Influence of sex on chronic steroid-induced glaucoma: 24-Weeks follow-up study in rats

The objective was to evaluate ocular changes based on sex in steroid-induced glaucoma models in rats comparing healthy controls, over 24 weeks follow-up. Eighty-nine Long-Evans rats (38 males and 51 females) with steroid-induced glaucoma were analysed. Two steroid-induced glaucoma models were generated by injecting poly-co-lactic-glycolic acid microspheres loaded with dexamethasone (MMDEX model) and dexamethasone-fibronectin (MMDEXAFIBRO model) into the ocular anterior chamber. Intraocular pressure was measured by rebound tonometer Tonolab®. Neuroretinal function was analysed using dark- and light-adapted electroretinography (Roland consult® RETIanimal ERG), and structure was analysed using optical coherence tomography (OCT Spectralis, Heidelberg® Engineering) using Retina Posterior Pole, Retinal Nerve Fibre Layer and Ganglion Cell Layer protocols over 24 weeks. Males showed statistically (p < 0.05) higher intraocular pressure measurements. In both sexes and models neuroretinal thickness tended to decrease over time. In the MMDEX model, males showed higher IOP values and greatest percentage thickness loss in the Ganglion Cell Layer (p = 0.015). Females receiving MMDEXAFIBRO experienced large fluctuations in thickness, a higher percentage loss (on average) in Retina Posterior Pole (p = 0.035), Retinal Nerve Fibre Layer and Ganglion Cell Layer than aged-matched males, and the highest thickness loss rate by mmHg. Although no difference was found by sex in dark- and light-adapted electroretinography, increased amplitude in photopic negative response was found in MMDEX males and MMDEXAFIBRO females at 12 weeks. Although both glaucoma models used dexamethasone, different intraocular pressure and neuroretinal changes were observed depending on sex and other influential cofactors (fibronectin). Both sex and the induced glaucoma model influenced neuroretinal degeneration.

Performance of the SolWat system operating in static mode vs. dynamic for wastewater treatment: Power generation and obtaining reclaimed water

Two hybrid SolWat systems operating in static (without flow circulation) versus dynamic (with flow circulation) mode were simultaneously compared. This work aims to demonstrate the viability of SolWat in dynamic mode to: a) adapt to the operation of the WWTP with a continuous flow, in which the wastewater flows continuously for treatment, b) treat a larger volume of water in the system and c) increase the cooling of the PV modules thanks to the cooling of the temperature of the water sample to improve the energy efficiency in the system. Real secondary wastewater effluents from wastewater treatment plants were used, using solar energy for water disinfection and photovoltaic energy production, in order to use the SolWat systems and implement it as a tertiary treatment. A total of five experiments were performed during autumn, winter, spring and summer. Solar disinfection of Escherichia coli, Enterococcus faecalis and Clostridium perfringens was assessed, and physicochemical parameters were also analysed. The UV dose received by the SolWat systems was the same, but not for the microorganisms in the water sample. The static SolWat irradiated a particle (microorganism) for 4 h, while the dynamic SolWat irradiated intermittently, so the latter system received a shorter UV exposure time, and therefore a lower UV dose. Results indicated that, although the microorganisms did not obtain the absolute bacterial inactivation during the SODIS treatment in any SolWat system, adequate inactivation levels were achieved to allow the reuse of the water for various uses (Royal Decree 1620/2007, Regulation (EU) 2020/741), although to a lesser extent for SolWat in dynamic mode, which treated twice the volume of water and reached cooler temperatures. C. perfringens proved to be the most resistant bacterium tested. The total photovoltaic energy production in the dynamic mode system was more energy efficient than the static mode, being even more efficient than the single PV reference system during the spring (3.5%) and summer (2.7%) test, due to the compensating effect by the cooling of the water on the photovoltaic module against the losses caused by radiation.

Long-term corticosteroid-induced chronic glaucoma model produced by intracameral injection of dexamethasone-loaded PLGA microspheres

PURPOSE

To evaluate a new chronic glaucoma model produced by intracameral injection of dexamethasone-loaded poly lactic-co-glycolic acid microspheres (Dex-PLGA-Ms) over six months.

METHODS

Healthy rats received two injections (at baseline and Week 4) of Dex-PLGA-Ms into the anterior chamber of the right eye. Clinical signs and intraocular pressure (IOP) were weekly recorded. The structure of the retina and optic nerve was in vivo evaluated using optical coherence tomography (OCT) every two weeks and functionally using dark- and light-adapted electroretinography at 0-12-24 weeks. Histological studies were also performed.

RESULTS

IOP progressively increased up to hypertension (23.22 ± 3.63 mmHg) in both eyes but did so later in left eyes. OCT quantified a decrease in full-thickness retina posterior pole (R), retinal-nerve-fiber layer (RNFL), and ganglion-cell layer (GCL) thickness up to 24 weeks. Right eyes showed higher neuroretinal thickness loss up to week 8. RNFL experienced the highest percentage thickness loss at the inferior-superior axis, while in GCL the inner sectors of the horizontal axis (Nasal-Temporal) suffered the greatest decrease in thickness. Retinal ganglion cell, photoreceptor, and intermediate cell functionality decreased over time. Increased deposition of collagen IV was also found in zonular fibers and the ciliary body.

CONCLUSIONS

This work shows the usefulness of drug delivery systems, not to treat pathology but to induce it. Only two injections of Dex-PLGA-Ms in the anterior chamber of rat eyes were enough to progressively create ocular hypertension and subsequent functional and structural neuroretinal degeneration, at least over 6 months.

Photovoltaic and solar disinfection technology meeting the needs of water and electricity of a typical household in developing countries: From a Solar Home System to a full-functional hybrid system

A novel SolWat system designed exclusively as a Solar Home System that also meets the drinking water access in a family of a rural community in a developing country has been designed, manufactured and tested outdoors. The system is composed of 5 photovoltaic modules of monocrystalline silicon solar cells technology, each 20 Wp, parallel-interconnected, adding up to a 100 Wp system. The modules have a water reactor on top with the capacity of providing a minimum of 37.5 L per day for a family of 5 members, guaranteeing the minimum daily needs. Experimental campaign run tests of SODIS of 3 h each, running the system 3 times per day (with a total of 9 h of experimentation per day). Results show that the water treatment of 3 h should be increased at certain periods of the day when the UV dose is not sufficient (late in the afternoon). E. coli and Enterococcus spp achieved total inactivation or almost total disinfection. Regarding electrical production, although energy losses of 5.6-10% were observed in comparison with a single PV module, it was sufficient to fully meet the load demand of the solar home system. The system could be used in a household of a developing country, using only solar energy to meet the electricity and drinking water demand.

Early diagnosis of multiple sclerosis by OCT analysis using Cohen's d method and a neural network as classifier

BACKGROUND

The consequences of inflammation, demyelination, axonal degeneration and neuronal loss in the central nervous system, typical of the development of multiple sclerosis (MS), are manifested in thinning of the retina and optic nerve. The purpose of this work is to diagnose early-stage MS patients based on analysis of retinal layer thickness obtained by swept-source optical coherence tomography (SS-OCT).

METHOD

OCT (Triton® SS-OCT device -Topcon, Tokyo, Japan-) recordings were obtained from 48 control subjects and 48 recently diagnosed MS patients. The following thicknesses were measured on a 45 × 60 grid: retinal nerve fibre layer (RNFL), ganglion cell layer (GCL+), GCL++, retinal thickness and choroid. Using Cohen's d effect size, it was determined the regions and layers with greatest capacity to discriminate between control subjects and patients. Points exceeding the threshold set were used as inputs for an automatic classifier: support vector machine and feed-forward neural network.

RESULTS

In MS at clinical onset the layer with greatest discriminant capacity is GCL++ [AUC = 0.83] which exhibits a horseshoe-like macular topographic distribution. It is followed by retina, GCL+ and RNFL; choroidal thicknesses do not provide discriminatory capacity. Using a neural network as a classifier between controls and MS patients, obtains sensitivity of 0.98 and specificity of 0.98.

CONCLUSIONS

This work suggest that OCT may serve as an important complementary role to other clinical tests, particularly regarding neurodegeneration. It is possible to characterise structural alterations in retina and diagnose early-stage MS with high degree of accuracy using OCT and artificial neural networks.

Brimonidine-LAPONITE® intravitreal formulation has an ocular hypotensive and neuroprotective effect throughout 6 months of follow-up in a glaucoma animal model

Intravitreal administration is widely used in ophthalmological practice to maintain therapeutic drug levels near the neuroretina and because drug delivery systems are necessary to avoid reinjections and sight-threatening side effects. However, currently there is no intravitreal treatment for glaucoma. The brimonidine-LAPONITE® formulation was created with the aim of treating glaucoma for extended periods with a single intravitreal injection. Glaucoma was induced by producing ocular hypertension in two rat cohorts: [BRI-LAP] and [non-bri], with and without treatment, respectively. Eyes treated with brimonidine-LAPONITE® showed lower ocular pressure levels up to week 8 (p < 0.001), functional neuroprotection explored by scotopic and photopic negative response electroretinography (p = 0.042), and structural protection of the retina, retinal nerve fibre layer and ganglion cell layer (p = 0.038), especially on the superior-inferior axis explored by optical coherence tomography, which was corroborated by a higher retinal ganglion cell count (p = 0.040) using immunohistochemistry (Brn3a antibody) up to the end of the study (week 24). Furthermore, delayed neuroprotection was detected in the contralateral eye. Brimonidine was detected in treated rat eyes for up to 6 months. Brimonidine-LAPONITE® seems to be a potential sustained-delivery intravitreal drug for glaucoma treatment.

