Imaging digital arteries in systemic sclerosis by tomographic 3-dimensional ultrasound

Objective methods are needed to quantify digital artery disease in systemic sclerosis (SSc) for clinical trials of vascular therapies. Our primary aim was to examine feasibility of a novel tomographic three-dimensional-(3-D) ultrasound (tUS) with high-frequency ultrasound (HFUS) or ultra-high-frequency ultrasound (UHFUS) to assess the digital arteries in patients with SSc compared to healthy controls. A secondary objective was to compare the total wall volume (TWV) as a measure of intimal/medial thickness. Eighteen patients with a confirmed diagnosis of SSc were studied by tUS HFUS (17.5 MHz, n = 10) or tUS UHFUS (48 and 70 MHz, n = 8) with equal numbers of healthy controls of similar age and gender. The majority of patients had limited cutaneous SSc and were representative of a spectrum of digital vasculopathy, with over half (n = 6 HFUS and n = 5 UHFUS) having previous digital ulceration. Over half were receiving oral vasodilatory therapy. TWV was measured in both digital arteries of the middle finger bilaterally. At least, two digital arteries could be identified at 17.5 MHz in all patients and healthy controls. Whereas, at least two digital arteries could be identified in relatively fewer patients compared to healthy controls using 48 MHz (n = 6 and 10) and especially 70 MHz (n = 4 and 10) UHFUS. The median difference in TWV between patients and healthy controls was -6.49 mm³ using 17.5 MHz, 1.9 mm³ at 48 MHz, and -0.4 mm³ at 70 MHz. tUS using UHFUS is a feasible method to measure TWV of digital arteries in SSc. Transducer frequency plays an important factor in successful digital artery measurement, with 48 MHz being the optimal frequency.

Transfer-printed micro-LED and polymer-based transceiver for visible light communications

Visible light communications (VLC) is an emerging technology that uses LEDs, such as found in lighting fixtures and displays, to transmit data wirelessly. Research has so far focused on LED transmitters and on photoreceivers as separate, discrete components. Combining both types of devices into a single transceiver format will enable bi-directional VLC and offer flexibility for the development of future advanced VLC systems. Here, a proof of concept for an integrated optical transceiver is demonstrated by transfer printing a microsize LED, the transmitter, directly onto a fluorescent optical concentrator edge-coupled to a photodiode, the receiver. This integrated device can simultaneously receive (downlink) and transmit (uplink) data at rates of 416 Mbps and 165 Mbps, respectively. Its capability to operate in optical relay mode at 337 Mbps is experimentally demonstrated.

Immunization with the Leishmania infantum recombinant cyclophilin protein 1 confers partial protection to subsequent parasite infection and generates specific memory T cells

Control of zoonotic visceral leishmaniosis can be achieved using several available drugs. These drugs present high toxicity and require longer treatment regimens which complicate compliance to the treatment. Other control measures directed to the vector or the reservoirs are useful tools to restrain the spreading of this disease but the effects are transitory. A safe, affordable and efficient vaccine conferring long lasting immunity should be the most cost effective way of controlling zoonotic visceral leishmaniosis. The present study aims at characterizing a cyclophilin protein 1 of Leishmania infantum (LiCyP1) and investigating whether recombinant LiCyP1 (LirCyP1) is able to confer protection against infection by evaluating viable parasite load and the generation of specific CD4(+) and CD8(+) effector and central memory T cells in rodent model. LiCyP1 is present in the cytoplasm of L. infantum amastigotes and promastigotes. Immunization of BALB/c mice with LirCyP1 confers high protection to L. infantum infection, causing a marked reduction in parasite replication in the liver and spleen. Furthermore, helper and cytotoxic memory T cell subsets able to specifically recognize parasite antigens expanded in immunized and in challenged mice. CD4(+) T cell subpopulation of intermediate phenotype (CD62L(high)CD127(low)) of challenging mice also presented an accentuated expansion after the recall. This study demonstrated that LirCyP1 confers partial protection to L. infantum infection, promoting the generation of a desired long lasting immunity. LirCyP1 can be considered a potential candidate for the design of a vaccine against zoonotic visceral leishmaniosis.

