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Biomedical subjects

E Mata

Publications and source records attributed to E Mata.

At least 19 recordsLinked to original sources
PubMed2006

Adjuvant activity of polymer microparticles and Montanide ISA 720 on immune responses to Plasmodium falciparum MSP2 long synthetic peptides in mice.

The purpose of this work was to test the immunogenicity in C57BL mice of two synthetic peptides derived from the constant region of 3D7 and FC27 Plasmodium falciparum MSP2 dimorphic proteins, either microencapsulated into poly-lactide-co-glycolide acid microparticles (PLGA MP) or delivered with the human compatible adjuvant Montanide ISA 720 for comparison. Potent and prolonged antibody responses were obtained for both peptides by using PLGA MP formulations after subcutaneous or intradermal injections. As compared to the subcutaneous route of immunization, the intradermal route induced greater immune responses. Montanide adjuvant was effective in eliciting antibodies against the 3D7 peptide but not against the FC27 peptide. Peptide-specific cytophilic antibodies (IgG2a) were detected after boosting with homologous peptide for all vaccine formulations. MP formulations elicited a lower IgE secretion as compared to that observed for both Montanide formulated vaccines. Our results demonstrate the ability of the polymer microparticles to overcome the lack of immunogenicity of FC27 MSP2 peptide in C57BL mice and their potential to induce desirable immune responses against malaria.

Adjuvants, Immunologic↗
PubMed1999

Criteria of evaluation and of interpretation of Sepharose drug IgE-RIA to anaesthetic drugs.

The detection of antidrug specific IgE in serum is usually performed by a sandwich-type immunoassay in which the serum IgE is first adsorbed to a reactive phase and subsequently quantified via the binding of an anti-IgE tracer. The preparation of a new drug-reactive phase requires one to establish carefully different steps of validation: 1) criteria of positivity of control sera 2) competitive inhibition assays with the soluble drug, which should include the determination of the inhibition constant rather than estimation of a single inhibition percentage, especially when the assay is performed for the identification of determinants 3) estimation of nonspecific binding of IgE to the solid phase, including hydrophobic binding. The competitive inhibition depends on the concentration of the competitor and of IgE in the test-tube and the concentration of reactive drug bound to the solid phase. We have improved the inhibition assay by performing the Dixon test for calculating the inhibition constant (Ki) of the competitor. The Ki of six different muscle relaxants was determined in 12 patients who experienced an anaphylactic reaction to muscle relaxants. The values ranged between 1.5 nM and 2.5 microM. This confirmed the great heterogeneity of drug IgE cross-reactivity among patients. The Ki value of the incriminated drug was the lowest (affinity, the highest) in eight of the 12 patients. It was better correlated to clinical data than the classical inhibition assay. A hydrophobic environment seemed to be necessary, close to the quaternary ion, to allow IgE binding to the muscle relaxant. By contrast, in tiemonium, a hydroxyl group present at a distance of about 3 A from the quaternary ion may explain why this molecule had a high Ki (microM). In conclusion, it should be recommended, in molecular-recognition studies, that the inhibition constant of the soluble drug and of the related compounds be determined to complement the experiments based only on hapten inhibition assays.

Anesthetics↗
PubMed1998

Association between giardiasis and allergy.

BACKGROUND: Previous studies have indicated that there may be an association between infection by the intestinal protozoan Giardia lamblia and the expression of allergic disease. OBJECT: We evaluated a group of children who attended the Outpatient Clinic of the Children's Hospital in Caracas, Venezuela, a group in which both allergic disease and giardiasis were common. METHODS: We performed feces examination and measured total and specific serum IgE (immunoglobulin E) in these children. RESULTS: We found that 70% of the children infected with G. lamblia presented symptoms of allergy, in contrast to 43% of the non-Giardia parasitized group (P <.05). In addition, the G. lamblia parasitized children showed significantly higher levels of total serum IgE (1194 IU/mL) than the non-Giardia group (822 IU/mL) (P <.005). Children infected with G. lamblia showed higher levels of specific serum IgE antibody against food allergens compared both with the non-parasitized group (P <.0001) and children infected with parasites other than Giardia (P <.05). In contrast, IgE responses against the house dust mite Dermatophagoides pteronyssinus were similar in all the groups studied. CONCLUSIONS: These results reveal a clear relationship between giardiasis and allergy, possibly because infection by this protozoon enhances sensitization towards food antigens, due to increased antigen penetration through damaged intestinal mucosa.

