Knowledge, attitudes and motivations among blood donors in Sao Paulo, Brazil

Recruiting safe, volunteer blood donors requires understanding motivations for donating and knowledge and attitudes about HIV. We surveyed 1,600 persons presenting for blood donation at a large blood bank in Sao Paulo, Brazil using a self-administered, structured questionnaire, and classified motivations into three domains as well as categorizing persons by HIV test-seeking behavior. Motivations, in descending order, and their significant associations were: ""altruism``: female gender, volunteer donor and repeat donor status; ""direct appeal``: female gender, repeat donor status and age 21-50 years; ""selfinterest``: male gender, age under 20 years, first-time donor status and lower education. HIV test-seekers were more likely to give incorrect answers regarding HIV risk behavior and blood donation and the ability of antibody testing to detect recent HIV infections. Altruism is the main motivator for blood donation in Brazil; other motivators were associated with specific demographic subgroups. HIV test-seeking might be reduced by educational interventions.

Impact of gender on benefits of exercise training on sympathetic nerve activity and muscle blood flow in heart failure

We compared the effects of exercise training on neurovascular control and functional capacity in men and women with chronic heart failure (HF). Forty consecutive HF outpatients from the Heart Institute, University of Sao Paulo, Brazil were divided into the following four groups matched by age: men exercise-trained (n = 12), men untrained (n = 10), women exercise-trained (n = 9), women untrained (n = 9). Maximal exercise capacity was determined from a maximal progressive exercise test on a cycle ergometer. Forearm blood flow was measured by venous occlusion plethysmography. Muscle sympathetic nerve activity (MSNA) was recorded directly using the technique of microneurography. There were no differences between groups in any baseline parameters. Exercise training produced a similar reduction in resting MSNA (P = 0.000002) and forearm vascular resistance (P = 0.0003), in men and women with HF. Peak VO(2) was similarly increased in men and women with HF (P = 0.0003) and VE/VCO(2) slope was significantly decreased in men and women with HF (P = 0.0007). There were no significant changes in left-ventricular ejection fraction in men and women with HF. The benefits of exercise training on neurovascular control and functional capacity in patients with HF are independent of gender.

Red Blood Cell Transfusions are Independently Associated with Intra-Hospital Mortality in Very Low Birth Weight Preterm Infants

Objective To test the hypothesis that red blood cell (RBC) transfusions in preterm infants are associated with increased intra-hospital mortality. Study design Variables associated with death were studied with Cox regression analysis in a prospective cohort of preterm infants with birth weight <1500 g in the Brazilian Network on Neonatal Research. Intra-hospital death and death after 28 days of life were analyzed as dependent variables. Independent variables were infant demographic and clinical characteristics and RBC transfusions. Results Of 1077 infants, 574 (53.3%) received at least one RBC transfusion during the hospital stay. The mean number of transfusions per infant was 3.3 +/- 3.4, with 2.1 +/- 2.1 in the first 28 days of life. Intra-hospital death occurred in 299 neonates (27.8%), and 60 infants (5.6%) died after 28 days of life. After adjusting for confounders, the relative risk of death during hospital stay was 1.49 in infants who received at least one RBC transfusion in the first 28 days of life, compared with infants who did not receive a transfusion. The risk of death after 28 days of life was 1.89 times higher in infants who received more than two RBC transfusions during their hospital stay, compared with infants who received one or two transfusions. Conclusion Transfusion was associated with increased death, and transfusion guidelines should consider risks and benefits of transfusion. (J Pediatr 2011; 159: 371-6).

Quality control of Toxoplasma gondii in meat packages: Standardization of an ELISA test and its use for detection in rabbit meat cuts

Toxoplasma gondii causes severe disease both to man and livestock and its detection in meat after slaughtering requires PCR or biological tests. Meat packages contain retained exudate that could be used for serology due to its blood content. Similar studies reported false negative assays in those tests. We standardized an anti-T. gondii IgG ELISA in muscle juices from experimentally infected rabbits, with blood content determination by cyanhemoglobin spectrophotometry. IgG titers and immunoblotting profiles were similar in blood, serum or meat juice, after blood content correction. These assays were adequate regardless of the storage time up to 120 days or freeze-thaw cycles, without false negative results. We also found 1.35% (1/74) positive sample in commercial Brazilian rabbit meat cuts, by this assay. The blood content determination shows ELISA of meat juice may be useful for quality control for toxoplasmosis monitoring. (C) 2011 Elsevier Ltd. All rights reserved.

