TOWARDS AN UNIFIED FRAMEWORK FOR VALIDATING DEEP LEARNING METHODS FOR COLORECTAL POLYPS: FIRST STEPS

INTRODUCTION

Deep learning techniques have significantly contributed to the field of medical imaging analysis. In case of colorectal cancer, they have shown a great utility for increasing the adenoma detection rate at colonoscopy, but a common validation methodology is still missing. In this study, we present preliminary efforts towards the definition of a validation framework.

MATERIAL AND METHODS

Different models based on different backbones and encoder-decoder architectures have been trained with a publicly available dataset that contains white light and NBI colonoscopy videos, with 76 different lesions from colonoscopy procedures in 48 human patients. A computer aided detection (CADe) demonstrator has been implemented to show the performance of the models.

RESULTS

This CADe demonstrator shows the areas detected as polyp by overlapping the predicted mask on the endoscopic image. It allows selecting the video to be used, among those from the test set. Although it only present basic features such as play, pause and moving to the next video, it easily loads the model and allows for visualization of results. The demonstrator is accompanied by a set of metrics to be used depending on the aimed task: polyp detection, localization and segmentation.

CONCLUSIONS

The use of this CADe demonstrator, together with a publicly available dataset and predefined metrics will allow for an easier and more fair comparison of methods. Further work is still required to validate the proposed framework.

Covid-19 and the role of smoking: the protocol of the multicentric prospective study COSMO-IT (COvid19 and SMOking in ITaly)

The emergency caused by Covid-19 pandemic raised interest in studying lifestyles and comorbidities as important determinants of poor Covid-19 prognosis. Data on tobacco smoking, alcohol consumption and obesity are still limited, while no data are available on the role of e-cigarettes and heated tobacco products (HTP). To clarify the role of tobacco smoking and other lifestyle habits on COVID-19 severity and progression, we designed a longitudinal observational study titled COvid19 and SMOking in ITaly (COSMO-IT). About 30 Italian hospitals in North, Centre and South of Italy joined the study. Its main aims are: 1) to quantify the role of tobacco smoking and smoking cessation on the severity and progression of COVID-19 in hospitalized patients; 2) to compare smoking prevalence and severity of the disease in relation to smoking in hospitalized COVID-19 patients versus patients treated at home; 3) to quantify the association between other lifestyle factors, such as e-cigarette and HTP use, alcohol and obesity and the risk of unfavourable COVID-19 outcomes. Socio-demographic, lifestyle and medical history information will be gathered for around 3000 hospitalized and 700-1000 home-isolated, laboratory-confirmed, COVID-19 patients. Given the current absence of a vaccine against SARS-COV-2 and the lack of a specific treatment for COVID-19, prevention strategies are of extreme importance. This project, designed to highly contribute to the international scientific debate on the role of avoidable lifestyle habits on COVID-19 severity, will provide valuable epidemiological data in order to support important recommendations to prevent COVID-19 incidence, progression and mortality.

Colonic adenosquamous carcinoma and mucinous adenocarcinoma with microsatellite instability

A 43-year-old man presented with two-month history of fatigue, weakness, paleness, rectal bleeding, sweating, and weight loss of 10 kg in the past one month. A complete blood count revealed anaemia. The patient underwent a right hemicolectomy. The microscopic examination revealed an adenosquamous carcinoma associated with a mucinous adenocarcinoma in a patient with microsatellite instability due to loss of MLH1 and PMS2 expression and retention of MSH2 and MSH6 expression in both the squamous and glandular components. We also observed an atypical immunohistochemical phenotype in the adenocarcinoma component showing CK7 expression and reduced CK20 and CDX2 expression.

Multifactorial Ethiopathogenic In Eating Disorders

Eating Disorders is a heterogeneous group of syndromes which includes many factors in their develop. The three main syndromes, AN, BN and EDNOS has been defined in last DSM as independent entities. However is well known that a group of patients may change its presentation along time, so also been at first diagnosed of AN, lately will fulfil criteria for BN or EDNOS.

In the other hand, if we compare two patients with the same syndrome, as BN, or AN…

We may easily find big differences in personality, stressors…and in some cases the only common factor is the clinical presentation.

Behind all of this is the fact that syndromic classification drives to empiric treatments that are far the most validated.

But although there is a well known evolution in this disorders, with a not so bad income as one could think initially (in some cases one third could recover without treatment), what may we do with those patients that are resistant for empiric treatments?

And it is our opinion that a deeper knowledge of all the factors that contribute to the syndrome or its presentation, as well as those related to treatments results, should be taken into account.

We have reviewed all knowledge about these issues and we have completed it with our clinical practise using a 50 patients data base, here we will show our results, that are basically that even the same factors interact in different ways in each patient, so it is not just the ingredients but the recipe.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Brief psychotherapy in eating disorders

First time we began to work with eating disorders, we used to hear the chronic course of the illness and the long-term treatment that our patients would need. When you have a team trained in brief psychotherapy, but not in this specific area, it sounds as just the opposite you try to reach with your patients. National guidelines however are full of psycho-educational and cognitive-conduct treatment's models, without any other validated kind of treatment. However, it was our experience that solution focused or problem focused therapy were also two clinical effective approaches to many psychiatric problems. In fact, we had a mature consult, in which as far as two thirds of patients had become, some way chronic. Problem was, as far as we can imagine, if that was a disease's effect or a lack of a deeper intervention, which were wider than those classic. So, we classified our patients in resistant or not resistant, and doing so we add brief therapy to the first group, reevaluating every week each intervention and the course of the illness. By doing so, we found that chronicity was, in same cases, just the result of limited treatments. Here we have analysed some chronic patients with a bad course and the alternatives that let them to recover.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Pla 1 1 and Ole e 1 pollen allergens share common epitopes and similar ultrastructural localization

BACKGROUND

English plantain (Plantago lanceolata L.) and olive (Olea europaea L.) pollens are important causes of pollinosis in large areas of North America, Australia, and the Mediterranean basin. The major pollen allergens of both plants, Pla I 1 and Ole e 1, share 38.7% of their amino acid sequences.