Antibodies, Protozoan↗
PubMed1995

Non-specific cross-reactivity of hydrophobic serum IgE to hydrophobic drugs.

The purpose of this work was to study the involvement of serum hydrophobic IgE in non-specific cross-reactions with hydrophobic drugs such as cyclohexenyl derivatives. Hydrophobic IgE were detected by radioimmunoassay. The results were expressed as the percentage of labelled anti-IgE which were adsorbed to the drug solid phase via IgE of the patient serum. Phenyl-Sepharose IgE-RIA was at 4.6 +/- 0.7%, 125 +/- 6.5% and 17.8 +/- 8.9% in control subjects (n = 24), in atopic patients with positive Phadiatop (n = 30) and in patients with drug allergy (n = 23), respectively. We selected five patients who were allergic to either penicillin, propofol, glafenin or paracetamol and who had a Phenyl-Sepharose IgE-RIA greater than 20%. In these five cases, IgE-RIA were positive (percentage at least twice more than that obtained with control sera) with all the solid phases prepared with hydrophobic drugs such as penicillin, propofol, glafenin, paracetamol and mexiletine. Inhibition of IgE binding by monoethylene-glycol showed that the cross-reactivity was due to hydrophobic binding of IgE to the drug. Three of the five patients were allergic to penicillin and underwent on adverse reaction against another cyclohexenyl derivative, namely propofol and glafenin. In conclusion, we have observed the presence of 'hydrophobic IgE (with positive Phenyl-Sepharose RIA)' in 64% of patients allergic to a hydrophobic drug.

Adsorption↗
PubMed1994

Surimi and native codfish contain a common allergen identified as a 63-kDa protein.

We have compared the allergenicity of codfish and surimi (prepared from codfish) by skin testing, specific IgE-RIA, and leukocyte histamine release (LHR) in six fish-allergic patients. Prick tests were positive for codfish and, to a lesser extent, surimi. The percentages of labeled anti-IgE bound to surimi-Sepharose were 1.55 +/- 0.19% and 3-6% with control and patient sera, respectively. Inhibition of the surimi protein-Sepharose IgE-RIA was greatest (80%) at protein concentrations of 13.4 and 408.5 micrograms/ml for codfish and surimi extract, respectively. The allergenic protein was isolated by gel filtration and subjected to SDS-PAGE. The eluate from codfish contained several proteins ranging from 13 to 63 kDa, while the eluate from surimi contained a single 63-kDa protein. It was concluded that surimi contained a single allergenic protein.

Adolescent↗
PubMed1993

Non specific interactions in anti-agent IgE-RIA to anesthetic agents.

The sensitivity of usual IgE-RIA for detecting seric anti-neuromuscular blocking drug (NMBD) IgE antibodies is low. Our group and other authors have proposed quaternary ammonium compounds other than NMBD for the preparation of sepharose solid drug phase. These compounds cannot be cyclohexenyl derivatives in order to prevent hydrophobic interactions with seric hydrophobic IgE. Allergic reactions against cyclohexenyl derivatives such as propofol could be linked to a non-specific hydrophobic binding of the drug to hydrophobic seric IgE. Such hydrophobic IgE are seen in 30% of atopic subjects, in 41% of patients with drug allergy and in 100% of those allergic to propofol. The latter had also anti-quaternary ammonium IgE in 5 out of the 8 cases studied. These NMBD antibodies could bind to the quaternary-ammonium ion of the lecithins from Diprivan micelles.

Antibodies, Anti-Idiotypic↗
PubMed1993

Platelet serotonin is a mediator potentially involved in anaphylactic reaction to neuromuscular blocking drugs.

