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Biomedical subjects

M J Torres

Publications and source records attributed to M J Torres.

At least 19 recordsLinked to original sources
PubMed2006

Nosocomial outbreak of Pseudomonas aeruginosa endophthalmitis.

We describe an outbreak of nosocomial endophthalmitis due to a common source, which was determined to be trypan blue solution prepared in the hospital's pharmacy service. We assume that viable bacteria probably gained access to the trypan blue stock solution during cooling after autoclaving. The temporal cluster of Pseudomonas aeruginosa endophthalmitis was readily perceived on the basis of clinical and microbiological findings, and an exogenous source of contamination was unequivocally identified by means of DNA fingerprinting.

Aged↗
PubMed2006

Sensitization to Anisakis simplex s.l. in a healthy population.

The main objective of this study was to determine the degree of sensitization to Anisakis simplex s.l. in healthy population. Using the determination of specific IgE, we studied the seroprevalence against A. simplex s.l. in blood donors selected at random in the region of Antequera (Southern Spain). We detected 22.1%. The immunoblotting technique revealed a band of approximately 60 kDa in the serum of individuals who also exhibited high values of specific IgE against A. simplex s.l. This band would be useful for diagnosis.

Adolescent↗
PubMed2006

Anti-oxidant enzyme activities and expression and oxidative damage in patients with non-immediate reactions to drugs.

Adverse drug reactions with an immunological basis (ADRIB) may involve activation of other concomitant, non-specific mechanisms, amplifying the specific response and contributing to the severity and duration. One concomitant mechanism could be the generation of reactive oxygen species (ROS) and/or their detoxification by anti-oxidants, including anti-oxidant enzymes. We analysed the activity of the anti-oxidant enzymes Cu/Zn-superoxide dismutase (SOD), catalase (CAT) and cellular glutathione peroxidase (GPX), as well as certain markers of oxidative damage (thiobarbituric acid reactive substances (TBARS) and carbonyl content) in peripheral blood mononuclear cells from patients with non-immediate ADRIB using spectrophotometric methods and the anti-oxidant enzymes expression by quantitative real-time reverse transcription-polymerase chain reaction. SOD activity and expression were increased in all types of non-immediate reactions (urticaria, maculopapular exanthema and toxic epidermal necrolysis). Regarding oxidative damage, TBARS were increased in urticaria and maculopapular exanthema, and carbonyl groups in all types of reactions. Our observations indicate that oxidative damage occurs in non-immediate reactions. Carbonyl stress and the inadequacy of the anti-oxidant defences are probable causes.

Adolescent↗
PubMed2006

IgE antibodies to betalactams: relationship between the triggering hapten and the specificity of the immune response.

BACKGROUND: In immunoglobulin (Ig)E-mediated responses to betalactams (BL) the antibody is directed to the hapten inducing the response. For benzylpenicillin (BP) the determinant is benzylpenicilloyl (BPO) and for amoxicillin (AX), amoxicilloyl (AXO). Because of cross-reactivity, IgE from some patients reacts to both drugs whereas others have a drug-selective recognition. After an allergic episode, there is an increase in IgE that decreases over time. We analysed the response of patients allergic to BL after penicillin administration, with emphasis on IgE cross-reactivity. METHODS: Subjects who developed an IgE antibody response were studied. Sequential follow-up samples were obtained at different times during the response. Changes in IgE specificity were analysed by competition immunoassays using different penicillin monomeric conjugates. RESULTS: Two patterns of response were existed: one with IgE directed to the culprit penicillin and another with IgE mainly reactive to BPO. In both, a variable cross-reactivity with the hapten triggering the boosting response was found. This pattern was maintained with no change in specificity over time, even in subjects who experienced one boosting event. CONCLUSION: The IgE response can be specific to the drug inducing the reaction or cross-reactive to the classical BPO determinant. This pattern is maintained throughout the whole period of the response, even if re-exposure occurs. The stability of the type of response can be explained by the phenomenon of original antigenic sin: in the presence of antibodies, memory B cells are more easily triggered than naive B cells.

Antibody Specificity↗
PubMed2006

Skin testing for immediate hypersensitivity to betalactams: comparison between two commercial kits.

INTRODUCTION: Skin testing with major and minor determinants of benzylpenicillin is the recommended standard practice to evaluate subjects with immediate hypersensitivity to betalactams. The withdrawal of these products from the market has set us back to the early days, before the introduction of reagents for in vivo testing. OBJECTIVES: To compare a recently released kit of benzylpenicillin conjugated to poly-l-lysine (PPL) and minor determinants mixture (MDM) with the previously existing kit in a positive control group of subjects sensitized to major and/or minor determinants of benzylpenicillin. METHODS: Skin tests with both kits were made in a group of positive subjects previously diagnosed with immediate hypersensitivity to penicillins and with positive results to PPL and/or MDM and in a negative control group. Radioallergosorbent test (RAST) inhibition assays with a pool of sera and individual samples were carried out to compare the inhibition capacity of PPL and MDM of both kits. RESULTS: Of 22 cases selected from our historical group, 14 were positive: eight to PPL, three to MDM and three to both. These results were equivalent for both kits. RAST inhibition studies showed similar potencies in the inhibition of PPL and MDM. CONCLUSIONS: Both tests show similar results in terms of RAST inhibition assays and skin tests sensitivity and specificity in the groups selected. The new assay can be used for the same purpose and indications as the previous test.

