Effects of creatine supplementation on homocysteine levels and lipid peroxidation in rats

Hyperhomocysteinaemia is an independent risk factor for CVD. Recent data show a relationship between homocysteine (Hcy) and free radical formation. Since creatine synthesis is responsible for most of the methyl group transfers that result in Hcy formation, creatine supplementation might inhibit Hcy production and reduce free radical formation. The present study investigated the effects of creatine supplementation on Hcy levels and lipid peroxidation biomarkers. Thirty rats were divided into three groups: control group; diet with creatine group (DCr; 2% creatine in the diet for 28 d); creatine overload plus diet with creatine group (CrO + D; 5 g creatine/kg by oral administration for 5 d + 2 % in the diet for 23 d). Plasma Hcy was significantly lower (P<0.05) in DCr (7.5 (SD 1.2) mu mol/l) and CrO + D (7.2 (SD 1.7) mu mol/l) groups compared with the control group (12.4 (SD 2.2) mu mol/l). Both plasma thiobarbituric acid-reactive species (TBARS) (control, 10 (SD 3.4); DCr, 4.9 (So 0.7); CrO + D, 2.4 (SD 1) mu mol/l) and plasma total glutathione (control, 4.3 (SD 1.9); DCr, 2.5 (SD 0.8); CrO + D, 1.8 (SD 0.5) mu mol/l) were lower in the groups that received creatine (P<0.05). In addition, Hcy showed significant negative correlation (P<0.05) with plasma creatine (r - 0.61) and positive correlation with plasma TBARS (r 0.74). Plasma creatine was negatively correlated with plasma TBARS (r - 0.75) and total peroxide (r - 0.40). We conclude that creatine supplementation reduces plasma Hcy levels and lipid peroxidation biomarkers, suggesting a protective role against oxidative damage. Modulating Hcy fort-nation may, however, influence glutathione synthesis and thereby affect the redox state of the cells.

Constitutional hypomorphic telomerase mutations in patients with acute myeloid leukemia

Loss-of-function mutations in telomerase complex genes can cause bone marrow failure, dyskeratosis congenita, and acquired aplastic anemia, both diseases that predispose to acute myeloid leukemia. Loss of telomerase function produces short telomeres, potentially resulting in chromosome recombination, end-to-end fusion, and recognition as damaged DNA. We investigated whether mutations in telomerase genes also occur in acute myeloid leukemia. We screened bone marrow samples from 133 consecutive patients with acute myeloid leukemia and 198 controls for variations in TERT and TERC genes. An additional 89 patients from a second cohort, selected based on cytogenetic status, and 528 controls were further examined for mutations. A third cohort of 372 patients and 384 controls were specifically tested for one TERT gene variant. In the first cohort, 11 patients carried missense TERT gene variants that were not present in controls (P<0.0001); in the second cohort, TERT mutations were associated with trisomy 8 and inversion 16. Mutation germ-line origin was demonstrated in 5 patients from whom other tissues were available. Analysis of all 3 cohorts (n = 594) for the most common gene variant (A1062T) indicated a prevalence 3 times higher in patients than in controls (n = 1,110; P = 0.0009). Introduction of TERT mutants into telomerase-deficient cells resulted in loss of enzymatic activity by haploinsufficiency. Inherited mutations in TERT that reduce telomerase activity are risk factors for acute myeloid leukemia. We propose that short and dysfunctional telomeres limit normal stem cell proliferation and predispose for leukemia by selection of stem cells with defective DNA damage responses that are prone to genome instability.

