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Biomedical subjects

J Delgado

Publications and source records attributed to J Delgado.

At least 73 records · Page 4Linked to original sources
PubMed1998

Effect of seasonal exposure to pollen on nonspecific interleukin-4, interleukin-5, and interferon-gamma in vitro release by peripheral blood mononuclear cells from subjects with pollinosis.

The immune response to environmental allergens depends on both genetic and environmental factors. Allergen exposure triggers the activation of allergen-specific Th2 cells in allergic patients, as well as increased Th2-type cytokine mRNA expression and eosinophil recruitment. Nevertheless, different patterns of release of cytokines could explain the heterogeneity of atopic response. In our study, 25 patients with pollinosis and 15 healthy donors were selected to characterize their release of Th2 (interleukin [IL]-4 and IL-5) and Th1 (interferon-gamma [IFN-gamma]) cytokines, both during and outside the pollen season. Peripheral blood mononuclear cells from patients and controls were isolated, cultured in the presence of phorbol-12-myristate-13-acetate plus ionomycine, and phytohemagglutinin (PHA), and cytokine release was assessed by titration in the supernatants. Both IL-4 and IL-5 showed higher levels during than outside the pollen season in pollinic patients (P<0.05) after nonspecific stimuli, whereas IFN-gamma levels were significantly lower during than outside the pollen season only after culture with PHA. Significant differences were not observed in the control group. Our results are consistent with the hypothesis that release of cytokines by peripheral blood mononuclear cells from patients with pollinosis depends on environmental exposure to sensitizing pollens, and that influence can be revealed by in vitro nonspecific stimulation. Nevertheless, the heterogeneity in results suggests that the use of mitogens to assess Th1/Th2 dominance may need careful evaluation.

Humans↗
PubMed1998

Low sensitivity of peripheral blood smear for diagnosis of subclinical visceral leishmaniasis in human immunodeficiency virus type 1-infected patients.

The peripheral blood smear is an easy method for the diagnosis of symptomatic visceral leishmaniasis (VL) in human immunodeficiency virus type 1 (HIV-1)-infected patients. However, its efficiency in diagnosing subclinical VL remains unknown. In this study, Leishmania amastigotes were seen in blood smears from 1 of 13 HIV-1-positive individuals with subclinical VL. This shows that this procedure is not suitable for subclinical-VL diagnosis.

AIDS-Related Opportunistic Infections↗
PubMed1998

Prevalence of and factors associated with visceral leishmaniasis in human immunodeficiency virus type 1-infected patients in southern Spain.

The actual prevalence of visceral leishmaniasis among human immunodeficiency type 1 (HIV-1)-infected patients in the Mediterranean basin remains unknown. There is also controversy about the risk factors for Leishmania infantum and HIV-1 coinfection. To appraise the prevalence of visceral leishmaniasis in patients infected with HIV-1 in southern Spain and to identify factors associated with this disease, 291 HIV-1 carriers underwent a bone marrow aspiration, regardless of their symptoms. Giemsa-stained samples were searched for Leishmania amastigotes. Thirty-two (11%) patients showed visceral leishmaniasis. Thirteen (41%) patients had subclinical cases of infection. Centers for Disease Control and Prevention (CDC) clinical category C was the factor most strongly associated with this disease (adjusted odds ratio [OR], 1.88 [95% confidence interval, 1.22 to 2.88]), but patients with subclinical cases of infection were found in all CDC categories. Female sex was negatively associated with visceral leishmaniasis (adjusted OR, 0.42 [95% confidence interval, 0.18 to 0.97]). Intravenous drug users showed a higher prevalence than the remaining patients (13.3 versus 4.9%; P = 0.04), but such an association was not independent. These results show that visceral leishmaniasis is a very prevalent disease among HIV-1-infected patients in southern Spain, with a high proportion of cases being subclinical. Like other opportunistic infections, subclinical visceral leishmaniasis can be found at any stage of HIV-1 infection, but symptomatic cases of infection appear mainly when a deep immunosuppression is present. There is also an association of this disease with male sex and intravenous drug use.

AIDS-Related Opportunistic Infections↗
PubMed1998

Multiple kinship in two Spanish regions: new model relating multiple and simple consanguinity.