Drug Hypersensitivity↗
PubMed2006

Immediate hypersensitivity reactions to penicillins and other betalactams.

Immediate hypersensitivity reactions to betalactams are IgE mediated and constitute the most frequent allergic reactions mediated by specific immunological mechanisms. IgE responses to benzyl penicillin (BP), the first antibiotic producing the benzyl penicilloyl structure (BPO), are characterized by a quick release of inflammatory mediators, resulting in anaphylactic shock, urticaria and angioedema. With the progressive appearance of other structures, comprising cephalosporins, carbapenems, monobactams and clavulanic acid, IgE selective responses and cross-reactivity reactions were observed. The diagnosis of betalactam hypersensitivity, classically based on skin testing with major and minor determinants of benzyl penicillin or in vitro IgE antibodies to BP, has been modified by the inclusion of different determinants generated from these compounds, for which amoxicillin (AX) is the most relevant, followed by cephalosporins. Some subjects develop positive responses to several betalactams, mostly within the same family, but others develop a selective response. These are relevant for the appropriate selection of antimicrobial drugs in patients who have immediate hypersensitivity to betalactams.

Drug Hypersensitivity↗
PubMed2006

[Molecular diagnosis of adult dominant polycystic kidney disease in the Canary Islands].

Adult dominant polycystic kidney disease is an hereditary condition responsible for 6% of end-stage renal failure in Spain. Two genes were located in chromosomes 16 and 4 as related to this age-dependent disease in the 90s (PKD1 and PKD2). The diagnosis can be easily achieved by sonographic study, but molecular analysis by means of linkage analysis has the advantage of an early diagnosis in asymptomatic genetic carriers, with a view to the preventive follow-up of these subjects and genetic counselling. In this paper we present the results of molecular analysis of 30 families with Adult Dominant Polycystic Kidney Disease (from the province of Las Palmas Spain), carried out linkage analysis with two series of microsatellite markers located within or in the vicinity ofPKD1 (D16S521, KG8, AC2.5, CW2, SM7) and PKD2 (D4S1538, D4S1534, D4S423,D4S414) genes. The objectives of the study were: first, to verify the informativeness, and therefore, the usefulness of these markers for family studies in our population; and second,to assess the sensitivity and specificity of the genetic analysis in our population. Most of the markers showed a high heterozygosity, comparable to data in other studies. Considering the alleles of the different markers together in a chromosome as an haplotype increased the informativeness of the markers, and allowed the unequivocal identification of genetic data in 97.7% of patients and 88.7% of healthy subjects. The sensitivity and specificity of the genetic analysis were 90.7% (CI 95%: 85.7-95.7) and 86.8% (CI 95%: 80.6-93.0), respectively.

Atlantic Islands↗
PubMed2005

Specificities of B cell reactions to drugs. The penicillin model.

Betalactams conjugate to protein carriers induced T and B cell effector responses. From these, IgE dependent reactions are the most common and better defined. These antibodies recognize a number of structures that can cross react or selective recognition may occur. The great variability in the chemical structure, specifically at the position R of penicillin and R1 of cephallosporins has made that the recognition of these structures may have clinical relevance in the evaluation of patients allergic to betalactams.

Animals↗
PubMed2005

Philibertain g I, the most basic cysteine endopeptidase purified from the latex of Philibertia gilliesii Hook. et Arn. (Apocynaceae).

A new papain-like cysteine peptidase isolated from latex of Philibertia gilliesii Hook. et Arn., Apocynaceae (formerly Asclepiadaceae) has been purified and characterized. The enzyme, named philibertain g I, is the most basic component present in latex extracts and was purified by acetone fractionation followed by cation exchange chromatography (SP-Sepharose HR) using FPLC system. Homogeneity was confirmed by SDS-PAGE and mass spectroscopy (MS). Molecular mass of the enzyme was 23,530 Da (MALDI-TOF MS), its isoelectric point was >10.25, and maximum proteolytic activity (casein) was achieved at pH 7-8. The new protease was inhibited by E-64 a cysteine peptidases inhibitor. Km was 0.15 mM, using PFLNA as substrate. The N-terminal sequence of philibertain g I (LPASVDWRKEGAVLPIRHQGQCG) was compared with those of twenty plant proteases. Philibertain g I showed the higher degree of identity (73%) with caricain, one of the Carica papaya endopepetidases.

Amino Acid Sequence↗
PubMed2005

Decrease of selective immunoglobulin E response to amoxicillin despite repeated administration of benzylpenicillin and penicillin V.