Identification of clusters in multifocal electrophysiology recordings to maximize discriminant capacity (patients vs. control subjects)

PURPOSE

To propose a new method of identifying clusters in multifocal electrophysiology (multifocal electroretinogram: mfERG; multifocal visual-evoked potential: mfVEP) that conserve the maximum capacity to discriminate between patients and control subjects.

METHODS

The theoretical framework proposed creates arbitrary N-size clusters of sectors. The capacity to discriminate between patients and control subjects is assessed by analysing the area under the receiver operator characteristic curve (AUC). As proof of concept, the method is validated using mfERG recordings taken from both eyes of control subjects (n = 6) and from patients with multiple sclerosis (n = 15).

RESULTS

Considering the amplitude of wave P1 as the analysis parameter, the maximum value of AUC = 0.7042 is obtained with N = 9 sectors. Taking into account the AUC of the amplitudes and latencies of waves N1 and P1, the maximum value of the AUC = 0.6917 with N = 8 clustered sectors. The greatest discriminant capacity is obtained by analysing the latency of wave P1: AUC = 0.8854 with a cluster of N = 12 sectors.

CONCLUSION

This paper demonstrates the effectiveness of a method able to determine the arbitrary clustering of multifocal responses that possesses the greatest capacity to discriminate between control subjects and patients when applied to the visual field of mfERG or mfVEP recordings. The method may prove helpful in diagnosing any disease that is identifiable in patients' mfERG or mfVEP recordings and is extensible to other clinical tests, such as optical coherence tomography.

Ethylene biosynthesis and perception during ripening of loquat fruit (Eriobotrya japonica Lindl.)

In order to gain insights into the controversial ripening behavior of loquat fruits, in the present study we have analyzed the expression of three genes related to ethylene biosynthesis (ACS1, ACO1 and ACO2), two ethylene receptors (ERS1a and ERS1b), one signal transduction component (CTR1) and one transcription factor (EIL1) in peel and pulp of loquat fruit during natural ripening and also in fruits treated with ethylene (10μLL^-1) and 1-MCP (10μLL^-1), an ethylene action inhibitor. In fruits attached to or detached from the tree, a slight increase in ethylene production was detected at the yellow stage, but the respiration rate declined progressively during ripening. Accumulation of transcripts of ethylene biosynthetic genes did not correlate with changes in ethylene production, since the maximum accumulation of ACS1 and ACO1 mRNA was detected in fully coloured fruits. Expression of ethylene receptor and signaling genes followed a different pattern in peel and pulp tissues. After fruit detachment and incubation at 20°C for up to 6days, ACS1 mRNA slightly increased, ACO1 experienced a substantial increment and ACO2 declined. In the peel, these changes were advanced by exogenous ethylene and partially inhibited by 1-MCP. In the pulp, 1-MCP repressed most of the changes in the expression of biosynthetic genes, while ethylene had almost no effects. Expression of ethylene perception and signaling genes was barely affected by ethylene or 1-MCP. Collectively, a differential transcriptional regulation of ethylene biosynthetic genes operates in peel and pulp, and support the notion of non-climacteric ripening in loquat fruits. Ethylene action, however, appears to be required to sustain or maintain the expression of specific genes.

Visual dysfunction and its correlation with retinal changes in patients with Parkinson's disease: an observational cross-sectional study

OBJECTIVES

To evaluate visual dysfunction and its correlation with structural changes in the retina in patients with Parkinson's disease (PD).

METHODS

Patients with PD (n=37) and controls (n=37) were included in an observational cross-sectional study, and underwent visual acuity (VA), colour vision (using the Farnsworth and Lanthony desaturated D15 colour tests) and contrast sensitivity vision (CSV; using the Pelli-Robson chart and CSV 1000E test) evaluation to measure visual dysfunction. Structural measurements of the retinal nerve fibre layer (RNFL), and macular and ganglion cell layer (GCL) thicknesses, were obtained using spectral domain optical coherence tomography (SD-OCT). Comparison of obtained data, and correlation analysis between functional and structural results were performed.

RESULTS

VA (in all different contrast levels) and all CSV spatial frequencies were significantly worse in patients with PD than in controls. Colour vision was significantly affected based on the Lanthony colour test. Significant GCL loss was observed in the minimum GCL+inner plexiform layer. A clear tendency towards a reduction in several macular sectors (central, outer inferior, outer temporal and superior (inner and outer)) and in the temporal quadrant of the RNFL thickness was observed, although the difference was not significant. CSV was the functional parameter most strongly correlated with structural measurements in PD. Colour vision was associated with most GCL measurements. Macular thickness was strongly correlated with macular volume and functional parameters (r>0.70, p<0.05).

CONCLUSIONS

Patients with PD had visual dysfunction that correlated with structural changes evaluated by SD-OCT. GCL measurements may be reliable indicators of visual impairment in patients with PD.

Patterns of individual change in a parenting program for child maltreatment and their relation to family and professional environments

In the area of child maltreatment prevention, little is known about the typology of changes that individuals undergo in response to parent-training interventions. In this study, we examined the patterns of change observed in parents immediately after their completion of the Apoyo Personal y Familiar (APF, Personal and Family Support) parenting program. We identified five clusters and classified 496 parents according to two criteria: (a) the amount of pre-post changes (total or partial) as reflected in their self-reports on implicit theories, parental agency and childrearing practices, and (b) the positive, negative or mixed character of these changes. The study also included a follow-up of a subset of 95 participants intended to examine the extent to which the patterns of change identified in the first part of the study might predict the quality of the childrearing environment at home and the successful integration of the APF program into social services structures one year on. In this follow-up study, external evaluators observed families' home environments and collected the parenting program facilitators' self-reports on changes to their work environment. The evaluators found higher-quality childrearing environments and more positive appraisals of the changes to the teams' work with families in those cases where participants had experienced partial or total positive changes as a result of the APF. This approach offers insights into processes of individual change that have practical implications for the successful implementation of parenting programs in child maltreatment prevention services.

Immunoquantitative measurement of soybean aeroallergen emissions at industrial sites

BACKGROUND

Asthma attacks and mortality due to inhalation of soybean antigens in Barcelona, Spain have been well documented. A new control scheme was adopted in the city to avoid the emission and dispersion of soybean dust into the atmosphere during unloading. We studied soybean allergen emission during unloading and at 3 industrial sites and compared the results obtained.

METHODS

Over a period of 31 months, 628 paired air samples from 3 plants (A, B, C) involved in soybean manipulation in Barcelona harbor were collected. Samples were analyzed by a radiometric competitive inhibition assay (RCIA) and the enzyme-linked immunosorbent assay (ELISA). A Bland-Altman plot was used to compare the soybean concentrations measured by each assay.

RESULTS

The median values for the 628 samples were 5535 U/m3 (range, 370-18,416,751) for the RCIA and 9955 U/m3 (range, 400-22,349,059) for the ELISA. Plant A had the lowest emission levels and the lowest Spearman rank correlation coefficient (0.409). The correlation coefficients were 0.747 and 0.794 for plants B and C. Soybean aeroallergen concentrations differed by plant. The highest variability in values was seen for plant A, which had the lowest allergen concentrations.

CONCLUSIONS

The competitive assays described are useful tools for the measurement of soybean allergen emission levels at industrial sites. These methods may be used to monitor unloading and the impact of environmental interventions.

Assessment of soy aeroallergen levels in different work environments

BACKGROUND

Airborne soybean hull proteins are known causes of asthma epidemics around harbours and soy processing plants. Soy flour dust proteins may cause occupational allergy in food and feed industries.

OBJECTIVE

To compare enzyme immunoassays (EIAs) for soy hull and soy flour aeroallergens, exposure assessment in various work environments.

METHODS

Airborne dust samples (n=324) from soy unloading and/or processing plants, the animal feed industry and pig stables were analysed by two soy flour assays: one assay for measuring complete soy hull proteins and two assays for measuring the purified low-molecular-weight (LMW) soy hull allergens.

RESULTS

Immunoblotting confirmed strong differences between antibody specificities and soy preparations. The results of the two soy flour assays and the assay for measuring complete soy hull proteins were highly correlated (r>0.85). The two LMW soy hull assays also showed a strong mutual correlation (r=0.91), but much less correlation with assays for measuring soy flour and complete soy hull. The levels of LMW soy hull proteins were the highest at sites of soybean unloading or processing, while soy flour levels were particularly high in the soy and animal feed industry.