The structure of the different categories of multiple consanguineous marriages (MCMs) and their historical variation patterns are analyzed in the Spanish dioceses of Alava (Basque Country) and Sigüenza-Guadalajara (Castile). Consanguineous marriages, up to third cousins, were taken from ecclesiastical dispensations, and the periods studied were 1831-1980 for Alava and 1861-1980 for Sigüenza-Guadalajara. Significant differences exist in the MCM rates in the two Spanish areas. In this study a model is proposed to prove that in a general population there may be dependence between MCM rates for specific relationships and the frequencies of those types of relationships in the form of simple consanguineous marriages (SCMs). The effects of avoidance and preferentiality and of underreporting are discussed to explain the deviations between observed and expected consanguineous marriage frequencies. A limit to the weight of remote consanguinity on the population inbreeding coefficient F is determined. The relationship between FT/FS and ms values from our two Spanish populations are fitted to curvilinear regressions. FT is the total population inbreeding coefficient, FS is the contribution to FT from SCMs, and ms is the relative observed frequency of SCMs in the general population.

Cohort Studies↗
PubMed1997

T-tubule membranes from chicken skeletal muscle possess an enzymic cascade for degradation of extracellular ATP.

The chicken T-tubule Mg2+-ATPase is an integral membrane glycoprotein that presents properties different from those of other ATPases located in skeletal muscle cells and exhibits ATP-hydrolysing activity on the extracellular side of the transverse tubule (TT) membranes. In this study we demonstrate that TT vesicles purified from chicken skeletal muscle possess ecto-ADPase and ecto-5'-nucleotidase activities that, along with ecto-ATPase, are able to sequentially degrade extracellular ATP to ADP, AMP and adenosine. Characterization studies of these TT ectonucleotidases revealed remarkable differences between ecto-ATPase and ecto-ADPase activities with respect to thermal stability, temperature dependence of the hydrolytic activity, effect of ionic strength, kinetic behaviour, divalent cation preference and responses to azide, N-ethylmaleimide, NaSCN, Triton X-100 and concanavalin A. Ecto-ATPase, but not ecto-ADPase, was inhibited by a polyclonal antibody against the chicken TT ecto-ATPase. On the basis of these results we propose that ATP and ADP hydrolysis are accomplished by two distinct enzymes and therefore the TT ecto-ATPase is not an apyrase. 5'-Nucleotidase activity was inhibited by adenosine 5'-[alpha,beta-methylene]diphosphate and concanavalin A, followed simple Michaelis-Menten kinetics and was released from the membranes by treatment with phosphatidylinositol-specific phospholipase C, indicating that AMP hydrolysis in T-tubules is catalysed by a typical ecto-5'-nucleotidase. Results obtained from electrophoresis experiments under native conditions suggest that ecto-ATPase, ecto-ADPase and 5'-nucleotidase might be associated, forming functional complexes in the T-tubule membranes. The TT ectonucleotidases constitute an enzymic cascade for the degradation of extracellular ATP that might be involved in the regulation of purinergic signalling in the muscle fibre.

5'-Nucleotidase↗
PubMed1997

Bronchoesophageal fistula secondary to aspiration of tongue adhesion button in a child with glossoptosis.

A newborn boy with obstructive apnea secondary to glossoptosis was treated by securing his tongue to his lower lip. Soon after, the button that served for posterior fixation became detached and was thought to have been evacuated via the digestive tract. Twenty-two months later the infant presented with pneumonia involving the right lower lobe and hemoptysis, causing an acute respiratory distress syndrome (ARDS). After mechanical ventilation was started marked gastric distention was observed. Esophagography and bronchography revealed a fistula between the right main stem bronchus and the esophagus. During surgical repair the plastic fixation button was found in the bronchial orifice of the fistula. Despite surgical correction of the fistula the child died of refractory respiratory failure.

Bronchi↗
PubMed1997

Anaphylaxis after ingestion of wheat flour contaminated with mites.

