Celso Pereira

Chemical analysis of giant stars in the young open cluster NGC 3114

Context. Open clusters are very useful targets for examining possibl e trends in galactocentric distance and age, especially whe n young and old open clusters are compared. Aims. We carried out a detailed spectroscopic analysis to derive t he chemical composition of seven red giants in the young open cluster NGC 3114. Abundances of C, N, O, Li, Na, Mg, Al, Ca, Si, Ti, Ni, Cr, Y, Zr, La, Ce, and Nd were obtained, as well as the carbon isotopic ratio. Methods. The atmospheric parameters of the studied stars and their ch emical abundances were determined using high-resolution optical spectroscopy. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis codemoog. The abundances of the light elements were derived using the spectral synthesis technique. Results. We found that NGC 3114 has a mean metallicity of [Fe/H] =−0.01±0.03. The isochrone fit yielded a turn-o ff mass of 4.2 M⊙. The [N/C] ratio is in good agreement with the models predicted by firs t dredge-up. We found that two stars, HD 87479 and HD 304864, have high rotational velocities of 15.0 km s −1 and 11.0 km s −1 ; HD 87526 is a halo star and is not a member of NGC 3114. Conclusions. The carbon and nitrogen abundance in NGC 3114 agree with the fi eld and cluster giants. The oxygen abundance in NGC 3114 is lower compared to the field giants. The [O/Fe] ratio is similar to the giants in young clusters. We detec ted sodium enrichment in the analyzed cluster giants. As far as the othe r elements are concerned, their [X/Fe] ratios follow the same trend seen in giants with the same metallicity.

Aeroallergens sensitization in an allergic paediatric population of Cova da Beira, Portugal

Cova da Beira is an interior central region of Portugal, with a population of 93,000 inhabitants. The first pollen counts performed in Portugal revealed the highest values of the country in this area. The aim of this study was to assess the aeroallergens sensitization in an allergic population, according to the age groups. In a 5 year period (1995-2000) 1790 consecutive outpatients were observed for suspected allergic symptoms. We included in this study all the 557 paediatric (< or = 15 years old) observed patients (317 male (57%) and 240 female (43%) with an average age of 7.6 < or = 4.2 years old). They were divided in three age groups (Group I: < or = 5 yr; Group II: 6-10 yr; Group III: 11-15 yr). 371 patients were submitted to skin prick tests to aeroallergens. 86.5% of these patients were sensitised to at least one allergen extract. The most representative aeroallergens sensitization were grasses mixture (44.9%), D. pteronyssinus (32.5%), D. farinae (29.1%), Olea europea (27.5%), Parietaria judaica (23.4%), cat dander (16.1%), Artemisia vulgaris (17.6%), Robinia pseudoacacia (12.2%), Platanus acerifolia (11.4%), Tilia cordata (11.4%) moulds mixture (11.2%), Plantago lanceolata (10.6%), dog dander (10.4%), and Pinus radiata (7.5%). The sensitisation to indoor aeroallergens, was similar in all age groups and it was less important than that of pollens. The prevalence of sensitisation to grasses was the greatest in all ages and the house dust mites sensitization was the second most prevalent. The highest pollens counts in this region could explain the early sensitisation even in young children.

Chemical abundances and kinematics of a sample of metal-rich barium stars ⋆,⋆⋆

Aims. We determined the atmospheric parameters and abundance pattern for a sample of metal-rich barium stars. Methods. We used high-resolution optical spectroscopy. Atmospheric parameters and abundances were determined using the local thermodynamic equilibrium atmosphere models of Kurucz and the spectral analysis code MOOG. Results. We show that the stars have enhancement factors, [s/Fe], from 0.25 to 1.16. Their abundance pattern of the Na, Al, αelements, and iron group elements as well as their kinematical properties are similar to the characteristics of the other metal-rich and super metal-rich stars already analyzed. We conclude that metal-rich barium stars do not belong to the bulge population. We also show that metal-rich barium stars are useful targets for probing the s-process enrichment in high-metallicity environments.

