Asma ocupacional en peluquería: una revisión de la literatura

Este artículo pretende realizar una revisión de la literatura vigente acerca del asma ocupacional secundaria a la exposición de los factores de riesgo identificados en peluquería. Se realizó una búsqueda sistemática en las bases de datos PubMed y Cochrane de artículos de revistas indexadas con las palabras claves “Asthma occupational, hairdressers, hairdresser, work related asthma”. Aplicando los criterios de selección descritos, se revisaron 26 artículos en total donde se incluían reportes de casos, estudios de prevalencia, incidencia, corte transversa y revisiones, abarcando principalmente los temas de epidemiologia, fisiopatología, diagnóstico y prevención. Se agruparon según la metodología PRISMA para su respectiva comparación. Se concluyó que a pesar de la importancia de esta patología en el sector de peluquería, existen factores asociados como la informalidad del sector, la falta de estudios de investigación originales de cohorte o el desconocimiento de un protocolo claro de diagnóstico en este tipo de trabajadores, que limitan datos concluyentes acerca de la misma. Sin embargo, la mayoría de los autores concluye la relación entre la patología y la labor de peluquería, así falte esclarecer los mecanismos fisiopatológicos relacionados con los alérgenos identificados.

Memory for allergies and health foods: how younger and older adults strategically remember critical health information

Objectives. While older adults often display memory deficits, with practice they can sometimes selectively remember valuable information at the expense of less value information. We examined age-related differences and similarities in memory for health-related information under conditions where some information was critical to remember. Method. In Experiment 1, participants studied three lists of allergens, ranging in severity from 0 (not a health risk) to 10 (potentially fatal), with the instruction that it was particularly important to remember items to which a fictional relative was most severely allergic. After each list, participants received feedback regarding their recall of the high-value allergens. Experiment 2 examined memory for health benefits, presenting foods that were potentially beneficial to the relative’s immune system. Results. While younger adults exhibited better overall memory for the allergens, both age groups in Experiment 1 developed improved selectivity across the lists, with no evident age differences in severe allergen recall by List 2. Selectivity also developed in Experiment 2, although age differences for items of high health benefit were present. Discussion. The results have implications for models of selective memory in older age, and for how aging influences the ability to strategically remember important information within health-related contexts.

Indoor and outdoor atmospheric fungal spores in the So Paulo metropolitan area (Brazil): species and numeric concentrations

The aim of this study was to estimate the indoor and outdoor concentrations of fungal spores in the Metropolitan Area of Sao Paulo (MASP), collected at different sites in winter/spring and summer seasons. The techniques adopted included cultivation (samples collected with impactors) and microscopic enumeration (samples collected with impingers). The overall results showed total concentrations of fungal spores as high as 36,000 per cubic meter, with a large proportion of non culturable spores (around 91% of the total). Penicillium sp. and Aspergillus sp. were the dominant species both indoors and outdoors, in all seasons tested, occurring in more than 30% of homes at very high concentrations of culturable airborne fungi [colony forming units(CFU) m(-3)]. There was no significant difference between indoor and outdoor concentrations. The total fungal spore concentration found in winter was 19% higher than that in summer. Heat and humidity were the main factors affecting fungal growth; however, a non-linear response to these factors was found. Thus, temperatures below 16A degrees C and above 25A degrees C caused a reduction in the concentration (CFU m(-3)) of airborne fungi, which fits with MASP climatalogy. The same pattern was observed for humidity, although not as clearly as with temperature given the usual high relative humidity (above 70%) in the study area. These results are relevant for public health interventions that aim to reduce respiratory morbidity among susceptible populations.

Skin prick test can identify eczematous infants at risk of asthma and allergic rhinitis

Background: Assessment of allergic sensitization is not routinely performed in infants and young children with eczema.

Objective: To determine whether infants who have atopic eczema (with sensitization) are at a greater risk of developing asthma and allergic rhinitis (AR) than those with non-atopic eczema (without concurrent sensitization).

Methods: The presence of eczema was prospectively documented until 2 years of age in a birth cohort of 620 infants with a family history of atopic disease. Sensitization status was determined by skin prick tests (SPTs) at 6, 12, and 24 months using six common allergens. Interviews were conducted at 6 and 7 years to determine the presence of asthma and AR.

Results: Within the first 2 years of life, 28.7% of the 443 children who could be classified had atopic eczema: 20.5% had non-atopic eczema, 19.0% were asymptomatic but sensitized and 31.8% were asymptomatic and not sensitized. When compared with children with non-atopic eczema in the first 2 years of life, children with atopic eczema had a substantially greater risk of asthma [odds ratio (OR)=3.52, 95% confidence interval=1.88–6.59] and AR (OR=2.91, 1.48–5.71). The increased risk of asthma was even greater if the infant had a large SPT (OR=4.61, 2.34–9.09) indicative of food allergy. There was no strong evidence that children with non-atopic eczema had an increased risk of asthma or AR compared with asymptomatic children.

Conclusion: In children with eczema within the first 2 years of life, SPT can provide valuable information on the risk of childhood asthma and AR.