Home and Ambulatory Blood Pressure to Identify White Coat and Masked Hypertension in the Pediatric Patient

OBJECTIVE To evaluate the effect of the environment and the observer on the measurement of blood pressure (BP) as well as to compare home BP (HBP) and ambulatory BP (ABP) measurements in the diagnosis of white coat hypertension (WCH) and masked hypertension (MH) in children and adolescents with hypertension (HT). METHODS BP of 40 patients with HT (75% of which had secondary HT and were on antihypertensive medication), mean age 12.1 years was evaluated through casual measurements at the clinic and at the HT unit, HBP for 14 days with the OMRON HEM 705 CP monitor (Omron, Tokyo, Japan) and ABP performed with SPACELABS 90207 (Spacelabs, Redmond, WA), for 24 h. RESULTS HT was diagnosed at the doctor`s office by ABP and HBP in 30/40, 27/40, and 31/40 patients, respectively. Based on office BP and ABP, 60% of patients were normotensive, 17.5% HT, 7.5% had WCH, and 15% had MH, whereas based on office BP and HBP 65, 12.5, 10, and 12.5% of patients were classified according to these diagnoses, respectively. There was considerable diagnostic agreement of HT by ABP and HBP (McNemar test, P < 0.01) (kappa = 0.56). CONCLUSION In hypertensive children and adolescents, HBP and ABP present comparable results. HBP appears to be a useful diagnostic test for the detection of MH and WCH in pediatric patients.

Aerobic training abolishes ambulatory blood pressure increase induced by estrogen therapy: A double blind randomized clinical trial

Emerging data reveal that oral estrogen therapy can increase clinic blood pressure (BP) in postmenopausal women; however, it is important to establish its effects on ambulatory BP, which is a better predictor for target-organ damage. Besides estrogen therapy, aerobic training is widely recommended for post-menopausal women, and it can decrease ambulatory BP levels. This study was designed to evaluate the effect of aerobic training and estrogen therapy on the ambulatory BP of post-menopausal women. Forty seven healthy hysterectomized women were randomly divided (in a double-blind manner) into 4 groups: placebo-control (PLA-CO = 12), estrogen therapy-control (ET-CO = 14), placebo-aerobic training (PLA-AT = 12), and estrogen therapy-aerobic training (ET-AT = 09). The ET groups received estradiol valerate (1 mg/day) and the AT groups performed cycle ergometer, 3x/week at moderate intensity. Hormonal status (blood analysis), maximal cardiopulmonary exercise test (VO(2) peak) and ambulatory BP (24-h, daytime and nighttime) was evaluated before and 6 months after interventions. A significant increase in VO(2) peak was observed only in women who participated in aerobic training groups (+4.6 +/- 1.0 ml kg(-1) min(-1), P=0.00). Follicle-stimulating hormone was a significant decreased in the ET groups (-18.65 +/- 5.19 pg/ml, P=0.00), and it was accompanied by an increase in circulating estrogen (56.1 +/- 6.6 pg/ml). A significant increase was observed in the ET groups for daytime (P=0.01) and nighttime systolic BP (P=0.01), as well as nighttime diastolic BP (P = 0.02). However, daytime diastolic BP was increased only in the ET-CO group (+3.4 +/- 1.2 mmHg, P=0.04), and did not change in any other groups. No significant effect was found in ambulatory heart rate. In conclusion, aerobic training abolished the increase of daytime ambulatory BP induced by estrogen therapy in hysterectomized, healthy, normotensive and postmenopausal women. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Change in blood flow velocity demonstrated by Doppler ultrasound in upper limb after axillary dissection surgery for the treatment of breast cancer

