Unraveling viscosity effects on the hysteresis losses of magnetic nanocubes.

Hysteresis losses in magnetic nanoparticles constitute the basis of magnetic hyperthermia for delivering a local thermal stress. Nevertheless, this therapeutic modality is only to be realised through a careful appraisal of the best possible intrinsic and extrinsic conditions to the nanoparticles for which they maximise and preserve their heating capabilities. Low frequency (100 kHz) hysteresis loops accurately probe the dynamical magnetic response of magnetic nanoparticles in a more reliable manner than calorimetry measurements, providing conclusive quantitative data under different experimental conditions. We consider here a set of iron oxide or cobalt ferrite nanocubes of different sizes, through which we experimentally and theoretically study the influence of the viscosity of the medium on the low frequency hysteresis loops of magnetic colloids, and hence their ability to produce and dissipate heat to the surroundings. We analyse the role of nanoparticle size, size distribution, chemical composition, and field intensity in making the magnetisation dynamics sensitive to viscosity. Numerical simulations using the stochastic Landau-Lifshitz-Gilbert equation model the experimental observations in excellent agreement. These results represent an important contribution towards predicting viscosity effects and hence to maximise heat dissipation from magnetic nanoparticles regardless of the environment.

Gold-iron oxide dimers for magnetic hyperthermia: the key role of chloride ions in the synthesis to boost the heating efficiency.

With the aim of producing Au-Fe x O y dimers with outstanding heating performances under magnetic hyperthermia conditions applicable to human patients, here we report two synthesis routes, a two-pot and a one-pot method. The addition of chloride ions and the absence of 1,2-hexadecanediol (HDDOL), a commonly used chemical in this synthesis, are the key factors that enable us to produce dimers at low temperature with crystalline iron oxide domains in the size range between 18-39 nm that is ideal for magnetic hyperthermia. In the case of two-pot synthesis, in which no chloride ions are initially present in the reaction pot, dimers are obtained only at 300 °C. In order to lower the reaction temperature to 200 °C and to tune the size of the iron oxide domain, the addition of chloride ions becomes the crucial parameter. In the one-pot method, the presence of chloride ions from the start of the synthesis (as counter ions of the gold salt precursor) enables a prompt formation of dimers directly at 200 °C. In this case, the reaction time is the main parameter used to tune the iron oxide size. A record value of specific absorption rates (SARs) up to 1300 W gFe-1 at 330 kHz and 24 kA m-1 was measured for dimers with an iron oxide domain of 24 nm in size.

Oxidative stress and susceptibility to mitochondrial permeability transition precedes the onset of diabetes in autoimmune non-obese diabetic mice.

Beta cell destruction in type 1 diabetes (TID) is associated with cellular oxidative stress and mitochondrial pathway of cell death. The aim of this study was to determine whether oxidative stress and mitochondrial dysfunction are present in T1D model (non-obese diabetic mouse, NOD) and if they are related to the stages of disease development. NOD mice were studied at three stages: non-diabetic, pre-diabetic, and diabetic and compared with age-matched Balb/c mice. Mitochondria respiration rates measured at phosphorylating and resting states in liver and soleus biopsies and in isolated liver mitochondria were similar in NOD and Balb/c mice at the three disease stages. However, NOD liver mitochondria were more susceptible to calcium-induced mitochondrial permeability transition as determined by cyclosporine-A-sensitive swelling and by decreased calcium retention capacity in all three stages of diabetes development. Mitochondria H2O2 production rate was higher in non-diabetic, but unaltered in pre-diabetic and diabetic NOD mice. The global cell reactive oxygen species (ROS), but not specific mitochondria ROS production, was significantly increased in NOD lymphomononuclear and stem cells in all disease stages. In addition, marked elevated rates of 2',7'-dichlorodihydrofluorescein (H2DCF) oxidation were observed in pancreatic islets from non-diabetic NOD mice. Using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and lipidomic approach, we identified oxidized lipid markers in NOD liver mitochondria for each disease stage, most of them being derivatives of diacylglycerols and phospholipids. These results suggest that the cellular oxidative stress precedes the establishment of diabetes and may be the cause of mitochondrial dysfunction that is involved in beta cell death.