OBJECTIVE

To analyze putative cross-reactivity between these 2 proteins.

METHODS

Several antibodies and patients' sera were used in immunoblot and immunocytochemistry experiments.

RESULTS

Two anti-Pla I 1 antibodies were able to bind to 3 polypeptides from olive pollen protein extracts, which correspond to the 3 glycosylation isoforms of Ole e 1 (18-22 kDa) previously described. Moreover, Pla I 1 protein was found in the cytoplasm of both the vegetative and the generative cells of P lanceolata mature pollen. On olive pollen sections, these anti-Pla I 1 antibodies displayed significant labeling in the cytoplasm of the vegetative cell and in both the exine and the material adhering to this outer layer of the pollen wall. In addition, the anti-Ole e 1 antibody 10H1 was found to cross-react with proteins of similar masses (16-20 kDa) to Pla I 1 variants. In Plantago pollen sections, the 10H1 antibody recognized proteins located in the cytoplasm of both the vegetative and generative cells. Cross-reaction was confirmed using sera from patients allergic to either plant pollen.

CONCLUSION

Both allergens share common epitopes, which can be cross-recognized by different antibodies and sera from different patients, although this antigenic similarity seems to have little clinical relevance.

1,3-beta-glucanases as candidates in latex-pollen-vegetable food cross-reactivity

BACKGROUND

1,3-beta-glucanases (group 2 of pathogenesis-related proteins) are enzymes widely distributed among higher plants and have been recently proven to be significant allergens.

OBJECTIVE

The aim of this work was to study the potential implication of 1,3-beta-glucanases in cross-reactivities among latex, pollen and vegetable foods.

METHODS

The cDNA encoding the N-terminal domain (NtD) of Ole e 9, a major allergenic 1,3-beta-glucanase from olive pollen, was amplified by polymerase chain reaction and produced as a recombinant protein in Pichia pastoris (recombinant N-terminal domain, rNtD). Circular dichroism, ELISA, immunoblotting and immunoblotting inhibition experiments were carried out. Sera from olive pollen allergic patients and a rNtD-specific polyclonal antiserum were used.

RESULTS

The NtD of Ole e 9 has been produced at high yield in the yeast P. pastoris and possesses 1,3-beta-glucanase activity. The expressed polypeptide conserves IgE and IgG immunodominant epitopes of the whole Ole e 9. A rNtD-specific polyclonal antiserum and sera from olive pollen allergic patients allowed detection of IgG and IgE reactive peptidic epitopes common to 1,3-beta-glucanase Ole e 9 in extracts from ash and birch pollen, tomato, potato, bell-pepper, banana and latex.

CONCLUSION

rNtD and homologous glucanases are new molecules to be used in diagnostic protocols as they could help to identify allergic pollen patients who are at risk for developing allergic symptoms to fruits, vegetables and latex.

Prevalence of sensitization to Artemisia allergens Art v 1, Art v 3 and Art v 60 kDa. Cross-reactivity among Art v 3 and other relevant lipid-transfer protein allergens

BACKGROUND

Artemisia vulgaris is a widespread weed in the Mediterranean area and several allergens have been detected in its pollen. One of them, Art v 3, belongs to the lipid-transfer protein (LTP) family and its prevalence in Artemisia-sensitized patients or its relationship with other LTP allergens is not clear.

OBJECTIVE

To assess the pattern of sensitization to an array of mugwort allergens in a Mediterranean population, and to study the cross-reactivity of Art v 3 with Pru p 3 and Par j 1, relevant LTP allergens in the area.

METHODS

Skin prick test was performed with whole extracts (A. vulgaris, Parietaria judaica and peach) and pure natural allergens Art v 1, Art v 3, Art v 60 kDa and Par j 1 in 24 mugwort-allergic patients from a Mediterranean area. In vitro assays included measurement of specific IgE and ELISA inhibition among LTP allergens.

RESULTS

The three Artemisia allergens elicited a positive skin response in 70-80% of the patients. Seven patients were clearly sensitized to Par j 1 and 11 to Pru p 3. There was no correlation between Par j 1 and Pru p 3 sensitization, but a highly significant correlation was found between peach extract and Art v 3 as regards the skin response. No IgE cross-reactivity was observed between Art v 3/Par j 1 or Pru p 3/Par j 1. In contrast, Art v 3 significantly inhibited the binding to Pru p 3 of IgE from three patients' sera out of six studied, but Pru p 3 was not able to inhibit the IgE binding to Art v 3.

CONCLUSION

Art v 3 is a major mugwort allergen and in some patients with IgE to both Art v 3 and Pru p 3, Art v 3 behaves as the primary sensitizing agent.

Monoclonal Antibody-Based ELISA to Quantify the Major Allergen of Cynodon dactylon (Bermuda Grass) Pollen, Cyn d 1

BACKGROUND

Pollen of Bermuda grass (Cynodon dactylon) is an important cause of pollinosis in many areas of the world. Most patients show sensitivity to the major allergen Cyn d 1, a glycoprotein composed of a number of isoforms with a molecular mass of 31-32 kDa. The aim of this work was to develop a monoclonal antibody (mAb)-based ELISA to quantify Cyn d 1, and to assess the correlation of the allergen content with the biological activity of C. dactylon pollen extracts.