Do boys do the atopic march while girls dawdle?

Background
The atopic march hypothesis suggests that infants with eczema are at increased risk of asthma. Others argue that eczema is not a risk factor for asthma unless there is also sensitization or early wheezing.
Objective
To examine the role of infantile eczema as a predictor of risk of childhood asthma, while allowing for the effects of early wheeze, sensitization, and sex, both as independent effects and possible effect modifiers.
Methods
A total of 620 infants with a family history of allergic disease was recruited. Eczema and wheeze was prospectively documented to 2 years of age. Sensitization was determined by skin prick tests at 6, 12, and 24 months to 6 common food and inhalant allergens. Interviews were conducted at 6 and 7 years to ascertain current asthma.
Results
Sufficiently complete data were available for 403 children. Eczema within the first 2 years of life was clearly associated with an increased risk of childhood asthma in boys (adjusted odds ratio, 2.45; 95% CI, 1.31-4.46) but not in girls (odds ratio, 0.88; 95% CI, 0.43-1.77; P for interaction = .031) even with adjustment for the effects of early allergic sensitization and wheeze. If these relationships are causal, an intervention to prevent eczema in boys might reduce the incidence of childhood asthma by as much as 28%.
Conclusion
Eczema in the first 2 years of life is associated with an increased risk of childhood asthma in boys, but there is no evidence of this in girls.

Identification and possible disease mechanisms of an under-recognized fungus, Aureobasidium pullulans

Background: Investigations into the occurrence and health effects of yeast-like fungi in the outdoor air in the US have been limited. We sought to identify a respirable-sized fungus common in the Pasadena air, locate a major source for the emissions and investigate its relevance to allergic disease. Methods: Yeast-like fungi sampled from the environment were isolated, microscopically examined and sequenced. Pasadena allergy patients were skin tested with commercially available fungal extracts. Patient serum was immunoanalyzed for specific IgE reactivity. Nearby vegetation was analyzed in a controlled emission chamber to find a major source for the aerosols. Results: Hyaline unicellular conidia comprised up to 90% (41,250 m^-3 of air) of total fungal counts and generally peaked at night and during periods of rainfall and ensuing winds throughout the fall and winter. Flowers were determined to be a major source of the emissions. The cellular and colonial morphology of isolates were consistent with Aureobasidium species. The sequence of the D1/D2 region of the 26S ribosomal subunit of isolates from flowers showed identity to two strains of Aureohasidium pullulans (black yeast). Seventeen percent (16/94) of atopic individuals had positive skin testing with A. pullulans extract. Patient sera gE identified several high molecular weight allergens in Aureobasidium extracts. Conclusions: Respirable-sized conidia of A. pullulans are emitted from flowers and form high concentrations in the air. They are associated with immediate reactivity on skin tests, bind to patient sera IgE, and might be relevant in allergic upper and lower airway diseases.

Links between pollen, atopy and the asthma epidemic

Pollen allergy has been found in 80–90% of childhood asthmatics and 40–50% of adult-onset asthmatics. Despite the high prevalence of atopy in asthmatics, a causal relationship between the allergic response and asthma has not been clearly established. Pollen grains are too large to penetrate the small airways where asthma occurs. Yet pollen cytoplasmic fragments are respirable and are likely correlated with the asthmatic response in allergic asthmatics. In this review, we outline the mechanism of pollen fragmentation and possible pathophysiology of pollen fragment-induced asthma. Pollen grains rupture within the male flowers and emit cytoplasmic debris when winds or other disturbances disperse the pollen. Peak levels of grass and birch pollen allergens in the atmosphere correlated with the occurrence of moist weather conditions during the flowering period. Thunderstorm asthma epidemics may be triggered by grass pollen rupture in the atmosphere and the entrainment of respirable-sized particles in the outflows of air masses at ground level. Pollen contains nicotinamide adenine dinucleotide phosphate (reduced) oxidases and bioactive lipid mediators which likely contribute to the inflammatory response. Several studies have examined synergistic effects and enhanced immune response from interaction in the atmosphere, or from co-deposition in the airways, of pollen allergens, endogenous pro-inflammatory agents, and the particulate and gaseous fraction of combustion products. Pollen and fungal fragments also contain compounds that can suppress reactive oxidants and quench free radicals. It is important to know more about how these substances interact to potentially enhance, or even ameliorate, allergic asthma.

Thunderstorm asthma

Thunderstorms have often been linked to epidemics of asthma, especially during the grass flowering season; however, the precise mechanisms explaining this phenomenon are unknown. Evidence of high respirable allergen loadings in the air associated with specific meteorologic events combined with an analysis of pollen physiology suggests that rupture of airborne pollen can occur. Strong downdrafts and dry, cold outflows distinguish thunderstorm rain from frontal rain. The weather system of a mature thunderstorm likely entrains grass pollen into the cloud base, where pollen rupture would be enhanced, then transports the respirablesized fragments of pollen debris to ground level where outflows distribute them ahead of the rain. The conditions occurring at the onset of a thunderstorm might expose susceptible people to a rapid increase in concentrations of pollen allergens in the air that can readily deposit in the lower airways and initiate asthmatic reactions.

