Dendritic cell-bound IgE functions to restrain allergic inflammation at mucosal sites.

Antigen-mediated cross-linking of Immunoglobulin E (IgE) bound to mast cells/basophils via FcɛRI, the high affinity IgE Fc-receptor, is a well-known trigger of allergy. In humans, but not mice, dendritic cells (DCs) also express FcɛRI that is constitutively occupied with IgE. In contrast to mast cells/basophils, the consequences of IgE/FcɛRI signals for DC function remain poorly understood. We show that humanized mice that express FcɛRI on DCs carry IgE like non-allergic humans and do not develop spontaneous allergies. Antigen-specific IgE/FcɛRI cross-linking fails to induce maturation or production of inflammatory mediators in human DCs and FcɛRI-humanized DCs. Furthermore, conferring expression of FcɛRI to DCs decreases the severity of food allergy and asthma in disease-relevant models suggesting anti-inflammatory IgE/FcɛRI signals. Consistent with the improved clinical parameters in vivo, antigen-specific IgE/FcɛRI cross-linking on papain or lipopolysaccharide-stimulated DCs inhibits the production of pro-inflammatory cytokines and chemokines. Migration assays confirm that the IgE-dependent decrease in cytokine production results in diminished recruitment of mast cell progenitors; providing a mechanistic explanation for the reduced mast cell-dependent allergic phenotype observed in FcɛRI-humanized mice. Our study demonstrates a novel immune regulatory function of IgE and proposes that DC-intrinsic IgE signals serve as a feedback mechanism to restrain allergic tissue inflammation.

Factores psicosociales implicados en el control de la hipertensión arterial / Psychosocial factors involved in hypertension control

La presión arterial alta o hipertensión arterial constituye uno de los principales factores de riesgo cardiovascular, cuya alta prevalencia y la posibilidad de ser modificada mediante la intervención terapéutica la convierten en un problema de gran interés sanitario y socioeconómico. Se entiende la hipertensión arterial como un problema de salud de origen multifactorial, en el que existen tres grandes categorías de factores implicados: los factores biológicos clásicos, los factores comportamentales de riesgo asociado (hábitos de alimentación, consumo de tabaco y alcohol, y la práctica de ejercicio físico) y los factores psicológicos, incluyendo en estos últimos tanto los efectos de estrés sobre el sistema cardiovascular, como las variables individuales de tipo disposicional (hostilidad e ira como rasgo) y emociones negativas como laira, la ansiedad o la depresión (AU)

High blood pressure or hypertension is a major risk factor for cardiovascular disease, whose high prevalence and the ability to be modified by therapeutic intervention, make it a major public health challenge. Hypertension is a multifactorial health problem, involving three large categories of factors: classical biological factors, behavioral risk factors (diet, smoking, alcohol intake, and exercise) and psychological factors. Psychological factors include both the effects of stress on the cardiovascular system and personality factors (hostility and anger) and negative emotions such as anger, anxiety and depression (AU)

Comparison of clinic, home self-measured, and work self-measured blood pressures.

Self-measured and clinic blood pressure (BP) estimates of patients' true levels of BP were compared as part of a controlled study of stress management training for essential hypertension. Forty-three patients underwent 6 to 9 clinic measurements and made 48 self-measured readings of BP at home and at work before and after treatment. Analyses showed that (a) self-measured BP values at work and at home were significantly correlated with each other but did not correlate with clinic blood pressure measurements at pretreatment, and (b) test-retest correlations over 2 months and intraclass correlations of self-measured BP measures were significantly higher than those of clinic BP measurements. Findings indicated that self-measurement improved the estimations of patients' true levels of BP and improved the sensitivity and feasibility of studies assessing the efficacy of antihypertensive treatments.

How many self-measured blood pressure readings are needed to estimate hypertensive patients' "true" blood pressure?