Three-dimensional coherent diffractive imaging on non-periodic specimens at the ESRF beamline ID10.

The progress of tomographic coherent diffractive imaging with hard X-rays at the ID10 beamline of the European Synchrotron Radiation Facility is presented. The performance of the instrument is demonstrated by imaging a cluster of Fe2P magnetic nanorods at 59 nm 3D resolution by phasing a diffraction volume measured at 8 keV photon energy. The result obtained shows progress in three-dimensional imaging of non-crystalline samples in air with hard X-rays.

Protection of rat skeletal muscle fibers by either L-carnitine or coenzyme Q10 against statins toxicity mediated by mitochondrial reactive oxygen generation.

Mitochondrial redox imbalance has been implicated in mechanisms of aging, various degenerative diseases and drug-induced toxicity. Statins are safe and well-tolerated therapeutic drugs that occasionally induce myotoxicity such as myopathy and rhabdomyolysis. Previous studies indicate that myotoxicity caused by statins may be linked to impairment of mitochondrial functions. Here, we report that 1-h incubation of permeabilized rat soleus muscle fiber biopsies with increasing concentrations of simvastatin (1-40 µM) slowed the rates of ADP-or FCCP-stimulated respiration supported by glutamate/malate in a dose-dependent manner, but caused no changes in resting respiration rates. Simvastatin (1 µM) also inhibited the ADP-stimulated mitochondrial respiration supported by succinate by 24% but not by TMPD/ascorbate. Compatible with inhibition of respiration, 1 µM simvastatin stimulated lactate release from soleus muscle samples by 26%. Co-incubation of muscle samples with 1 mM L-carnitine, 100 µM mevalonate or 10 µM coenzyme Q10 (Co-Q10) abolished simvastatin effects on both mitochondrial glutamate/malate-supported respiration and lactate release. Simvastatin (1 µM) also caused a 2-fold increase in the rate of hydrogen peroxide generation and a decrease in Co-Q10 content by 44%. Mevalonate, Co-Q10 or L-carnitine protected against stimulation of hydrogen peroxide generation but only mevalonate prevented the decrease in Co-Q10 content. Thus, independently of Co-Q10 levels, L-carnitine prevented the toxic effects of simvastatin. This suggests that mitochondrial respiratory dysfunction induced by simvastatin, is associated with increased generation of superoxide, at the levels of complexes-I and II of the respiratory chain. In all cases the damage to these complexes, presumably at the level of 4Fe-4S clusters, is prevented by L-carnitine.

Enhanced diagnosis of pollen allergy using specific immunoglobulin E determination to detect major allergens and panallergens.

BACKGROUND: Pollen is one of the main causes of allergic sensitization. It is not easy to make an etiological diagnosis of pollen-allergic patients because of the wide variety of sensitizing pollens, association with food allergy, and increasing incidence of polysensitization, which may result from the presence of allergens that are common to different species, as is the case of panallergens. OBJECTIVE: To compare the results of skin prick tests (SPT) using whole pollen extract with specific immunoglobulin (Ig) E determination for several allergens (purified panallergens included) in the diagnosis of polysensitized pollen-allergic patients. METHODS: The study sample comprised 179 pollen-sensitized patients who underwent SPT with pollen extract and allergen-specific IgE determination against different allergens. RESULTS: The level of concordance between the traditional diagnostic test (SPT) and IgE determination was low, especially in patients sensitized to the panallergens profilin and polcalcin. In the case of SPT, the results demonstrated that patients who are sensitized to either of these panallergens present a significantly higher number of positive results than patients who are not. However, IgE determination revealed that while patients sensitized to polcalcins are sensitized to allergens from a higher number of pollens than the rest of the sample, this is not the case in patients sensitized to profilins. On the other hand, sensitization to profilin or lipid transfer proteins was clearly associated with food allergy. CONCLUSIONS: Sensitization to panallergens could be a confounding factor in the diagnosis of polysensitized pollen-allergic patients as well as a marker for food allergy. However, more studies are required to further investigate the role of these molecules.