METHODS

After fusion of myeloma cells with spleen cells from a BALB/c mouse immunized with C. dactylon pollen extract, Cyn d 1-specific mAbs secreting hybridomas were selected, and the antibodies characterized. One of them (4.4.1) was used as the capture antibody in an ELISA method for Cyn d 1 quantitation. An anti-Cyn d 1 rabbit serum was used as the second antibody. Cyn d 1 was purified by immunoaffinity chromatography with mAb 4.4.1, characterized, and used as the standard in the assay.

RESULTS

The identity, purity and isoallergen composition of affinity-purified Cyn d 1 was confirmed by N-terminal amino acid sequencing, SDS-PAGE, Western blot and 2D electrophoresis. The Cyn d 1 ELISA is highly specific and sensitive, with a detection limit of 0.24 ng/ml and a linear range of 1.1-9.2 ng/ml. An excellent correlation was found when the content of Cyn d 1, measured in 16 different extracts, was compared with the allergenic activity of the same extracts determined by RAST inhibition.

CONCLUSIONS

The results prove the usefulness of the Cyn d 1 ELISA for the standardization of C. dactylon-allergen products on the basis of major allergen content.

Monoclonal antibody-based ELISA to quantify the major allergen of Artemisia vulgaris pollen, Art v 1

BACKGROUND

Pollen of Artemisia vulgaris (mugwort) is a relevant cause of pollinosis in temperate and humid regions. Recently, the major allergen of this pollen, Art v 1, has been characterized.

OBJECTIVE

To develop a monoclonal antibody (mAb)-based enzyme-linked immunosorbent assay (ELISA) to quantify Art v 1, and to assess the correlation of Art v 1 content with the biological activity of mugwort pollen extracts.

METHODS

Art v 1-specific mAbs were obtained from a BALB/c mouse immunized with high-performance liquid chromatography (HPLC)-purified Art v 1. One of these antibodies (Av 3.7), which recognizes the N-terminal defensin-like domain of Art v 1, was used as the capture antibody in an ELISA method for allergen quantitation. An anti-A. vulgaris rabbit serum was used as the second antibody. Art v 1 was purified by immunoaffinity chromatography and used as the standard in the assay.

RESULTS

The purity and identity of the affinity-purified Art v 1 was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), mass spectrometry, amino acid composition, and N-terminal amino acid sequencing. The prevalence of specific IgE against Art v 1, determined by radioallergosorbent test (RAST) in a population of 44 mugwort-allergic patients, was 79%. The Art v 1-ELISA developed displays a detection limit of 0.1 ng/ml, and a practical working range of 0.2-10 ng/ml. The concentration of Art v 1 was measured in 10 A. vulgaris pollen extracts, and a good correlation was observed between the Art v 1 content and the allergenic activity of the extracts.

CONCLUSIONS

The results prove the usefulness of the Art v 1-ELISA for the standardization of A. vulgaris pollen extracts intended for clinical use.

Studies on the carbohydrate moiety of Pla l 1 allergen. identification of a major N-glycan and significance for the immunoglobulin E-binding activity

BACKGROUND

Pla l 1, the major allergen of Plantago lanceolata pollen, is a glycoprotein that contains an N-glycosylation site. Carbohydrate moieties of many allergenic glycoproteins have been reported to be IgE-binding determinants responsible for cross-reactivity among different species.

OBJECTIVE

To identify the kind of linkages and the type of glycans present in Pla l 1 and to investigate their contribution to the allergic response to this allergen.

METHODS

Pla l 1 was deglycosylated by N-glycosidase A and the IgE-binding ability of the unglycosylated protein was evaluated by dot-blot. Identification of beta1 --> 2 xylose and/or alpha1 --> 3 fucose residues in Pla l 1 N-glycan was carried out by incubation with specific antibodies from rabbit antiserum against HRP (anti-HRP). The contribution of this N-glycan to total IgE reactivity was analysed quantitatively by pre-incubation of Pla l 1 with anti-HRP prior to incubation with sera. The role of the carbohydrate moiety of Pla l 1 in cross-reactivity was studied by RAST using unrelated glycoproteins with known sugar composition and structure.

RESULTS

The effectiveness of N-glycosidase A to deglycosylate Pla l 1 and the ineffectiveness of the treatment with PNGase F indicate that Pla l 1 carries a complex N-glycan with an alpha1 --> 3 fucose residue in its structure. Furthermore, the presence of beta1 --> 2 xylose and/or alpha1 --> 3 fucose residues was identified in this N-glycan by means of an ELISA. Pre-incubation of Pla l 1 with an anti-HRP antibody caused a weak but significant reduction in IgE reactivity. Some sera from P. lanceolata-allergic patients reacted positively with four glycoproteins that bear N-glycans of complex type but not with fetuine.

CONCLUSIONS

Pla l 1 is a glycoprotein that carries at least a complex, major N-linked glycan, with a alpha1 --> 3 fucose residue in its structure and probably also a beta1 --> 2 xylose. This glycan moiety does not seem to constitute a relevant allergenic epitope of Pla l 1.

Monoclonal antibodies against the major allergen of Plantago lanceolata pollen, Pla l 1: affinity chromatography purification of the allergen and development of an ELISA method for Pla l 1 measurement

BACKGROUND

Plantago lanceolata (English plantain) pollen is a relevant cause of pollinosis in temperate regions. The major allergen of this pollen, Pla l 1, is recognized by the specific IgE from more than 80% of plantain-sensitive patients. It displays significant sequence homology with the major olive-pollen allergen Ole e 1. The objective was to develop a monoclonal antibody-based ELISA to quantify Pla l 1, and to assess the correlation of Pla l 1 content with the biologic activity of plantain pollen extracts. We also aimed to establish the specificity of the monoclonal antibodies against the potentially cross-reactive allergen Ole e 1, and to investigate the presence of Pla l 1-like proteins in psyllium and melon that have been reported to cross-react with P. lanceolata pollen.