The present research was aimed at determining the number of self-measured blood pressure (BP) readings needed to attain reliable estimates of true BP in hypertensive patients. Correlation coefficients and standard deviation of differences between pairs of measurements as well as generalizability theory were applied to data from a controlled study on stress management training for essential hypertension (García-Vera et al., 1997). Forty-three hypertensive patients self-recorded 48 readings of BP (at home and at work) at both the pretreatment and the posttreatment (separated by a period of 2 months) and 24 readings of BP at follow-up (6 months after the pretreatment). The results showed that it is enough to take two readings, one at work and the other at home, from each of 3 consecutive days to get reliable estimates of SBP and DBP across settings, over 1 week and over 2 months. This same criterion would be valid to get reliable estimates of DBP over 6 months, but two readings, one at work and the other at home, from 8 or more consecutive days may need to be taken to achieve similarly reliable results for SBP.

Potential protective effect of calcium carbonate as liming agent against copper toxicity in the African tilapia Oreochromis mossambicus.

The lipid peroxidative effects of copper sulfate singly (4 mg/l CuSO4.5H2O) and in combination with calcium carbonate (4 mg/l CuSO4.5H2O + 50 mg/l CaCO3) were determined in the liver of the African tilapia Oreochromis mossambicus following exposures of the fish to the chemicals for 24, 48, 72, 96 and 168 h. Lipid peroxidative effects of the treatment with calcium carbonate (50 mg/l CaCO3) and with a known hepatotoxicant, carbon tetrachloride (0.25 ml/l CCl4) were also determined. Fish not exposed to any chemical served as negative controls. The extent of lipid peroxidation was based on hepatic malondialdehyde (MDA) levels as assayed using the thiobarbituric acid reaction test. Results suggested the lipid peroxidative property of the copper salt which was associated with the toxic nature of the heavy metal, although, this effect was not as potent as that of CCl4. Findings also indicated a measure of protection against copper hepatotoxicity provided by the addition of calcium carbonate as a liming agent in the water.

Psychological changes accompanying and mediating stress-management training for essential hypertension.

In a previous controlled study, 21 participants with essential hypertension were treated with a program based on education, relaxation and D'Zurilla problem-solving training, and another 21 participants were assigned to a waiting list control condition (García-Vera, Labrador, & Sanz, 1997). In this report, the pre-post-treatment psychological changes accompanying those conditions were examined with the Jenkins Activity Survey, the Rosenbaum Self-Control Schedule, the Spielberger State-Trait Anxiety Inventory, and the D'Zurilla-Nezu Social Problem-Solving Inventory. Treatment yielded significant psychological changes that included an increase of problem-solving abilities. Moreover, correlation and multiple regression analyses revealed that, when clinic blood pressure (BP) values were considered, increases in problem-solving abilities were correlated with systolic and diastolic BP reductions for participants in the stress-management condition, and they mediated partially the antihypertensive effects of stress-management training on BP. No significant correlations were found between psychological changes and self-measured systolic or diastolic BP reductions.

Stress-management training for essential hypertension: a controlled study.

Forty three patients with essential hypertension participated in a study on the effectiveness of stress-management training for essential hypertension. After 6-9 clinic and 48 self-measured readings of systolic and diastolic blood pressures (SBP and DBP), 22 patients were treated with a program based on education, relaxation, and problem-solving training; and another 21 patients were assigned to a waiting list control group. At post-treatment, mean reductions of clinic BP (17/13 mm Hg vs. 6.9/4.7 mm Hg for SBP/DBP), percentages of subjects who achieved at least a 5 mm Hg reduction (86/86% vs. 48/48% for SBP/DBP) and percentages of subjects who in addition achieved a normotensive level (59/68% vs. 29/14% for SBP/DBP) were significantly higher in the treated group than in the control group. Concerning self-measured BP, the effectiveness of the stress-management training was not so considerable (mean reductions of 3.6/2.4 mm Hg and percentages of subjects who achieved a 5 mm Hg reduction of 52/38% for SBP/DBP), but it was significant and maintained in a 4-month follow-up assessment (mean reductions of 4/2 mm Hg and percentages of subjects who achieved a 5 mm Hg reduction of 48/33% for SBP/DBP). It is suggested that stress-management training can be beneficial for treatment of essential hypertension.