A platelet serotonin release test was performed on blood from 10 patients who had suffered from an IgE-dependent allergic reaction to a neuromuscular blocking drug. The results were compared with those of a leukocyte histamine release test. The upper limit of serotonin release induced by neuromuscular blockers was estimated to be 2.3% in non-allergic patients. The test was positive in six patients and was consistent with histamine release in five. Serotonin release induced by neuromuscular blockers comprised 2.9-25% of total platelet serotonin content. We conclude that serotonin is one of the mediators associated with histamine release during anaphylaxis to neuromuscular blockers. Platelet serotonin release tests may be useful for the investigation of anaphylactic responses to neuromuscular blocking drugs.

Adolescent↗
PubMed1992

Clinical evaluation of in vitro leukocyte histamine release in allergy to muscle relaxant drugs.

We have evaluated the in vitro leukocyte histamine release tests for the diagnosis of allergy to muscle relaxant drugs in 40 patients (Group A) and a control group of 44 subjects with negative leukocyte histamine release (Group B). Non-IgE dependent histamine release, expressed as a percentage of the total blood histamine, was 3.94% +/- 0.49 in Group B. The upper limit of positivity was estimated to be 5% (mean + 2 SD). Leukocyte histamine release tests were positive in 65% of the patients from Group A. The concordance between LHR and QAS-RIA was 64%. The maximal histamine release was observed at dilutions of 10(-2)-10(-4) in 20 of the 26 positive cases. The maximal histamine release was 43.8% +/- 23.3. The spontaneous histamine release was as low as 1.7% +/- 1.1. Cross-reactivity among the 5 different muscle relaxant drugs has been investigated and compared by intradermal testing. The muscle relaxant drugs which gave the lower skin reaction (M2) and the drug responsible for shock (M1) were selected for the study of in vitro leukocyte histamine release. Of 20 M2. All of the 10 cases had negative ID tests with M2. Three of these patients subsequently underwent general anesthesia with the muscle relaxant chosen as harmless (M2) without any clinical reaction.

Adult↗
PubMed1991

Evaluation of a new reactive solid phase for radioimmunoassay of serum specific IgE against muscle relaxant drugs.

Until now, immunoassays for detection of anti-muscle relaxant IgE in serum have been performed with the drug coupled to epoxy-activated Sepharose or to RAST papers dics. In the present work we have used a quaternary ammonium-Sepharose in which the quaternary ammonium reactive group (choline chloride) was directly coupled to Sepharose via an ether linkage. 50 microliters of the quaternary ammonium solid phase (QAS) was incubated with 50 microliters of serum for 3 h, washed, incubated 18 h with 125I-anti-IgE and washed again. The results were expressed as the percentage of 125I-anti-IgE absorbed onto the solid phase. The results were at 1.3 +/- 0.5% for 20 control sera, with an upper normal limit estimated to 2.3%. The within-run reproducibility ranged from 3.2% to 10.0%. The results were significantly correlated with those obtained with either alcuronium-epoxy-Sepharose, choline-epoxy-Sepharose, the RAST-alcuronium or with the RAST-succinyl choline (respectively, r = 0.66, r = 0.80, r = 0.81, r = 0.40 and r = 0.85). The values obtained with the sera of 83 patients ranged from 0.3 to 38.5%. The sensitivity was estimated at 87.9%, 66.7% and 40.7% with the QAS-RIA, the RAST-succinyl choline and the RAST-alcuronium, respectively. The inhibition of adsorption of specific IgE onto the gel ranged from 13.0 to 90.6% in presence of 130 nmol of soluble muscle relaxants. In 83.3% of 30 cases, the highest inhibition was obtained with the muscle relaxant which was clinically incriminated.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcuronium↗
PubMed1991

Basophil histamine release in atopic patients after in vitro provocation with thiopental, Diprivan and chlormethiazole.