CONCLUSIONS

The optimal EIA procedure for soy aeroallergen exposure assessment depends on the type of work environment and the local soy dust composition. Thus, the type of work environment should always be taken into account in future soy allergy studies in order to prevent a possible underestimation of the workers' actual risk of developing soy allergy.

Optimized methods for fungal ?-amylase airborne exposure assessment in bakeries and mills

BACKGROUND

In order to enable reproducible and comparable exposure measurements of fungal alpha-amylase (alpha-amylase) in different laboratories and countries, the entire procedure from sampling of airborne dust to measuring extracted samples (including standards and the used enzyme) immunoassays must be standardized. The aim of this study was to establish optimal elution and assay conditions.

METHODS

A parallel sampler was used for simultaneous collection of 10 samples of inhalable dust in bakeries and mills in Germany, England, the Netherlands and Spain. Three enzyme-immunoassays (EIAs) for detection of fungal alpha-amylase based on monoclonal antibodies or polyclonal antibodies were used for the measurement of the parallel-sampled filters (n=432) extracted using several methods. The results were analysed by regression analysis of variance. Additional filters (n=54) were extracted and analysed using two EIAs to investigate the storage stability of the extracts.

RESULTS

Although alpha-amylase concentrations correlated well (r> or =0.88), differences were found between the EIAs in the sensitivity and nominal values (up to a mean factor 5.8). The best elution medium for airborne filters (phosphate-buffered saline 'PBS' with 0.05% Tween-20) led to 1.2 to two times higher alpha-amylase allergen yields than extraction in PBS only, while higher Tween-20 concentrations decreased the extracted alpha-amylase yield. During storage of frozen dust/filter extracts for 3-4 months at -20 degrees C, a loss of approximately 40% of measurable alpha-amylase was observed, which could be partially prevented by addition of 0.1% casein to the medium directly after extraction.

CONCLUSION

Although the effects of only a few of many possible causes of variation were investigated, for these factors a clear choice could be made with regard to optimal elution conditions and the use of validated EIAs with calibrated standards, thus making significant progress towards a completely standardized procedure for airborne alpha-amylase measurements.

Common Variable Immunodeficiency

BACKGROUND

Malabsorption syndrome often develops in patients with common variable immunodeficiency (CVID). Why structural damages appear in some CVID patients and not in others is not fully understood. Memory B cells (MBs) are responsible for the production of specific antibodies, and their defects have previously been related to autoimmune, granulomatous, and lymphoproliferative complications of CVID. The objective of this study was to ascertain whether a relationship exists between MB defects and the clinical outcome of respiratory and intestinal involvement in these patients.

METHODS

Forty-one CVID patients were grouped as follows, according to the quantification of peripheral MBs: the MB2 group (n = 7) included patients with normal MBs; the MB1 group (n = 16) included patients with low switched MBs; and the MB0 group (n = 18) included patients with absent/low MBs. The clinical outcome of respiratory and intestinal involvement of patients was then compared among the three groups.

RESULTS

In the MB0 group, chronic lung disease (ie, bronchiectasis and diminished FVC and/or FEV1) developed in 50% of patients vs 13% in the MB1 group and 0% in the MB2 group (p < 0.05). In the MB0 group, malabsorption syndrome or chronic noninfectious diarrhea developed in 50% of patients vs 19% in the MB1 group and 0% in the MB2 group (p < 0.05). No differences were found among the three groups for age at onset of symptoms, delay in diagnosis/treatment, months of follow-up/treatment, and prediagnostic serum IgG concentration.

CONCLUSIONS

Alterations in MB count appear to be associated with a severe clinical outcome of respiratory and intestinal involvement in CVID. The MB count could be a useful laboratory parameter for orienting the prognosis and management of CVID patients.

Airborne exposure to wheat allergens: measurement by human immunoglobulin G4 and rabbit immunoglobulin G immunoassays

BACKGROUND

Exposure to airborne wheat allergens in the bakery trade is associated with a high risk of occupational allergy and asthma. Control and reduction of allergen exposure require relatively simple but reliable monitoring techniques. We developed new rabbit IgG-based enzyme immunoassays (EIA) for wheat allergens, which might be a convenient alternative for the thus far used human IgG4 inhibition assay.

METHODS

The reactivity and specificity of rabbit antibodies were assessed by EIA and immunoblotting, and compared with those of IgE from wheat-sensitized bakers, and with the antibodies used in the IgG4 inhibition EIA. An IgG inhibition and a sandwich EIA were developed for analysis of airborne dust samples.

RESULTS

Human IgG4 and rabbit IgG inhibition EIAs had comparable sensitivities, with limits of detection (LOD) between 18 and 88 ng/mL, while the sandwich EIA was much more sensitive (LOD<0.2 ng/mL). Human IgG4 and rabbit IgG reacted in immunoblotting with most of the IgE-binding wheat proteins, although with quantitative differences. All three assays showed a strong reaction with wheat proteins, and some cross-reactivity with rye and barley, but were further highly specific for cereal flour proteins. Concentrations measured with the three EIAs in 432 airborne dust samples were highly correlated (r>0.95) and their absolute values showed less than 10-20% differences.

CONCLUSION

The rabbit IgG EIAs are valid substitutes for the human IgG4 inhibition EIA, with important practical advantages. The inhibition EIA is recommended for routine wheat allergen measurements. The sandwich EIA may be used to measure low allergen levels, as in short task-related exposure measurements or in subfractions of airborne dust samples.

An amplified sandwich EIA for the measurement of soy aeroallergens

BACKGROUND

Soy hull low-molecular-weight (SHLMW) allergens were responsible for the soy asthma epidemics in Barcelona, with one 7.5 kDa protein (Gly m 1) being the main IgE-binding component. The aims of this study were to develop a sensitive sandwich enzyme immunoassay (EIA) using rabbit polyclonal antibodies to measure low levels of SHLMW allergens, and to compare this method with the previously described human IgE EIA-inhibition technique.

METHODS

IgG was isolated from serum of rabbits immunized with a chromatographically purified SHLMW extract (SHLMWE). Antibody-binding profiles were compared with those of human IgE anti-soy protein antibodies by Western blot analysis. An amplified sandwich EIA was developed using the purified SHLMWE as a calibration standard. Results were expressed in nanograms per millilitre. To compare the two assays, 54 air samples were analysed by both methods.

RESULTS

SDS-PAGE of the SHLMWE revealed four bands of 6, 8, 15 and 17 kDa. Gly m 1 in the SHLMWE was identified by fingerprinting. The detection limit of the assay was 40 pg/mL. The two methods correlated well (r=0.89; P<0.001). The allergen concentration was detected in all 54 (100%) samples by the sandwich EIA but in only 37 (68.5%) by the EIA inhibition.

CONCLUSIONS

The amplified sandwich EIA for SHLMW components has a high sensitivity and appeared to be a useful tool for the measurement of airborne SHLMW allergens, even at relatively low concentrations. Moreover, the method uses rabbit antibodies at high dilutions and does not require human sera, with limited availability and quantitative and qualitative pool-to-pool variability.

Airborne exposure to wheat allergens: optimised elution for airborne dust samples

Well-validated methods for measuring airborne occupational allergens are essential for effective control and reduction of allergen exposures. For wheat flour allergens, specific immunoassays are available, but there is a need for optimisation and standardization of sample processing procedures. Wheat flour allergen elution and storage were studied using airborne dust samples collected in bakeries with a new parallel sampler. Forty-eight series of 9 parallel filters were subjected to extraction procedures varying in elution medium, shaking method, extraction vial, and centrifugation speed. Wheat allergens were measured with enzyme immunoassays, and the effect of various procedures evaluated by mixed regression analyses. The stability of the eluted allergens was assessed after storage for 20 days and 4 months at -20 degrees C, in the presence or absence of casein in the medium. Only the type of elution medium had significant effects on allergen recovery: addition of Tween-20 resulted in 3- to 100-fold increased levels, an effect that was most pronounced at low concentrations. Allergen levels in extracts were stable for at least 4 months at -20 degrees C, irrespective of the presence of casein in the medium. Addition of Tween-20 to the elution medium is essential for optimal extraction of wheat allergen. The recommended procedure further includes the use of conventional polystyrene tubes, simple shaking methods, and centrifugation after extraction. Wheat dust extracts in PBS-Tween can be stored frozen for at least 4 months, and addition of a stabilising protein is not required.

Immunoglobulin therapy to control lung damage in patients with common variable immunodeficiency

BACKGROUND

Lung damage progression is the most frequent condition in patients with common variable immunodeficiency (CVID). Appropriate immunoglobulin dose adjustments and follow-up guidelines to evaluate this have not been well established.

OBJECTIVE

To assess the evolution of lung damage once stable residual serum levels of IgG over 600 mg/dl had been achieved.

METHODS

A prospective study was conducted in 24 adult patients consecutively diagnosed with CVID, with no previous intravenous immunoglobulin (IVIG) treatment. IVIG dose, total serum IgG level, bacterial infection rate, pulmonary function tests (PFTs) and high resolution computed tomography (HRCT) of the thorax were monitored over 2 years. Moreover, outcome data were determined by measurement of chronic pulmonary disease (CPD).

