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Biomedical subjects

C Pascual

Publications and source records attributed to C Pascual.

At least 73 records · Page 4Linked to original sources

In vitro detection of specific IgE antibodies to erythromycin.

BACKGROUND: In vitro tests for detecting drug-specific IgE would be useful in identifying patients at risk for immediate hypersensitivity reactions to therapeutic doses of a drug. OBJECTIVE: We attempted to verify that IgE-mediated reactions to erythromycin occur and to identify IgE antibodies specific for erythromycin in serum from a patient who had urticaria immediately after administration of the drug. METHODS: Skin prick testing was performed on the patient and five control subjects. Serum from the patient, pooled sera from nonatopic subjects allergic to common aeroallergens, and cord blood controls were analyzed for erythromycin-specific IgE by radioimmunoassay. Sepharose (Pharmacia, Uppsala, Sweden) was used as solid phase covalently linked to erythromycin. RESULTS: We were able to detect erythromycin-specific IgE antibodies in serum from the patient who had an allergic reaction to this antibiotic, but specific IgE could not be detected in control sera. CONCLUSION: Immunologic IgE-mediated reactions to erythromycin do occur, and in vitro diagnosis of such reactions can be made by using Sepharose as a solid phase covalently linked to this drug.

Adult↗

Phylogenetic analysis of the genus Corynebacterium based on 16S rRNA gene sequences.

The 16S rRNA gene sequences of 30 strains representing 23 validated Corynebacterium species and 7 currently non-valid Corynebacterium species were determined. These sequences were aligned with the sequences of other Corynebacterium species and related actinomycete taxa. A comparative sequence analysis revealed that there is considerable phylogenetic depth and internal structure in the genus Corynebacterium. Turicella otitidis and the amycolate species Corynebacterium amycolatum were located at the periphery of the genus Corynebacterium. It was evident that the species of the genus Corynebacterium form a monophyletic association and, together with other chemotype IV and mycolic acid-containing taxa (including the genera Dietzia, Gordona, Mycobacterium, Nocardia, Rhodococcus, and Tsukamurella), form a natural suprageneric group.

Base Sequence↗

Allergic reactions associated with airborne fish particles in IgE-mediated fish hypersensitive patients.

We evaluated the clinical characteristics found in 21 children who showed allergic reactions upon incidental inhalation of fish odors or fumes, from 197 diagnosed with IgE-mediated fish hypersensitivity. Allergic reactions to fish via ingestion began in most patients (86%) within the first 24 months of life. The vast majority (19/21) of patients showed cutaneous symptoms, either alone or, less frequently, associated with other clinical manifestations. Hake and flounder were the species of fish most frequently implicated in eliciting clinical manifestations upon ingestion. After diagnosis, all these patients were placed on a strict fish-avoidance diet. During this period of avoidance, patients reported allergic reactions (mean age 7 years) after incidental exposure to airborne fish odors or fumes. Clinical manifestations through inhalation were respiratory (mainly wheezing) in 12 patients and cutaneous (mainly urticaria) in nine patients. Nineteen of 21 patients reported three or more episodes upon exposure to fish aerosols; in most cases, these episodes occurred at home when other people were eating fish. In conclusion, incidental inhalation of fish odors or fumes could play an important role in accidental and unknown encounters with fish in children on fish-avoidance diets for fish IgE-mediated hypersensitivity. Such exposures could elicit clinical symptoms and could have some effect in delaying the development of tolerance.

Air Pollutants↗

Occupational rhinoconjunctivitis and bronchial asthma due to Phoenix canariensis pollen allergy.

We report a case of occupational bronchial asthma and rhinoconjunctivitis caused by Phoenix canariensis (PC) pollen. The canary palm is a type of palm tree, belonging to the Arecaceae family, which is widely distributed in frost-free regions as an ornamental tree. Our patient was referred because he suffered symptoms of bronchial asthma, rhinoconjunctivitis, and contact urticaria when pruning dried leaves from PC during the pollination months. The skin prick test (SPT) with a PC pollen extract was positive, as was the specific IgE to PC pollen determined by Phadezym RAST, indicating an IgE-mediated sensitization. The nonspecific bronchial provocation test (BPT) performed with methacholine disclosed a mild bronchial hyperreactivity, and specific BPT with PC pollen elicited an immediate fall of 25% in FEV1 with respect to baseline. On RAST inhibition studies, a significant cross-reactivity was found between PC pollen and date palm (P. dactylifera) pollen. These results suggest that PC pollen could be a potential allergen in PC-growing areas.

Asthma↗

Cross-reactivity of IgE-binding components between boiled Atlantic shrimp and German cockroach.

