Primary Headaches and School Performance-Is There a Connection?

PURPOSE OF REVIEW: Headache is a common complaint among children and adolescents. School functioning is one of the most important life domains impacted by chronic pain in children. This review discusses the epidemiological and pathophysiological connections between headaches and school functioning including a suggested clinical approach. RECENT FINDINGS: The connection between recurrent and chronic headache and learning disabilities might be psychosocial (fear of failure) or anatomical (malfunctioning of the frontal and prefrontal areas). Only few population-based and clinical studies were done and good studies are still needed in order to understand the complex relationship better. However, relating to our patients' learning and school performance, history is crucial when a child with primary headaches is evaluated. Learning disabilities seem to have a high prevalence among children with primary headache syndromes especially migraine. The connection between the two is complex and might be either part of a common brain pathophysiology and/or a consequence of poor quality of life.

Acute selenium selenite exposure effects on oxidative stress biomarkers and essential metals and trace-elements in the model organism zebrafish (Danio rerio).

Selenium (Se) is an essential trace-element that becomes toxic when present at high concentrations. Little is known regarding Se effects on parameters such as oxidative stress biomarkers. The aim of the present study was to investigate the effects of acute selenium exposure on oxidative stress biomarkers in a model organism, zebrafish (Danio rerio). Fish were exposed to selenium selenite at 1mgL(-1). Reduced glutathione (GSH), and metallothionein (MT) concentrations were determined in liver, kidney and brain, with MT also being determined in bile. Essential metals and trace-elements were also determined by inductively coupled mass spectrometry (ICP-MS) in order to verify possible metal homeostasis alterations. GSH concentrations in liver, kidney and brain increased significantly (1.05±0.03µmolg(-1) ww, 1.42±0.03µmolg(-1) ww and 1.64±0.03µmolg(-1) ww, respectively) in the Se-exposed group when compared to the controls (0.88±0.05µmolg(-1) ww, 0.80±0.04µmolg(-1) ww and 0.89±0.03µmolg(-1) ww for liver, kidney and brain, respectively). MT levels in Se-exposed liver (0.52±0.03µmolg(-1) ww) decreased significantly in comparison to the control group (0.64±0.02µmolg(-1) ww), while levels in bile increased, albeit non-significantly. This is in accordance with previous studies that indicate efficient biliary MT action, leading to a rapid metabolism and elimination of contaminants from the body. Levels in the brain increased significantly after Se-exposure (0.57±0.01µmolg(-1) ww) when compared to the control group (0.35±0.03µmolg(-1) ww) since this organ does not present a detoxification route as quick as the liver-gallbladder route. Several metal and trace-elements were altered with Se-exposure, indicating that excess of selenium results in metal dyshomeostasis. This is the first report on metal dyshomeostasis due to Se-exposure, which may be the first step in the mechanism of action of selenium toxicity, as is postulated to occur in certain major human pathophysiologies.

Electrophoresis and spectrometric analyses of adaptation-related proteins in thermally stressed Chromobacterium violaceum.

Chromobacterium violaceum is a Gram-negative proteobacteria found in water and soil; it is widely distributed in tropical and subtropical regions, such as the Amazon rainforest. We examined protein expression changes that occur in C. violaceum at different growth temperatures using electrophoresis and mass spectrometry. The total number of spots detected was 1985; the number ranged from 99 to 380 in each assay. The proteins that were identified spectrometrically were categorized as chaperones, proteins expressed exclusively under heat stress, enzymes involved in the respiratory and fermentation cycles, ribosomal proteins, and proteins related to transport and secretion. Controlling inverted repeat of chaperone expression and inverted repeat DNA binding sequences, as well as regions recognized by sigma factor 32, elements involved in the genetic regulation of the bacterial stress response, were identified in the promoter regions of several of the genes coding proteins, involved in the C. violaceum stress response. We found that 30 °C is the optimal growth temperature for C. violaceum, whereas 25, 35, and 40 °C are stressful temperatures that trigger the expression of chaperones, superoxide dismutase, a probable small heat shock protein, a probable phasing, ferrichrome-iron receptor protein, elongation factor P, and an ornithine carbamoyltransferase catabolite. This information improves our comprehension of the mechanisms involved in stress adaptation by C. violaceum.