Influence of pollen level on hospitalizations for asthma

The effect of pollen level on asthma hospitalizations is still under debate. The aim of this study was to analyze hospital admissions due to asthma and its relation with environmental pollen and meteorological factors. During 13 years, we included every patient admitted with asthma as primary or secondary diagnosis. For this purpose, we used a case-crossover analysis to compare pollen concentrations at the time of admission with values of the same variables 2 to 6 days before admission. We included 6,687 hospital admissions. High maximum temperature and low humidity were associated with lower risk of asthma admissions. High mean pollen levels exerted a moderate effect and high maximum pollen levels led to a dramatic increase of hospital admissions due to asthma, especially among females. In conclusion, environmental pollen level increases the risk of asthma hospital admissions.

Standardisation of the waist circumference (WC) for each range of body mass index (BMI) in adult outpatients attended to in Endocrinology and Nutrition departments

By this study we seek the expectable range of waist circumference (WC) for every degree of body mass index (BMI), which will serve to studies targeting ascertaining the health risk. We studied 2,932 patients (39.6% men and 60.4% women, between 18 and 96 years ) of the same ethnic group who consecutively attended outpatient departments of our clinics between 2000 and 2004. BMI correlated linearly with the WC (cc: 0.85; p < 0.001). The men, the obese, and diabetics were older (p < 0.001). BMI was greater in women and WC in men. The women had a greater WC if they had diabetes (p < 0.01), being equal to diabetic males. The men had greater WC when they had diabetes (p < 0.001). Waist at risk was detected (men > or = 102 cm and women > or = 88 cm) in 94.3% of the obese, in 32.3% of overweight patients, in 3.8% of patients with BMI < 25, in 84.3% of diabetics, and in 72.6% of patients without diabetes. We made graphic standardisation of WC with regard to BMI, and we calculated the percentiles 10, 25, 50, 75 and 90, grouping in ranges of 2 kg/m(2) of BMI. The diabetic patients are grouped in ranges of 4 kg/m(2). As conclusion we present a standardisation of the WC measurement of patients attended to in our Endocrinology and Nutrition practices distributed in percentiles as a clinically usable tool to define the ranges of WC for every BMI value.

Acute ischaemic colitis due to hypotension and amoxicillin allergy

A case of acute ischaemic colitis, confirmed by colonoscopy and colon biopsy, caused by IgE mediated allergy to amoxicillin is presented. The damage to the gut seemed to occur as a result of the hypotension suffered during the anaphylactic episode.

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.

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.

Treatment of chronic iliac artery occlusions with guide wire recanalization and primary stent placement

PURPOSE

To evaluate the results of primary stent placement without initial thrombolysis in the treatment of iliac occlusions.

MATERIALS AND METHODS

During a 3-year period, 61 iliac artery occlusions were treated in 59 patients. The mean length of the occluded segment was 10 cm (range, 4-25 cm). The occluded arteries were treated with primary placement of self-expandable metallic stents.

RESULTS

Successful recanalization with primary stent placement was possible in 56 of 61 occlusions (92% technical success rate). Mean Doppler ankle/brachial index increased from 0.51 to 0.90 immediately after treatment and was 0.91 on the last follow-up (P < .05). Primary patency rate at 24 months was 73%, and secondary patency rate was 88%. Procedural complications included distal embolization (n = 4) and an episode of massive intra-abdominal bleeding. Three patients developed a hematoma at the puncture site that did not require additional therapy. Late complications included stent occlusion (n = 9) and significant stenosis related to intimal hyperplasia (n = 1). Mean follow-up period was 29 months (range, 7-55 months).

CONCLUSION

Primary stent placement is an effective therapeutic option for iliac artery occlusions.