Clinical evolution of patients with respiratory allergic disease due to sensitisation to Alternaria alternata being treated with subcutaneous immunotherapy

Introduction: Sensitisation to Alternaria is a cause of respiratory disease in Spain, particularly in childhood, but it is also a significant marker of the severity of this disease. Therefore, the use of an aetiological treatment (allergen specific immunotherapy) is essential, and both subjective and objective clinical parameters should be used to follow up this treatment. Objective: This open-label, uncontrolled, observational, prospective study was designed inorder to study the evolution of these patients on allergen specific immunotherapy therapy in daily clinical practice and to assess the use of different monitoring tools. Material and Methods: A total of 99 patients were included. They were monosensitised to this perennial allergen and treated with subcutaneous allergen specific immunotherapy. Afterone year of follow-up, these patients were assessed for the presence of symptoms, use of medication, clinical incidents, quality of life and asthma control. Results: After one year of treatment a significant fall was observed in the use of concomitant medication ( 2-agonists: p = 0.0278, inhaled corticosteroids: p = 0.0007, anti-leukotrienes:p = 0.0495), nasal symptoms (p = 0.0081), quality of life (PAQLQ, p < 0.0001) and asthma control (ACQ, p < 0.0001). Twenty-one patients had to attend emergency department due to exacerbation of their allergic disease, and only one of them had to be admitted to hospital. Conclusion: respiratory allergic disease due to Alternaria alternata is a disease which is hard to control, and in our daily practice, the use of specific subcutaneous immunotherapy can be of significant benefit in our paediatric patients (AU)

Clinical evolution of patients with respiratory allergic disease due to sensitisation to Alternaria alternata being treated with subcutaneous immunotherapy.

INTRODUCTION: Sensitisation to Alternaria is a cause of respiratory disease in Spain, particularly in childhood, but it is also a significant marker of the severity of this disease. Therefore, the use of an aetiological treatment (allergen specific immunotherapy) is essential, and both subjective and objective clinical parameters should be used to follow up this treatment. OBJECTIVE: This open-label, uncontrolled, observational, prospective study was designed in order to study the evolution of these patients on allergen specific immunotherapy therapy in daily clinical practice and to assess the use of different monitoring tools. MATERIAL AND METHODS: A total of 99 patients were included. They were monosensitised to this perennial allergen and treated with subcutaneous allergen specific immunotherapy. After one year of follow-up, these patients were assessed for the presence of symptoms, use of medication, clinical incidents, quality of life and asthma control. RESULTS: After one year of treatment a significant fall was observed in the use of concomitant medication (ß2-agonists: p=0.0278, inhaled corticosteroids: p=0.0007, anti-leukotrienes: p=0.0495), nasal symptoms (p=0.0081), quality of life (PAQLQ, p<0.0001) and asthma control (ACQ, p<0.0001). Twenty-one patients had to attend emergency department due to exacerbation of their allergic disease, and only one of them had to be admitted to hospital. CONCLUSION: respiratory allergic disease due to Alternaria alternata is a disease which is hard to control, and in our daily practice, the use of specific subcutaneous immunotherapy can be of significant benefit in our paediatric patients.

Understanding patient sensitization profiles in complex pollen areas: a molecular epidemiological study.