Hydride generation using a metallic atomizer after microwave-assisted extraction for inorganic arsenic speciation in biological samples.

The present speciation method reports the determination of inorganic arsenic forms, using metallic furnace hydride generation atomic absorption spectrometry. The inorganic As speciation is carried out using mild conditions for hydride formation, such as slightly acid pH media (4.50) and low tetrahydridoborate(1-) concentration (0.1% (w/v)). Limits of detection and quantification of 2.0 and 6.6 µg L(-1) of iAs(III) are obtained using optimized conditions. Additionally, microwave-assisted extraction using water as solvent is carried out to provide the appropriate environment for As species extraction as well as impeding inter-conversion between species. With these analytical strategies, As was accurately determined (at 99.9% confidence level) in water and plankton samples.

Heme modulates smooth muscle cell proliferation and migration via NADPH oxidase: a counter-regulatory role for heme oxygenase system.

Accumulation of vascular smooth muscle cells (VSMC) in response to inflammatory stimuli is a key event in atherogenesis, which commonly occurs in sinuous vessels with turbulent blood flow what leads to hemolysis and consequent free heme accumulation, a known pro-oxidant and pro-inflammatory molecule. In this work, we investigated the effects of free heme on VSMC, and the molecular mechanisms underlying this process. Free heme induces a concentration-dependent migration and proliferation of VSMC which depends on the production of reactive oxygen species (ROS) derived from NADPH oxidase (NADPHox) activity. Additionally, heme activates redox-sensitive proliferation-related signaling routes, such as mitogen activated protein kinase (MAPK) and NF-κB, and induces heme oxygenase-1 (HO-1) expression. NADPHox-dependent proliferative effect of heme seems to be endogenously modulated by HO since the pretreatment of VSMC with HO inhibitors potentiates heme-induced proliferation and, in parallel, increases ROS production. These effects were no longer observed in the presence of heme metabolites, carbon monoxide and biliverdin. The data indicate that VSMC proliferation induced by heme is endogenously modulated by a critical counter-regulatory crosstalk between NADPHox and HO systems.

Frequent headaches in the preadolescent pediatric population: a population-based study.

OBJECTIVES: To estimate the prevalence of chronic daily headaches (CDH) and of high-frequency episodic headaches (HFEH) in preadolescent children from the general population. BACKGROUND: Early-onset cases of neurologic diseases often reflect increased biologic predisposition, specific risk factors, or both. METHODS: Of 2,173 children identified as the target sample, consents were obtained from 1,870 (86.0%), and analyzable data were provided by 1,547 (71.2%). Parents and children were interviewed using a questionnaire consisting of 97 questions, with a validated headache module (10 questions). Crude and adjusted prevalences of HFEH (10-14 headache days per month) and CDH (15 or more headache days per month) were calculated. RESULTS: The prevalence of CDH was 1.68% (girls 2.09%, boys 1.33%). The overall prevalence of HFEH was 2.52% (girls 2.8%, boys 2.3%). After adjusting for gender, age, parental history of headaches, income, and school of origin, the prevalence of CDH was higher in girls than in boys (2.2% vs 1.1%, p < 0.01) and in nonwhite vs white children (2.2% vs 1.2%, p < 0.01). Similar differences were seen for HFEH (girls 3.1%, boys 2.0%, p < 0.01), (nonwhite 3.1%, white 1.9%, p < 0.01). Income significantly contributed to the model. CONCLUSION: High-frequency episodic headaches and chronic daily headaches are common in the preadolescent pediatric population. Health care providers and educators should be aware of the magnitude of the problem to properly identify and treat children with headaches.

Image analysis of two-dimensional gel electrophoresis for comparative proteomics of transgenic and non-transgenic soybean seeds.

Considering the importance of bidimensional electrophoresis and image analysis in comparative proteomics, the parameters that influence the analysis of protein expression of transgenic and non-transgenic soybean seeds were evaluated. The loaded mass of the proteins (150-500 microg), the pH separation range (3-10 or 4-7), and manual/automatic image editing were evaluated. Additionally, after optimizing the conditions, histograms and matchings were obtained in order to accurately analyze the variations (90%) in protein expression. From this, 10 proteins displayed significant differences in expression, and eight of them were characterized and identified by mass spectrometry.