Goat's milk allergy

BACKGROUND Goats milk (GM) allergy not associated with allergy to cows milk (CM) is a rare disorder. Caseins have been implicated has the major allergens eliciting symptoms. METHODS We report the case of a 27 years-old female patient that experienced two episodes of urticaria related to ingestion of goats cheese (GC). She tolerated CM, dairy products and sheep cheese. Skin prick tests were performed with GM, CM, bovine casein and alpha -lactalbumin and fresh milk and GC. Serum specific IgE to GM, CM and its fractions, and GM and CM immunobloting assays with inhibition were also evaluated. RESULTS Skin tests were positive to GM and GC and negative to CM. GM immunoblot showed an IgE-binding 14 kDa band that was totally inhibited after serum pre-incubation with GM. CONCLUSIONS Allergens other than casein can be involved in allergy to GM. Even small quantities of protein can elicit symptoms.

Specific sublingual immunotherapy with peach LTP (Pru p 3). One year treatment: a case report.

IntroductionFood allergy is an increasing problem with limited therapeutic approaches apart from to the eviction diet.Case presentationA 40-year-old female patient with food allergy symptoms was polysensitized to almost all vegetable food since the age of 36; the onset of symptoms was during pregnancy. The allergological study demonstrated positive skin prick tests (SPT) to nuts, legumes, cereals, spices, several fresh fruits including peach, and other groups of vegetable foods however, it was negative to common aeroallergens. Serum specific IgE levels were negative (<0.35 kU/L) to profilin and carbohydrate determinants, but positive to Pru p 3 (3.5 kU/L). Positive double-blind placebo-controlled food challenge to peach confirmed the allergic disease. She received specific sublingual immunotherapy with native Pru p 3 at a concentration of 40 μg/ml with 5 administrations per week and a cumulative dose of 200 μg of nPru p 3 per month. After an ultra-rush build-up phase concluded in one day she continued therapy during a year with 5 administrations per week. The clinical evolution and laboratory studies demonstrated an early reduction on SPT reactions with no relevant changes on serum specific IgE, IgG, IgG1 and IgG4 to Pru p 3 during the immunotherapy period. The challenge test was negative 4 months after the beginning of the SLIT. Regarding clinical response she markedly improved after the first month of treatment, and by the 3th month she had no major vegetable dietary restrictions, except for nuts and pepper.ConclusionThese results demonstrate the excellent efficacy and safety of sublingual specific protein immunotherapy developed according to the patient specific sensitivity profile to Pru p3.

Different Frequencies of Tc17/Tc1 and Th17/Th1 Cells in Chronic Spontaneous Urticaria

Background: Chronic urticaria is associated with an immune dysregulation usually mediated by T lymphocytes. Recently, Th17 and Tc17 have been implicated in autoimmune diseases; however, their role in urticaria is not clear yet. Methods: For the study we recruited 20 patients [10 of them had autoreactive chronic spontaneous urticaria (positive autologous intradermal serum test response, ASST+), and the other 10 were nonautoreactive chronic spontaneous urticaria patients (ASST–)] and 17 healthy age- and gender-matched controls (HG). The frequency and functional activity of Th17/Tc17 and Th1/Tc1 cells were evaluated by flow cytometry and type 2 cytokine mRNA by real-time PCR. Results: Our results demonstrated a significant decrease in Th17 frequency in both chronic urticaria groups compared to HG; regarding the amount of IL-17, at the single cell level, it was reduced in ASST– compared to HG. Concerning the Th1 and Th17 cells producing IFN-γ, IL-2, and TNF-α, a lower frequency was noted in chronic urticaria patients compared to HG. In contrast, a significantly increased frequency of Tc1 cells producing these cytokines was noted in ASST+ compared to HG and ASST–. Also, the frequency of Tc17 cells producing TNF-α was increased in ASST+ compared to HG; however, with respect to the amount of TNF-α, at the single cell level, we found a decrease in ASST+ compared to HG. Regarding type 2 cytokine mRNA, a higher expression was verified in ASST+ compared to HG. Conclusion: Our data suggest a probable involvement of cytotoxic T cells, mainly the Tc1 and Tc17 subsets, in chronic urticaria, particularly in the ASST+ group.

Sensitization to profilin in the Central region of Portugal.