METHODS

After fusion of myeloma cells with spleen cells from a BALB/c mouse, two Pla l 1-specific monoclonal antibodies secreting hybridomas were selected, and the antibodies characterized. One of them (2A10) was used as the capture antibody in an ELISA for Pla l 1 quantitation. An anti-P. lanceolata rabbit serum was used as the second antibody. Pla l 1 was purified by immunoaffinity chromatography and used as the standard in the assay.

RESULTS

The ELISA developed was highly reproducible and sensitive, with a detection limit of 0.1 ng/ml, and a practical working range of 0.4-12 ng/ml. The specificity was demonstrated against a large battery of allergens, including Ole e 1. The concentration of Pla l 1 was measured in 19 extracts of P. lanceolata pollen, and a good correlation was observed between the Pla l 1 content and the allergenic activity of the extracts. Pla l 1 was not detected in psyllium or melon extracts.

CONCLUSION

The results prove the usefulness of the Pla l 1-ELISA for the standardization of extracts of P. lanceolata pollen intended for clinical use.

Purification and characterization of the main allergen of Plantago lanceolata pollen, Pla l 1

English plantain (Plantago lanceolata) pollen is an important cause of pollinosis in the temperate regions of North America, Australia and Europe. However, very little is known about its allergen composition. The aim of this study was to identify plantain allergens, and to isolate and characterize a major allergen. Allergens were identified by immunoblotting with individual allergic patients' sera. Isolation of the major allergen was achieved by sequential reverse-phase and size-exclusion HPLC. Allergenic characterization was performed by ELISA and immunoblotting after SDS-PAGE with sera from plantain-allergic patients. N-terminal amino acid sequence was established by Edman degradation. Allergograms showed that 13 out of the 14 sera assayed had IgE to a group of proteins with a molecular weight in the range of 16-20 kd, that turned out to be different isoforms or variants of the major allergen Pla l l. Eighteen amino acid residues from the N-terminal end of one of the isoforms, and 10 of three others, were sequenced, and a partial sequence identity with Ole e 1 was found. Prevalence of specific IgE to purified Pla l 1 in plantain allergic patients was 86%, and represents about 80% of the total IgE-binding capacity of the plantain extract. The most relevant allergen from P.lanceolata pollen, Pla l 1, has been purified and characterized. This contributes to a greater knowledge of the allergen composition of this important weed, and clears the way for the standardization of plantain allergen products in terms of major allergen content.

Factors influencing the clinical picture and the differential sensitization to house dust mites and storage mites

Sensitization to house dust mites and storage mites has been studied in a number of papers, but several environmental factors and clinical conditions that differently affect sensitization to these mites are still controversial. The purpose of this study was to determine the influence of climatic conditions, occupation and patient age in the differential sensitization to house dust and storage mites, and also to search for possible different symptoms caused by each group of mites. Eighty patients sensitized to mites but not to other inhalant allergens were studied by case history and by skin prick test and serum IgE to Dermatophagoides pteronyssinus. Dermatophagoides farinae, Lepidoglyphus destructor and Tyrophagus putrescentiae. Home conditions, including content of the allergens Der p 1, Der f 1, Lep d 2 and Tp, were determined for all patients. Human activities, such as farming or similar occupations, and humidity are conditions for preferential sensitization to storage mites, while we found no difference between living in rural or urban areas. Mean age for the onset of sensitization was 6.7 years for house dust mites and 18.7 years for storage mites. Conjunctivitis was more frequent in patients allergic to storage mites, whereas perioral syndrome (itching of the tongue and swelling of the lips) was only seen in patients sensitized to T. putrescentiae. We concluded that climatic and damp conditions and human activity, but not urban or rural living environments, influence the differential sensitization to house dust mites and storage mites.

Occupational asthma caused by soybean flour in bakers--differences with soybean-induced epidemic asthma

BACKGROUND

Soybean dust has been identified as the causative agent of occupational asthma and asthma epidemics. Two main soybean hull allergens responsible for asthma outbreaks, Gly m 1 and Gly m 2, have been identified and purified.

OBJECTIVE

The soybean allergens causing occupational asthma in exposed bakers were investigated and compared with those involved in epidemic asthma.

METHODS

We report four bakers or confectioners with work-related respiratory symptoms who were exposed to soybean flour used as a baking additive. The causative role of soybean flour was investigated by immunological tests and specific inhalation challenge tests. Soybean flour allergens causing occupational asthma were characterized by immunoblotting. Immunoglobulin (Ig) E-reactivity to Gly m 1 and Gly m 2 was assessed using enzyme-linked immunosorbent assay.

RESULTS

Sensitization to soybean flour was demonstrated by skin and serological tests and was confirmed by positive inhalation tests. Bronchial challenge test to soybean flour extract elicited immediate or dual asthmatic responses. Immunoblotting with soybean flour and soybean hull extracts showed IgE-binding mainly to high molecular weight (MW) allergens. There was an important individually different allergic response to inhalant soybean components. None of the patients showed IgE-reactivity against Gly m 1 and only one patient showed IgE-reactivity to the soybean hull allergen Gly m 2.

CONCLUSION

These bakery workers had developed IgE-mediated occupational asthma to soybean flour. The allergens involved in occupational asthma caused by soybean flour are predominantly high MW proteins that are present both in soybean hull and flour, and they are different from the allergens causing asthma outbreaks, which are mainly low MW proteins concentrated in the hull.