Group 5 determination in Pooideae grass pollen extracts by monoclonal antibody-based ELISA. Correlation with biologic activity

A solid-phase, monoclonal antibody-based ELISA was set up to quantitate group 5 allergens in pollen extracts of wild and cultivated Pooideae grasses. The method was able to evaluate group 5 concentration in mass units with a sensitivity in the ng/ml range and a practical working range of 1-100 ng/ml. The group 5 ELISA was compared with rocket immunoelectrophoresis for determination of allergen levels in several Phleum pratense extracts, and a very good quantitative correlation was found (r = 0.98; P < 0.0001). A highly significant correlation (r > 0.8) was also obtained in comparing allergenic potency determined by RAST inhibition to group 5 content in several wild and cultivated grass species. The results proved the usefulness of the method in the standardization of Pooideae pollen extracts employed in diagnosis and treatment.

Quantification in mass units of Bet v 1, the main allergen of Betula verrucosa pollen, by a monoclonal antibody based-ELISA

BACKGROUND

Fagales pollens are considered among the main agents responsible for allergic diseases in many countries of the northern hemisphere and single major allergens have been shown to be responsible for these responses.

OBJECTIVE

To develop a solid phase immunoassay for the quantification of Bet v 1, the main allergen from Betula verrucosa (birch), and to assess its suitability for quantitating the equivalent major allergen in other Fagales species as well.

METHODS

The assay is based on the use of two different anti-Bet v 1 monoclonal antibodies which were immobilized on the solid phase and, as a primary standard, affinity purified Bet v 1, the protein content of which was determined by amino acid analysis.

RESULTS

The ELISA proved to measure less than 0.2 ng/mL of Bet v 1 with a practical range of 0.4-40 ng/mL and could be suitable to quantify the equivalent major allergen in other Fagales species such as Corylus avellana (hazel), Carpinus betulus (horbeam) and Alnus glutinosa (alder). The method was compared with quantitative electrophoresis and rocket immuno-electrophoresis for the determination of the allergen content in several Betula verrucosa extracts, and a very good quantitative correlation was found. Likewise, the Bet v 1 content exhibited a good correlation (r = 0.87; P < 0.005) with the allergenic potency values obtained by RAST inhibition.

CONCLUSIONS

The results indicate that the Bet v 1-assay could be useful for standardization purposes in Fagales pollen extracts intended for clinical use.

[Association of metabolic risk factors and blood pressure in a natural population (Mora de Toledo)]

OBJECTIVE

Evaluate relationships between the next variables in an adult natural population: total cholesterol, LDL-cholesterol, HDL-cholesterol, triglicerides, total cholesterol/HDL-cholesterol and glucose blood levels with blood pressure (systolic and diastolic).

DESIGN

A crossover observation study with descriptive and analytic components.

PATIENTS

Random sample of 251 individuals taken from census and representative of the adult general population from Mora de Toledo (with 10,000 inhabitants approximately).

SETTING

A medical station in a health centre.

MEASUREMENTS AND MAIN RESULTS

Blood pressure measurements and lipids and glucose blood levels were got in the selected patients. Some positive and significant relationships were got in the adult population from Mora de Toledo between systolic and diastolic blood pressure with the next variables: total cholesterol, LDL-cholesterol, total cholesterol/HDL-cholesterol, triglicerides and glucose blood levels. These associations are stronger in young people from 21-40 years-old. When we consider the relationship with HDL-cholesterol, we can see it is mildly positive but not significant.

CONCLUSION

These results agree with others encountered in different countries and support the hypothesis that there is an association between blood pressure and the cardiovascular metabolic risk factors.

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.

Lepidoglyphus destructor acarus in the urban house environment

To assess the presence of Lepidoglyphus destructor in the household environment of sensitized children living in an urban environment, samples of house dust were collected at the homes where two groups of patients were living, as well as in two bakeries in the city of Valencia, which were taken as a reference. Patients were divided into two groups. Group A included atopic children suffering from rhinitis and/or asthma, who were sensitized to L. destructor, as proven by prick test and specific IgE (CAP). Group B included children with the same features as those included in Group A, who were sensitized to Dermatophagoides pteronyssinus, with prick and CAP tests showing no significant sensitization to L. destructor. The samples of dust were analyzed, and the amounts of Der p I, Der f I, Der II and Lep d I per gram of dust were assessed through a solid-phase ELISA with monoclonal antibodies. In Group A, all patients but two showed a sensitization to D. pteronyssinus by prick test and serum IgE. At the homes of the patients from both groups, significant levels of Dermatophagoides were found. In Group A, only three houses showed levels of L. destructor which were comparable to those found in bakeries. Lep d I was not found in the houses of Group B patients. This means that a sensitization to L. destructor, as assessed with full extracts, is not always an indicator of its presence at the patient's house environment; it may rather refer to cross-reactivity to Dermatophagoides. Thus, availability of the main antigen Lep d I seems necessary to increase the specificity of the allergologic study.

