PubMed Health⌕ Search

Biomedical subjects

I Moneo

Publications and source records attributed to I Moneo.

At least 55 records · Page 3Linked to original sources
PubMed1995

Comparison of the anti-laminin antibody response in patients with systemic lupus erythematosus (SLE) and parasitic diseases (filariasis).

In this study, we analyzed the presence of antibodies against the basement membrane antigen laminin (LMN) in patients with systemic lupus erythematosus (SLE), filariasis, and normal controls. By ELISA, 13.8% of SLE (12/87), 66.7% of parasitized patients (20/30), and two of the normal controls had these antibodies. IgG1 anti-LMN response was elevated in all groups, whereas IgG2 and IgG3 were also elevated in parasitized patients. The analysis of the IgG anti-laminin binding capacity in SLE and parasitized patients showed similar average antibody affinity. These antibodies did not react with fibronectin by a competition ELISA. By Western blot, the anti-laminin antibodies could be demonstrated in parasitized patient sera but not in SLE sera. Moreover, the ability of these antibodies to bind to heat-treated LMN (100 degrees C for 4 min) was different. The study of the binding capacity with native or denatured LMN by Western blot and dot-blot assays showed that the anti-LMN antibodies from parasitized patients were able to react with both native and denatured forms of LMN, whereas in SLE patients these antibodies were demonstrated only with native LMN. On the other hand, the reactivity detected in the normal control sera seems to be different from the anti-LMN antibodies from SLE and parasitized patients, and probably reflects the existence of natural antibodies in these sera. The presence of anti-LMN antibodies correlates significantly with the ability of inhibition of U937 cell adhesion to LMN-coated surfaces (P < 0.0025). The difference of anti-laminin reactivity suggests that antibodies produced following immunization with autoantigens or similar molecules present in parasites have different specificities from those spontaneously produced by individuals with autoimmune diseases.

Animals↗
PubMed1995

Skin-prick tests for hypersensitivity to alpha-amylase preparations.

Twenty-five asthmatic subjects with suspected alpha-amylase hypersensitivity were studied by skin-prick tests, a capture ELISA, immunoblotting and bronchial provocation tests. At the same time, different amylases were analysed by SDS-PAGE and immunoblotting using a polyclonal rabbit antiserum. Eight patients showed a positive bronchial response to amylase. Seven of them had positive skin-prick tests, with this method being the most sensitive approach for diagnosis. However, in four cases, skin tests were also positive although the patients had a negative provocation test, thus demonstrating that skin tests are not specific. ELISA and blotting showed similar results in terms of sensitivity and specificity. The enzymes used by the workers included several antigens besides alpha-amylase. The rabbit antiserum to alpha-amylase detected a protein in a wheat flour extract. In one case, the IgE antibodies were specific only for a contaminant of lower molecular weight than amylase. These facts suggest that proteins from the culture medium could be responsible for some cases of amylase hypersensitivity, making the diagnosis difficult. The presence of amylase in another enzymatic extract, a protease produced by Aspergillus oryzae, was proved by means of skin tests and immunoblotting, thus demonstrating the allergenic properties of this enzymatic preparation.

Asthma↗
PubMed1995

Characterization of latex and chestnut antigens by immunoblotting.

BACKGROUND: Cross-reactions between latex, chestnut, and other fruits have been demonstrated by RAST, although the results show some discrepancies. OBJECTIVE: To detect and characterize cross-reacting antigens in both extracts by immunoblotting. METHODS: Polyclonal rabbit antisera were raised against ammoniated latex and an aqueous chestnut extract. The antigenic extracts were studied by immunoblotting using a diffusion transfer method. Cross-reactivities were measured by immunoblotting inhibition. RESULTS: Both antisera detected a high number of antigenic proteins in both latex and chestnut extracts. Latex was a good self-inhibitor and inhibitor of chestnut with respect to both antisera. Chestnut was only a good inhibitor for the two antisera on the chestnut-blot as well as on the latex-blot when the anti-chestnut antiserum was employed. No inhibition was obtained on latex immunoblotting by chestnut using anti-latex antiserum. CONCLUSIONS: The results suggested that latex and chestnut contained common epitopes detected by antibodies raised by immunization with both antigens. The anti-latex antiserum, however, possessed antibodies that could not be inhibited by other allergens. This could explain why latex has been described as a good inhibitor of chestnut-RAST while no inhibition by chestnut was found on the latex-RAST in latex and chestnut allergic patients. Other common pollen extracts were also inhibitors of immunoblotting with the exception of the latex/anti-latex pair. This suggests that antibodies induced by immunization with latex or chestnut showed unexpected cross-reactions.

Animals↗
PubMed1994

alpha-Amylase hypersensitivity in non-exposed millers.