BACKGROUND: Allergy diagnosis in patients exposed to multiple pollen species is complex and misdiagnosis is often a cause for unsuccessful specific immunotherapy. OBJECTIVE: We studied the sensitization profile of individual allergens (major, minor and pan-allergens) in pollen-sensitized patients in a region with high exposure to olive pollen by investigating the influence of minor allergens on allergic disease and the association between pan- and minor allergen sensitizations. METHODS: A panel of 13 purified allergens, which included the most relevant allergens in the area, as well as minor olive allergens and pan-allergens, were screened using a high-capacity technology (ADVIA-Centaur) in 891 patients. RESULTS: Olive allergy as measured by specific IgE to Ole e 1 was the leading pollinosis in the area. The minor olive allergens Ole e 7 and Ole e 9 were markers of more severe allergic illness. Profilin sensitization was associated mainly with grass allergy, the second most prevalent pollinosis. Salsola kali pollen allergy was the third most common cause of pollinosis in the area. The prevalence of sensitization to the peach allergen Pru p 3, a nonspecific lipid-transfer protein, was notable. CONCLUSION: Epidemiological analysis by component-resolved diagnosis is a new method, which elucidates the interaction between allergen exposure gradient and patient sensitization. High exposure leads to differential sensitization profiles some of which are associated with more severe allergic conditions. Profilin sensitization, related mainly to grass pollinosis, was a marker of more severe grass pollen sensitization.

Surface anisotropy broadening of the energy barrier distribution in magnetic nanoparticles.

The effect of surface anisotropy on the distribution of energy barriers in magnetic fine particles of nanometer size is discussed within the framework of the Tln(t/τ(0)) scaling approach. The comparison between the distributions of the anisotropy energy of the particle cores, calculated by multiplying the volume distribution by the core anisotropy, and of the total anisotropy energy, deduced by deriving the master curve of the magnetic relaxation with respect to the scaling variable Tln(t/τ(0)), enables the determination of the surface anisotropy as a function of the particle size. We show that the contribution of the particle surface to the total anisotropy energy can be well described by a size-independent value of the surface energy per unit area which permits the superimposition of the distributions corresponding to the particle core and effective anisotropy energies. The method is applied to a ferrofluid composed of non-interacting Fe(3-x)O(4) particles of 4.9 nm average size and x about 0.07. Even though the size distribution is quite narrow in this system, a relatively small value of the effective surface anisotropy constant K(s) = 2.9 × 10(-2) erg cm(-2) gives rise to a dramatic broadening of the total energy distribution. The reliability of the average value of the effective anisotropy constant, deduced from magnetic relaxation data, is verified by comparing it to that obtained from the analysis of the shift of the ac susceptibility peaks as a function of the frequency.

Development and validation of a new Spanish instrument to measure health-related quality of life in patients with allergic rhinitis: the ESPRINT questionnaire.

OBJECTIVES: To develop and validate an instrument to measure health-related quality of life (HRQOL) specific to patients with allergic rhinitis (AR) and primarily for use in Spanish and Spanish-speaking populations. METHODS: An initial item pool was generated from literature review, focus groups with AR patients, and consultations with clinical experts. Item reduction was performed using clinimetric and psychometric approaches after administration of the item pool to 400 AR patients. The resulting instrument's internal consistency, test-retest (2-4 weeks) reliability, known groups and convergent validity, and sensitivity to change were tested in a longitudinal, observational, multicenter study in 210 AR patients who also completed the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). RESULTS: The new questionnaire took a mean (SD) of 7.1 (5.4) minutes to answer. Floor and ceiling effects were less than 15% on all dimensions. Cronbach's alpha values and intraclass correlation coefficient values for six of the sevendimensions and the overall score exceeded 0.70. Statistically significant differences (P < 0.01) were observed on all ESPRINT-28 dimensions and the overall score between patients with mild (mean overall score 1.97, SD 0.99), moderate (mean overall score 2.78, SD 0.88), and severe AR (mean overall score 3.89, SD 0.87). Patients with persistent AR had worse scores (P < 0.05) on all dimensions than patients with intermittent AR. Correlations between the ESPRINT-28 and the RQLQ were generally as expected. Effect sizes for score changes between the two study visits ranged from 0.96 to 1.76 for individual dimensions and the overall score. CONCLUSIONS: This new, Spanish-developed instrument to measure HRQOL in AR patients has shown good reliability, validity, and sensitivity to change. It has also proved easy to use and administer.