Effects of changing blood viscosity and heart rate on vena contracta width as evaluated by color Doppler flow mapping. An in vitro study with a pulsatile flow model

Background: There is only limited knowledge on how the quantification of valvular regurgitation by color Doppler is affected by changing blood viscosity. This study was designed to evaluate the effect of changing blood viscosity on the vena contracta width using an in vitro model of valvular insufficiency capable of providing ample variation in the rate and stroke volume. Methods: We constructed a pulsatile flow model filled with human blood at varying hematocrit (15%, 35%, and 55%) and corresponding blood viscosity (blood/water viscosity: 2.6, 4.8, 9.1) levels in which jets were driven through a known orifice (7 mm(2)) into a 110 mL compliant receiving chamber (compliance: 2.2 mL/mmHg) by a pulsatile pump. In addition, we used variable pump stroke volumes (5, 7.5, and 10 mL) and rates (40, 60, and 80 ppm). Vena contracta region was imaged using a 3.5 MHz transducer. Pressure and volume in the flow model were kept constant during each experimental condition, as well as ultrasound settings. Results: Blood viscosity variation in the experimental range did not induce significant changes in vena contracta dimensions. Also, vena contracta width did not change from normal to low hematocrit and viscosity levels. A very modest increase only in vena contracta dimension was observed at very high level of blood viscosity when hematocrit was set to 55% . Pump rate, in the evaluated range, did not influence vena contracta width. These results in controlled experimental settings suggest that the vena contracta is an accurate quantitative method for quantifying valvular regurgitation even when this condition is associated with anemia, a frequent finding in patients with valvular heart disease.

Sustained Ventricular Tachycardia Is Associated with Regional Myocardial Sympathetic Denervation Assessed with (123)I-Metaiodobenzylguanidine in Chronic Chagas Cardiomyopathy

Cardiac sympathetic denervation and ventricular arrhythmia are frequently observed in chronic Chagas cardiomyopathy (CCC). This study quantitatively evaluated the association between cardiac sympathetic denervation and sustained ventricular tachycardia (SVT) in patients with CCC. Methods: We prospectively investigated patients with CCC and left ventricular ejection fraction (LVEF) greater than 35% with SVT (SVT group: n = 5 15; mean age +/- SD, 61 +/- 8 y; LVEF, 51% +/- 8%) and patients without SVT (non-SVT group: n = 11; mean age +/- SD, 55 +/- 10 y; LVEF, 57% +/- 10%). Patients underwent myocardial scintigraphy with (123)I-metaiodobenzylguanidine ((123)I-MIBG) for the evaluation of sympathetic innervation and resting perfusion with (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) for the evaluation of myocardial viability. A visual semiquantitative score was attributed for regional uptake of each radiotracer using a 17-segment left ventricular segmentation model (0, normal; 4, absence of uptake). A mismatch defect was defined as occurring in segments with a 99mTc-MIBI uptake score of 0 or 1 and a (123)I-MIBG score of 2 or more. Results: Compared with the non-SVT group, the SVT group had a similar (99m)Tc-MIBI summed score (6.9 +/- 7.5 vs. 4.4 +/- 5.2, respectively, P = 0.69) but a higher (123)I-MIBG summed score (10.9 +/- 7.8 vs. 22.4 +/- 9.5, respectively, P = 0.007) and a higher number of mismatch defects per patient (2.0 +/- 2.2 vs. 7.1 +/- 2.0, respectively, P < 0.0001). The presence of more than 3 mismatch defects was strongly associated with the presence of SVT (93% sensitivity, 82% specificity; P = 0.0002). Conclusion: In CCC, the amount of sympathetically denervated viable myocardium is associated with the occurrence of SVT. Myocardial sympathetic denervation may participate in triggering malignant ventricular arrhythmia in CCC patients with relatively well-preserved ventricular function.

The Association of Hemoglobin A1c With Incident Heart Failure Among People Without Diabetes: The Atherosclerosis Risk in Communities Study