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.

Epitope mapping of beta-lactam antibiotics with the use of monoclonal antibodies

In order to evaluate the antigenic contribution of different regions of the penicillin molecule, monoclonal antibodies were raised against amoxicillin-protein conjugates and their specificities analysed in detail. A random sample of the clones produced was analysed by a quantitative inhibition-ELISA, using, as inhibitors, monomeric conjugates of the following antibiotics to butylamine (BA), amoxicillin (AX), ampicillin (AMP), benzylpenicillin (BP) and the nuclear part of these, 6-aminopenicillanic acid (6-APA); and different parts of the following molecules: N-(p-hydroxyphenyl)-glycine (PHPG), N-phenylglycine (NPG), phenylacetic acid (PA) and thiazolidine (TIAZ). The results showed that 92% of the antibodies recognized an epitope in which the side chain was a major constituent, although with variable contributions from other regions of the molecule. There was a high degree of crossreactivity with aminopenicillins, but low or absent crossreactivity with BP. None of the antibodies recognized the thiazolidine ring or the conjugated nuclear region of the penicillins. Finally, one antibody seemed to recognize, equally, all the different structures tested. The possible relevance of these results to penicillin allergy is discussed.

Isolation and partial characterization of allergens from Helianthus annuus (sunflower) pollen

We have purified four allergens from Helianthus annuus (sunflower) pollen, hereafter named as allergens a, b, c, and d. Under native conditions, allergen a has a mol. mass of 32, allergen b has one of 24, and allergens c and d each have one of 55 kDa. At the least, allergens b, c, and d demonstrate charge heterogeneity, and the electrophoretic mobility of allergens c and d increases when these allergens are deglycosylated with trifluoromethanesulfonic acid. Cross-reactivity among the four allergens and with the whole extract is very high, and each allergen recognizes IgE in a high proportion of patients sensitized to sunflower pollen.

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.

cDNA sequence analysis of the main olive allergen, Ole e I

Olea europaea (Ole e) I-specific cDNA sequences were amplified by 3'-RACE-PCR, using specific primers based on the N-terminal sequence of the allergen, and cloned into appropriate vectors. The nucleotide sequence data obtained revealed the presence of isogenic variation in Ole e I gene(s). The molecular mass, pI, amino acid composition and sequence of the predicted polypeptides agree with data previously obtained by analysis of purified Ole e I from pollen. Furthermore, by treatment of purified Ole e I with specific glycopeptide hydrolases it has been demonstrated the presence of N-glycosylation in the allergen, and there is a unique concensus site for N-linked glycosylation at positions 111-113 of the deduced amino acid sequence. The Ole e I predicted sequence shows a significant homology with three putative proteins encoded respectively by the another-specific LAT52 gene from tomato and the pollen specific genes Zmc13 from maize and OSPSG from rice, suggesting that these proteins could have a role in one of the development processes unique to male gametophytes.

[Study of primary resistance to antitubercular drugs in Galicia]

The primary resistance of 100 specimens of Mycobacterium tuberculosis isolated in patients with active tuberculosis confirmed bacteriologically was studied prospectively over a period of 15 months. Strains resistant to 1 or more drugs were found in 5 patients. Three patients presented resistance to 2 drugs (isoniazide and streptomycin in 2 and rifampicin and isoniazid, streptomycin and ethambutol); and the fifth was resistant only to pyrazinamide. Owing to the few instances of primary resistance found, it was impossible to establish whether any of the factors analyzed in each patient was related to a higher index of resistance, although 4 of the 5 resistant strains came from respiratory specimens. We conclude that the index of primary resistance in our area is low and this allows us to do without prescribing a fourth drug in the first two months of anti-tuberculosis therapy, and makes routine sensitivity tests unnecessary for patients with no history of prior treatment for tuberculosis.