Intensive care unit management of fulminant hepatic failure.

OBJECTIVE: The aim of this open/retrospective study was to evaluate the outcomes of intensive care unit patients treated for fulminant hepatic failure (FHF) for predictive indices. METHODS: All patients were recovered in the intensive care units with a diagnosis of FHF. We considered three groups of patients: (1) survivors, deceased, and transplanted. SUBJECTS: All patients were fully screened, including liver function indices such as AST, ALT, total and bound bilirubin, albumin and pre-albumin, factors 5 and 7, alpha fetal protein (alpha-PP), other coagulation tests (PT, aPTT, INR, ATIII), and renal function (BUN and creatinine) parameters. For each patient Apache II score was calculated upon admission to the intensive care unit. RESULTS: Apache II score showed efficacy. alpha-PP increased in both surviving and deceased, but not in the transplanted group. After intensive care unit admission, AST and ALT peaks were higher in the deceased DP than in the transplanted group. The INR value at the third day after ICU admission improved in the survivors compared with the other two cohorts. Factor 5 levels were lower among patients undergoing transplantation, but increased in the other two groups. The prognosis was strictly dependent upon the development of renal failure. CONCLUSION: The Apache II score was a sensitive predictive index for outcome. alpha-PP and factor 5 were not related to outcome, but useful for decision making when determining potential liver transplantation. INR can be used as a prognostic index. Intensive treatment beforehand is of primary importance to prevent multiple organ failure.

L-selectin expression on neutrophils from allergic patients.

BACKGROUND: L-selectin (CD62L) is an adhesion molecule involved in leucocyte attachment to endothelium at sites of inflammation, and it has been demonstrated that L-selectin is rapidly shed after neutrophil activation. Recently, it has been reported that there is increasing evidence of neutrophil participation in asthma and the allergic process. OBJECTIVE: The present study was designed to determine whether an IgE-dependent mechanism can modulate L-selectin expression on the surface of neutrophils. Moreover, we analyse the potential implication of intracellular signal-transduction pathways and whether specific immunotherapy (IT), glucocorticoids and antihistamines might regulate this process. METHODS: Peripheral blood neutrophils from three groups of donors (asthmatic group without IT treatment, IT-treated asthmatic group and healthy group) were used. Cells were challenged in vitro with the specific allergen that produced clinical symptoms in asthmatic patients and also with the allergen to which the patients were not sensitive. Neutrophils from healthy donors were also challenged with allergens. Expression of CD62L on the neutrophil surface was analysed by flow cytometry, and soluble CD62L (sCD62L) in culture supernatant by ELISA. In an attempt to discover which IgE receptor is involved, we also challenged the neutrophils with monoclonal antibody to FcepsilonRI, FcepsilonRII (CD23) and galectin-3 receptors. RESULTS: When neutrophils from allergic patients were challenged with specific allergens that produce clinical allergy symptoms, L-selectin was down-regulated from the surface of those cells, accompanied by a concomitant up-regulation of soluble L-selectin in the supernatant. The challenge with antibodies against FCepsilonRI, FCepsilonRII (CD23) and galectin-3, induces down-modulation of L-selectin on the surface of the neutrophils in all three cases. Calphostin C, wortmannin and manoalide attenuated CD62L down-regulation, suggesting the potential implication of protein kinase C, phosphatidylinositol 3-kinase and phospholipase A(2) in the process. IT and glucocorticoids modulated allergen-dependent CD62L down-regulation, whereas antihistamines (terfenadine, loratadine and cetirizine) or nedocromil sodium did not affect the shedding of L-selectin. CONCLUSIONS: We present evidence that the neutrophil surface expression of CD62L can be modulated by an allergen-dependent mechanism. The modulation of CD62L expression can be induced through the three receptors of IgE. This process can be affected by IT.