Cellular localization of water soluble, allergenic proteins in rye-grass (Lolium perenne) pollen using monoclonal and specific IgE antibodies with immunogold probes

A postembedding method has been developed for localizing water soluble allergens in rye-grass pollen. This uses dry fixation in glutaraldehyde vapour, followed by 2,2-dimethoxypropane, prior to a 100% ethanol series leading into embedment in LR Gold. This has allowed the attachment of specific monoclonal antibodies to the allergen, which are themselves probed with specific immunogold labels to the antibodies. Wall and cytoplasmic sites have been identified, representing an improvement of fixation and localization of allergens over previous studies employing polyclonal, broad spectrum antibodies.

Rye-grass allergens are labelled in mature pollen grains in the exine (tectum, nexine and central chamber), and in the electron opaque areas of the cytoplasm, especially mitochondria. The allergens are absent from the intine, polysaccharide (P) particles, amyloplasts, Golgi bodies and endoplasmic reticulum. IgE antibodies derived from humans allergic to rye-grass pollen, bind to similar sites in the cytoplasm but only to the outer surface of the pollen grain wall. This method now provides a valuable tool for further developmental studies on the pollen grains, in order to establish the site/s of synthesis of the allergens.

Immunologic significance of respirable atmospheric starch granules containing major birch allergen Bet v 1

Background: Birch-pollen allergens are an important cause of early spring hay fever and allergic asthma. Recently, we reported a mechanism for the release of respirable allergenic particles from birch pollen containing the major allergen Bet v 1. In this study, we aimed to assess the immunologic significance of the released Bet v 1-containing starch granules in the environment.

Methods: A two-site monoclonal antibody-based assay (ELISA) was employed to quantitate Bet v 1 in high-volume air sampler filter extracts, and immunogold-labelling was used on sections of these extracts to localize Bet v 1. Immunoblot analyses were performed with pooled sera from patients sensitive to birch pollen.

Results: Atmospheric starch granules contained Bet v 1, and the concentration increased upon light rainfall. Sera from patients allergic to birch allergens recognized extracts from isolated starch granules.

Conclusions: The clinical implications of these findings are that starch granules released from birch pollen are potentially able to trigger allergic asthmatic reactions to Bet v 1, since the allergen occurs in respirable particles. Thus, clinicians can advise asthma patients to remain indoors on days of light rainfall during the birch-pollen season to avoid high levels of allergen exposure.

Source of Bet v 1 loaded inhalable particles from birch revealed

Allergenic proteins present in pollen grains, when inhaled, interact with the airways to cause an attack of asthma in susceptible humans. In one system, grass pollen grains rupture osmotically in rainfall, releasing allergen-containing inhalable particles into the atmosphere. In contrast, birch tree pollen grains do not rupture under these conditions, yet the major allergen, Bet v 1, has been detected in the atmosphere in inhalable particles of unknown origin. It is possible that Bet v 1 may diffuse from intact settled pollen grains and the allergenic material may again become airborne, interacting with settled fine particles from other sources prior to resuspension. This study investigates the mechanism for the release of birch pollen allergen-containing inhalable particles from pollen grains. We propose the hypothesis that (1) airborne birch pollen grains settle on nearby leaf surfaces; (2) then, following light rainfall, the grains germinate and, (3) later, pollen tubes burst, releasing inhalable particles carrying Bet v 1 into the atmospheric aerosol.   We used microscopic analyses of pollen behaviour following anther opening, a Burkard volumetric trap for pollen counts and a high volume air sampler with a two-stage cascade impactor for quantitative immunochemical analyses of Bet v 1. On dry days of high birch pollen count (48 grains/m3, 1.5 ng/m3 of Bet v 1), we found that the surfaces of birch leaves became coated with pollen. This ”pollen rain” is a source of secondary emission of allergens into the atmosphere. We observed that following light rainfall (<1 mm per day), about 80% of the birch pollen grains germinated, producing pollen tubes, especially in the sticky surface secretions of leaf glands. These pollen tubes may grow up to 300 μm in length prior to rupturing, each releasing about 400 starch granules coated with allergen molecules that may, after drying, be dispersed into the aerosol. On these days following light rainfall, the highest atmospheric levels of Bet v 1 (1.18 ng/m3) are associated with inhalable particles. Following heavy rainfall, both pollen and inhalable particles are washed from the atmosphere. Immunoprinting studies show that Bet v 1 is associated with starch granules rather than the smaller orbicules. Bet v 1 is present in the atmosphere in large particles, i.e. in particular pollen grains and in inhalable particles, i.e. in particular starch granules.

A new approach to the investigation of allergenic respirable particles using a modified Anderson Impactor

Pollen allergens have been shown to occur in fine particles much smaller than pollen grains. As such allergenic particles have a high probability of entering the lower human airways, it is important to further investigate their origin and their biological and immunological properties. Accordingly, we have modified the particle collection surface of an Andersen Impactor using adhesive coated microscope slides to enable identification by high resolution microscopic analysis and immunodetection of allergenic particulates.