The degree of histamine release induced by three different anesthetic drugs was studied in vitro using basophil leukocytes from atopic patients (n = 11) and controls (n = 14). In all, eight dilutions (1/2 to 10(-5)) of Diprivan and its solvent Intralipid, thiopental and chlormethiazole in aqueous solution, were used. Histamine was released in four controls with weak dilutions (1/2 to 10(-5)) of Diprivan (n = 2) and thiopental (n = 2). The reaction with thiopental was greater than that with Diprivan. Five of the atopic subjects released histamine with one or more drug: thiopental and Diprivan four times each, Intralipid twice, and chlormethiazole once. Histamine release was greater in these patients than in controls, and occurred with dilutions ranging from 1/2 to 10(-2), except for one case. It is concluded that atopic patients release histamine with hypnotic anesthetic drugs more easily than normal subjects. In the clinical setting, where blood concentration of the drugs studied is equivalent to a dilution of less than 10(-3), they do not release much histamine. They may be used in atopic patients if the drugs are injected slowly.

Basophils↗
PubMed1989

[Probable allergy to polyvidon, responsible for a reaction to iodinated contrast medium: a case of asthma after hysterosalpingography].

A case of asthma induced by a iodinated medium (ICM) is reported. The ordinary ICM for urography were well tolerated. The suspected drug included polyvidon (PVP). Skin test, human basophil degranulation tests and leukocyte histamine release are negative for meglumine ioxitalamate, and positive for PVP. PVP is a macromolecule, used in different drugs, and as a clarifying agent of alcohols. An IgE-dependent allergy to PVP is postulated.

Asthma↗
PubMed1986

Skeletal muscle regeneration after myonecrosis induced by Bothrops asper (terciopelo) venom.

In order to assess the extent of regeneration, creatine kinase content of injected gastrocnemius muscle were determined at four time intervals after inoculation. Simultaneously, the diameters of regenerating fibers were measured, the wet weight of the gastrocnemius was recorded and electrophoretic patterns of muscle proteins and histology of the tissue were analyzed. Injection of crude B. asper venom caused myonecrosis and hemorrhage; in these cases regeneration was very poor, as there was only a small increase in creatine kinase content by four weeks. Histologically, large areas of fibrosis were observed, intermixed with small areas of regenerating muscle. Furthermore, the diameter of regenerating muscle cells was abnormally small, even four weeks after envenomation. In order to test the role of hemorrhage in impairment of regeneration, we also studied the effects of B. asper venom that had been incubated with a volume of antivenom that completely neutralized hemorrhagic activity, but not myotoxic activity. At 24 hr mice showed a generalized picture of myonecrosis, without hemorrhage. Afterwards, regeneration proceeded and significant increases in creatine kinase content were demonstrated at 1, 2 and 4 weeks. Also, histological observations showed the presence of many areas of regenerating muscle, intermixed with small areas of fibrosis and adipose tissue. The diameter of regenerating cells increased with time, reaching values of 25.8 microns by four weeks. Electrophoretic analyses of muscle proteins showed that muscle injected with partially neutralized venom underwent a more complete regeneration than muscle injected with crude venom.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Prophylactic use of penicillin V in teeth with necrotic pulps and asymptomatic periapical radiolucencies.

As a result of (1) clinical experience with flare-ups occurring in teeth with necrotic pulps and asymptomatic periapical radiolucencies and (2) on apparent reduction to the incidence of such flare-ups by the administration of penicillin V at the first sign of swelling, this study on the prophylactic administration of penicillin V in similar cases was undertaken. The subjects were 100 consecutive clinic patients whose teeth had necrotic pulps and asymptomatic periapical radiolucencies. At the initial visit, all teeth were instrumented completely to the radiographic apex, with 0.5% to 2.54% sodium hypochlorite as the irrigant. Sterile, dry cotton pellets and ZOE restorations were used. Alternate patients were given 250 mg of penicillin V and an identical-appearing placebo with instructions to take two tablets every 6 hours for the first 24 hours, followed by one tablet every 6 hours until all tablets were taken. Pain and swelling were graded by the patients on five-point scales, and flare-ups were scored when either pain and/or swelling necessitated an unscheduled emergency visit. Fifteen patients developed flare-ups, with significantly more flare-ups in the placebo group (p less than 0.05). The findings indicate that, in selected cases, prophylactic penicillin can be used to prevent flare-ups.

Dental Pulp Necrosis↗