Molecularly imprinted polymer as a solid phase extractor in flow analysis.

Molecularly imprinted polymers (MIPs) are novel alternative materials for solid phase extraction. Applications in flow analysis are recent and enhanced in-line separation/concentration procedures have been proposed. Use of flow systems is very important in the context. The aim of this review is then to highlight the implementation of MIP as solid phase extractor in flow analysis, emphasizing potentialities, limitations and applications.

Grape bagasse as an alternative natural adsorbent of cadmium and lead for effluent treatment.

This work investigated the utilization of grape bagasse as an alternative natural adsorbent to remove Cd(II) and Pb(II) ions from laboratory effluent. X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, nuclear magnetic resonance, thermogravimetric analyses, surface analysis, porosity and porous size were used for characterization of the material. Batch experiments were carried out to evaluate the adsorption capacity of the material. Parameters such as adsorption pH and contact time were optimized for the maximum accumulation onto the solid surface. The pH values found were 7 and 3 for Cd(II) and Pb(II), respectively, and contact time was 5 min for both metals. Adsorption capacity for metals were calculated from adsorption isotherms by applying the Langmüir model and found to be 0.774 and 0.428 mmol g(-1) for Cd(II) and Pb(II), respectively. The competition between metals for the same adsorption sites on grape bagasse was also evaluated, showing an increasing affinity for Pb(II) over Cd(II) when only these metals are present. The potential of this material was demonstrated by efficient metal removal from laboratory effluent using a glass column. The results indicate that the referred material could be employed as adsorbent for effluent treatment, especially due to its easy acquisition and low cost as well as the fast adsorption involved.

Grape bagasse as a potential biosorbent of metals in effluent treatments.

Grape bagasse generated in the wine production process was characterized through X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, nuclear magnetic resonance and thermogravimetric analysis. The efficiency of this natural material for Cd(II) and Pb(II) adsorption was evaluated using a batch adsorption technique. Factors affecting metal adsorption such as pH and contact time were investigated. Maximum adsorption was found to occur at pH 7.0 and 3.0 for Cd(II) and Pb(II), respectively, and a contact time of 5min was required to reach equilibrium for both metals. With these conditions, adsorption studies were performed using a single solution. In addition, to calculate the adsorption capacities for each metal, the Langmüir isotherm model was used. The adsorption capacities were found to be 0.479 and 0.204mmolg(-1) for Cd(II) and Pb(II), respectively. The results showed that grape bagasse could be employed as a low-cost alternative adsorbent for effluent treatment.

Novel lipid mediator aspirin-triggered lipoxin A4 induces heme oxygenase-1 in endothelial cells.

Lipoxins (LX) and aspirin-triggered LX (ATL) are eicosanoids generated during inflammation via transcellular biosynthetic routes that elicit distinct anti-inflammatory and proresolution bioactions, including inhibition of leukocyte-mediated injury, stimulation of macrophage clearance of apoptotic neutrophils, repression of proinflammatory cytokine production, and inhibition of cell proliferation and migration. Recently, it was reported that aspirin induces heme oxygenase-1 (HO-1) expression on endothelial cells (EC) in a COX-independent manner, what confers protection against prooxidant insults. However, the underlying mechanisms remain unclear. In this study, we investigated whether an aspirin-triggered lipoxin A(4) stable analog, 15-epi-16-(para-fluoro)-phenoxy-lipoxin A(4) (ATL-1) was able to induce endothelial HO-1. Western blot analysis showed that ATL-1 increased HO-1 protein expression associated with increased mRNA levels on EC in a time- and concentration-dependent fashion. This phenomenon appears to be mediated by the activation of the G protein-coupled LXA(4) receptor because pertussis toxin and Boc-2, a receptor antagonist, significantly inhibited ATL-1-induced HO-1 expression. We demonstrate that treatment of EC with ATL-1 inhibited VCAM and E-selectin expression induced by TNF-alpha or IL-1beta. This inhibitory effect of the analog is modulated by HO-1 because it was blocked by SnPPIX, a competitive inhibitor that blocks HO-1 activity. Our results establish that ATL-1 induces HO-1 in human EC, revealing an undescribed mechanism for the anti-inflammatory activity of these lipid mediators.