The aim of this study was to evaluate the arterial and venous blood flow in women who underwent upper limb axillary dissection surgery for the treatment of breast cancer. Sixty women were divided into two groups: group 1 (G1)-30 women who underwent breast surgery with axillary dissection level II or III (55.6 +/- A 8.6 years); group 2 (G2)-control, 30 women with no breast cancer (57.4 +/- A 7.0 years). Blood flow profile was evaluated by a continuous wave ultrasound Doppler device (Nicolet Vascular Versalab SE(A (R))) with an 8 MHz probe. Axillary, brachial arteries and veins, arm circumference, volumes, and the ankle-brachial index (ABI) were examined. Wilcoxon test and Mann-Whitney tests were applied to analyze blood flow velocity intra-group and between G1 and G2, respectively. The G1 results showed no lymphedema and no peripheral arterial disease (ABI > 0.9). Moreover, the mean blood flow velocity of the vessels ipsilateral to the surgery was significantly higher than the contralateral ones for all vessels examined (P < 0.05). The mean velocity of blood flow of the vessels contralateral to surgery was significantly higher than the axillary artery in G2 (P < 0.05). It can be concluded that women who underwent axillary dissection due to breast cancer showed probable stenosis in the arterial and venous axillary and brachial vessels of the upper limb ipsilateral to the surgery, confirmed by the increase of blood flow velocity, and such obstruction might affect the limb contralateral to the operation site.

Turbulent blood flow plays an essential localizing role in the development of atherosclerotic lesions in experimentally induced hypercholesterolaemia in rats

Taking into account that atherosclerosis is a focal disease and high levels of plasma cholesterol are closely correlated with its pathogenesis, it is a challenge to explain how equal concentrations of cholesterol bathing the endothelium can produce local, rather than global, effects on arteries. The focal distribution of atherosclerotic lesions has been considered to be dependent, at least in part, on hydrodynamic factors. The present study was carried out to further test the hypothesis that these forces are an important localizing factor in rats feeding a hypercholesterolaemic diet and submitted to infra-diaphragmatic aortic constriction. These animals develop a normotensive prestenotic region with laminar blood flow that serves as control for a normotensive poststenotic region with turbulent blood flow. Our findings clearly demonstrated that the combination of turbulent blood flow and low wall shear stress (WSS) in the presence of hypercholesterolaemia and oxidative stress creates conditions to the formation of focally distributed incipient atherosclerotic lesions observed in the poststenotic segment. In contrast, only diffuse fatty streaks could be observed in the normotensive prestenotic segment with laminar blood flow and normal WSS in the presence of hypercholesterolaemia and oxidative stress. Although haemodynamic forces are not by themselves responsible for the pathogenesis of atherosclerosis, they prime the local vascular wall in which the lesion develop. Further studies are required to establish how haemodynamic forces are detected and transduced into chemical signalling by the cells of the artery wall and then converted into pathophysiologically relevant phenotypic changes.

Blood and Salivary Oxidative Stress Biomarkers Following an Acute Session of Resistance Exercise in Humans

The aim of the present study was to compare oxidative stress biomarkers determined in blood and saliva before and after acute resistance exercise. 1 week after 1 maximum repetition (1RM) test 11 healthy well-trained males completed a hypertrophy acute session of resistance training including 3 sets of 10 repetitions at 75% of the 1RM, with 90s rest periods between sets. Venous blood and saliva samples were collected before (pre) and 10 min after (post) the resistance training session. A significant (p < 0.05) rise in blood lactate accumulation (pre: 1.6 +/- 0.4 vs. post: 9.5 +/- 2.4) was found post-acute resistance training compared with baseline values. Significant increases (p < 0.05) in TBARS (42%), AOPP (28%), uric acid (27%) and GSH (14%) were detected post-acute resistance training in relation to pre in blood samples. A significant increase (p < 0.05) in uric acid (36%) was found in saliva post-acute resistance training as well as a significant correlation (p < 0.05) between uric acid determined in blood and saliva. Statistical analysis did not reveal any other change in the salivary oxidative stress biomarkers. In conclusion, an acute session of resistance exercise induces oxidative stress in plasma of trained men after acute resistance training, which was not found in saliva samples except for uric acid.

