables affecting the relationship between coronary anatomy and myocardial perfusion likely account for some of the observed discrepancies between coronary angiography and SPECT results.

Influence of a hypercholesterolemic diet on the collagen composition of the bladder wall extracellular matrix in rats

Purpose: To investigate the effects of hypercholesterolemic diet on the collagen composition of urinary bladder wall. Materials and methods: Forty-five female 4-week-old Wistar rats were divided into three groups: 1) control group fed a normal diet (ND); 2) model of bladder outlet obstruction (BOO) group fed a ND; and 3) group fed a HCD (1.25% cholesterol). Total serum cholesterol, LDL cholesterol and body weight were assessed at baseline. Four weeks later, group 2 underwent a surgical procedure resulting in a partial BOO, while groups 1 and 3 underwent a sham similar surgical procedure. Six weeks later, all animals had their bladders removed; serum cholesterol and LDL cholesterol levels and body weights were measured. Morphological and morphometric analysis was performed by Picrosirius staining and collagen types I and III were identified by immunofluorescence. Statistical analysis was completed and significance was considered when p<0.05. Results: Rats fed an HCD exhibited a significant increase in LDL cholesterol levels (p<0.001) and body weight (p=0.017), when compared to the groups fed a ND during the ten-week study period. Moreover, the HCD induced morphological alterations of the bladder wall collagen, regarding thin collagen fibers and the amounts of type III collagen when compared to the control group (p=0.002 and p=0.016, respectively), resembling the process promoted in the BOO model. Conclusions: A hyper-cholesterolemic diet in Wistar rats promoted morphological changes of the bladder types of collagen, as well as increases in body weight and LDL cholesterol.

Effect of cilostazol and pentoxifylline on gait biomechanics in rats with ischemic left hindlimb

Objective: The purpose of this study was to determine the impact of pharmacologic treatment with cilostazol and pentoxifylline on gait biomechanics of ischemic rat hindlimbs compared with nonischemic controls. Methods: An experimental study was designed using 30 Wistar rats divided into five groups (n = 6): control (C); ischemia (I) - animals submitted to left common iliac artery interruption without pharmacologic treatment; pentoxifylline (Pen) - rats submitted to procedure and treated with pentoxifylline 3 mg/kg twice a day for 6 weeks; cilostazol (Cil) - animals submitted to procedure and treated with cilostazol 30 mg/kg twice a day for 6 weeks; and sham (S) - animals submitted to procedure without artery interruption. Gait analysis was performed using a computed treadmill. Time, number, and duration of each hindlimb contact were obtained. The total number of contacts (TNC) and the total duration of contacts (TDC) were compared between left and right hindlimb and among groups. Left hindlimb ischemic incapacitation index (LHII) was defined by the formula: LHII = (1 - TNCleft x TDCleft/TNCright x TDCright) x 100 Results: Left hindlimb TNC values were twofold lower in I, Pen, and Cil groups than in C and S groups (P < .01). In I, Pen, and Cil groups, TNC values for the left hindlimb were half of the right hindlimb ones (P < .01). Left hindlimb TDC values were lower in I and Pen groups than the other groups (P < .01). Cil group presented twofold increased values, not different from C and S groups (P = 0.16). Right hindlimb TNC values were greater for I group (P < .01). LHII was around zero in C and S groups and 82 in both I and Pen groups (P < .01). Cil group presented a LHII of 42; higher than C and S groups, but lower than I and Pen groups (P < .01). Conclusions: Cilostazol at a dose of 30 mg/kg twice a day promoted improvement in gait performance in rats submitted to chronic hindlimb ischemia. Pentoxifylline at a dose of 3 mg/kg twice a day did not show this effect. (J Vasc Surg 2012;56:476-81.)