Importance of albumin in cross-reactivity among cat, dog and horse allergens

Different allergenic proteins have been involved in cross-reactivity among animals. Albumins seem to be cross-sensitizing allergenic components. The aim of this study was to assess the importance of albumin as a cross-reactive allergen in patients sensitized to cat, dog and horse. One hundred and seventeen patients sensitized to cat were tested for IgE reactivity using skin prick tests and RAST assays with cat, dog and horse hair/dander extracts and their purified albumin extracts. RAST-inhibition studies were carried out to assess cross-reactivity among cat, dog and horse and among their purified albumins. It was found that 22% of patients exhibited specific IgE to cat albumin; 41% of patients sensitized to cat were also sensitized to dog and horse. Out of these patients, 21% had IgE to three albumins and 17% to two. Reciprocal inhibitions were observed among cat, dog and horse albumins and also among cat, dog and horse hair/dander extracts, using in the latter experiment sera from patients not sensitized to albumins. IgE binding to horse extract was inhibited 30% by its homologous albumin and IgE binding to cat and dog extracts in almost 15% by their respective albumins. It was concluded that albumins from these three animals share some epitopes that account for the cross-reactivity observed in around one-third of patients sensitized to cat, dog and horse. Nevertheless, more than 50% of specific IgE that cross-reacts among these three animals is directed to allergens other than albumin.

Monoclonal antibody-based method to quantify Gly m 1. Its application to assess environmental exposure to soybean dust

BACKGROUND

The demonstration that some asthma epidemics have been caused by allergens of soybean-hull dust prompted us to develop a two-site ELISA, suitable for the quantification of the major allergen (Gly m 1), to be used for the prevention of new episodes.

METHODS

BALB/c mice were injected with Gly m 1 purified from soybean hulls. After fusion and screening, 10 monoclonal antibodies (mAbs) were obtained that were shown to be specific for Gly m 1 Two of them (6G1 as the capture antibody; 1G10 as the tracer) were selected to develop a quantitative two-site ELISA for the indoor and outdoor determination of Gly m 1.

RESULTS

The two-site ELISA developed is very sensitive, with a detection limit of less than 0.2 ng/ml and a practical working range of 0.4-10 ng/ml. The assay is also highly reproducible with an intra-assay coefficient of variation of 3.5% and an interassay coefficient of variation of 12.5%. The method was applied to measure the concentration of Gly m 1 in air-sampler filters and in house-dust samples. Our results illustrate that there is a good correlation between the content of Gly m 1 in a number of samples and the allergenic activity as measured by ELISA inhibition.

CONCLUSIONS

A specific and sensitive method is presented that can be used for the quantification of Gly m 1. The application of this method may allow the establishment of risk limits for soybean dust, and thus may contribute to the control of environmental contamination and to the prevention of new asthma epidemics.

Immunotherapy with a mass unit Parietaria judaica extract: a tolerance study with evidence of immunological changes to the major allergen Par j 1

Specific immunotherapy with Parietaria judaica pollen extract has been proven to be effective in the treatment of patients with respiratory allergy induced by this pollen. Nevertheless, there is some controversy about its tolerability. We conducted an open uncontrolled study to evaluate the tolerability of an aluminium adsorbed P. judaica pollen extract whose major allergen (Par j 1) content was known. Changes in immunological parameters to a complete P. judaica extract and to a purified Par j 1 preparation were monitored. Twenty-one patients (12 women, 9 men; mean age 30.2 years) suffering from rhinoconjunctivitis and/or asthma due to Parietaria pollen were enrolled. The maximum dose was established at 10 BU/ml (0.6 microgram Par j 1). Skin and conjunctival reactivity as well as serum levels of specific IgE, IgG, IgG1 and IgG4 were evaluated before therapy (T0), when 1 BU was given (T1), 2 weeks after the maintenance dose was reached (T2) and after the pollen season (T3). Four-hundred and fifteen doses were administered during immunotherapy. Only one systemic reaction (0.24% of doses) and two local reactions were registered. Reactions occurred during the administration of the highest concentrated vial. Before immunotherapy, purified Par j 1 accounted for 94.2% of the cutaneous response elicited by the complete extract. A statistically significant decrease in cutaneous response was detected after 8 weeks of treatment. There were no significant changes in conjunctival reactivity throughout the study. Specific IgG, IgG1 and IgG4 showed a pronounced and significant increase during the study, while specific IgE levels initially decreased and increased after the pollen season. The kinetics of specific antibodies to P. judaica complete extract and purified Par j 1 showed a parallel trend. The present study demonstrates that immunotherapy with P. judaica extract is well tolerated in patients suffering from rhinoconjunctivitis and/or asthma due to Parietaria pollen. This therapy induces specific changes in the immunological response to P. judaica and to purified Par j 1. These changes can be detected at very early stages of therapy.

Cluster versus conventional immunotherapy in patients allergic to Dermatophagoides pteronyssinus: a controlled study of in vivo and in vitro parameters

We designed a cluster schedule of immunotherapy for patients allergic to Dermatophagoides pteronyssinus which showed good safety and clinical efficacy. Here we compare the in vivo and in vitro changes with those of a conventional schedule in a controlled trial. Sixty-three patients were randomized as follows: 29 were treated with the cluster schedule, 15 with a conventional schedule and 19 received no immunotherapy. A standardized extract was used. Changes in in vivo parameters (skin prick test and conjunctival provocation test) and in in vitro parameters (IgE, IgG, IgG1 and IgG4 for the complete extract, Der p 1 and Der p 2) were measured before immunotherapy (T0), on reaching maintenance phase (T1), and after 6 (T2), 12 (T3) and 18 months of maintenance (T4). Cutaneous reactivity showed a significant decrease from T1 in both the cluster and conventional schedules, and conjunctival reactivity was also significantly lowered from T1 in these groups. Specific IgE decreased and specific IgG, IgG1 and IgG4 increased significantly from T1 in the cluster and conventional schedules. Neither of these parameters showed any changes in the group without immunotherapy. In conclusion, our cluster schedule induced changes in cutaneous and conjunctival reactivity and in immunological parameters that were similar to those achieved with the conventional schedule; these changes did not appear in patients who did not undergo immunotherapy.