Salicylates dilate blood vessels through inhibiting PYK2-mediated RhoA/Rho-kinase activation

Aims Compared with other non-steroid anti-inflammatory drugs (NSAIDs), aspirin is not correlated to hypertension. It has been shown that aspirin has unique vasodilator action in vivo, offering an explanation for the unique blood pressure effect of aspirin. In the present study, we investigate the mechanism whereby salicylates (aspirin and sodium salicylate) dilate blood vessels. Methods and results Rat aortic or mesenteric arterial rings were used to test the vascular effect of salicylates and other NSAIDs. RhoA translocation and the phosphorylation of MYPT1, the regulatory subunit of myosin light chain phosphatase, were measured by western blot, as evidenced for RhoA/Rho-kinase activation. Salicylates, but not other NSAIDs, relaxed contraction induced by most tested constrictors except for calyculin A, indicating that RhoA/Rho-kinase-mediated calcium sensitization is involved. The involvement of RhoA/Rho kinase in vasodilation by salicylates was confirmed by measurements of RhoA translocation and MYPT1 phosphorylation. The calculated half maximal inhibitory concentration (IC(50)) of vasodilation was apparently higher than that of cyclooxygenase inhibition, but comparable to that of proline-rich tyrosine kinase 2 (PYK2) inhibition. Over-expression of PYK2 induced RhoA translocation and MYPT1 phosphorylation, and these effects were markedly inhibited by sodium salicylate treatment. Consistent with the ex vitro vascular effects, sodium salicylate acutely decreased blood pressure in spontaneous hypertensive rats but not in Wistar Kyoto rats. Conclusion Salicylates dilate blood vessels through inhibiting PYK2-mediated RhoA/Rho-kinase activation and thus lower blood pressure.

Occult risk factor for the development of cerebral edema in children with diabetic ketoacidosis: possible role for stomach emptying

The incidence of cerebral edema during therapy of diabetic ketoacidosis (DKA) in children remains unacceptably high-this suggests that current treatment may not be ideal and that important risk factors for the development of cerebral edema have not been recognized. We suggest that there are two major sources for an occult generation of osmole-free water in these patients: first, fluid with a low concentration of electrolytes that was retained in the lumen of the stomach when the patient arrived in hospital; second, infusion of glucose in water at a time when this solution can be converted into water with little glucose. In a retrospective chart review of 30 patients who were admitted with a diagnosis of DKA and a blood sugar > 900 mg/dL (50 mmol/L), there were clues to suggest that some of the retained fluid in the stomach was absorbed. To minimize the likelihood of creating a dangerous degree of cerebral edema in patients with DKA, it is important to define the likely composition of fluid retained in the stomach on admission, to look for signs of absorption of some of this fluid during therapy, and to be especially vigilant once fat-derived brain fuels have disappeared, because this is the time when glucose oxidation in the brain should increase markedly, generating osmole-free water.

Ethanolic extract of Casearia sylvestris and its clerodane diterpen (caseargrewiin F) protect against DNA damage at low concentrations and cause DNA damage at high concentrations in mice`s blood cells

Casearia sylvestris is used in Brazil as a popular medicine to treat ulcer, inflammation and tumour. Caseargrewiin F is a clerodane diterpene isolated from the ethanolic leaf extract of C.sylvestris. The aim of the study was to assess the capacity of the ethanolic extract of C.sylvestris leaves and caseargrewiin F to protect DNA and verify if both the compounds cause some DNA damage, using the micronucleus (MN) test and comet assay in mice. Balb-C mice were treated with the extract [3.13, 6.25, 12.5, 25, 50 and 75 mg/kg body weight (b.w.)] and caseargrewiin F (0.16, 0.32, 0.63, 1.3, 2.5 and 3.8 mg/kg b.w.) for 14 days. On day 15, DNA damage was induced by intra-peritoneal (i.p.) injection of cyclophosphamide (CP) (i.p.) at 50 mg/kg b.w. after the MN test and comet assay were performed. A protective effect of ethanolic extract was observed in MN test (6.25 and 12.5 mg/kg b.w.) and the comet assay (3.13 and 6.25, 12.5 and 25 mg/kg b.w.). Caseargrewiin F showed protective effect at 0.63, 1.3 and 2.5 mg/kg b.w. only in comet assay. We also tested the ability of compounds of C.sylvestris to induce MN and to increase the comet assay tail moment. The experimental design was similar to the DNA protection assay except that in test groups we omitted the CP challenge. We observed increased damage at 50 and 75 mg/kg b.w. of ethanolic extract of C.sylvestris and caseargrewiin F at 3.18 mg/kg b.w. in both the MN test and comet assay. We conclude that ethanolic extract of C. sylvestris and caseargrewiin F can protect cells against DNA damage induced by CP at low concentrations, but at high concentrations these compounds also induce DNA damage.