ENVIRONMENTAL TOBACCO SMOKE INDUCES OXIDATIVE STRESS IN DISTINCT BRAIN REGIONS OF INFANT MICE

Environmental tobacco smoke (ETS) leads to the death of 600,000 nonsmokers annually and is associated with disturbances in antioxidant enzyme capacity in the adult rodent brain. However, little is known regarding the influence of ETS on brain development. The aim of this study was to determine levels of malonaldehyde (MDA) and 3-nitrotyrosine (3-NT), as well as enzymatic antioxidant activities of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and superoxide dismutase (SOD), in distinct brain structures. BALB/c mice were exposed to ETS twice daily for 1 h from postnatal day 5 through postnatal day 18. Acute exposure was performed for 1 h on postnatal day 18. Mice were euthanized either immediately (0) or 3 h after the last exposure. Immediately after an acute exposure there were higher GR and GST activities and MDA levels in the hippocampus, higher GPx and SOD activities in the prefrontal cortex, and higher GST activity and MDA levels in the striatum and cerebellum. Three hours later there was an increase in SOD activity and MDA levels in the hippocampus and a decrease in the activity of all enzymes in the prefrontal cortex. Immediately after final repeated exposure there were elevated levels of GST and GR activity and decreased GPx activity in the hippocampus. Moreover, a rise was found in GPx and GST activities in the prefrontal cortex and increased GST and GPx activity in the striatum and cerebellum, respectively. After 3 h the prefrontal cortex showed elevated GR and GST activities, and the striatum displayed enhanced GST activity. Data showed that enzymatic antioxidant system in the central nervous system responds to ETS differently in different regions of the brain and that a form of adaptation occurs after several days of exposure.

Effects of Continuous Erythropoietin Receptor Activator in Sepsis-Induced Acute Kidney Injury and Multi-Organ Dysfunction

Background: Despite advances in supportive care, sepsis-related mortality remains high, especially in patients with acute kidney injury (AKI). Erythropoietin can protect organs against ischemia and sepsis. This effect has been linked to activation of intracellular survival pathways, although the mechanism remains unclear. Continuous erythropoietin receptor activator (CERA) is an erythropoietin with a unique pharmacologic profile and long half-life. We hypothesized that pretreatment with CERA would be renoprotective in the cecal ligation and puncture (CLP) model of sepsis-induced AKI. Methods: Rats were randomized into three groups: control; CLP; and CLP+CERA (5 mu g/kg body weight, i.p. administered 24 h before CLP). At 24 hours after CLP, we measured creatinine clearance, biochemical variables, and hemodynamic parameters. In kidney tissue, we performed immunoblotting-to quantify expression of the Na-K-2Cl cotransporter (NKCC2), aquaporin 2 (AQP2), Toll-like receptor 4 (TLR4), erythropoietin receptor (EpoR), and nuclear factor kappa B (NF-kappa B)-and immunohistochemical staining for CD68 (macrophage infiltration). Plasma interleukin (IL)-2, IL-1 beta, IL-6, IL-10, interferon gamma, and tumor necrosis factor alpha were measured by multiplex detection. Results: Pretreatment with CERA preserved creatinine clearance and tubular function, as well as the expression of NKCC2 and AQP2. In addition, CERA maintained plasma lactate at normal levels, as well as preserving plasma levels of transaminases and lactate dehydrogenase. Renal expression of TLR4 and NF-kappa B was lower in CLP+CERA rats than in CLP rats (p<0.05 and p<0.01, respectively), as were CD68-positive cell counts (p<0.01), whereas renal EpoR expression was higher (p<0.05). Plasma levels of all measured cytokines were lower in CLP+CERA rats than in CLP rats. Conclusion: CERA protects against sepsis-induced AKI. This protective effect is, in part, attributable to suppression of the inflammatory response.

Ethanol consumption increases the expression of endothelial nitric oxide synthase, inducible nitric oxide synthase and metalloproteinases in the rat kidney

Objectives The effects of longterm ethanol consumption on the levels of nitric oxide (NO) and the expression of endothelial NO synthase (eNOS), inducible NO synthase (iNOS) and metalloproteinase-2 (MMP-2) were studied in rat kidney. Methods Male Wistar rats were treated with 20% ethanol (v/v) for 6 weeks. Nitrite and nitrate generation was measured by chemiluminescence. Protein and mRNA levels of eNOS and iNOS were assessed by immunohistochemistry and quantitative real-time polymerase chain reaction, respectively. MMP-2 activity was determined by gelatin zymography. Histopathological changes in kidneys and indices of renal function (creatinine and urea) and tissue injury (mitochondrial respiration) were also investigated. Results Chronic ethanol consumption did not alter malondialdehyde levels in the kidney. Ethanol consumption induced a significant increase in renal nitrite and nitrate levels. Treatment with ethanol increased mRNA expression of both eNOS and iNOS. Immunohistochemical assays showed increased immunostaining for eNOS and iNOS after treatment with ethanol. Kidneys from ethanol-treated rats showed increased activity of MMP-2. Histopathological investigation of kidneys from ethanol-treated animals revealed tubular necrosis. Indices of renal function and tissue injury were not altered in ethanol-treated rats. Conclusions Ethanol consumption increased renal metalloproteinase expression/activity, which was accompanied by histopathological changes in the kidney and elevated NO generation. Since iNOS-derived NO and MMPs contribute to progressive renal injury, the increased levels of NO and MMPs observed in ethanol-treated rats might contribute to progressive renal damage.