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.

The main allergen of Olea europaea (Ole e I) is also present in other species of the Oleaceae family

Three major pollen allergens from Fraxinus excelsior, Ligustrum vulgare and Syringa vulgaris belonging to the Oleaceae family were purified. Monoclonal antibodies previously raised against the main allergen of Olea europaea (Ole e I) were used for their purification by affinity chromatography. The three new purified allergens were able to bind human IgE from serum of olive-allergic patients in a way analogous to Ole e I. Crossed radioimmunoelectrophoresis of the four allergens, using anti-olive extract rabbit serum, showed a unique immunoprecipitation arc with the same characteristics. The four purified proteins had similar molecular weights on SDS-PAGE and the N-terminal sequences for the first 20 amino acids were identical. Furthermore, the concentration of the allergens could be determined using a two-side solid phase assay previously developed for the allergen Ole e I. Our results indicate that the four purified proteins share, to a great extent, antigenic and allergenic epitopes leading to cross-reactivities which could cause common clinical manifestations. We propose for the newly purified allergens the nomenclature of Fra e I, Lig v I and Syr v I.

Presence of IgG4 on the membrane of human basophils. Histamine release is induced by monoclonal antibodies directed against the Fab but not the Fc region of the IgG4 molecule

We have studied the possible role of human IgG4 as an anaphylactic antibody. For that purpose, we have determined the induction of histamine release (HR) from human basophils by anti-IgE and anti-IgG4 monoclonal antibodies (MoAbs) recognizing different epitopes located at the Fc and Fab regions of the IgG4 molecule. The results show that anti-IgG4 (Fab) MoAb was able to induce HR in 93% of donors tested, with no differences between atopics and non-atopics. That HR is calcium dependent and is accompanied by the synthesis and release of leukotriene C4. In contrast, no HR could be induced by anti-IgG4(Fc) MoAbs in any individual, even in the presence of D2O or after a second challenge with a polyclonal goat anti-mouse IgG antibody. The results obtained suggest the presence of IgG4 on the basophil membrane and that the epitope recognized by the anti-IgG4 (Fc) MoAbs is probably hidden in cell-bound IgG4. This was demonstrated by immunofluorescence techniques: IgG4 bound to the basophil membrane could be detected with anti-IgG4(Fab) but not with anti-IgG4(Fc) MoAbs. In addition, we found that nine donors were unresponsive to an anti-IgE stimulus, while they released histamine efficiently after challenge with anti-IgG4(Fab), suggesting the existence of different receptors for both immunoglobulins.

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.

[New trends in medical education. Evaluation of placements in health centers]

Whether to use just hospitals or a wider range of health resources is one of the debating-points in the updating of undergraduate medical training programmes. The Faculty of Medicine in the Autonomous University of Madrid integrated obligatory Primary Care placements for students in the last year of their course, into its syllabus as from 1988/89. This programme and the students' own assessment of it was studied by means of a systematic, voluntary and anonymous survey, which covered various aspects of their assignments to Primary Care teams. 93% (473) replied. Every student took part in the clinical activities, both on demand and as programmed. 76% went on home visits along with their tutors. 88% considered that their placement was active. The overall evaluation of the placement by the students is 8 out of 10. Half believe that a month is too short a period and suggest that more time is offered as an optional placement. 98% consider that the Centre in which they were placed was sufficiently or very capable of teaching at the undergraduate level. Placing medical students in Primary Care teams is an essential part of today's medical teaching and is feasible within the present health system. The relationship between the University and the general physicians who act as tutors is seen as the main obstacle that needs to be overcome.