Tolerance and short-term effect of a cluster schedule with pollen-extracts quantified in mass-units.

We performed a prospective, multicenter study to assess the tolerance and possible short-term effects of allergen vaccines administered according to a cluster schedule in the months immediately preceding the onset of the pollen season. The study was carried out in eight centers and included 191 patients (children and adults) with allergic respiratory disease due to sensitization to olive tree and/or grass pollen. Of these, 34 patients acted as controls and the remaining patients received immunotherapy administered in the initiation phase according to a cluster schedule of eight doses injected on four visits. After 3 months of treatment, significant differences were found between the two groups in medication consumption (antihistamines in drops and oral formulations: p = 0.045 and p = 0.001, respectively; short-acting beta2-agonist treatments: p = 0.004) and respiratory symptoms (wheezing and coughing: p = 0.035 and 0.014, respectively). The cytokine profile (interleukin [IL]-4, 5, 10 and 2, interferon [IFN-gamma], and tumor necrosis factor [TNF-alpha]) was determined before the start of treatment and at the end of follow-up (4-5 months). Levels of IL-4, 5 and 10 (Th2 profile) decreased while those of IL-2, IFN-gamma, and TNF-alpha (Th1 profile) decreased. These differences were more marked in the active group than in the control group but were not statistically significant. No severe adverse effects were recorded. This study shows that the schedule tested had an acceptable tolerance profile and produced significant changes in symptom and medication scores after a few months of treatment. A double-blind, placebo-controlled study is needed to confirm these results.

Tolerance and short-term effect of a cluster schedule with pollen-extracts quantified in mass-units

We performed a prospective, multicenter study to assess the tolerance and possible short-term effects of allergen vaccines administered according to a cluster schedule in the months immediately preceding the onset of the pollen season. The study was carried out in eight centers and included 191 patients (children and adults) with allergic respiratory disease due to sensitization to olive tree and/or grass pollen. Of these, 34 patients acted as controls and the remaining patients received immunotherapy administered in the initiation phase according to a cluster schedule of eight doses injected on four visits. After 3 months of treatment, significant differences were found between the two groups in medication consumption (antihistamines in drops and oral formulations: p = 0.045 and p = 0.001, respectively; short-acting β2-agonist treatments: p = 0.004) and respiratory symptoms (wheezing and coughing: p = 0.035 and 0.014, respectively). The cytokine profile (interleukin [IL]-4, 5, 10 and 2, interferon [IFN-γ], and tumor necrosis factor [TNF-α]) was determined before the start of treatment and at the end of follow-up (4-5 months). Levels of IL-4, 5 and 10 (Th2 profile) decreased while those of IL-2, IFN-γ, and TNF-α (Th1 profile) decreased. These differences were more marked in the active group than in the control group but were not statistically significant. No severe adverse effects were recorded. This study shows that the schedule tested had an acceptable tolerance profile and produced significant changes in symptom and medication scores after a few months of treatment. A double-blind, placebo-controlled study is needed to confirm these results (AU)