Prevalence of Salmonella serotypes in environmental waters and their relationships with indicator organisms

The incidence of serotypes of Salmonella in three types of environmental water (sea, river and fresh reservoirs) from north-east Spain was investigated. The study was performed at specific sampling locations during the summer for a period of five years (1992-1996). A total of 823 strains were isolated and 55 different serotypes were identified, 42 were recovered from sea water, 32 from river water and 12 from freshwater reservoirs. The most frequently isolated serotypes coincided with those involved in clinical cases in the area studied. Salmonella enteritidis was the most common (111 isolates), it was found in all types of water, although most predominantly in sea water (16.1% of the isolates). This serotype, together with S. hadar, significantly increased in frequency during the five year study period. The most frequent serotypes in river water and freshwater reservoirs were S. virchow (9.5%) and S. mikawasima (23.8%) respectively. Significant differences were assessed in the indicator organism densities between the samples with serotypes of clinical significance (S. enteritidis, S. infantis, S. typhimurium, S. virchow and S. paratyphi B) and those without clinical significance. Therefore their presence in all environmental waters may be of epidemiological significance.

Evaluation of the oxolinic acid--esculin--azide medium for the isolation and enumeration of faecal streptococci in a routine monitoring programme for bathing waters

m-Enterococcus agar (m-Ent) has been generally considered the reference medium for faecal streptococci in bathing waters. However, it shows several shortcomings, and therefore it is important to test newly developed media that can guarantee more precise results. In this sense, the recently described oxolinic acid--esculin--azide agar medium (OAA) and m-enterococcus agar (m-Ent) were comparatively evaluated for the detection of faecal streptococci from seawater and fresh water. The OAA medium showed a significantly higher relative recovery percentage and specificity for both types of water than m-Ent. A similar spectrum of species was recorded from both media, Enterococcus faecium being predominant in fresh water and Enterococcus faecalis, in seawater. The superior performance of the OAA medium in both types of bathing waters, added to the fact that it does not require the use of complementary confirmative tests, makes this medium an excellent candidate to be employed for monitoring programmes.

Evaluation of the oxolinic acid - esculin - azide medium for the isolation and enumeration of faecal streptococci in a routine monitoring programme for bathing waters

m-Enterococcus agar (m-Ent) has been generally considered the reference medium for faecal streptococci in bathing waters. However, it shows several shortcomings, and therefore it is important to test newly developed media that can guarantee more precise results. In this sense, the recently described oxolinic acid - esculin - azide agar medium (OAA) and m-enterococccus agar (m-Ent) were comparatively evaluated for the detection of faecal streptococci from seawater and fresh water. The OAA medium showed a significantly higher relative recovery percentage and specificity for both types of water than m-Ent. A similar spectrum of species was recorded from both media, Enterococcus faecium being predominant in fresh water and Enterococcus faecalis, in seawater. The superior performance of the OAA medium in both types of bathing waters, added to the fact that it does not require the use of complementary confirmative tests, makes this medium an excellent candidate to be employed for monitoring programmes.Key words: faecal streptococci, water, monitoring, oxolinic acid - esculin - azide medium, m-enterococcus medium.

Occupational allergy caused by Dianthus caryophillus, Gypsophila paniculata, and Lilium longiflorum

BACKGROUND

Occupational allergy to ornamental flowers is seldom reported.

METHODS

We report a case of a 35-year-old male flower supplier who developed IgE-mediated allergic rhinoconjunctivitis with nasal polyps, and contact urticaria and dermatitis after handling Gypsophila paniculata. Dianthus caryophillus, and Lilium longiflorum.

RESULTS

Studies revealed the presence of positive immediate skin prick tests. Rubbing tests were positive to G. paniculata and D. caryophillus. Serum specific IgE was detected against G. paniculata and L., longiflorum. In IgE immunoblot, two IgE-binding bands (15 and 17 kDa) were obtained against D. caryophillus, and two different bands (19 and 22 kDa) were visible against L. longiflorum.

CONCLUSIONS

These findings suggest an IgE-mediated reaction as the mechanism responsible for the respiratory and cutaneous symptoms of the patient. No similar cases of allergy to D. caryophillus and L. longiflorum have been previously reported.

Alimentary allergy to pork. Crossreactivity among pork kidney and pork and lamb gut

BACKGROUND

A patient suffered from anaphylaxis after the ingestion of pork gut and kidney, but she tolerated pork meat. Clinical symptoms were also triggered upon intake of lamb gut.

OBJECTIVE

To demonstrate an IgE-mediated hypersensitivity and identify the pork proteins involved. And also, to study the possible cross-allergenicity among proteins from lamb gut and pork.

METHODS AND RESULTS

The patient had strong positive skin-prick test responses to pork kidney, gut and liver, and lamb gut and kidney. RAST technique showed specific IgE to pork kidney, gut and meat. Immunoblotting after SDS-PAGE disclosed the presence of four prominent IgE-binding polypeptides in pork kidney (200, 90, 57, and 47 kDa), two in gut (57 and 27 kDa), and three in meat (51, 40, and 28-30 kDa), apart from other weaker radiostained bands in each extract. The binding of IgE to 200 and 90 kDa allergens from pork kidney was inhibited by gut from pork and lamb in immunoblotting inhibition assays. No inhibition was produced by pork meat.

CONCLUSIONS

A mechanism of IgE-mediated hypersensitivity has been demonstrated in this case of anaphylaxis provoked by pork products. Four main allergens were detected in pork kidney, two of which (200 and 90 kDa) share allergenic epitopes with proteins from pork and lamb gut. On the other hand, pork meat does not seem to have allergenic epitopes in common with pork kidney.