OBJECTIVE-This study sought to investigate an association of HbA1c (A1C) with incident heart failure among individuals without diabetes and compare it to fasting glucose. RESEARCH DESIGN AND METHODS-We studied 11,057 participants of the Atherosclerosis Risk in Communities (ARIC) Study without heart failure or diabetes at baseline and estimated hazard ratios of incident heart failure by categories of A1C (<5.0, 5.0-5.4 [reference], 5 5-59, and 6.0-6.4%) and fasting glucose (<90, 90-99 [reference], 100-109, and 110-125 mg/dl) using Cox proportional hazards models. RESULTS-A total of 841 cases of incident heart failure hospitalization or deaths (International Classification of Disease, 9th/10th Revision, 428/150) occurred during a median follow-up of 14.1 years (incidence rate 5.7 per 1,000 person-years). After the adjustment for covariates including fasting glucose, the hazard ratio of incident heart failure was higher in individuals with A1C 6.0-6.4% (1.40 [95% CI, 1 09-1.79]) and 5.5-6.0% (1.16 [0.98-1 37]) as compared with the reference group. Similar results were observed when adjusting for insulin level or limiting to heart failure cases without preceding coronary events or developed diabetes during follow-up. In contrast, elevated fasting glucose was not associated with heart failure after adjustment for covariates and A1C. Similar findings were observed when the top quartile (A1C, 5.7-6.4%, and fasting glucose, 108-125 mg/dl) was compared with the lowest quartile (<5 2% and <95 mg/dl, respectively). CONCLUSIONS-Elevated A1C (>= 5.5-6 0%) was associated with incident heart failure in a middle-aged population without diabetes, suggesting that chronic hyperglycemia prior to the development of diabetes contributes to development of heart failure. Diabetes 59:2020-2026, 2010

Food energy content influences food portion size estimation by nutrition students

Background: Food portion size estimation involves a complex mental process that may influence food consumption evaluation. Knowing the variables that influence this process can improve the accuracy of dietary assessment. The present study aimed to evaluate the ability of nutrition students to estimate food portions in usual meals and relate food energy content with errors in food portion size estimation. Methods: Seventy-eight nutrition students, who had already studied food energy content, participated in this cross-sectional study on the estimation of food portions, organised into four meals. The participants estimated the quantity of each food, in grams or millilitres, with the food in view. Estimation errors were quantified, and their magnitude were evaluated. Estimated quantities (EQ) lower than 90% and higher than 110% of the weighed quantity (WQ) were considered to represent underestimation and overestimation, respectively. Correlation between food energy content and error on estimation was analysed by the Spearman correlation, and comparison between the mean EQ and WQ was accomplished by means of the Wilcoxon signed rank test (P < 0.05). Results: A low percentage of estimates (18.5%) were considered accurate (+/- 10% of the actual weight). The most frequently underestimated food items were cauliflower, lettuce, apple and papaya; the most often overestimated items were milk, margarine and sugar. A significant positive correlation between food energy density and estimation was found (r = 0.8166; P = 0.0002). Conclusions: The results obtained in the present study revealed a low percentage of acceptable estimations of food portion size by nutrition students, with trends toward overestimation of high-energy food items and underestimation of low-energy items.

Targeting the Acute Myeloid Leukemia Stem Cells

The idea that within the bulk of leukemic cells there are immature progenitors which are intrinsically resistant to chemotherapy and able to repopulate the tumor after treatment is not recent. Nevertheless, the term leukemia stem cells (LSCs) has been adopted recently to describe these immature progenitors based on the fact that they share the most relevant features of the normal hematopoetic stem cells (HSCs), i.e. the self-renewal potential and quiescent status. LSCs differ from their normal counterparts and from the more differentiated leukemic cells regarding the default status of pathways regulating apoptosis, cell cycle, telomere maintenance and transport pumps activity. In addition, unique features regarding the interaction of these cells with the microenvironment have been characterized. Therapeutic strategies targeting these unique features are at different stages of development but the reported results are promising. The aim of this review is, by taking acute myeloid leukemia (AML) as a bona fide example, to discuss some of the mechanisms used by the LSCs to survive and the strategies which could be used to eradicate these cells.

T allele of-344C/T polymorphism in aldosterone synthase gene is not associated with resistant hypertension

Resistant hypertension (RH) is the maintenance of elevated blood pressure concurrent with the use of three different antihypertensive drugs, one of which is a diuretic. The Renin-Angiotensin-Aldosterone System plays a major role in volume-dependent hypertension. Therefore, its components are interesting targets for genetic association studies. This work focused on the -344 C/T polymorphism in the CYP11b2 gene, which encodes aldosterone synthase. This work evaluates the association between T allele and resistance to anti-hypertensive treatment. Genotyping analysis included 88 subjects with RH, 142 who were responsive to anti-hypertensive treatment and 110 subjects as a control group. Plasmatic concentrations of aldosterone, renin and cortisol, carotid intima-media thickness and carotid-femoral pulse wave velocity were assessed in a smaller subset of hypertensive patients. An association was found between T allele and hypertension (P < 0.005), but there was no difference in allele frequencies between both hypertensive groups. There was no difference in plasmatic parameters either, in remodeling indicators between the genotypic groups.