Occupational hypersensitivity to alpha-amylase among bakers and workers in the pharmaceutical industry has been described. We present the results of skin tests and in vitro methods used to assess alpha-amylase sensitivity in 259 millers. There was no occupational contact with the enzyme in this population. Positive skin tests to this allergen were obtained in 16 subjects (6.18 per cent), specific IgE values were found in seven subjects (2.7 per cent), specific IgG was detected on 45 workers (17.37 per cent) and high values for IgG (> 2.5 absorbance units) were found in 12 subjects (4.63 per cent). Furthermore, specific IgE and IgG could be determined in several sera by immunoblotting. All these facts suggested that millers were sensitized to Aspergillus oryzae alpha-amylase, although the allergen was not used by these workers. A cross-reaction cannot be excluded; however, it is the authors' opinion that wheat or wheat flour is a natural substrate for fungi and that the moulds that grow on cereals or cereal-derived by-products need to secrete amylases to support their own development. Hence the workers may be indirectly sensitized to amylases.

Aspergillus oryzae↗
PubMed1993

Sensitization from chestnuts and bananas in patients with urticaria and anaphylaxis from contact with latex.

We present eight patients allergic to latex and fruit (chestnut and banana), seven of whom are women, and aged 17 to 42 years (mean 25 years). Four had family and five personal atopic histories. The total IgE varied from 41 to 520 Ku/L (mean 263). The symptoms followed ingestion of fruit (anaphylaxis) in four patients and contact with rubber (contact urticaria and anaphylaxis) in the other four. Skin prick test (SPT) with latex and radioallergosorbent test to latex were positive in all the patients. Histamine release (HR) to latex was carried out on six patients and was positive in three. In the six patients with symptoms after having eaten chestnuts the SPT was positive and specific IgE was detected in five of them. Histamine release to chestnuts was positive in three of the six patients tested and one of them (-SPT and + IgE) tolerated the fruit. Two out of five patients with symptomatic banana allergy had negative SPT with banana while the test was positive in one patient who tolerated this fruit, this being the only case with specific IgE to banana. Histamine release with banana was only positive in one case. The important correlation between SPT, RAST, and HR results to latex and chestnut together with the total inhibition of the chestnut RAST with a serum pool by preincubation with latex suggests cross-reactivity among these allergens.

Adolescent↗
PubMed1992

Occupational asthma caused by alpha-amylase inhalation: clinical and immunologic findings and bronchial response patterns.

Inhalation of dust from different enzymes can be the cause of occupational asthma in exposed workers. alpha-Amylase, derived from Aspergillus oryzae, is one of these enzymes, although there are few studies in the medical literature that refer to its allergologic properties and to clinical studies in sensitized patients. The results obtained in a study performed in 83 pharmaceutical-industry workers exposed to powdered alpha-amylase are described in this article. The existence of sensitization to this enzyme was demonstrated in 26 of the workers by positive skin tests. Specific IgE values were significantly higher in workers with positive skin tests than in workers with negative skin tests (p less than 0.001). The bronchial provocation test with alpha-amylase was positive in six of the 14 patients challenged, and only immediate bronchial responses were observed; the same type of response was obtained by nasal provocation. One of the workers had a positive response to oral provocation with this enzyme, presenting abdominal, skin, and respiratory symptoms a few minutes after ingestion. Consequently, we consider that the bronchial asthma presented by the workers was due to an immediate-type, IgE-dependent, immunologic mechanism.

Adult↗
PubMed1990

Epitope mapping of the major allergen from yellow mustard seeds, Sin a I.

The antigenic sites on the major allergen from yellow mustard (Sinapis alba L.) seeds were studied using murine (BALB/c) monoclonal antibodies (mAb) and human IgE antibodies. Ten IgG1 (K) mAb from two fusions were analyzed. Competition and complementation studies performed with peroxidase labeled mAb reveal the existence of two main antigenic sites in Sin a I. All the described mAb failed to recognize the unordered carboxyamidomethylated polypeptide chains, with the single exception of 2B3, which binds the alkylated large chain. However, this mAB cannot react with the tetranitromethane-modified protein which retains the native conformation. This fact suggests that the only tyrosine of Sin a I, located in the large chain, may be part of a sequential epitope of the allergen. This chemical modification also alters the binding of the mAb 4A11 and 3F3 to the allergen, besides 2B3. The three mAb belong to the same complementation group. Specific IgE binding cannot be inhibited either by the large or small carboxyamidomethylated polypeptide chains, while the nitrated allergen shows a weaker inhibitory activity than the native Sin a I. 4A11, which is a tyrosine-dependent mAb, causes the greatest binding inhibition of the tested mAb on human IgE from atopic individuals, as determined from a reverse enzyme immunoassay, suggesting an important role played by tyrosine in the immunochemical recognition of Sin a I.

Allergens↗
PubMed1990

[Validity of a score of clinical parameters as a screening method in acute bacterial diarrhea in childhood].