Relationship between presence of Salmonella and indicators of faecal pollution in aquatic habitats

The presence of Salmonella and its relationship with indicators of faecal pollution was investigated in aquatic habitats. The highest frequency was obtained in rivers (58.7% of samples) followed by freshwater reservoirs (14.8%) and sea water (5.9%). The sporadic presence of Salmonella (< 30%) on beaches with low concentrations of faecal streptococci (mean 25 CFU (100 ml)-1) may represent a potential risk for bathers in agreement with data found in previous epidemiological studies. Absence of Salmonella was observed only on beaches with very low densities (CFU (100 ml)-1) of indicator organisms (25 total coliforms, 13 faecal coliforms and 17 faecal streptococci).

[A new infusion method for a prostacyclin analogue]

BACKGROUND

Iloprost, a prostaglandin I2, is chemically stable and it has been successfully used by intravenous infusion in severe limb ischemia. Usually Iloprost is diluted in 0.9% sodium chloride solution and infused intravenously for six hours each day for 28 days in hospital.

METHODS

In the present study after the first three days of infusion with a traditional pump in hospital, a home pump has been utilised for the infusion of Iloprost at home. This device allows the continue infusion of Iloprost at a flow rate of 2 ml/h for six days, then the pump is filled with a new solution. The home pump consists of a protective shell in polycarbonate (10 x 12 cm), 270 ml of volume, inside there is a balloon reservoir (3 membranes) which is filled with Iloprost. The structure of Iloprost does not change into the home pump as evidenced by HPLC studies and its continue infusion allows plasmatic high levels of its active isomers during the 28 days of therapy. In 30 patients, 25 men and 5 women (mean age 61 years) with Fontaine stage IIB (6), III (5) and IV (19) POAD Iloprost has been infused with the home pump. The follow-up period was 1 to 16 months.

RESULTS

The results have shown 4 major amputations and 1 death, in 9 patients complete pain relief and ulcer healing, and in 6 patients only improvement in relief of rest pain and ulcers.

CONCLUSIONS

All the patients appreciated this system of infusion because they had a normal life; in addition it is less expensive because the patients stay in hospital only 3 days.

[Eosinophilic gastroenteritis caused by bee pollen sensitization]

A 34-year-old Spanish woman with a lifelong history of seasonal rhinoconjunctivitis and honey intolerance (pyrosis and abdominal pain) developed, 3 weeks after starting ingestion of bee pollen, astenia, anorexia, abdominal pain, diarrhoea, peripheral blood hypereosinophilia and elevated serum total IgE levels. A duodenal biopsy showed eosinophilic infiltration of the mucosal layer. Other causes of hypereosinophilia were not found. Repeated parasitological stool studies, as well as a duodenal aspirate showed negative results. Symptoms, hypereosinophilia and elevated IgE levels resolved after bee pollen ingestion was stopped. This is a typical case of eosinophilic gastroenteritis by ingestion of bee pollen in a woman with intolerance to honey bee, because the patient fulfilled the usual diagnostic criteria: gastrointestinal symptoms were present, eosinophilic infiltration of the digestive tract was demonstrated by biopsy, no eosinophilic infiltration of other organs was found and the presence of parasites was excluded. Honey intolerance and/or bee pollen administration should be considered as a cause of eosinophilic gastroenteritis.

Specific depletion of the house dust mite allergen Der p 1 cereal flour prolamins

BACKGROUND

Quantitation of Der 1 and Der 2 in dust samples by specific monoclonal antibodies is a method used increasingly to evaluate mite allergen exposure. The level of Der 1 has been proposed as a risk factor for sensitization.

AIM

We report a drastic decrease in the Der 1/Der 2 ratio when dust samples are collected in bakeries.

METHODS

Wheat flour and purified mites were extracted simultaneously; levels of Der p 1 and Der p 2 and cysteine protease activity were determined by ELISA and inhibition experiments.

RESULTS

High titers of Der 2, but only trace amounts of Der p 1, were detected in dust collected from bakeries. Both the level and proteolytic activity of Der p 1 appeared greatly decreased when mites and wheat flour were coextracted.

CONCLUSION

Group 1 protein was found to be masked by flour components, resulting in an underestimation of the mite content in bakery dust. This problem was not found for group 2 allergen.

Quantitation of the major allergen of several Parietaria pollens by an anti-Par 1 monoclonal antibody-based ELISA. Analysis of crossreactivity among purified Par j 1, Par o 1 and Par m 1 allergens

BACKGROUND

Plants of the genus Parietaria, Urticaceae family, represent a major cause of pollinosis in the Mediterranean area. Different Parietaria species crossreact to a great extent, but studies on the crossreactivity among the major allergens of these pollens have not been carried out so far.

OBJECTIVE

To develop an immunochemical method to quantify the major Parietaria judaica allergen, Par j 1, as well as to verify the presence of Par j 1-like proteins in different Urticaceae pollens. These proteins would be purified in order to study the cross-reactivity among them.

METHODS

Immunoaffinity chromatography with a monoclonal antibody, solid-phase enzyme-linked immunoassays and SDS-PAGE.

RESULTS

A monoclonal antibody-based ELISA for the quantification of Par j 1 has been developed. The assay has a sensitivity of 0.2 ng/mL and shows a high correlation with the allergenic activity of P. judaica extracts determined by radioallergosorbent assay (RAST) inhibition. By means of this assay, proteins homologous to Par j 1 were detected in P. officinalis and P. mauritanica. These proteins (Par o 1 and Par m 1, respectively) were purified by affinity chromatography using the same monoclonal antibody employed in the ELISA. Crossed-inhibition experiments demonstrated that Par j 1, Par o 1, and Par m 1, competed for the binding of specific IgE from a P. judaica-sensitive patients serum pool.

CONCLUSION

The results here described suggest that shared allergenic epitopes are present in the three main allergens investigated, which may simplify the diagnosis and therapy for Parietaria allergy.