RESULTS

IVIG dose variability (205-372 mg/kg/21 days) to obtain the required serum IgG levels was determined. Patients with CPD needed higher doses than those without CPD (p=0.045). A significant reduction in severe and mild infections/patient-year was observed during treatment. Overall, there were no changes in PFTs and HRCT scores in patients without CPD, but both improved in patients with CPD. An increase of over 15% in overall HRCT score was detected in two patients without evidence of impairment in either clinical status or PFT values.

CONCLUSIONS

Residual levels of total IgG over 600 mg/dl may help prevent progression of lung damage in patients with CVID. Levels of IgG, clinical manifestations and PFTs seem sufficient for routine follow-up. HRCT examination of the thorax, at least biennially, may help to identify patients in whom lung injury is progressing even though they may remain symptom-free and with stable PFTs.

Clinical significance of antinuclear antibodies in malignant diseases: association with rheumatic and connective tissue paraneoplastic syndromes

Our objective was to determine the prevalence of antinuclear antibodies (ANAs) in patients with malignancies and to investigate if their presence might be related with development of musculoskeletal symptoms or paraneoplastic rheumatic syndromes. Antinuclear antibodies were determined by indirect immunofluorescence on Hep-2 cells in 274 neoplastic patients and in a control group of 140 age-adjusted healthy subjects. Antinuclear antibody specificities (anti-DNA and anti-ENA) were investigated in patients with rheumatological symptoms and positive ANA. Antinuclear antibodies were detected in 76 of 274 (27.7%) patients with malignancies and in nine of 140 (6.4%) healthy subjects. Twenty patients reported paraneoplastic rheumatic symptoms or syndromes. Two of them developed clinical symptoms mimicking rheumatoid arthritis (rheumatoid-like arthropathy), one systemic lupus erythematosus (lupus-like syndrome), one dermatomyositis and four cutaneous vasculitides. Musculoskeletal symptoms and paraneoplastic rheumatic symptoms and syndromes were both more frequently observed in patients with positive ANA. Antinuclear antibody specificities were found in only two cases. We can conclude that there is an increased incidence of antinuclear antibodies in malignant conditions. Musculoskeletal symptoms and rheumatic paraneoplastic symptoms and syndromes seem to be more frequent in patients with cancer-related positive ANAs. The failure to find ANA specificities (anti-ENA, anti-DNA) in patients with malignancies and positive ANAs in our study may simply reflect molecular differences between the autoantigens involved in cancer and those characteristically involved in the systemic autoimmune diseases.

Association study of proposed candidate genes/regions in a population of Spanish asthmatics

A number of genes/regions have recently been reported to be linked to asthma or its related phenotypes (i.e. atopy and bronchial hyperresponsiveness), by genetic linkage and allele-sharing methods. We have performed a case-control study comparing the allelic distribution of nine microsatellite markers and two genetic variants in a group of patients attended at emergency room departments because of an acute attack of asthma with respect to an external healthy population of controls. A total of 146 asthmatic subjects and 50 population controls from Barcelona, Spain, were genotyped for nine microsatellite markers from some asthma/atopy candidate genes/regions: the beta-subunit of the high-affinity IgE receptor (Fc epsilonRI-beta) located on chromosome 11; the 5q31-32 candidate region; the T-cell receptor genes, TCR-alpha on chromosome 14 and TCR-beta on chromosome 7. Two genetic variants of the beta-subunit of the high-affinity IgE receptor (Fc epsilonRI-beta) gene were also analyzed. None of the asthmatic or control individuals carried the Ile181Leu variant. There were no significant differences between asthmatic and control subjects neither for the polymorphic markers nor for the other variant of the beta-subunit of the high-affinity IgE receptor (Fc epsilonRI-beta) gene. No association could be observed in this sample of Spanish asthmatics with the genes/regions studied.

Utility of the antibody response to a conjugated Haemophilus influenzae type B vaccine for diagnosis of primary humoral immunodeficiency

Antibody response to an Haemophilus influenzae type b (Hib)-conjugated vaccine was studied in 59 healthy adults (mean age: 32 yr) and 22 patients with humoral immunodeficiencies (mean age: 32 yr) to determine its usefulness in the diagnosis of defective antibody formation. Twenty of the healthy adults and nine of the patients were also immunized with a pneumococcal vaccine. Serum specific antibodies were measured by ELISA. Adequate response to both vaccines was defined using the lower limit of the two-tailed 90% probability interval of postimmunization specific IgG of the healthy adults. By using this cutoff, responders were considered to be those with an absolute increase in anti-Hib IgG titers higher than 2.28 microgram/ml, and in anti-Streptococcus pneumoniae IgG higher than 395 arbitrary units/ml. With these criteria, 85% (50 of 59) of the healthy adults responded with anti-Hib IgG and 75% (15 of 20) with anti-pneumococcal IgG. All healthy adults receiving both vaccines responded to at least one. None of the patients with humoral immunodeficiencies responded to either vaccine. Evaluation of the antibody response to both the Hib and pneumococcal vaccines may facilitate the diagnosis of humoral immunodeficiency and selection of patients to receive immunoglobulin therapy.

An amplified ELISA inhibition method for the measurement of airborne soybean allergens

BACKGROUND

Measurement of the soybean aeroallergen in Barcelona and other cities where soybean is unloaded is of increasing importance in controlling population exposure and evaluating the influence of such exposure on the persistence of asthma symptoms.

OBJECTIVE

The aims of the study were: (1) to standardize an amplified ELISA inhibition method for the quantification of soybean aeroallergen and (2) to compare this method to a previously described RAST inhibition method.

METHODS AND RESULTS

An amplified competitive ELISA inhibition method with a biotin-streptavidin system was carried out using a pool of sera from soybean-sensitized patients. The results were expressed as U/ml using a low-molecular-mass soybean allergen as reference standard. Reproducibility was calculated by statistically comparing the slope of the regression lines of the standard curve of 4 consecutive assays and by determining the coefficient of variation (CV) of the percent inhibition data for each point of several independent standard curves, each from the same assay (intra-assay) and also from a separate assay (inter-assay). No significant differences in the slopes were obtained by analysis of covariance (ANCOVA) F = 1.04. The CV between assays varied between 4 and 22% (for the assay range used in the reference standard) and was greater than the CV within assays (5-10%). Only values with a CV(%) smaller than 20% were considered acceptable. 78.5% of the samples satisfied this criterion. The RAST inhibition and ELISA inhibition methods were compared by difference plots from the values of 338 air filter eluates. The intraclass correlation coefficient was 0.456 (p < 0.001). After the results of both methods were classified as lower and higher than 165 U/m(3), the kappa index was 0.46 (p < 0.001).

CONCLUSIONS

The data obtained in the present study are comparable to those reported from other similar immunoassays. Moreover, despite the difficulty in comparing air-sampling values from different laboratories, the kappa index may be taken to represent fairly good agreement beyond chance between both methods. All these data demonstrate that the present immunoassay is useful for measuring airborne soybean aeroallergens and can also be applied to evaluate the relationship between exposure and the development of asthma symptoms.

Detection of specific antibodies to pigeon serum and bloom antigens by enzyme linked immunosorbent assay in pigeon breeder's disease

BACKGROUND

Pigeon breeder's disease is an extrinsic allergic alveolitis in the lungs of sensitised people, caused by hypersensitivity reactions to inhaled pigeon antigens. Antigens from different sources of the animal are used for diagnostic purposes, with serum being the most widely used. Bloom is rarely used; very little is known of its antigenicity and diagnostic performance, particularly when used with the enzyme linked immunosorbent assay (ELISA) method, which is the most popular test as it permits measurement of the antibody response.

METHODS

To (a) standardise an ELISA for the measurement of specific IgG against pigeon serum and pigeon bloom extract; (b) to establish reference values for specific IgG in 73 non-exposed controls, (c) to show the presence of specific IgG against pigeon serum and bloom in serum samples of 17 patients with bird fancier's lung and 11 asymptomatic fanciers, and (d) to study the similarity of the two antigen sources by cross reactivity experiments.

RESULTS

Reference values of specific IgG were defined with the 97.5 percentile (367.9 U/ml for pigeon serum and 953.7 U/ml for pigeon bloom extract). Of symptomatic patients 100% had values higher than the cut off for both antigens. In asymptomatic fanciers values were higher than the cut off for pigeon serum in 45% and bloom extract in 54%. Cross reactivity experiments showed that the two antigens differed in antigenic content although some components may be common to both.

CONCLUSION

The ELISA methods used proved to be useful tools for evaluating specific IgG antibody responses against both antigens. The diagnostic performance of both ELISA methods performed with these antigen sources was similar, showing very high sensitivity but moderate specificity. Although some antigenic similarity was found between pigeon serum and bloom extract, cross reactivity studies showed that various antigens seemed to be specific to the bloom extract. However, the antigens responsible for pigeon breeder's disease seem to be present in both antigenic sources.