We report a prospective study of the cases of acute diarrhea admitted to our pediatric service during one year (n = 172) to elaborate a screening method to identify patients with bacterial diarrhea. A bacterial causative organism was identified in 31.4%. The most common species was Salmonella, followed by Campylobacter. We evaluated the clinical presentation parameters, looking for differences between the group were a bacterial organism was isolated and in the group where it was not. We designated a score valid as a first level screening for bacterial diarrhea. With a score greater than or equal to 7 the sensitivity was 81.5% and the specificity 60.2%. The latter increased to 95% when occult blood in feces was associated with the greater than or equal to 7 score (second screening level). We propose this clinical score as a criterion for the indication of fecal cultures in children with acute gastroenteritis.

Acute Disease↗
PubMed1990

Contact urticaria caused by Obeche wood (Triplochiton scleroxylon). Report of eight patients.

A variety of plant substances may induce contact urticaria and the list of substances responsible for such reactions is increasing. We report eight patients suffering from occupational asthma caused by Obeche wood sawdust. These patients also presented with urticaria when they worked with this wood. Studies revealed immediate positive skin test reactivity to Obeche wood extracts in all patients. The presence of specific IgE antibodies against Obeche wood could also be demonstrated by a reverse ELISA method. Finally, skin provocation tests (rubbing test) on the eight patients evoked a positive reaction within 20 minutes. These findings strongly suggest an IgE-mediated immunologic mechanism as responsible for the patients' urticaria. Obeche wood should be considered a health hazard capable of causing both bronchial asthma and contact urticaria. At the present time, this timber constitutes the most frequently commercially exported African wood. Many individuals, including carpenters and hobbyists, may come into contact with this wood due to the common use of Obeche wood in the "Do it yourself" type of shops.

Adult↗
PubMed1990

Purification and characterization of an allergen of mustard seed.

A protein allergen has been isolated from mustard seed extracts by gel filtration. In RAST-inhibition experiments the allergen inhibited more than 60% of the binding of mustard-specific IgE from a pool of seven patients' sera. The allergenic activity was also demonstrated by histamine release from whole blood from two sensitive patients. The allergen had an isoelectric point close to 10.5 and an apparent molecular weight of 14,000. It was stable in alkaline and acid solutions and showed resistance to heating and to degradation by proteolytic enzymes.

Allergens↗
PubMed1988

Primary structure of the major allergen of yellow mustard (Sinapis alba L.) seed, Sin a I.

Sin a I, a 2-S albumin from the seeds of yellow mustard, is herein described as the major allergen of these seeds. This protein is composed of two disulfide-linked polypeptide chains of 39 and 88 amino acids, whose primary structures are reported. The Sin a I allergen is found to be related to other low-molecular-mass albumins, such as those isolated from rapeseed, castor bean and Brazil nut. Additional structural similarity has also been found between the glutamine-rich large chain of Sin a I and a proline-rich zein, a gliadin, and trypsin and alpha-amylase inhibitors isolated from the seeds of several monocotyledons. Internal amino acid sequence similarity has been detected at both termini of the small and large chains of Sin a I and involves the location of proline and glycine residues at similar positions in relation to the processing cleavage sites. Prediction of secondary structure, based on the amino acid sequences of the mature chains of the mustard allergen, indicates that the precursor polypeptide is cleaved at regions showing a high beta-turn probability. This is also observed with the amino acid sequence deduced from the rapeseed napin gene nucleotide sequence.

Allergens↗
PubMed1987

Occupational asthma caused by Voacanga africana seed dust.

We report a case of a nonatopic patient in whom exposure to Voacanga africana (VA) dust precipitated asthma. The patient was indirectly exposed to this dust by her husband, a chemist working in a pharmaceutical plant in which VA is used for the production of vinburnine, an alkaloid derivative. Vinburnine (Cervoxan) is widely used in conditions associated with cerebral circulatory insufficiency. Studies revealed the presence of immediate skin test reactivity to VA dust, and specific anti-VA antibodies were detected in the patient's serum by the reverse enzyme immunoassay technique. Bronchial challenge with a VA extract also resulted in an immediate asthmatic response without late reaction. These findings suggest a type I IgE-mediated immunologic mechanism as being responsible for the patient's respiratory symptoms. Unexposed persons did not exhibit reactivity to this seed with any of the tests referred to above. To the best of our knowledge, this is the first reported case of occupational asthma caused by VA seeds.

Adult↗
PubMed1987

Anaphylaxis after intra-articular injection of orgotein. Detection of an IgE-mediated mechanism.

Orgotein, a recently introduced anti-inflammatory agent, is the generic name accepted in the U.S.A. for the drug version of copper-zinc superoxide dismutase. This metallo-enzyme is obtained from bovine liver and has a molecular weight of about 32,000. We report on a patient to whom an intra-articular injection of orgotein caused an anaphylactic reaction. An IgE-mediated mechanism was suggested by an immediate positive skin test to orgotein and by the finding of specific IgE against orgotein in the patient's serum.

Adult↗