BACKGROUND Profilin is a panallergen found in pollens and fruits. Sensitization to this protein may explain some sensitization to multiple pollen species. We aimed to evaluate sensitization to profilin in patients suffering from respiratory allergy sensitized to pollens, in the Central region of Portugal. METHODS Patients were evaluated for asthma symptoms, rhinitis, conjunctivitis and food allergy. Skin prick tests (SPT) to aeroallergens including 12 different pollens and profilin (nPho d 2) were performed. The patients were divided into two study groups according to the region of residence: A--inland region and B--coastal region. RESULTS A total of 370 patients were evaluated (277-group A; 93-group B). 65.9% showed positive skin prick tests and 76.2% were positive to pollens (87.1%-group A; 42.85%-group B; p<0.0001). All the patients sensitized to pollens had rhinitis (p=0.001). Sensitization to profilin was associated with pollen sensitization (p=0.014). 43 patients were sensitized to profilin (40-group A; 3-group B; p=0.006). 21.0% of patients sensitized to pollens, were also sensitized to profilin. 39 patients were sensitized to at least two pollens (p<0.0001). Four profilin and pollen sensitized patients had oral allergy syndrome complaints to melon. This syndrome was related with profilin sensitization (p=0.001). CONCLUSIONS It is advisable to perform SPT to profilin, particularly in the Inland region, for a better differential diagnosis between cross-reactivity and true sensitization to pollens. The results together with the medical history may support the choice for a specific immunotherapy option.

Nasal Provocation Test in the Diagnosis of Allergic Rhinitis

The specific provocation tests, since its introduction by Blackley in 1853, have been widely used in the investigation of pathophysiological mechanisms, immunological and therapeutic aspects of allergic disease, as they mimic the response to allergen exposure, under controlled conditions. However, it has not been broadly used in the diagnosis of allergic disease in clinical practice, because of the lack of standardization of the methodology and the need of other complementary diagnostic tests for monitoring specific provocation tests. Nevertheless, the importance of such test is enormous in many circumstances, since it is the only method that can establish the exact etiology of allergic disease. Although the usefulness of these tests has not been questioned, the need to standardize the methodology for monitoring the response has been stressed. In this review, these aspects will be discussed.

Dynamics of CD86 Expression on Allergic Inflammation - New Insights

CD86 is a well-known costimulatory molecule in its interaction with CD28 and/or CTLA present on T cells, and is essential for full activation of naïve T-cell and subsequent differentiation. Usually the B7 molecules are expressed mainly on APCs and B cells and in specific conditions on other activated cells. These costimulatory molecules are involved in the development of allergic inflammation and airways hyperreactivity (AHR) in allergen-challenged mice. Activated T cells, CD4(+)CD25(+), express CD86 in the first 60 minutes after the specific inhalatory exposure. These T cells can be relevant in IgE mediated allergic reaction possibly by an autocrine costimulation via CD28/CTLA activation pathway. The blockage of the expression of CD86 could be a potential therapeutical target to reduce the magnitude or the progression of the allergic reaction. The review article also discussed relevant patents.

A study of two high-velocity red horizontal branch stars

Context. High-velocity halo stars provide important information about the properties of the extreme Galactic halo. The study of Population II unbound and bound stars enables us better estimate the mass of the halo. Aims. We carried out a detailed spectroscopic and kinematic study of two red horizontal branch stars, CD-41 15048 and HD 214362. Methods. The atmospheric parameters, chemical abundances, and kinematical properties were determined using high-resolution optical spectroscopy and employing the local thermodynamic equilibrium model atmospheres of Kurucz and the spectral analysis code moog. Results. We found that CD-41 15048 and HD 214362 are metal-poor red horizontal branch stars. Their abundance patterns are similar to other metal-poor halo stars already investigated. Our kinematic analysis of the 3D space motions shows that HD 214362 has a highly eccentric (e = 0:95) orbit and passes at 2 kpc from the Galactic center. CD-41 15048, for an adopted distance of 1.3 kpc, has an extreme retrograde motion and travels with very high velocity relative to the Galactocentric reference frame (VGRF = 583 km s 1 ). Conclusions. CD-41 15048 is a bound or an unbound star, depending on the adopted Galactic potential. We also show that the red horizontal branch star BD+09 3223 is another example of a hypervelocity star. Whether it is bound or unbound to the Galaxy depends on the assumed mass and adopted Galactic potential. Possible origins of these two high-velocity stars are briefly discussed. CD-41 15048 and BD+09 3223 are further examples of evolved stars to join the restricted group of hypervelocity stars. Finally, our results seem to contradict the idea that a passage of a star very close to the Galactic center is the only possible origin of hypervelocity stars.