ST Elevation Myocardial Infarction in the elderly

Acute coronary syndromes (ACS) are the leading causes of death in the elderly. The suspicion and diagnosis of ACS in this age group is more difficult, since typical angina is less frequent. The morbidity and mortality is greater in older age patients presenting ACS. Despite the higher prevalence and greater risk, elderly patients are underrepresented in major clinical trials from which evidence based recommendations are formulated. The authors describe, in this article, the challenges in the diagnosis and management of ST elevation myocardial infarction in the elderly, and discuss the available evidence.

Anatrophic Nephrotomy as Nephron-Sparing Approach for Complete Removal of Intraparenchymal Renal Tumors

Objective: Partial nephrectomy for small kidney tumors has increased in the last decades, and the approach to non-palpable endophytic tumors became a challenge, with larger chances of positive margins or complications. The aim of this study is to describe an alternative nephron-sparing approach for small endophytic kidney tumors through anatrophic nephrotomy. Patients and Methods: A retrospective analysis of patients undergoing partial nephrectomy at our institution was performed and the subjects with endophytic tumors treated with anatrophic nephrotomy were identified. Patient demographics, perioperative outcomes and oncological results were evaluated. Results: Among the partial nephrectomies performed for intraparenchymal tumors between 06/2006 and 06/2010, ten patients were submitted to anatrophic nephrotomy. The mean patient age was 42 yrs, and the mean tumor size was 2.3 cm. Mean warm ischemia time was 22.4 min and the histopathological analysis showed 80% of clear cell carcinomas. At a mean follow-up of 36 months, no significant creatinine changes or local or systemic recurrences were observed. Conclusion: The operative technique described is a safe and effective nephron-sparing option for complete removal of endophytic renal tumors.

Kinin-B2 Receptor Mediated Neuroprotection after NMDA Excitotoxicity Is Reversed in the Presence of Kinin-B1 Receptor Agonists

Background: Kinins, with bradykinin and des-Arg(9)-bradykinin being the most important ones, are pro-inflammatory peptides released after tissue injury including stroke. Although the actions of bradykinin are in general well characterized; it remains controversial whether the effects of bradykinin are beneficial or not. Kinin-B2 receptor activation participates in various physiological processes including hypotension, neurotransmission and neuronal differentiation. The bradykinin metabolite des-Arg(9)-bradykinin as well as Lys-des-Arg(9)-bradykinin activates the kinin-B1 receptor known to be expressed under inflammatory conditions. We have investigated the effects of kinin-B1 and B2 receptor activation on N-methyl-Daspartate (NMDA)-induced excitotoxicity measured as decreased capacity to produce synaptically evoked population spikes in the CA1 area of rat hippocampal slices. Principal Findings: Bradykinin at 10 nM and 1 mu M concentrations triggered a neuroprotective cascade via kinin-B2 receptor activation which conferred protection against NMDA-induced excitotoxicity. Recovery of population spikes induced by 10 nM bradykinin was completely abolished when the peptide was co-applied with the selective kinin-B2 receptor antagonist HOE-140. Kinin-B2 receptor activation promoted survival of hippocampal neurons via phosphatidylinositol 3-kinase, while MEK/MAPK signaling was not involved in protection against NMDA-evoked excitotoxic effects. However, 100 nM Lys-des-Arg(9)-bradykinin, a potent kinin-B1 receptor agonist, reversed bradykinin-induced population spike recovery. The inhibition of population spikes recovery was reversed by PD98059,showing that MEK/MAPK was involved in the induction of apoptosis mediated by the B1 receptor. Conclusions: Bradykinin exerted protection against NMDA-induced excitotoxicity which is reversed in the presence of a kinin-B1 receptor agonist. As bradykinin is converted to the kinin-B1 receptor metabolite des-Arg(9)-bradykinin by carboxypeptidases, present in different areas including in brain, our results provide a mechanism for the neuroprotective effect in vitro despite of the deleterious effect observed in vivo.