[Occupational asthma due to isocyanates: a study of 21 patients]

BACKGROUND

A descriptive-evolutive study of a series of patients diagnosed with bronchial occupational asthma due to isocyanate exposure.

SUBJECTS AND METHODS

Retrospective study of 21 patients diagnosed with bronchial occupational asthma due to isocyanates. Family story, clinical data, functional respiratory study, allergic and laboratory tests were collected. Clinical and functional performance one year after diagnosis was evaluated in patients who had and who had not stopped causal exposure.

RESULTS

17 men and 4 women aged 22 to 59 years were evaluated. In 5 cases (23.8%) family story of atopy was documented and 12 (57.14%) patients were smokers. Seven out of 21 patients were exposed to paint related products at work being this the most common reason. Average time (SD) from the beginning of exposure to development of symptoms was 16.10 (22.5) months. IgE levels were high in 6 (28.57%) and specific IgE to isocyanates was high in 8 (38%), in all cases bronchial hyperreactivity was detected. In 18 patients (85.7%), the study of maxim expiratory flow (MEF) register demonstrated occupational asthma while in the remaining 3 patients a provocation test was performed with positive result. In the annual follow up visit, the 17 patients who avoided casual exposure showed clinical improvement, 7 of them also with functional improvement while in the remaining 10 patients no significant functional change was observed. On the other hand, 3 of the 4 patients who, although protected, underwent exposure, became clinical and functionally worse (p = 0.003, Fisher test).

CONCLUSIONS

The etiology of occupational asthma due to isocyanates is not often assessed and usually lately diagnosed. This aspect is worth considering as the illness prognosis seems related to casual agent avoidance.

Specific antibody response against the 23-valent pneumococcal vaccine in patients with alpha(1)-antitrypsin deficiency with and without bronchiectasis

OBJECTIVE

To assess the specific antibody response against polyvalent pneumococcal vaccine in patients with alpha(1)-antitrypsin deficiency (AATD) and respiratory infections.

DESIGN AND PARTICIPANTS

We investigated specific IgG, IgG1, and IgG2 antibody responses against the 23-valent antipneumococcal vaccine in 18 patients with AATD phenotype PiZZ, 9 of whom had bronchiectasis and 4 a history of recurrent pneumonia, and compared them with a control group of 40 healthy volunteers.

INTERVENTIONS

Blood samples were drawn just prior to and 3 weeks after immunization.

MEASUREMENTS AND RESULTS

Quantification of specific IgG and its subclasses was performed by an enzyme-linked immunosorbent assay. For patients with AATD, mean increases in specific antipneumococcal titers were 4.7-fold (25 to 75% quartiles, 2.5- to 6.8-fold) for total IgG, 3.2-fold (1.2- to 4.9-fold) for IgG1, and 2.1-fold (1.8- to 3.7-fold) for IgG2. For the control group, the values were 3.3-fold (1.8- to 5.8-fold) for total IgG, 2. 5-fold (1.9- to 3.4-fold) for IgG1, and 3.1-fold (1.9- to 4.5-fold) for IgG2; differences were not significant. Patients with bronchiectasis showed a tendency toward higher levels of IgG subclasses than both control subjects and patients without bronchiectasis; however, there was a tendency toward lower postvaccination serum levels of specific antipneumococcal IgG, IgG1, and IgG2 in patients with bronchiectasis compared with patients without bronchiectasis, but this trend did not reach statistical significance. Three of the four patients with recurrent pneumonia did not show an appropriate IgG2 response.

CONCLUSIONS

These results suggest that, as a group, patients with AATD have a preserved antibody response against pneumococcal polysaccharides. Patients with bronchiectasis show a tendency toward a decreased antibody response, even with increased serum levels of most Ig types. Individuals with an impaired IgG2 response seem to be at increased risk of recurrent pneumonia. Considering the pernicious effect of pulmonary infections on these patients and the preserved antibody response in a majority of them, pneumococcal vaccination should be recommended to patients with AATD.

Long term outcome of soybean epidemic asthma after an allergen reduction intervention

BACKGROUND

Asthma outbreaks due to the inhalation of soybean dust released from handling of soybean in the city harbour occurred in Barcelona, Spain from 1981 to 1987. The installation of bag filters in the responsible silo was followed by a substantial reduction of airborne soybean dust released into the atmosphere and the disappearance of asthma outbreaks. A study was undertaken to assess the relevant outcomes in asthma patients affected by soybean epidemic asthma eight years after this environmental intervention.

METHODS

A repeat case-control study was performed in 1995 on a population of subjects with epidemic and non-epidemic asthma previously assessed in 1989. The same protocol was used in both surveys to collect data from patients via a questionnaire and respiratory function, skin and laboratory tests were performed under blinded conditions with regard to epidemic and non-epidemic status. Environmental soybean allergen in pollution filters was measured by means of a RAST inhibition technique.

RESULTS

During 1995 and 1996 the 24 hour mean airborne levels of soybean allergen on a sample of 39 unloading days (range 31-269 U/m(3)) were systematically below the lowest level ever detected during an epidemic day (1500 U/m(3)). Measurable levels of serum IgE antibodies against soybean were still present in 55% of patients with epidemic asthma compared with 6.0% of those with non-epidemic asthma (p<0.05). These proportions were almost identical to those observed in 1989. The proportion of patients with soybean asthma with symptoms in 1989 who reported the absence of symptoms in 1995 was similar to the control subjects, so most of the relative risks (RRs) of improvement were near to 1. The only statistically significant differences between the two groups were a smaller proportion of patients with epidemic asthma showing improvement in terms of being woken up by attacks of coughing (RR improvement 0.47; 95% CI 0.22 to 0.99) and the need for treatment at the emergency room (RR improvement 0.63; 95% CI 0.41 to 0.96).

CONCLUSIONS

Eight years after a large reduction in the levels of airborne soybean allergen half of the former soybean epidemic asthma patients were still sensitised to soybean. These results indicate an initial improvement in soybean epidemic asthma in the two years following the intervention with no further improvement in subsequent years.

Isolation and expression analysis of two stress-responsive sucrose-synthase genes from the resurrection plant Craterostigma plantagineum (Hochst.)

The enzyme sucrose synthase (UDP-glucose: D-fructose 2alpha-glucosyltransferase, EC 2.4.1.13) is a key enzyme in carbohydrate metabolism, catalyzing the reversible conversion of sucrose uridine-diphosphate into fructose and UDP-glucose. We report the molecular characterization of two classes of cDNA and genomic clones encoding sucrose synthase from Craterostigma plantagineum Hochst., a resurrection plant in which the turnover of sucrose is considered to have an important role in the unique phenomenon of surviving desiccation. Sucrose-synthase transcript and protein levels are modulated by dehydration and rehydration. In-situ hybridization revealed that transcripts preferentially accumulate in phloem tissues. Promoter analysis underlined a role for class-I sucrose-synthase genes in dehydration stress and in response to cis-abscisic acid. A DNA sequence motif common to class-I sucrose-synthase and sucrose-phosphate-synthase genes was discovered.

Increased positivity of skin test and allergenic stability of glycerinated soybean hull extracts

BACKGROUND

Results obtained from previous experiences with soybean hull antigens suggest that the addition of glycerine to the extract increases positivity of the skin test.

OBJECTIVE

The purpose of this study was to investigate the effect of this glycerine addition and the influence of different storage temperatures on the potency of soybean hull extracts.

METHODS

Twenty-two asthmatic patients admitted to emergency rooms during one of the soybean-related Barcelona asthma epidemics were evaluated 2 years after the last epidemic for: (1) sensitivity to prick test with glycerinated and non-glycerinated extracts, both fresh and stored at 4 degrees C, - 20 degrees C and - 70 degrees C for 30 days, and (2) specific IgE to a fresh hull extract. All extracts were also studied by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE).

RESULTS

No differences in positivities were detected for prick tests performed the same day of preparation between non-glycerinated (5/22; 22.7%) and glycerinated (4/22; 18.2%) extracts. After 30 days storage, positivities of prick test with non-glycerinated extracts stored at 4 degrees C did not significantly differ from the results obtained on the first day. However, prick tests performed with glycerinated extracts stored for 30 days showed increased positivity for the extracts stored at 4 degrees C (7/22; 31%) (P < 0.05) as well as for those stored at - 20 degrees C and - 70 degrees C (9/22; 40.9%) (P < 0.001). This latter percentage is similar to that of specific immunoglobulin E detected by radioimmunoassay (10/22; 45. 4%). Also, for the glycerinated extracts only, the quantitative response showed an increase in mean diameter of the induration at 30 days at the three temperatures, even though owing to the great standard deviation and limited number of patients, it was only significant for the extract stored at - 20 degrees C (P < 0.01). SDS-PAGE gel densitometry at 30 days demonstrated a loss of protein in the bands with a molecular weight higher than 66.2 kDa for non-glycerinated extracts stored at 4 degrees C.