BACKGROUND: Anaphylaxis after ingestion of flours contaminated with mites has been recently reported. OBJECTIVE: The study was designed to determine whether four-induced reactions in the absence of food sensitivity may result from mite contamination. METHODS: Patients with systemic reactions after ingestion of foods containing wheat flour and without food sensitivities were included in a prospective study. The flours were examined microscopically, and major Dermatophagoides allergens were quantified by monoclonal antibody techniques. Skin prick tests and IgE determinations to mites and flours were performed. Single-blind, placebo-controlled oral challenges were also performed. RESULTS: Sixteen patients were included in our protocol. They showed respiratory allergies to dust mites (100%) and intolerance to acetylsalicylic acid (87%). Microscopic examination of four flours implicated in allergic reactions revealed a high degree of mite contamination: Dermatophagoides farinae in one case and Thyreophagus entomophagus in three cases. Our patients' skin test and specific IgE responses to the flours implicated in the reactions were positive. A high level of Der 2 was found in the flour infested by D. farinae. Three of six food challenges with contaminated flours resulted in systemic reactions. Good tolerance to control flours was shown in our patients. CONCLUSION: Ingestion of foods contaminated with mites may induce systemic anaphylactic reactions in patients with respiratory allergy to mites.

Adolescent↗
PubMed1997

Inhibitory effects of okadaic acid on rat uterine contractile responses to different spasmogens.

In the present study, we examined the effects of okadaic acid, a selective inhibitor of type 1 and 2A protein phosphatases, on the mechanical responses evoked by oxytocin, K(+)- and Na(+)-modified solutions and ouabain in estrogen-primed rat myometrium. Oxytocin elicited a rapid, phasic contraction followed by rhythmic oscillations. The phasic response was partially resistant to the absence of external Ca2+. Okadaic acid (1 microM) and the L-type calcium channel blocker nifedipine (1 microM) abolished the oscillatory component and reduced the initial, phasic response to about 80% of the control response. High K+ (60 mM) solution, ouabain (1 mM), K(+)-free medium and low Na+ (25 mM) solution induced extracellular Ca(2+)-dependent biphasic responses composed by an early rapid (KCl, ouabain and K(+)-free solution) or slower developed (25 mM Na+ solution) phasic contraction followed by a sustained increase in tension. Okadaic acid and nifedipine, alone or in combination, abolished or decreased similarly the contractile response evoked by these stimulants. The okadaic acid- and nifedipine-insensitive responses to ouabain, K(+)-free and low Na+ solution were enhanced by increasing the extracellular concentration of Ca2+ in the medium and were inhibited in a dose-dependent manner by amiloride (0.05-0.5 mM). These data suggest that, in estrogen-primed rat uterus, dephosphorylating mechanisms by OA-sensitive protein phosphatases play an important role in regulating myometrial contractions elicited by Ca2+ entry through voltage-sensitive Ca2+ channels.

Animals↗
PubMed1997

Occupational allergy in greenhouse workers: sensitization to Tetranychus urticae.

BACKGROUND: Tetranychus urticae (TU) is a macroscopic mite which is found infesting a large number of plants of economic interest. It has rarely been described as a cause of occupational allergic disease in agricultural workers. OBJECTIVE: To describe TU sensitization in greenhouse workers attending the outpatient allergy unit and its clinical associations, and to characterize the allergens involved. MATERIALS AND METHODS: Twenty-four consecutive carnation greenhouse workers with allergy-related symptoms, referred to our outpatient clinic during a 6-month period, were included. We made the diagnostic extract from carnation leaves heavily infested with TU. Skin-prick test, specific IgE measurement and bronchial provocation test with TU extract were carried out in all subjects. Allergen characterization was achieved by SDS-PAGE (sodium dodecylsulfate-polyacrylamide gel electrophoresis) and immunoblotting. RESULTS: Sixteen patients (66%) presented positive skin-prick test and specific IgE and were diagnosed allergic to TU. Fifteen patients suffered from bronchial asthma, 14 rhinitis and five urticaria. Twelve exhibited positive bronchial provocation test to the TU extract. On RAST-inhibition studies, there was no evidence of crossreactivity between TU extract and D. pteronyssinus. An allergen at 19 kDa was determined in the TU extract by SDS-PAGE immunoblotting studies. CONCLUSION: TU could be an important occupational allergen in greenhouse workers showing allergic symptomatology. There is no crossreactivity between this mite and the house dust mite D. pteronyssinus.

Adolescent↗
PubMed1996

Cloning and sequencing of a dextranase-encoding cDNA from Penicillium minioluteum.