Effects of reversible inactivation of the dorsal hippocampus on the behavioral and cardiovascular responses to an aversive conditioned context

In rats, conditioned fear to context causes freezing immobility and cardiovascular changes. The dorsal hippocampus (DH) has a critical role in several memory processes, including conditioning fear to contextual information. To explore a possible involvement of the DH in contextual fear conditioning-evoked cardiovascular (mean arterial pressure and heart rate increases) and behavioral (freezing) responses, DH synaptic transmission was temporarily inhibited by bilateral microinjections of 500 nl of the nonselective synapse blocker, cobalt chloride (COCl2, 1 mmol/l), at different periods of the experimental procedure. During re-exposure to the foot shock chamber in which conditioning had taken place, bilateral DH inhibition 10 min before the conditioning session had no effect on either behavioral or cardiovascular responses. Bilateral DH inhibition immediately after the conditioning session (110 min) decreased both behavioral and cardiovascular responses during the context test. Finally, 48 h after the conditioning session, bilateral DH inhibition 10 min before re-exposure to the foot shock chamber significantly reduced cardiovascular responses but not freezing responses. These results suggest that contextual fear conditioning acquisition does not depend on the DH. This structure, however, is crucial for the consolidation of contextual fear. Moreover, although the DH appears to be less important for the behavioral (freezing) changes induced by re-exposure to the aversive conditioned context, it may play an important role on the cardiovascular responses generated by this model.

eNOS haplotype associated with hypertension in obese children and adolescents

Objective: The aim of our study is to investigate whether genetic polymorphisms in the endothelial nitric oxide synthase (eNOS) gene (in the promoter region T(-786)C, in exon 7 (Glu298Asp) and in intron 4 (4b/4a)) or eNOS haplotypes are associated with hypertension in obese children and adolescents. Methods: We genotyped 175 healthy (controls), 110 normotensive obese and 73 hypertensive obese children and adolescents. Genotypes were determined by Taqman allele discrimination assay and real-time PCR, and by PCR followed by fragment separation by electrophoresis. We compared the distribution of eNOS genotypes, alleles and haplotypes in the three study groups of subjects. We have also measured whole-blood nitrite concentrations. Results: The 4a4a genotype for the intron 4 polymorphism was more common in normotensive obese and hypertensive obese (P < 0.01). The AspAsp genotype for Glu298Asp polymorphism was less common in normotensive obese (P < 0.02). No significant differences were found in allele distributions for the three eNOS polymorphisms. However, the haplotype combining the C, 4b and Glu variants for the three polymorphisms was more common in hypertensive obese than in normotensive obese or control children and adolescents (odds ratio = 2.28 and 2.79, respectively; 95% confidence interval: 1.31-4.31 and 1.39-5.64, respectively; both P < 0.00625). This haplotype was not associated with significantly different nitrite concentrations (P > 0.05). Conclusions: Our findings suggest that the eNOS haplotype, C b Glu, is associated with hypertension in obese children and adolescents. Further studies examining the possible interactions of eNOS haplotypes with environmental factors and other genetic markers involved in the development of obesity and its complications are warranted. International Journal of Obesity (2011) 35, 387-392; doi:10.1038/ijo.2010.146; published online 27 July 2010

Cysteinyl-leukotriene type 1 receptors transduce a critical signal for the up-regulation of eosinophilopoiesis by interleukin-13 and eotaxin in murine bone marrow