Sensitization to the storage mite Lepidoglyphus destructor in wheat flour respiratory allergy

Occupational allergy due to hypersensitivity to cereal flours is relatively common among bakers and grain-store workers. Storage mites can contaminate wheat flour and could be an important cause of allergic symptoms due to inhalation. Forty-three patients with criteria for allergic sensitization to wheat flour (skin tests, specific IgE to wheat flour and positive challenge tests) were included in a study to investigate the prevalence of cosensitization to Lepidoglyphus destructor (Ld). This mite was the predominant species in the wheat flour samples supplied by our patients. We found that 30% of the patients had IgE-mediated hypersensitivity of Ld. Of these, 23% did not have a relationship with any bakery or agriculture. We conclude that the prevalence of sensitization to Ld in patients sensitized to wheat flour is important.

Monoclonal antibodies against major allergen: Allergenic activity of affinity-purified allergen and depleted extract and development of a radioimmunoassay for the quantitation of the allergen

Several monoclonal antibodies (MAbs) were raised against Olea europaea pollen-extract components. Two of these antibodies, named OL 2 and OL 7, recognize two nonoverlapping, nonrepeating epitopes on the olive-allergen Ole e I, as demonstrated by different techniques. The allergen was purified in a single step by MAb-based affinity chromatography, and the allergen revealed a band at molecular weight 20 kd as well as a minor band at 18 kd on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The contribution of allergen Ole e I to the allergenic activity of O. europaea pollen extracts was determined from the effect of allergen depletion by affinity chromatography on skin reactivity and a histamine-release test. The removal of allergen caused a large reduction in the activity of the preparation in 25 monospecific olive-allergic patients. In agreement, the affinity-purified allergen demonstrated a similar response when it was compared with the whole extract in these assays. The results indicated that Ole e I is by far the most important olive-pollen allergen. A two-site solid-phase radioimmunoassay was developed for the quantitation of the allergen Ole e I in mass units. The assay was based on the MAbs, OL 2 and OL 7, and had a detection limit in the nanogram range. A good correlation was found between allergenic activity, as determined by RAST inhibition, and allergen content in 18 olive-pollen extracts. This result indicates that the assay can be a good alternative to RAST inhibition for the standardization of O. europaea extracts.

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.

Identification of IgE-binding proteins from Lepidoglyphus destructor and production of monoclonal antibodies to a major allergen

The allergen composition of one of the most important storage mites, Lepidoglyphus destructor, has been studied by immunodetection after SDS-PAGE with individual patient sera. An allergenic polypeptide of 14 kDa was identified with 95% of the sera. This major allergen was isolated in the supernatant of 60% ammonium sulfate salt precipitation of the whole extract, which was subsequently used to immunize BALB/c mice so as to produce monoclonal antibodies. Four mAbs recognizing molecules with IgE-binding ability were obtained. The specificity of the mAbs was assayed against different allergenic extracts, and the molecules recognized by them were characterized by immunoblotting. Two mAbs (Le5B5 and Le9E4) were directed to the 14-kDa allergen; the other two to several proteins of lesser allergenic significance.

Monoclonal antibodies against human IgE. Identification of an epitope sharing properties with the high-affinity receptor binding site

Three monoclonal antibodies to human IgE are described. One of them recognizes an epitope located within a region of 76 amino acids that has been shown to contain the Fc epsilon RI binding site. That epitope is shown to be susceptible to heating and to alkylation of cysteines involved in inter heavy chain bonds, but not to their reduction alone. In addition, this monoclonal antibody, although having a high affinity for free IgE, is unable to bind Fc epsilon RI-linked IgE. Based on these results, we discuss the possibility that the antibody recognizes the Fc epsilon RI binding site of the IgE molecule.