IgE-antibody reactivity to boiled Atlantic shrimp (Pandalus borealis) and German cockroach (Blattella germanica) of sera from 89 patients, sensitive to one or the other, was investigated with an enzymatic immunoassay for specific IgE detection (CAP-FEIA System, Pharmacia, Sweden). IgE serum levels to both antishrimp and anticockroach allergens were found to be positive in 76 of the 89 (85.4%) tested sera. A positive anticockroach IgE was very rare in the absence of detectable antishrimp IgE (five of 89 sera). Linear regression analysis on antishrimp and anti-German cockroach IgE levels-log plot revealed a correlation coefficient (r) of 0.73. Inhibition experiments showed that boiled Atlantic shrimp extract inhibited CAP with German cockroach, and vice versa. Immunoblotting showed the strongest IgE binding for both allergenic extracts between 30 and 43 kDa. By blot inhibition, the binding capacity of German cockroach was totally abolished by Atlantic shrimp extract, while German cockroach extract only partially IgE binding to Atlantic shrimp. Cross-reactivity exists between shrimp, an important food allergen, and German cockroach, which has an increasing role in allergic asthma. It could be important to determine the clinical significance of cross-allergy to both allergens, in which exposures occur in different ways.

Adolescent↗

Frequency of food allergy in a pediatric population from Spain.

We evaluated the prevalence and characteristics of the principal foods implicated in 355 children diagnosed with IgE-mediated food allergy. Diagnosis was established on the basis of positive clinical history for the offending food, positive specific IgE by skin prick test and RAST, and open food challenge. Our results showed the principal foods involved in allergic reactions are: eggs, fish, and cow's milk. These are followed in frequency by fruits (peaches, hazelnuts and walnuts), legumes (lentils, peanuts and chick peas) and other vegetables (mainly sunflower seeds). The legumes demonstrated the highest degree of clinical cross-reactivity. Most patients with food allergy reacted to one or two foods (86.7%). Only 13.3% of patients reacted to 3 or more foods, mostly to legumes and fruits. We found that food allergy begins most frequently in the first (48.8%) and second (20.4%) years of life. Allergy to proteins of cow's milk, egg, and fish begins predominantly before the second year, demonstrating a clear relationship with the introduction of these foods into the child's diet. Allergy to foods of vegetable origin (fruits, legumes and other vegetables) begins predominantly after the second year.

Age Factors↗

Phenotypic and phylogenetic characterization of some unknown coryneform bacteria isolated from bovine blood and milk: description of Sanguibacter gen.nov.

16S rRNA gene sequencing studies were performed on some Gram-positive coryneform bacteria of unknown taxonomic position isolated from blood and milk of healthy cows. Comparative sequence analysis demonstrated that the milk isolates corresponded to Oerskovia xanthineolytica whereas those from blood consisted of two distinct, albeit highly related species, within the family Cellulomonadaceae. Based on the phylogenetic and phenotypic distinctiveness of the blood isolates, it is proposed that they be classified in a new genus Sanguibacter.

Actinomycetales↗

Transformation of Aspergillus parasiticus using autonomously replicating plasmids from Aspergillus nidulans.

A genetic transformation system for the aflatoxin-producing fungus Aspergillus parasiticus using two autonomously replicating plasmids from A. nidulans (ARp1 and pDHG25) is reported. Transformation frequencies using the plasmid pDHG25 were from 5 x 10(2) to 2.5 x 10(4) transformants per 10(6) viable protoplasts and microgram DNA. The stability of the plasmids in the transformants was also studied. This transformation system offers a new opportunity to clone genes related to aflatoxin production using appropriate aflatoxin-defective mutants.

Aspergillus↗

[An analysis of domiciliary medical care in 7 health centers of Alicante Province].

OBJECTIVE: To know the characteristics of medical care at home done by the doctor and to what extent it is justified. DESIGN: An observational, descriptive-prospective study. Form filled out by the doctor after completing the visit. SETTING: Outpatients, 7 hospitals in area 17 of the Valencian Community. PATIENTS: 188 different patients attended in February 1993 by 15 family doctors. The statistical tests used were ji-squared test, Student's t-test and Anova. MEASUREMENTS AND MAIN RESULTS: An average of 0.4 visits/doctor/day were made. Less than 2 hours/week/doctor were needed. 80.5% of the cases were resolved using usual means available in the doctors emergency briefcase. 64.5% of the patients attended were over the age of 65.66% of the visits were considered to be justified. CONCLUSIONS: 66% of medical care at home was considered justified and did not require excessive time. Elderly patients are the ones who most require medical care at home.

Adult↗

Scavenging action of propolis extract against oxygen radicals.