Lower Extremities Magnetic Resonance Angiography With Blood Pressure Cuff Compression: Quantitative Dynamic Analysis

Purpose: To quantitatively evaluate changes induced by the application of a femoral blood-pressure cuff (BPC) on run-off magnetic resonance angiography (MRA). which is a method generally previously proposed to reduce venous contamination in the leg. Materials and Methods: This study was Health Insurance Portability and Accountability Act (HIPAA)- and Institutional Review Board (IRB)-compliant, We used time-resolved gradient-echo gadolinium (Gd)-enhanced MRA to measure BPC effects on arterial, venous, and soft-tissue enhancement. Seven healthy volunteers (six men) were studied with the BPC applied at the mid-femoral level unilaterally using a 1.5T MR system after intravenous injection of Gd-BOPTA. Different statistical tools were used such as the Wilcoxon signed rank test and a cubic smoothing spline fit. Results: We found that BPC application induces delayed venous filling (as previously described), but also induces significant decreases in arterial inflow, arterial enhancement, vascular-soft tissue contrast, and delayed peak enhancement (which have not been previously measured). Conclusion: The potential benefits from using a BPC for run-off MRA must be balanced against the potential pitfalls, elucidated by our findings.

The influence of age on blood pressure evaluation of hypertensive subjects

The aim of this study was to determine whether age influences the concordance between different methods of blood pressure (BP) measurement and ambulatory BP monitoring (ABPM) in hypertensive subjects. We studied two groups: I, individuals younger than 50 years (n = 57), and II, individuals aged 60 years or older (n = 55). They were submitted to the performance of one ABPM, office BP measurements, home BP monitoring (HBPM), and BP measurements at a public health center (PHCBP). Student`s t-test, Fisher`s test and Lin coefficient were calculated. For Group II, systolic and diastolic pressures measured by HBPM were higher than by day ABPM (p < 0.01). The concordance between day ABPM and the other methods was lower for Group II than for Group I. There was a good concordance between systolic day ABPM and office BP, and between systolic ABPM and PHCBP only for Group I (Lin coefficient = 0.71 and 0.73). Group II reported better sleep quality after ABPM (p < 0.05). Considering 24-h ABPM, 52.6% of Group I and 29% of Group II were controlled (p < 0.01). Concluding, there was worse concordance between different methods of BP measurements and day ABPM in the older group, which had lower hypertension control rate and better tolerance of ABPM. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Influence of Blood Contamination on Bond Strength of a Self-etching Adhesive to Dental Tissues

Purpose: The aim of this study was to detect the influence of (1) storage period of heparinized blood, (2) type of blood and presence of contaminant, (3) application mode of cleansing agents, and (4) efficacy of cleansing agents on contaminated enamel and dentin during the adhesion process of a one-step adhesive system. Materials and Methods: One hundred four human molars were sectioned into halves along the long axis for enamel and dentin tests. Heparinized and fresh blood were obtained from the same donor, applied and dried to maintain a layer of dry blood on the top of samples. The cleansing agents used were hydrogen peroxide, anionic detergent, and antiseptic solution. A one-step adhesive system (Clearfil S3 Bond) was applied on the dental surface, and composite resin cylinders were built up using Tygon tubing molds. After 24 h, the mu SBS test (1 mm/min) and fracture analysis were performed. Results: There was no statistically significant difference in bond strength values regarding the storage period of heparinized blood and the types of blood. Groups without contamination presented higher bond strengths than contaminated groups. The application mode of the cleansing agents had no influence on bond strength results. There was no statistically significant difference among cleansing agents and they were as effective as a water stream in counteracting the effect of blood contamination. Conclusion: Heparinized blood can be used as a contaminant for up to one week, and it is a reliable procedure to standardize the contaminant. The cleansing agents can be used without friction. A water stream is sufficient to remove blood contamination from dental tissues, before the application of a one-step adhesive system.