Se ha llevado a cabo un estudio prospectivo y multicéntrico con el objetivo de valorar la tolerancia y posible efecto a corto plazo de las vacunas alergénicas administradas bajo pauta cluster en los meses inmediatamente anteriores al inicio de la estación polínica. El estudio se realizó en 8 centros, incluyéndose un total de 191 pacientes (niños y adultos) con enfermedad alérgica respiratoria por sensibilización a polen de olivo y/o gramíneas. De ellos, 34 actuaron como controles y a los pacientes restantes se les administró inmunoterapia bajo una pauta cluster, en la fase de iniciación, de 8 dosis administradas en 4 visitas. Tras 3 meses de tratamiento, se registraron diferencias significativas entre ambos grupos en el consumo de medicación (antihistamínicos en colirio y orales -p = 0,045 y p = 0,001 respectivamente- y ß2 de corta duración -p = 0,004-) así como en síntomas pulmonares (sibilancias y tos -p = 0,035 y 0,014 respectivamente-). Por otro lado, se determinó el perfil de citocinas (IL-4, 5, 10 y 2, IFN-gamma y TNF-a) de forma previa al inicio del tratamiento y al finalizar el seguimiento (4-5 meses). Se observaron descensos en los niveles de IL-4, 5 y 10 (perfil TH2) y aumento en los valores de IL-2, IFN-gamma y TNF-a (perfil TH1), más marcados en el grupo activo que en el control, sin alcanzar significación estadística. No se registraron efectos adversos severos. Por tanto, podemos observar que la pauta ensayada mostró un adecuado perfil de tolerancia, y tras pocos meses de tratamiento se registraron cambios significativos en la puntuación de síntomas y medicación, siendo necesaria la realización de un estudio con un diseño doble ciego frente a placebo para confirmar los resultados obtenidos (AU)

¿Es el neutrófilo una célula reguladora del eosinófilo en los procesos alérgicos mediados por la IgE? / Is the neutrophil leukocyte an eosinophil­ regulating cell in IgE- mediated allergic processes?

Aunque desde hace años se ha implicado al eosinófilo en la fisiopatología de los procesos alérgicos mediados por la lgE todavía no se conocen lo mecanismo exactos que atraen a esta células al órgano de choque del proceso atópico. Por una parte se habla de la propia presencia de lo tres receptores de la lgE (Fcel R, FccRII y galectina 3) en los eosinófilos de los pacientes alérgicos. pero si exite es mínima. Y por la otra no e ha podido activar a esos eosinófilo mediante un mecanismo mediado por la IgE. Pero el neutrófilo. que es una célula cuya participación en la respuesta alérgica es cada día más evidente, posee también los tres receptores de la IgE y. al contrario de lo que sucede en los eosinófilo . puede activarse a través de un mecanismo dependiente de la lgE como nuestro grupo ha demostrado en reiterada ocasiones. En este artículo comentamos como la activación mediada por la lgE de los neutrófilos puede modular la respuesta de los eosinófilos en los procesos atópicos (AU)

Even though the eosinophil has been implicated in the pathophysiology of IgE­mediated allergic processes for many a year. the precise mechanism that attract the e cells to the target organ of the aiopic proces are a yet unknown. Sorne author invoke the presence of the three lgE receptor (Fcalk. FccRII and gallectin 3) on the eosinophils of allergic patient ; yet, if so. such a presence is minimal. Furthermore. it ha not been posible to activate those eosinophil through an IgE­mediated mechanim. However, the neutrophil, a cell who e participation in the allergic repone i increasingly evident, al o possese the three IgE receptor and, to the contrary of what happen with the eosinophil. it can be activated through an IgE­mediated rnechanism, a our group has repeatedly hown. We here di cus how IgE­mediated neutrophil activation may modulate the repone of eosinophil in atopic procese (AU)

Allergen-dependent CD14 modulation and apoptosis in monocytes from allergic patients.