Metal-binding proteins scanning and determination by combining gel electrophoresis, synchrotron radiation X-ray fluorescence and atomic spectrometry.

In the present work, protein bands from in vitro embriogenic callus (Citrus sinensis L. Osbeck) were investigated using micro-synchrotron radiation X-ray fluorescence (muSR-XRF) after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation. Metal-binding protein quantification was done after microwave oven decomposition of gel by synchrotron radiation total reflection X-ray fluorescence (SR-TXRF), flame atomic absorption spectrometry (FAAS) and flame atomic emission spectrometry (FAES). According to the analysis of the protein bands, it is possible to observe that both 81 and ca. 14 kDa proteins present different Fe signal intensity at different positions. The analysis of 53 kDa protein, showed even more interesting results. Besides Fe, the muSR-XRF experiments indicate the presence of Ca, Cu, K and Zn. Chemical elements such as Cu, K, Fe and Zn were determined by SR-TXRF, Mg by FAAS and Na by FAES. Ca was determined by SR-TXRF and FAAS only for accuracy check. In the mineralised protein bands of 81 and around 14 kDa band, only Fe was determined (105 and 21.8 microg g(-1)). For those protein bands (86-ca. 14 kDa) were determined, Ca, K, Cu and Zn in a wide concentration range (42.4-283, 2.47-96.8, 0.91-15.9 and 3.39-29.7 microg g(-1), respectively).

Determination of Cd and Pb in food slurries by GFAAS using cryogenic grinding for sample preparation.

A simple method combining slurry sampling after cryogenic grinding and the use of a permanent modification of the integrated platform inside the transversely heated graphite atomizer (THGA) was proposed for the determination of Cd and Pb in foods. Potentialities of the cryogenic grinding were evaluated for grinding different materials of difficult homogenization such as high fat and high fiber tissues. Animal and vegetal samples were cut into small pieces and ground in liquid nitrogen for 2 min. Slurries were prepared directly in the autosampler cup after cryogenic grinding by transferring an exact amount of homogeneous powdered material (5-20 mg) to the cup, followed by 1.00 mL of 0.2% (v/v) HNO3 containing 0.04% (v/v) Triton X-100 and sonication for 30 s, before transferring into the platform previously coated with 250 microg W and 200 microg Rh. Use of a tungsten carbide-rhodium permanent modifier combined with NH4H2PO4 conventional modifier improves tube lifetime and increases the pyrolysis temperature for Cd. Homogeneity tests, carried out by comparing the between- and within-batch precision for each kind of sample, showed no significant differences at the 95% confidence level, indicating good homogeneity for 5-20 mg masses. Detection limits were 3.3 ng g(-1) Cd and 75 ng g(-1) Pb for 1% m/v slurries. Results for determination of Cd and Pb in foods slurries were in agreement with those obtained with digested samples, since no statistical differences were found by the paired t-test at the 95% level.

Fatty acid incorporation by Rhodnius prolixus midgut.

[(14)C]Oleic acid injected into the hemocoel of Rhodnius prolixus females was shown to rapidly associate with lipophorin particles. Half of the lipophorin-associated [(14)C]oleic acid was transferred in about 5 min to different organs, but the midgut was the main organ to take it up on day 10 after a blood meal. The rate of [(14)C]oleic acid incorporation by the midgut was high up to 15 min after injection and then declined. The [(14)C]oleic acid incorporated by the midgut was found in phospholipids (58.6%) and neutral lipids (37.4%). The midgut capacity to incorporate [(14)C]oleic acid varied on different days after a meal: it increased up to day 10 and then decreased. The fate of the [(14)C]lipids synthesized by the midgut was followed and it was observed that 10 days after feeding diacylglycerol was the main lipid released to hemolymph and that most of phospholipids and triacylglycerols remained associated with the midgut. The metabolism of free fatty acids in Rhodnius prolixus females is discussed in the context of major biological events that follow a blood meal such as digestion and oogenesis.

Induction of NOS in rat blood PMN in vivo and in vitro: modulation by tyrosine kinase and involvement in bactericidal activity.