The ethanolic extracts of two types of cuban propolis (R and P) showed a similar manner of scavenging action against different species of oxygen radicals which were generated by specific chemical reactions. Chemiluminescence produced by superoxide generated from the xanthine-xanthine oxidase reaction was 50% inhibited by approximately 5 micrograms/ml of propolis R and 9.5 micrograms/ml of propolis P and by catechin (0.15 micrograms/ml) and superoxide dismutase (72 ng/ml). Alkoxy radical scavenging effect was similar to that produced by 0.11 micrograms/ml of alpha-tocopherol: inhibition of chemiluminescence by 50% was caused by approximately 0.6 micrograms/ml of both propolis preparations. The results indicate that the antioxidative properties of both propolis could be attributed to their free radical scavenging activity against alkoxy radicals and to a lesser degree against superoxide.

Catechin↗

On the use of the quenching of luminol luminescence to evaluate SOD activity.

Addition of horseradish peroxidase to a luminol solution (pH = 9.4) produces a burst of light followed by a steady luminescence that lasts for several minutes. This steady-state luminescence is readily quenched by SOD, with a Q1/2 concentration (the additive concentration needed to decrease by one-half the emitted luminescence intensity) of c.a. 4 ng/ml (14 mU/ml). The luminescence intensity decrease can then be employed to evaluate SOD activity in SOD-containing samples. However, the light intensity can also be quenched by additives, such as Trolox, that are able to trap luminol-derived intermediates. It is proposed that double quenching experiments must be performed in order to be able to relate the observed effect of an additive to its SOD-like activity.

Antioxidants↗

Relationship between pollinosis and fruit or vegetable sensitization.

The prevalence of vegetable sensitization in children with pollinosis (Group A; n = 48) and the prevalence of pollen sensitization in children with fruit or vegetable allergy (Group B; n = 42) were studied by means of prick-test and determination of serum specific IgE to several pollens, fruits and vegetables. Fifteen patients from Group A (31%) showed sensitivity to fruits and/or vegetables, but only three of them had any symptoms after ingestions. Twenty nine patients from Group B (69%) showed pollen sensitization, mainly to grass and Compositae pollen. An association was found between sensitivity to Compositae pollen and sensitivity to several fruits and vegetables (Compositae, Fagaceae, Brassica, Betulaceae and Leguminoseae).

Adolescent↗

Visible chemiluminescence associated with the reaction between methemoglobin or oxyhemoglobin with hydrogen peroxide.

Visible chemiluminescence is emitted in the irreversible deactivation of hemoglobin or methemoglobin with excess H2O2. The emission takes place in two phases. The most intense one lasts a few seconds and is followed by a second phase of lower intensity that remains for longer periods. This second phase presents chaotic or sustained oscillations. Free radicals are implicated in the luminescent process since the emission can be reduced by free radical scavengers such as 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) or ascorbic acid. These additives lead to a delay in reaching the maximum intensity, which can be related to their consumption, implying substantial recycling of the hemoprotein. Chemiluminescence is also observed in the oxidation of hemin by H2O2, suggesting a role for the heme group in the processes leading to the excited state production. The lower intensity observed in the presence of hemin can be related to the contribution of the globin chains.

Animals↗

In vitro activation of hepatic glutathione reductase from mice by lobenzarit disodium.

Glutathione reductase activity from mice liver is significantly enhanced by lobenzarit disodium at concentrations between 0.3 and 1.5 mM. A maximum activation of almost 30% is achieved at a drug concentration of 0.9 mM. Similar results were observed with glutathione reductase from human leukocytes, but not with the enzyme from yeast. By preincubation with the enzyme from mice liver, lobenzarit also proved to prevent, at least partially, the immediate inhibition caused by the well-known thiol-reacting agents, thus indicating a protecting effect on the catalytically important thiol residue of the enzyme. The results here obtained explain in part the recently found hepatoprotective effect of lobenzarit disodium against acute liver toxicity induced by acetaminophen in mice.

Animals↗

Analysis of cross-reactivity between sunflower pollen and other pollens of the Compositae family.

The sera of 20 patients with Compositae pollen allergy were investigated for the presence of IgE antibodies reacting against sunflower pollen by means of RAST and immunoblotting studies. Thirteen IgE-binding bands were detected with molecular weights ranging from 14.4 to 94 kd. Two of these bands, with molecular weights of 24 and 25 kd, contained major allergens that reacted strongly with 100% (24 kd) and 95% (25 kd) of the sera, respectively. Cross-reactivity between sunflower and other Compositae pollens (mugwort, marguerite, dandelion, golden rod, and short ragweed) was revealed by RAST and immunoblotting inhibition experiments. Mugwort pollen exhibited the greatest degree of allergenic homology (cross-reactivity) with sunflower pollen, whereas at the other end of the spectrum, short ragweed showed less cross-reactive epitopes.

Allergens↗