IL-13 and eotaxin play important, inter-related roles in asthma models. In the lungs, CysLT, produced by the 5-LO-LTC4S pathway, mediate some local responses to IL-13 and eotaxin; in bone marrow, CysLT enhance IL-5-dependent eosinophil differentiation. We examined the effects of IL-13 and eotaxin on eosinophil differentiation. Semi-solid or liquid cultures were established from murine bone marrow with GM-CSF or IL-5, respectively, and the effects of IL-13, eotaxin, or CysLT on eosinophil colony formation and on eosinophil differentiation in liquid culture were evaluated, in the absence or presence of: a) the 5-LO inhibitor zileuton, the FLAP inhibitor MK886, or the CysLT1R antagonists, montelukast and MK571; b) mutations that inactivate 5-LO, LTC4S, or CysLT1R; and c) neutralizing mAb against eotaxin and its CCR3 receptor. Both cytokines enhanced GM-CSF-dependent eosinophil colony formation and IL-5-stimulated eosinophil differentiation. Although IL-13 did not induce eotaxin production, its effects were abolished by anti-eotaxin and anti-CCR3 antibodies, suggesting up-regulation by IL-13 of responses to endogenous eotaxin. Anti-CCR3 blocked eotaxin completely. The effects of both cytokines were prevented by zileuton, MK886, montelukast, and MK571, as well as by inactivation of the genes coding for 5-LO, LTC4S, and CysLT1R. In the absence of either cytokine, these treatments or mutations had no effect. These findings provide evidence for: a) a novel role of eotaxin and IL-13 in regulating eosinophilopoiesis; and b) a role for CysLTRs in bone marrow cells in transducing cytokine regulatory signals. J. Leukoc. Biol. 87: 885-893; 2010.

Neuromuscular activity of BaTX, a presynaptic basic PLA(2) isolated from Bothrops alternatus snake venom

We have previously isolated a Lys49 phospholipase A(2) homolog (BaTX) from Bothrops alternatus snake venom using a combination of molecular exclusion chromatography and reverse phase HPLC and shown its ability to cause neuromuscular blockade. In this work, we describe a one-step procedure for the purification of this toxin and provide further details of its neuromuscular activity. The toxin was purified by reverse phase HPLC and its purity and molecular mass were confirmed by SIDS-PAGE, MALDI-TOF mass spectrometry, amino acid analysis and N-terminal sequencing. BaTX (0.007-1.4 mu M) produced time-dependent, irreversible neuromuscular blockade in isolated mouse phrenic nerve-diaphragm and chick biventer cervicis preparations (time to 50% blockade with 0.35 mu M toxin: 58 +/- 4 and 24 +/- 1 min, respectively; n = 3-8; mean +/- S.E.) without significantly affecting the response to direct muscle stimulation. In chick preparations, contractures to exogenous acetylcholine (55 and 110 mu M) or KCl (13.4 mM) were unaltered after complete blockade by all toxin concentrations. These results, which strongly suggested a presynaptic mechanism of action for this toxin, were reinforced by (1) the inability of BaTX to interfere with the carbachol-induced depolarization of the resting membrane, (2) a significant decrease in the frequency and amplitude of miniature end-plate potentials, and (3) a significant reduction (59 +/- 4%, n=12) in the quantal content of the end-plate potentials after a 60 min incubation with the toxin (1.4 mu M). In addition, a decrease in the organ bath temperature from 37 degrees C to 24 degrees C and/or the replacement of calcium with strontium prevented the neuromuscular blockade, indicating a temperature-dependent effect possibly mediated by enzymatic activity. (C) 2009 Elsevier Inc. All rights reserved.

Increased basal FSH levels as predictors of low-quality follicles in infertile women with endometriosis