BACKGROUND: CD14 is a most important monocyte surface molecule. Recently, it has been reported that there is an important relationship between CD14 and immunoglobulin E, and that regulation of CD14 expression is an effector mechanism mediating apoptosis of monocytes. OBJECTIVE: The present study was designed to determine whether specific allergens were able to modulate CD14 expression and apoptosis by monocytes from allergic patients or whether specific immunotherapy (IT) might affect these processes. METHODS: One group of adult allergic asthmatic patients had received IT for the previous 3 years. Another similar group was not treated with IT. We challenged peripheral blood monocytes from both groups of asthmatic patients in vitro with the specific allergen that produced clinical symptoms in asthmatic patients. The cells were also challenged with allergen to which the patients were not sensitive. Monocytes from normal subjects were also challenged with allergens. Expression of CD14 on the monocyte surface was analyzed by flow cytometry, and soluble CD14 (sCD14) in culture supernatant by enzyme-linked immunosorbent assay. The three groups of subjects were challenged with allergens, and apoptosis was analyzed by flow cytometry. RESULTS: When monocytes from non-IT-treated asthmatic patients were cultivated with the allergens to which the patients were sensitive, a significant up-regulation on the monocyte surface was observed compared with results from the healthy group (P < 0.003) and from the IT asthmatic group (P < 0.003). A significantly higher sCD14 level was observed in the culture supernatant of the monocytes from the IT asthmatic group were observed compared with those from the healthy group (P < 0.001) and those from the non-IT asthmatic group (P < 0.001). A significantly higher apoptosis level was observed in monocytes from the IT asthmatic group compared with those from the healthy group (P < 0.001) and those from the non-IT asthmatic group (<0.001). CONCLUSIONS: We present evidence that the expression of CD14 on the surface of monocytes and the apoptosis of the same cells can be modulated by an allergen-dependent mechanism. These processes can be affected by IT.

Tolerance of a cluster schedule on the treatment of seasonal allergic respiratory disease with pollen extracts quantified in mass units.

In order to evaluate the tolerance of a cluster schedule on specific immunotherapy (SIT), 306 patients were included in a multicenter study. The patients were suffering from rhinoconjunctivitis with/without asthma, caused by sensitization to olive and/or grass pollen. SIT was administered subcutaneously according to a cluster schedule in which the maintenance dose is reached after four visits (3 weeks). The extracts were biologically standardized with major allergens quantified in mass units. Local reactions appeared in 7.2% of the patients and 1.3% of the doses. Systemic reactions (SR) were recorded in 1.2% of the doses administered to 9.5% of the patients. No anaphylactic shock was registered, and all the SR responded fully and rapidly to treatment. There was no difference in SR according to diagnosis or allergen extract used. The majority of SR occurred with the administration of vial of higher concentration (Vial 2: 7 SR (22%), Vial 3: 32 SR (78%), p < 0.05). Of the 32 SR recorded with Vial 3, 13 (41%) were immediate, with no existing association between dose administered and appearance of SR. However, of the 18 delayed SR (56%), 14 occurred after the administration of the first two doses of Vial 3 and four occurred after administration of the second two doses (78% vs 22%, p < 0.05). On the other hand, this regime realized an important saving in cost and time compared to the conventional schedule (1581 fewer doses and 2754 fewer visits were necessary to reach the optimal dose). Considering all these factors, the clinical profile of the proposed regime may be qualified as good. However, future studies are necessary in order to better adjust the schedule to avoid the delayed SR that occurred after the administration of the first two doses of Vial 3.

Respiratory burst in neutrophils from asthmatic patients.

BACKGROUND: The role of oxygen radicals has been implicated in disease processes of asthma. We have previously shown that specific allergens were able to activate respiratory burst by neutrophils from allergic patients sensitized to allergens of the same type as those which produce clinical allergy. OBJECTIVES: In this study, we attempted to evaluate the production of respiratory burst by an anti-IgE Ab in neutrophils from asthmatic allergic patients (with and without immunotherapy treatment) and in neutrophils from healthy subjects. METHOD: Neutrophils were stimulated by 10 microg/mL of anti-IgE Ab for 15 min at 37 degrees C. The production of respiratory burst from neutrophils was assayed by luminol-amplified chemiluminescence method. RESULTS: The respiratory burst was significantly higher in neutrophils from non-IT-asthmatic patients than in neutrophils from both healthy (p < 0.001) and IT-asthmatic (p < 0.001) groups. The IT-asthmatic group presented levels of respiratory burst approximately equal to those from non-allergic subjects (p=0.426). CONCLUSIONS: We conclude that neutrophils obtained from allergic asthmatic patients have an increased propensity to generate respiratory bursts, in comparison with neutrophils from healthy subjects. Immunotherapy actively modifies the respiratory burst by neutrophils from allergic asthmatic patients.