CONCLUSIONS

The results of this study confirm previous observations with soybean hull allergen extracts and indicate that (1) storage of soybean hull extracts with glycerine addition for 30 days at the concentration studied (1:100 w/v) determines a significant increase in the positivity of skin tests, and (2) glycerine addition stabilizes soybean hull extracts at any of the temperatures studied.

The characterization of gio, a new pea mutant, shows the role of indoleacetic acid in the control of fruit development by the apical shoot

Fruit-set and fruit growth in pea (Pisum sativum L.) depend on gibberellins (GAs). The authors have isolated a new pea mutant, gio, which appeared spontaneously within the population of the cultivar Alaska, characterized by unpollinated ovaries much less sensitive to applied GAs. The mutant also has elongated peduncles, and is taller than the wild-type (WT) because the upper plant internodes are longer. Contrary to WT, the gio ovaries respond very little to benzylaminopurine (BAP) and 2,4-dichlorophenoxyacetic acid, but become fully sensitive to GA(3) when this hormone is applied together with BAP. The gio phenotype is determined by a mutation at a single mendelian locus. The mutation is recesive, shows incomplete penetrance, and its expression depends on environmental culture conditions. The sensitivity of the ovaries to GA(3) can be recovered by removing the apical shoot (plant decapitation) and by blocking the transport of indoleacetic acid (IAA) from the apical shoot with 2,3,5-triiodobenzoic acid. The content of IAA in methanolic extracts and phloematic exudates of the apical shoot of gio is about double that in the WT. The rate of transport of [(3)H]IAA applied to the apex of the mutant is also twice that in the WT. This indicates that the insensitivity of the gio ovaries to GAs is due to the inhibitory effect of the higher basipetal IAA transport from the shoot. The interaction between the fruit and the apical shoot mediated by IAA probably also involves cytokinins transported from the basal part of the plant.

Hormonal Control of Parthenocarpic Ovary Growth by the Apical Shoot in Pea

The role of the apical shoot as a source of inhibitors preventing fruit growth in the absence of a stimulus (e.g. pollination or application of gibberellic acid) has been investigated in pea (Pisum sativum L.). Plant decapitation stimulated parthenocarpic growth, even in derooted plants, and this effect was counteracted by the application of indole acetic acid (IAA) or abscisic acid (ABA) in agar blocks to the severed stump. The treatment of unpollinated ovaries with gibberellic acid blocked the effect of IAA or ABA applied to the stump. [3H]IAA and [3H]ABA applied to the stump were transported basipetally, and [3H]ABA but not [3H]IAA was also detected in unpollinated ovaries. The concentration of ABA in unpollinated ovaries increased significantly in the absence of a promotive stimulus. The application of IAA to the stump enhanced by 2- to 5-fold the concentration of ABA in the inhibited ovary, whereas the inhibition of IAA transport from the apical shoot by triiodobenzoic acid decreased the ovary content of ABA (to approximately one-half). Triiodobenzoic acid alone, however, was unable to stimulate ovary growth. Thus, in addition to removing IAA transport from the apical shoot, the accumulation of a promotive factor is also necessary to induce parthenocarpic growth in decapitated plants.

Survival prognostic factors and markers of morbidity in Spanish patients with systemic sclerosis

OBJECTIVE

To identify survival prognostic factors and markers of morbidity among patients with systemic sclerosis (SSc).

PATIENTS AND METHODS

The study included 72 patients diagnosed with SSc. According to the extent of skin involvement, three groups of patients were established: group 1, without sclerosis and with sclerosis of fingers and neck; group 2, with sclerosis of face and distal to elbows and knees; group 3, with generalised sclerosis including the trunk. All patients were included in a study protocol to determine visceral involvement. Cumulative survival after first symptom has been estimated according to the Kaplan-Meier method. The association between a hypothetical prognostic factor and cumulative survival after first symptom was assessed by log rank test. The association between a hypothetical risk factor and the prevalence of severe morbidity was assessed by the odds ratio. Multiple logistic regression models were used to identify the main predictors of severe morbidity.

RESULTS

Survival was estimated to be 85% 10 years after first SSc symptom. Survival was higher among SSc patients with skin involvement distal to elbows and knees than among the rest of patients; a forced vital capacity (FVC) on spirometry lower than 70% of expected value was associated with a shorter survival, even after adjustment for diffuse SSc. Skin involvement proximal to elbows or knees was associated with a higher prevalence of severe morbidity (OR = 46.57; p < 0.001). According to a multiple logistic regression, severe morbidity was higher among patients with skin involvement proximal to knees or elbows (OR = 40.92; p < 0.001) or among patients with pulmonary hypertension detected by Doppler echocardiography (OR = 23.66 p < 0.001).

CONCLUSIONS

In patients with SSc the extent of skin sclerosis was found to be a determining factor on the prognosis. According to skin sclerosis extent two main subsets of SSc patients with different survival incidence and degree of morbidity could be clearly established: limited SSc, formed by patients with no skin sclerosis or with sclerosis distal to elbows and knees and diffuse SSc, formed by patients with skin sclerosis distal and proximal to elbows and knees. Moreover, lung involvement (FVC < 70% on survival study and pulmonary hypertension on morbidity study) was an important and independent prognostic factor.

HLA class II genes in soybean epidemic asthma patients

From 1981 to 1987, 26 outbreaks of asthma caused by the inhalation of soybean dust, affecting a total of 688 individuals, were detected in Barcelona, Spain. Because only a small proportion of asthmatic individuals living in Barcelona expressed the epidemic phenotype, it is hypothesized that a genetically determined human leukocyte antigen (HLA) Class II factor could have played a role in the susceptible individuals. Accordingly, we studied the distribution of both HLA-DR and HLA-DQ in soybean epidemic asthmatic patients. An analysis of the HLA-DR and HLA-DQ genes for genetic polymorphisms of the beta 1 chain was done with the polymerase chain reaction (PCR) in 78 soybean epidemic asthma patients, and the findings were compared with those for 67 nonepidemic asthmatic individuals and 168 individuals from the general population. An allelic disequilibrium could be established; the risk of epidemic asthma was particularly associated with the DRB1*13 gene (p value corrected for multiple comparisons < 0.02). The association observed for the DRB1*13 gene was stronger in individuals in the lowest tertile for total IgE, with an estimated risk with a 95% confidence interval (CI), of 14.5 (1.6 to 130.8). The combination of two genes from among the DRB1*05-05, DRB1*05-06, and DRB1*06-06 genes was present in epidemic asthmatic subjects only. No association with an HLA-DQB1 allele could be observed. Genetic predisposition could contribute to the response of some asthmatic patients to exposure to soybean dust, having led to their being affected during the epidemics of asthma in Barcelona.

High prevalence of mollusc shell hypersensitivity pneumonitis in nacre factory workers

Following the discovery of hypersensitivity pneumonitis caused by the inhalation of mollusc shell dust in two workers from a nacre-button factory, the health status of 26 workers employed in sawing mollusc shells was investigated. The evaluation included the administration of two questionnaires and radiological, functional and immunological assessments of all workers at the outset and 1 year later, when hygienic and therapeutic measures had been taken. Six workers, in whom specific inhalation challenge test was positive, were diagnosed with mollusc shell hypersensitivity pneumonitis, thus yielding a prevalence of 23%. Evidence of diffuse lung disease and systemic symptoms was found in these patients. Nonspecific bronchial hyperreactivity was also found more frequently in patients with mollusc shell hypersensitivity pneumonitis. Specific immunoglobulin G (IgG) level and specific skin testing failed to differentiate patients with mollusc shell hypersensitivity pneumonitis from other exposed workers; whereas, nonspecific skin testing, which was impaired in the patients, did differentiate. Bronchoalveolar lavage and transbronchial biopsy performed in patients with mollusc shell hypersensitivity pneumonitis were consistent with the disease. Removal from an environment containing mollusc shell dust was followed by regression of clinical, radiological and functional changes. The clinical picture of the 20 workers who did not present mollusc shell hypersensitivity pneumonitis remained unchanged, but functional decline was observed despite improvement in the environmental conditions of the factory. This report describes the first series of patients with mollusc shell hypersensitivity pneumonitis studied, and underlines the importance of careful follow-up of workers occupationally-exposed to mollusc shell dust.

High prevalence of mollusc shell hypersensitivity pneumonitis in nacre factory workers

Following the discovery of hypersensitivity pneumonitis caused by the inhalation of mollusc shell dust in two workers from a nacre-button factory, the health status of 26 workers employed in sawing mollusc shells was investigated. The evaluation included the administration of two questionnaires and radiological, functional and immunological assessments of all workers at the outset and 1 year later, when hygienic and therapeutic measures had been taken. Six workers, in whom specific inhalation challenge test was positive, were diagnosed with mollusc shell hypersensitivity pneumonitis, thus yielding a prevalence of 23%. Evidence of diffuse lung disease and systemic symptoms was found in these patients. Nonspecific bronchial hyperreactivity was also found more frequently in patients with mollusc shell hypersensitivity pneumonitis. Specific immunoglobulin G (IgG) level and specific skin testing failed to differentiate patients with mollusc shell hypersensitivity pneumonitis from other exposed workers; whereas, nonspecific skin testing, which was impaired in the patients, did differentiate. Bronchoalveolar lavage and transbronchial biopsy performed in patients with mollusc shell hypersensitivity pneumonitis were consistent with the disease. Removal from an environment containing mollusc shell dust was followed by regression of clinical, radiological and functional changes. The clinical picture of the 20 workers who did not present mollusc shell hypersensitivity pneumonitis remained unchanged, but functional decline was observed despite improvement in the environmental conditions of the factory. This report describes the first series of patients with mollusc shell hypersensitivity pneumonitis studied, and underlines the importance of careful follow-up of workers occupationally-exposed to mollusc shell dust.