Intravenous administration of lipopolysaccharide (LPS) to rats increased the production of nitric oxide (NO) metabolites (NOx) by blood polymorphonuclear neutrophils (PMN) in vitro. Both dexamethasone and L-NMMA, added in vitro to neutrophil cultures, inhibited the production of NO. On the other hand, the production of NO was not affected by the treatment, in vivo or in vitro, with different inhibitors of cyclooxygenase or 5-lipoxygenase or with a platelet-activating factor (PAF) antagonist. The incubation of blood PMN from normal rats in vitro with neutrophil activators (PAF, leukotriene B4, and interleukin-8) and different cytokines [interleukin-1, tumor necrosis factor alpha, and interferon-gamma (IFN-gamma)] showed that only IFN-gamma was able to induce the production of high amounts of NO. This induction was directly correlated with the expression of iNOS and an increase in in the enzyme activity in blood PMN. The tyrosine kinase inhibitor genistein inhibited NO production induced by IFN-gamma, suggesting that the signal transduction pathway leading to NOS induction in rat PMN involves phosphorylation by tyrosine kinase. We also showed that NO produced by IFN-gamma activated rat blood PMN involved in the killing of Pseudomonas aeruginosa.

Mechanised flow system for on-line microwave digestion of food samples with off-line catalytic spectrophotometric determination of cobalt at ng l-1 levels.

A mechanised system for on-line slurry food sample digestion was developed and an off-line cobalt determination was performed. The stabilised slurry sample was introduced into an air carrier stream until reaching the digestion coils located inside a household microwave oven. Software written in Visual Basic 3.0 was developed to permit the transport of the slurry samples and the programming of the microwave oven and also the control of the mineralization valve. The proposed system was optimized for determination of cobalt in certified samples such as mussels, bovine liver and fish and also uncertified fish samples. The digestion parameters were established as 3 mol l-1 HNO3 for mussels, 3 mol l-1 HNO3 plus 0.16% v/v H2O2 for bovine liver and 12 mol l-1 HNO3 for fish employing maximum power for 5 min of microwave actuation. In the subsequent spectrophotometric method for the catalytic determination of cobalt, the Tiron and hydrogen peroxide concentrations were 1.8 x 10(-3) and 3.0 x 10(-4) mol l-1, respectively, and the sample residence time was 300 s as determined by an optimisation process. The proposed method features a linear range from 10 to 200 ng l-1 Co (r > 0.996) with detection and quantification limits of 1.7 and 5.5 ng l-1 Co, respectively. The precision, expressed as RSD, was 2.4% (n = 12) for repeatability and 5.2% (n = 10) for reproducibility and the accuracy of the proposed method was assessed by using certified samples and an alternative technique (ETAAS).

Cluster headache: report of seven cases in three families.

We report here 7 patients with episodic cluster headache belonging to three families. During follow-up, we investigated the occurrence of migraine and other disorders in the patients and their relatives. In two of the three families we recorded the occurrence of migraine and in one of these the presence of chronic daily headache, tension headache, essential tremor and cyclic depression. In the third family we detected the occurrence of systemic arterial hypertension in the father and childhood hyperkinesia in the son. We discuss the possible relations between these diseases, especially between migraine and cluster headache, and suggest a better investigation of cluster headache co-morbidity since such a study may help to further understanding of the physiopathology of the disorder.

Propranolol vs flunarizine vs flunarizine plus propranolol in migraine without aura prophylaxis. A double-blind trial.

Fourty-five migraine without aura patients underwent a parallel double-blind trial aiming the comparison of the effects of propranolol 60 mg/day to flunarizine 10 mg/day and to propranolol 60 mg/day plus flunarizine 10 mg/day simultaneously. There were 3 groups, each one with 15 patients. After a 20-day-baseline period, each group received one kind of treatment during 120 days. Migraine index on propranolol was 23.4*, on flunarizine 18.7* and on both drugs 14.4*, mean frequency of attacks on propranolol was 1.26**, on flunarizine 1.2** and on both drugs 1.13** (*p < 0.05, **p < 0.01 compared to baseline) and global evaluation was reduced with all forms of treatment. It was not found statistical differences between groups, nevertheless there was a trend in the group using two drugs reaching lower values in migraine index, frequency of attacks and global evaluation. In individuals using flunarizine (alone or associated with propranolol) the therapeutic effect was largely maintained up to 45 days after drug withdrawal.