Studies on the biochemical structure of the major cat allergen Felis domesticus I

The major cat allergen, Fel d I, was purified to homogeneity from cat dander extract by sequential mAb affinity chromatography and HPLC size exclusion. The purity and allergenic activity of the preparation was demonstrated by different techniques such as HPLC, RAST inhibition, skin prick tests and CIE/CRIE. Fel d I showed a mol. wt of about 35,000 by HPLC gel filtration and of 18,000 by SDS-PAGE, confirming that it is a non-covalently linked dimer. However, SDS-PAGE analysis under reducing conditions as well as labelling experiments with 14C-iodoacetamide of 2-ME-reduced Fel d I showed that each mol. wt 18,000 monomer is comprised of two covalently S-S bound polypeptides with apparent mol. wt. of 4000 (alpha-chain) and 14,000 (beta-chain). Reduction and alkylation of Fel d I obliterated most of its allergenic activity, as determined by RAST inhibition and immunoblotting, suggesting that most of the IgE-binding sites are conformational. On the other hand, treatment of Fel d I by N-glycanase under reducing and non-reducing conditions indicated the presence of N-linked oligosaccharides in the beta-chain. Carbohydrate analysis data of the whole Fel d I molecule showed the presence of a relatively high carbohydrate content (approximately 20%). RAST inhibition experiments of native and deglycosilated allergen suggest that most IgE epitopes are located in the protein moiety of the molecule. However, the deglycosilated allergen showed a 2-4 fold reduction in its inhibition capacity of RAST as compared to the native allergen, suggesting that carbohydrates could have some role in keeping the active conformation of those epitopes. The N-terminal amino acid sequence of the beta-chain (20 residues) and most of the alpha-chain (40 residues) were determined. Both chain sequences showed no homology with other known protein sequences.

Liposomes as carriers for allergy immunotherapy

With the aim of obtaining an efficient but safer vaccine for allergy immunotherapy, the possibility of using liposomes as adjuvants has been considered given their proven low toxicity, adjuvant properties and ability to maintain the encapsulated substance in their interior for some time in vivo. Different methods of encapsulating allergenic extracts into neutral, positively, and negatively charged DPPC: cholesterol liposomes have been investigated and the immune response provoked by these in mice was studied and compared to the immune response to free allergen or other adjuvants such as aluminium hydroxide. The results obtained show that allergen encapsulated in all three types of liposomes elicit an increase in specific IgG levels higher than that provoked by free allergen, however, both encapsulation efficiency and specific IgG titre were higher when positively charged (DPPC: cholesterol stearylamine) liposomes were used. Specific IgE levels to allergen in positive and neutral liposomes was lower than to allergen in negative liposomes or adsorbed to Al(OH)3. No difference were found in the behaviour of liposomes prepared by different methods (the results were obtained from pooled sera from different groups of mice so there is no statistical data). These results confirm the immunoadjuvant effect of liposomes for allergy immunotherapy. Further studies to determine their lack of toxicity, pharmacokinetic studies and human clinical studies are necessary to confirm their adequacy for human use and advantage over current immunotherapy methods.

Identification of soybean proteins responsible for respiratory allergies

Serum samples from 32 patients who suffered attacks during the asthma outbreaks of 1987 and 1988 in Cartagena, Spain, supposedly caused by soybean dust, were studied. At least 90% had specific IgE to shell components and only 13% showed specific IgE to shell-depleted soybean grains. A control group of 32 patients who also suffered asthma attacks but on different days from those of the outbreaks were negative. The shell's most important allergen with an apparent molecular weight of 8 kDa was not present in shell-depleted grains. This allergen as well as other less important shell allergens may be different from the allergens already identified by using serum from patients suffering food allergy to soya.

Studies on the relationship between structure and IgE-binding ability of Parietaria judaica allergen I

The main allergen of Parietaria judaica pollen, Par j I, is a glycopolypeptide with mol. wt about 10,000. It shows a considerable charge heterogeneity which is mostly due to the carbohydrate prosthetic groups, since treatment with trifluoromethanesulfonic acid yielded a deglycosylated protein with 8500 mol. wt that displayed only a few bands on IEF, in a narrow pH-region around 5.0. Deglycosylated Par j I exhibited a specific allergenic activity slightly lower than that of native Par j I; however, no allergenic determinants should be located on the sugar moiety since both native and deglycosylated Par j I inhibited up to a similar extent the binding of specific human IgE to P. judaica-coated wells in ELISA. The decrease of specific allergenic activity following deglycosylation could be ascribed to conformational changes evidenced by CD experiments. On the other hand, fluorescence spectroscopy showed that Par j I bears unidentified yellow-brown chromophores strongly linked to the polypeptide chain. These chromophores were not removed by TFMS treatment. Finally, reduction and alkylation caused the complete loss of allergenic activity, showing that disulphide bridges are essential for the IgE-binding ability of Par j I.