A cDNA from Penicillium minioluteum HI-4 encoding a dextranase (1,6-alpha-glucan hydrolase, EC 3.2.1.11) was isolated and characterized. cDNA clones corresponding to genes expressed in dextran-induced cultures were identified by differential hybridization. Southern hybridization and restriction mapping analysis of selected clones revealed four different groups of cDNAs. The dextranase cDNA was identified after expressing a cDNA fragment from each of the isolated groups of cDNA clones in the Escherichia coli T7 system. The expression of a 2 kb cDNA fragment in E. coli led to the production of a 67 kDa protein which was recognized by an anti-dextranase polyclonal antibody. The cDNA contains 2109 bp plus a poly(A) tail, coding for a protein of 608 amino acids, including 20 N-terminal amino acid residues which might correspond to a signal peptide. There was 29% sequence identity between the P. minioluteum dextranase and the dextranase from Arthrobacter sp. CB-8.

Amino Acid Sequence↗
PubMed1996

Cloning of the Penicillium minioluteum gene encoding dextranase and its expression in Pichia pastoris.

The DEX gene encoding an extracellular dextranase was isolated from the genomic DNA library of Penicillium minioluteum by hybridization using the dextranase cDNA as a probe. Comparison of the gene and cDNA sequences revealed that the DEX gene does not contain introns. Amino acid sequences comparison of P. minioluteum dextranase with other reported dextranases reveals a significant homology (29% identity) with a dextranase from Arthrobacter sp. CB-8. The DEX gene fragment encoding a mature protein of 574 amino acids was expressed in the methylotrophic yeast Pichia pastoris by using the SUC2 gene signal sequence from Saccharomyces cerevisiae under control of the alcohol oxidase-1 (AOX1) promoter. Over 3.2 g/l of enzymatically active dextranase was secreted into the medium after induction by methanol. The yeast product was indistinguishable from the native enzyme in specific activity and the N-terminus of both proteins were identical.

Amino Acid Sequence↗
PubMed1996

Mercury determination by CV-AAS in wastewater and sewage sludge from a stabilization pond system.

The mercury concentrations in wastewater and sewage sludge of a stabilization pond system have been evaluated. The system is built by three parallel facultative ponds followed by two systems of three maturation ponds in series. The samples of wastewater and sludge were digested using nitric acid and placed into a Parr-type bomb for 4 h at 110 degrees C. Mercury was measured by Cold Vapour Atomic Absorption Spectrometry (CV-AAS) at 253.7 nm with sodium tetrahydroborate as reductant. The methodologies were checked with an USEPA quality control sample, a standard reference material from NIST and with another method of mineralization (cold mineralization) showing good results. Concentrations of mercury in wastewater between 1.47 +/- 0.75 microgl(-1) have been found at the entrance of the system and 0.74 +/- 0.0 microgl(-1) at the exit, while in sludge the results were between 0.29 +/- 0.12 microgkg(-1) in the facultative pond and 0.04 +/- 0.02 microgkg(-1) in the second maturation pond (exit).

Journal Article↗
PubMed1996

Intolerance to nonsteroidal antiinflammatory drugs: results of controlled drug challenges in 98 patients.

BACKGROUND: Controlled oral challenge is the only definitive way to detect the different clinical manifestations of intolerance to nonsteroidal antiinflammatory drugs (NSAIDs). OBJECTIVE: This study was carried out to describe the clinical manifestations of drug challenges in a population with histories of intolerance to NSAIDs. METHODS: Two-hundred forty subjects were included in a single-blind, placebo-controlled drug challenge protocol. RESULTS: Eighty patients exhibited a positive response to drug challenge: 52 had isolated periorbital angioedema, 13 had cutaneous rashes, eight had bronchial asthma (7 with associated periorbital angioedema), three had nasoocular reactions, and four had systemic anaphylaxis. In another 18 patients who were referred for treatment because of a reaction suggesting systemic anaphylaxis, the implicated drug was not given, but tolerance to other NSAIDs was found. The mean age of patients with isolated periorbital angioedema was significantly lower (p < 0.001) than that of the other groups of NSAID reactors. A significant increase (p < 0.001) in atopy was found among patients with isolated periorbital angioedema (100%) in comparison with other patients with NSAID intolerance (45.6%). NSAID cross-reactivity was a common finding, but cross-reactivity was not found in two cases of periorbital angioedema, one case of urticaria, one case of bronchial asthma, and 18 cases of systemic anaphylaxis. CONCLUSION: In atopic subjects, isolated periorbital angioedema constitutes the most frequent manifestation of NSAID intolerance. Such patients are younger than other NSAID reactors and commonly have intolerance to several NSAIDs.

Administration, Oral↗