Objective: To determine whether basal levels of follicle-stimulating hormone (FSH) and anti-mullerian hormone (AMH), antral follicle count (AFC), and the numbers of dominant follicles, oocytes, and mature oocytes retrieved after ovarian stimulation differed between infertile women with endometriosis and healthy women undergoing assisted reproduction techniques (ART). Method: Of 77 consecutive ART candidates, 27 were infertile and had endometriosis. A male factor caused the infertility of the other 50, who acted as controls. Results: The AMH and AFC levels were similar in the 2 groups. The FSH levels were higher (8.28 mIU/ML [range, 5.25-24.1 mIU/ML] vs 5.91 mIU/mL [range, 2.47-18.7 mIU/ML]; P<0.01) in the study group. And the numbers of retrieved (n = 5 [range, 0-12] vs n = 9 [range, 0-27]; P<0.05) and mature oocytes (n = 4 [range, 0-11] vs n = 5 [range, 0-16]; P<0.05) were less in the study group. Conclusion: Because AMH levels were unchanged, endometriosis seems not to damage the primordial pool of follicles and oocytes, but to lessen the quality of the ovarian response to the hCG injection. Basal FSH levels may be of value in predicting ART success in women with the disease. (C) 2010 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Depersonalization and personality in panic disorder

Background: Prevalence and clinical correlates of depersonalization symptoms have been associated with panic disorder. Personality traits might increase the likelihood of experiencing depersonalization symptoms or depersonalization disorder in panic patients. Aims: The objectives of this study are to establish the prevalence of depersonalization symptoms during the panic attack and in depersonalization disorder and to examine the personality factors associated with the presence of depersonalization in patients with panic disorder. Methods: The sample comprised 104 consecutive adult outpatients with panic disorder, diagnosed according to the Semistructured Clinical Interview for DSM-IV (Axis I/II disorders). Participants were assessed with the Cambridge Depersonalization Scales, the Temperament and Character Inventory, and the Panic and Agoraphobia Scale. Results: Forty-eight percent of the sample had depersonalization symptoms during the panic attack, whereas 20% of patients had a depersonalization disorder. Women presented more depersonalization disorders than did men (P = .036). Patients with panic disorder with depersonalization disorder had a more severe panic disorder (P = .002). Logistic regression analysis showed that self-transcendence trait (odds ratio, 1.089; 95% confidence interval, 1.021-1.162; P = .010) and severity of panic (odds ratio, 1.056; 95% confidence interval, 1.005-1.110; P = .032) were independently associated with depersonalization disorder. Conclusions: A high prevalence of depersonalization symptoms and depersonalization disorder was confirmed in patients with panic disorder, supporting a dosage effect model for understanding depersonalization pathology. Self-transcendence trait and severity of panic disorder were reported as risk factors for depersonalization disorder. (C) 2011 Elsevier Inc. All rights reserved.

Comparison of corneal changes after phacoemulsification using BSS Plus versus Lactated Ringer`s irrigating solution: a prospective randomised trial

Background/aims To compare two intraocular irrigating solutions, Balanced Salt Solution Plus (BSS Plus) versus Lactated Ringer`s (Ringer), for the preservation of corneal integrity after phacoemulsification. Methods 110 patients undergoing phacoemulsification were randomised to either BSS Plus (n = 55) or Ringer (n = 55) as the irrigating solution. Patients were examined at baseline and at 1, 8, 15, 30 and 60 days postoperatively. Evaluations included specular microscopy to evaluate endothelial cell density (ECD) and endothelial cell size variability (CV), and corneal pachymetry for central corneal thickness (CCT) measurement. Results Groups were well balanced regarding baseline ECD, CV and CCT (p>0.05). There was no statistically significant difference between ECD reduction in group BSS Plus 13.1 +/- 2.0% and Ringer 9.2 +/- 1.9% (p<0.05) at day 60 or in any study visit. There was no statistically significant difference between CV increase in group BSS Plus 23.0 +/- 3.0% and Ringer 20.2 +/- 4.0% (p<0.05) at day 60 or in any study visit. CCT was significantly increased (p<0.05) at 1, 8, 15 and 30 days postoperatively, returning to baseline at 60 days in both groups. There was no significant difference in CCT increase in both groups at any visit. Interestingly, there were statistically significant correlations between ECD loss and phacoemulsification time (p<0.0001) and ECD loss and irrigation solution volume (p<0.0001) in the Ringer group, but not in the BSS Plus group. Conclusions Ringers solution was similar to BSS Plus for corneal preservation in atraumatic cataract surgery. However, our study demonstrates that there is a trend towards lower postoperative endothelial cell density for surgeries with longer phacoemulsification time and higher irrigation volumes if Ringer is used.