Quantitation of major allergens in dust samples from urban populations collected in different seasons in two climatic areas of the Basque region (Spain)

We present the results of allergen content evaluation in 80 dust samples from 31 homes of atopic patients from two climatic areas (humid and subhumid), collected in two seasons of the year (autumn and winter). Monoclonal antibody-based immunoassays were used to quantify Der p 1, Der f 1, Der 2, Lep d 1, and Fel d 1. The results were compared according to climate, season, and the type of sensitization (Pyroglyphidae mites, storage mites, or grass pollens). We underline the predominance of Dermatophagoides pteronyssinus (89% of samples) over D. farinae (16% of samples) in our environment. Der p 1 rates were higher in the humid area (Mann-Whitney P < 0.001), especially in the autumn (Wilcoxon P < 0.05). Lep d 1 was detected in 23% of samples and Lep d 1 levels were higher in the homes of patients sensitized to storage mites (Mann-Whitney P < 0.05), whereas this allergen was not detected in the homes of pollen-allergic patients. Fel d 1 was detected in nine of the 31 homes (16% of samples) although there was a cat in only one home.

Primary structure of Lep d I, the main Lepidoglyphus destructor allergen

The most relevant allergen of the storage mite Lepidoglyphus destructor (Lep d I) has been characterized. Lep d I is a monomer protein of 13273 Da. The primary structure of Lep d I was determined by N-terminal Edman degradation and partially confirmed by cDNA sequencing. Sequence polymorphism was observed at six positions, with non-conservative substitutions in three of them. No potential N-glycosylation site was revealed by peptide sequencing. The 125-residue sequence of Lep d I shows approximately 40% identity (including the six cysteines) with the overlapping regions of group II allergens from the genus Dermatophagoides, which, however, do not share common allergenic epitopes with Lep d I.

Isolation by mAb based affinity chromatography of two Par j I isoallergens. Comparison of their physicochemical, immunochemical and allergenic properties

We report the identification and separation of two isoallergen components of Par j I, the major allergen from Parietaria judaica pollen. First, electrophoretic conditions for consistently separating both isoforms in an SDS-PAGE system were established, and mol. wt values of 13,000 (isoallergen IA) and 10,500 (isoallergen IB) were estimated. Immunoblot, after SDS-PAGE experiments, with individual P. judaica-sensitive human sera revealed a slightly different IgE-binding pattern for each isoallergen. Four anti-Par j I mAbs were obtained from BALB/c mice immunized with a purified Par j I preparation comprising IA and IB isoallergens. Three mAbs were directed to an epitope shared by both isoallergens, and the fourth one recognized specifically one epitope on Par j IB. Dot-blot experiments with the deglycosylated allergen showed that the mAbs did not recognize the carbohydrate prosthetic group of the molecules. Affinity chromatography using the mAbs allowed the separation of the isoallergens that retained their IgE-binding ability after the purification process. Amino acid composition analyses and partial N-terminal sequencing demonstrated an extensive homology and also the existence of some structural differences between Par j I isoallergens, which is in agreement with the high, but not complete, cross-reactivity observed in competition ELISA experiments. Finally, skin prick tests performed on 28 P. judaica-sensitive patients showed that all of them recognized both isoforms and that allergenic epitopes present in Par j IA and IB are responsible for most of the allergenic activity of the whole extract.

Purification and characterization of major inhalant allergens from soybean hulls

Proteins responsible for respiratory allergy to soybean have been purified from an extract of soybean hulls. The purification procedure combined size exclusion and reverse-phase HPLC. Two pure glycoproteins (S1 and S2) exhibiting IgE-binding ability, as demonstrated by immunoblotting and ELISA techniques, were obtained. Both proteins displayed low molecular weight values on SDS-PAGE (S1, 7.0 kD; S2 7.5 kD). Protein S1 showed charge microheterogeneity, rendering two bands at pH 6.1-6.2 on IEF, whereas S2 showed a single band at pH 6.8. Amino acid composition analyses revealed a strong homology between S1 and S2 and, as a characteristic feature, a high percentage of hydrophobic residues, mainly leucine and isoleucine. Concerning the allergenic activity, both proteins were recognized by the specific IgE from 95% of patients who suffered asthma attacks during the asthma outbreaks of 1987 and 1988 in Cartagena (Spain), caused by soybean dust. Besides, proteins S1 and S2 were able to, separately, inhibit up to 75% the binding of specific IgE to the whole extract. Moreover, purified proteins totally crossreacted, even though protein S2 seemed to be slightly more active in all the immunochemical techniques employed. Results presented allow us to conclude that both proteins are isoallergens and to name them as Gly m IA (protein S2) and Gly m IB (protein S1), according to the IUIS-allergen nomenclature system.

Purification and characterization of Lep d I, a major allergen from the mite Lepidoglyphus destructor

A major allergen of the storage mite Lepidoglyphus destructor (Lep d I) has been purified by affinity chromatography using an anti-Lep d I monoclonal antibody. The purity of the protein obtained by this procedure was assessed by reverse-phase HPLC. Lep d I displayed a molecular weight of 14 kD on SDS-PAGE under non-reducing conditions, and 16 kD in the presence of a reducing agent. Analytical IEF revealed a little charge microheterogeneity, showing three bands with pIs 7.6-7.8. Purified Lep d I retained IgE-binding ability, as proved by immunoblotting experiments after SDS-PAGE and RAST with individual sera from L. destructor-sensitive patients. Results from the latter technique demonstrated that 87% of L. destructor-allergic patients had specific IgE to Lep d I, and a good correlation between IgE reactivity with L. destructor extract and Lep d I was found. In addition, RAST inhibition experiments showed that IgE-binding sites on Lep d I are major L. destructor-allergenic determinants, since Lep d I could inhibit up to 75% the binding of specific IgE to L. destructor extract; on the other hand, Lep d I did not cross-react with D. pteronyssinus allergens.