Blood sample processing effect on eosinophil cationic protein concentration

BACKGROUND

Asthma is considered to be an inflammatory disease. The most important cell involved in the inflammation is the eosinophil. These cells and their mediators, such as eosinophil cationic protein (ECP), are potential markers of the inflammation's severity. Eosinophil cationic protein may be used for monitoring antiasthma treatment. It is well known that sample processing conditions can affect the ECP blood levels.

OBJECTIVE

The aim of this work is to study the effect of temperature, time, and anticoagulants on ECP levels.

METHODS

We studied five asthmatic patients and five healthy controls. We obtained three different blood samples from each subject, one with heparin, one with EDTA, and one without anticoagulant. To evaluate the effect of temperature, serum samples were clotted for an hour, one at 0 degree C, one at room temperature, and the other at 37 degrees C. Plasma (heparin and EDTA) samples were treated as follows: one was immediately centrifuged, and two were stored for an hour, one at 0 degree C, and the other at room temperature. Eosinophil cationic protein levels were measured by fluoroimmunoassay (CAP-System ECP FEIA Pharmacia).

RESULTS

A higher temperature during blood clotting resulted in a higher ECP concentration. There were no differences between ECP determination in serum samples and plasma samples with heparin, under the same conditions of time and temperature; so clotting may not be necessary for ECP release in vitro. Eosinophil cationic protein was not released in plasma samples with EDTA, neither at 0 degree C nor room temperature.

CONCLUSIONS

More studies must be done to clarify the mechanism of the ECP release in vitro.

Characterization of specific immunoglobulin G (IgG) and its subclasses (IgG1 and IgG2) against the 23-valent pneumococcal vaccine in a healthy adult population: proposal for response criteria

The aim of the study was to standardize an enzyme-linked immunosorbent assay (ELISA) method for the quantification of immunoglobulin G (IgG) and its subclasses (IgG1 and IgG2) against the 23-valent pneumococcal vaccine and to establish the criteria for a normal response to the vaccine. Forty healthy individuals (20 women and 20 men; mean age, 29 years) were studied. All were vaccinated with the 23-valent pneumococcal vaccine; blood samples were drawn just prior to and 3 weeks after immunization. Quantification of specific IgG and its subclasses was performed by an ELISA with the vaccine as the antigen. The linearity of the ELISA method was demonstrated by the similar slopes of the linear regression lines generated from the titration of sera with different antibody concentrations. The specificity of the antibodies against the vaccine was demonstrated by (i) an absorption test with pneumococcal vaccine, (ii) a cross-reactivity experiment with Haemophilus influenzae type b polysaccharide, and (iii) affinity chromatography with protein A-Sepharose. Response to the vaccine was defined by using the lower level of the 90% probability interval (one-tailed) for postimmunization-specific IgG, IgG1, and IgG2. By using this cutoff, responders were considered to be those with an absolute increase in antibody titers higher than 395 arbitrary units/ml for IgG, 0.350 A450 units for IgG1, and 0.314 A450 units for IgG2. Overall, 20 (50%) subjects had IgG, IgG1, and IgG2 responses, 9 (22.5%) had IgG and IgG2 responses, 4 (10%) had IgG1 responses, 3 (7.5%) had IgG and IgG1 responses, and 4 (10%) were nonresponders. Ninety percent of our population responded to the 23-valent pneumococcal vaccine. Up to 10% of healthy individuals may respond to an IgG subclass without significant increases in total IgG titers. The ELISA method that is described may be useful for evaluating the specific antibody response against polysaccharides.

IgG subclass deficiencies associated with bronchiectasis

Only a small number of patients with IgG subclass deficiencies (IgGSD) have been observed to have bronchiectasis. Moreover, in the series of patients with bronchiectasis, IgGSD have not been found at any frequency, and the etiology of bronchiectasis remains unclear in 29 to 49% of cases. Serum concentrations of total IgG, IgA, and IgG subclasses as well as pulmonary function were measured in 65 patients (aged: 10 to 74 yr) with bronchiectasis of unknown etiology. An ELISA test was performed to quantify subclasses 1 through 4 using subclass-specific antihuman monoclonal antibodies. IgG subclass estimation in a healthy population with age-stratified normal ranges was derived from 100 adults, 37 children aged between 10 and 12 yr, and 27 adolescents aged between 13 and 16 yr. Serum concentrations of specific IgG antibodies to Haemophilus influenzae type b capsular polysaccharide (Hib-PRP) were also assayed by an ELISA test in 19 of the patients (10 with IgGSD and nine with non-IgGSD) and in 58 healthy individuals before and 3 wk after immunization with Hib-PRP conjugated to meningococcal outer membrane protein complex (OMPC). Thirty-one patients (48%) had low serum concentrations of one or more IgG subclasses (19 IgG2 deficiencies, 2 IgG3 deficiencies, 3 IgG4 deficiencies, and 7 combined subclass deficiencies). All patients showed increased levels of total IgG, IgG1, and IgA, but this rise was significantly higher in patients without IgGSD. Patients with IgGSD showed impaired antibody response to Hib-PRP compared with patients with non-IgGSD and the control group. IgGSD, particularly IgG2 deficiency, are not an unusual cause of bronchiectasis. Therefore, serum levels of IgG subclasses must be assayed whenever other causes of bronchiectasis have been ruled out.

Effect of conditions in obtaining blood samples for ECP testing in children

Eosinophil Cationic Protein (ECP) is a basic protein found in eosinophil granules. This cell and its mediators are currently considered to be potential indicators of the severity of inflammation in the organism. ECP concentration can be reliably tested using several RIA or ELISA methods. It is well known that the conditions of sample obtention can affect the ECP values in blood. The aim of this study is to establish which parameters affect ECP testing during regular blood sample collection and how they affect it. Blood samples taken for the routine study of five children attended in our department were analysed: four were asthmatic and one child had atopic dermatitis. In the results we observed that ECP was not detected in the blood samples taken with EDTA tripotassium. In both the plasma samples taken with heparin as well as with serum, more ECP was released at a higher temperature. In the release of ECP obtained by coagulation, samples at 37 degrees showed values of between 4 and 20 higher than those obtained for an hour at 0 degrees. There is a considerable variability in the testing of ECP depending on the blood test extraction conditions, the range is bigger in the samples with eosinophils. These results imply the need to define a stricter protocol for obtaining samples than that suggested at present.

Diagnosis of soybean-induced asthma

BACKGROUND

The role of soybean dust as a causal agent of asthma has been clearly established since the Barcelona asthma epidemics in the 1980s. The large number of patients who were first seen with asthma symptoms during those epidemics provided an excellent opportunity to study the possibilities of different diagnostic tests.

OBJECTIVE

This study was designed to evaluate the usefulness of the skin test and amplified ELISA technique for quantifying specific IgE in the diagnosis of soybean asthma.

PATIENTS AND RESULTS

Ninety epidemic asthmatic patients and 95 nonepidemic asthmatic patients were studied 2 years after the last epidemic. Results of prick tests and ELISAs for specific IgE with hull and dust extracts showed a significant difference between the two groups of patients (p < 0.001). Sensitivity and specificity of glycerinated prick test with hull extract in epidemic asthmatic patients were 57.7% and 95.3%, respectively, and ELISA values were 56.6% and 93.7%, respectively. Similar results were obtained with dust extracts.

CONCLUSION

Glycerinated skin prick tests and ELISAs with soybean hull and dust extracts have proved effective in the diagnosis of soybean asthma, even 2 years after the epidemics. Taking into account the sensitivity (90.5%) and specificity (93.7%) of ELISA test results for epidemic asthmatic patients found when the epidemic occurred, data from this study suggest that both tests may be very useful for the diagnosis of soybean dust-induced asthma.

[Espartosis. A new type of extrinsic allergic alveolitis among construction plasterers]

The clinical characteristics of three plasterers in contact with esparto and who presented a picture of extrinsic allergic alveolitis which was peculiar because of their being hyperacute and causing hypoxemia. In addition to a review of 5 previously published sporadic cases the clinical picture of this new type of apparently infrequent alveolitis is described. The causal antigen is unknown although contamination by fungus or the addition of raw esparto may be the origin of the disease. After a review of the literature regarding this subject, the authors suggest that, in addition to cases of asthma and chronic airway obstruction, the patients with extrinsic allergic alveolitis be included under the name of espartosis following esparto dust inhalation.