[Gastroenteritis with eosinophilia caused by Giardia lamblia]

A case of gastroenteritis due to Giardia lamblia with severe dehydration and complicated with arterial thrombosis, accompanied by eosinophilia and increased serum IgE levels, is presented. The relationship between Giardia and eosinophilia and allergic manifestations is discussed as well as its pathogenesis.

HPLC purification of the main allergen of Parietaria judaica pollen

A two-step purification procedure of Par j I from the whole Parietaria judaica pollen extract is described. The first step consisted of gel filtration HPLC using a TSKG 3000 SW column, and 0.1% trifluoroacetic acid as the eluant. By this method, proteins were separated from the highly colored material present in the extract. Then, Par j I-containing fractions were chromatographed on a reversed-phase HPLC column (Vydac C4) using an acetonitrile gradient. This second step yielded pure Par j I as assessed by SDS-PAGE and CIE. Previously reported microheterogeneity was still observed, but amino acid analysis of various RP-HPLC fractions suggested that the heterogeneity of Par j I might not be due to changes in its primary structure. Allergenic activity of Par j I was shown to be retained after the purification procedure by several immunochemical techniques.

Obtention of monoclonal antibodies against human IgG4 using two different immunization strategies: development of a biotin-based ELISA for IgG4 quantitation

Several monoclonal antibodies (MAbs) against human IgG4 have been produced in two fusion experiments. In fusion I, Balb/c mice were conventionally immunized and most of the antibodies obtained recognized IgG class-specific epitope(s). Therefore, a second fusion experiment was performed using IgG4-immunized mice that had been made tolerant to epitopes shared by the four IgG subclasses, and most of the hybridomas derived from this second fusion secreted antibodies specific for IgG4. Five MAbs which were found to be specific for both IgG4 isoallotypes (4a and 4b) were selected from the two fusion experiments. These antibodies define at least two non-overlapping epitopes located on the Fab and Fc regions of IgG4 molecule, respectively. Two MAbs were used to develop a two-site ELISA for IgG4 quantitation, in which one MAb (anti-Fab) was immobilized in the solid phase and the other one (anti-Fc) was biotin-labeled. The assay had a detection limit below 1 ng/ml and a practical working range between 4 and 200 ng/ml. The use of these MAbs should improve our understanding of the role of IgG4 in different clinical conditions.

Anaphylaxis produced by rubber glove contact. Case reports and immunological identification of the antigens involved

A study was carried out on six subjects suffering from anaphylactic reactions including asthma, rhinoconjunctivitis, contact urticaria and hypotension following contact with rubber gloves. All of them showed skin sensitivity and serum specific IgE to various preparations of natural latex, and not to other chemicals used in glove manufacturing. Immunoblotting techniques demonstrated that at least four soluble polypeptides from natural latex had the ability to bind specific human IgE. The results suggested that natural latex proteins present in rubber gloves can cause severe specific hypersensitivity reactions.

Monoclonal antibody based radioimmunoassay for the quantitation of the main cat allergen (Fel d I or Cat-1)

A two-site solid-phase radioimmunoassay has been developed for the quantitation of the main cat allergen, Fel d I or cat allergen 1. The assay is based on two different monoclonal antibodies which recognize different epitopes on the Fel d I molecule; one antibody (C5/24) was immobilized on the solid phase and the other (C5/8) was labeled with 125I, being the allergen molecule sandwiched between them. The assay is specific for the Fel d I molecule and sensitive enough to detect as little as 0.25 ng/ml of allergen. The Fel d I RIA was compared with a radial immunodiffusion technique for the determination of allergen levels in several cat extracts and a good quantitative correlation was found. The same good correlation was found when the results obtained with the Fel d I RIA were compared with the determination of the total allergenic activity by RAST inhibition. The results indicate that the MAb RIA could be very useful in the standardization of allergenic extracts from feline origin.