Evolutionary analysis of the picornavirus family

An exhaustive evolutionary analysis of the picornavirus family has been carried out using the amino acid sequences of several proteins of the viruses including: the capsid proteins (1D, 1B, and 1C) situated at the 5' end of the genome and responsible for the serotype of the viruses, and the viral polymerase (3D), located at the 3' end of the genome. The evolutionary relationships found among the viruses studied support the new classification, recently suggested, in contrast to the classical one, and the existence of a new genus for the picornavirus family. In the new taxonomic organization, five genera form the picornavirus family: (1) aphthoviruses, (2) cardioviruses, (3) hepatoviruses (previously classified as enteroviruses), (4) renteroviruses (which mainly constitute a combination of the previous genera rhinovirus and enterovirus), and (5) a new genus, with a new and unique representative: the echovirus 22. Our analysis also allowed us, for the first time, to propose the most probable sequence of speciation events to have given rise to the current picornavirus family. The bootstrap procedure was used to check the reliability of the phylogenetic trees obtained. The application of the method of the statistical geometry in distance space to internal branches of the tree revealed a high degree of evolutionary "noise," which makes the resolution of some internal branching points difficult.

Relationship between serum IgE and airway responsiveness in adults with asthma

BACKGROUND

General population studies have shown a relationship between total serum IgE levels and airway responsiveness, but this association has not been documented in patients with asthma.

OBJECTIVE

The study assesses the cross-sectional relationship between IgE levels and airway responsiveness in 208 subjects who had had emergency department treatment for asthma at least 2 years earlier.

METHODS

All participants completed a standardized respiratory questionnaire and underwent spirometry, allergy skin testing, and a dose-response methacholine challenge test.

RESULTS

After adjusting for age and gender, the percentage of patients with asthma and airway responsiveness (provocative concentration causing a 20% fall in forced expiratory volume in 1 second [PC20] < or = 8 mg/ml) increased from 52% in the lower quintile of IgE to 72% in the upper quintile (p < 0.01). After adjusting for age, gender, baseline percent predicted forced expiratory volume in 1 second, and smoking, the association between IgE (both in quintiles and continuous) and PC20 appeared consistent and statistically significant (p < 0.01). This association was stronger in patients who were not given inhaled steroid (odds ratio for twice the concentration of IgE, 1.42; 95% confidence interval, 1.09 and 1.84), than in patients treated with inhaled steroid (odds ratio, 1.10; 95% confidence interval, 0.82 and 1.50). Eosinophilia and skin reactivity were associated with PC20 although to a lesser extent.

CONCLUSION

These findings strengthen the role played by IgE in facilitating the development of bronchial responsiveness in patients with asthma.

The value of complement activation products in the assessment of systemic lupus erythematosus flares

Complement activation products (CAP) have been reported as sensitive markers of disease activity in systemic lupus erythematosus (SLE). We have measured seven parameters of the complement system (C3, C4, factor B, C3a, C4a, iC3b, and the terminal complement complex-TCC-) in 61 SLE patients to study their interrelationship and relative efficacy as diagnostic indicators of lupus activity. Disease activity was judged according to a clinical index (SLEDAI) to be active in 22 and inactive in 39 patients. Subjects with active SLE showed increased levels of C3a, C4a, and TCC compared with those of stable lupus and normal controls, and plasma concentrations of these CAP manifested a positive correlation with disease activity scores. However, values of factor B and iC3b did not correlate with lupus flares. Serum C3 levels were a better reflection of the degree of SLE activity than were C4 levels. The anaphylatoxins were extremely sensitive markers of disease activity but they lacked enough specificity, and iC3b was not at all informative for this purpose. On the whole, TCC concentration was the most useful parameter (77% sensitivity, 80% specificity) to monitor lupus activity, correlating the best with the activity scoring system, and thus offers a better laboratory marker of lupus severity than conventional measurements of complement.

Clinical and functional characteristics of patients two years after being affected by the soybean asthma epidemic in Barcelona

BACKGROUND

Patients affected during the asthma outbreaks caused by soybean dust inhalation in Barcelona presented with sudden onset of severe asthma followed by the rapid relief of symptoms after treatment. Two years after the epidemics ended, a case-control study was conducted in which the clinical, functional, and immunological characteristics of these asthma patients (a randomised sample of asthmatic patients admitted as emergency cases on epidemic days, n = 213) were compared with those of a control group (a random sample of asthmatic patients admitted as emergency cases for attacks of asthma on non-epidemic days, n = 170).

METHODS

The study included the administration of the ATS-DLD78 standardised respiratory questionnaire, the measurement of atopy, and performance of spirometric tests and a methacholine inhalation test.

RESULTS

Patients with epidemic asthma reported fewer symptoms of asthma, had attended emergency departments less frequently during the previous year for acute attacks of asthma, were taking fewer inhaled corticosteroids at the time of the study, and attended medical follow up less frequently than did the patients with non-epidemic asthma. However, the cases and controls showed no differences in ventilatory capacity or reactivity to the methacholine bronchoprovocation test.

CONCLUSIONS

Two years after the end of the soybean epidemics, people affected by epidemic asthma had a favourable prognosis. This finding contrasts with a higher risk of life threatening asthma and death during the epidemics. This paradox could be the result of a complex interaction between host and conditions of exposure.

Preventing asthma epidemics due to soybeans by dust-control measures

BACKGROUND

The inhalation of soybean dust released during the unloading of soybeans into a silo caused outbreaks of asthma in Barcelona, Spain. This study was designed to determine morbidity due to asthma and serum IgE reactivity before and after the installation of filters in the silo.

METHODS

We measured soybean-allergen concentrations in 136 samples of air collected for 9 months before and 24 months after the installation of filters. We compared the number of days on which there was an unexpected increase in emergency room visits for asthma, the number of days on which the number of emergency room visits for asthma in one four-hour period was so high that it was unlikely to be due to chance, and the mean daily number of emergency room and intensive care unit admissions for asthma for a total of 60 months before and after filter installation. Serum IgE antibodies against soybean allergens were measured in 38 patients before and after filter installation.

RESULTS

The concentration of airborne soybean allergens on days when soybeans were unloaded decreased from 324 to 25 U per cubic meter after the installation of filters (P < 0.001). The number of days on which there was an unusually large number of visits to the hospital for asthma and the number of days on which asthma was epidemic both decreased significantly (both P < 0.001), from 29 to 6 and from 18 to 0, respectively. The mean daily number of emergency room and intensive care unit admissions for asthma on days when soybeans were unloaded decreased from 8.3 to 5.4 and from 0.26 to 0.01, respectively (both P < 0.001). The mean serum IgE antibody concentrations in the 38 patients studied decreased from 2 Pharmacia reference units per milliliter to 1 (P < 0.001).

CONCLUSIONS

Installing filters on silos to prevent airborne dissemination of allergenic soybean dust eliminates outbreaks of asthma caused by inhalation of the dust, thus supporting the idea that the avoidance of allergens helps prevent asthma.

Localised alveolar-septal amyloidosis with hypersensitivity pneumonitis

Localised alveolar-septal amyloidosis has been thought irreversible. A woman exposed to the dust of sea-snail shells during the manufacture of nacre buttons had clinical and immunological features typical of hypersensitivity pneumonitis; however, transbronchial lung biopsy showed alveolar-septal amyloidosis. There was no evidence of other diseases known to be associated with amyloidosis, nor were amyloid deposits found in other organs. After a year without exposure to the antigen there was no trace of either pneumonitis or amyloidosis.

Risk factors of soybean epidemic asthma. The role of smoking and atopy

Epidemics of emergency room admissions for asthma occurring in Barcelona during the period 1981 to 1987 were caused by inhalation of soybean dust. To investigate the risk factors that determined why some asthma patients became reactive to soybean and were consequently affected by the asthma epidemics of Barcelona but others did not do so, a case-control study was conducted during 1989, 2 yr after the cessation of asthma epidemics. Patients with asthma admitted in emergency room services during epidemic asthma days (n = 169) were compared with asthma patients admitted in the same services during nonepidemic days and who were never admitted during the epidemics (n = 147). Risk factors other than soybean exposure, namely skin reactivity against at least one common allergen (odds ratio [OR] 3.0, 1.7 to 5.3), age over 64 yr (OR 2.8, 1.4 to 6.0), cigarette smoking at the time of the epidemics (OR 2.3, 1.2 to 2.4), past smoking (OR 1.8, 0.9 to 3.7), and total immunoglobulin E (IgE) higher than 100 IU/ml (OR 1.7, 1.0 to 3.0), were found independently related to epidemic asthma. The role of smoking was especially important for those who had a positive skin reaction and were exposed to soybean dust (OR 7.9, 1.8 to 36.0). In this group, a dose-response pattern with pack-years was observed (p less than 0.01). The present findings suggest a multifactorial process for epidemic asthma, in which atopy and cigarette smoking played an important synergistic role. This has a preventive potential for IgE-related asthma.