BACKGROUND: Subjects with IgE responses to betalactams can develop selective or cross-reactive responses after the administration of penicillin derivatives. After the reaction, however, the hapten induces a boosting phenomenon, which may increase the titre and the affinity of the antibody, with the resulting risk of developing allergic reactions to other penicillins. OBJECTIVE: To determine in subjects with selective responses to amoxicillin (AX) and good tolerance to benzylpenicillin (BP) and penicillin V (PV) whether the administration of these compounds induced any change in specificity, measured by either skin or in vitro testing, which could predict the appearance of cross-reactivity. METHODS: Ten subjects with a selective response to AX were followed-up for 2 years with the periodic administration of penicillin G and V (Group A) and compared with another group composed of 10 persons with identical clinical characteristics but without repeated penicillin administration (Group B). Periodic in vitro and in vivo measurements of specific IgE antibodies were performed at 6-month intervals. Patients were randomized to Group A or B according to their order of inclusion. RESULTS: In both groups, skin test reactivity tended to decrease, and although greater in Group A, the difference was not significant compared with Group B. Median RAST values also decreased over time and showed no differences in the exposed group compared with the controls. One patient in Group A became positive to benzylpenicilloyl (BPO), despite becoming negative to AX. CONCLUSION: Subjects with selective IgE responses to side-chain-specific determinants seem to become negative, with no influence from subsequent administration of a closely related penicillin.

Adolescent↗
PubMed2005

Drug hypersensitivity: insights into pathomechanisms.

In adverse reactions to drugs with an immunological basis (ADRIB) specific IgE antibodies or sensitised effector T cells take part. Each type of response induces well defined clinical entities. For T cell reactions, classically known as Type IV Gel and Coomb responses, different subtypes have been classified. These correspond to different clinical entitles and each have characteristically histopathological findings. Advanced in vitro studies by development of T cell liens and T cell clones to different drugs compounds and the monitorisation of the immunological response during the course of these diseases has provided new insights for a better understanding and evaluation of ADRIB.

Chemotaxis, Leukocyte↗
PubMed2004

The diagnostic interpretation of basophil activation test in immediate allergic reactions to betalactams.

BACKGROUND: Basophil activation by allergens, including drugs, has been used to determine sensitivity and to study IgE recognition and cross-reactivity. OBJECTIVE: We sought to determine the sensitivity and specificity of a basophil activation test (Basotest) in patients with immediate allergic reactions to betalactams, with a later comparison between patients who were selective (those recognizing the culprit drug excluding benzylpenicillin (BP)) and cross-reactors (those recognizing several penicillin determinants including BP). METHODS: Basotest to different haptens was performed in 70 patients with immediate allergic reactions to betalactams, classified into three groups: (A) skin test positive independently of CAP/RAST immunoassay value, (B) skin test negative and CAP/RAST positive, and (C) skin test and CAP/RAST negative but drug provocation test positive. Basotest was carried out by flow cytometry following the manufacturer's instructions using different betalactam determinants and results expressed as a stimulation index. RESULTS: Of the 70 patients, 34 (48.6%) were positive to Basotest (sensitivity: 48.6%), 31 (44.3%) to CAP/RAST and 46 (65.7%) to either one or the other. Considering the different groups, Basotest was positive in 50.9% of patients in Group A, 60% in Group B and 14.3% in Group C. The specificity was 91.3%. Positivity to the haptens was 28.6% to amoxicillin (AX), 21.7% to BP, 20% to benzylpenicilloyl-poly-l-lysine, 12.5% to ampicillin and 2.2% to minor determinant mixture. In patients with cephalosporin reactions, Basotest to the culprit cephalosporin was positive in 77.7%. There were differences between the two reactor groups in the sensitivity of Basotest (selective to AX=50%, cross-reactors=28.6%; chi(2)=10.809, P=0.004) and in the CAP/RAST (selective to AX=28.6%, cross-reactors=61.9%; chi(2)=8.944, P=0.011). CONCLUSIONS: The sensitivity of Basotest is similar to immunoassays (CAP/RAST). Sensitivity is improved when used in combination. Although further studies are required, Basotest results for cephalosporin allergy seem very promising. This technique does not help differentiate between selective reactors and cross-reactors.

Adult↗
PubMed2004

Different cytokine production and activation marker profiles in circulating cutaneous-lymphocyte-associated antigen T cells from patients with acute or chronic atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is an inflammatory skin disease whose lesions can have two stages: acute and chronic. In skin biopsies a biphasic pattern of cytokine expression has been shown, Th2 in acute lesions and Th1 in chronic AD lesions. OBJECTIVE: We investigated the expression of an activation marker and a homing receptor, as well as cytokine production, in different peripheral blood T cell subpopulations from AD patients with chronic (Group A) and acute lesions (Group B) and controls. METHODS: We evaluated 26 adult AD patients (12 Group A, 14 Group B) and 14 non-atopic controls. IgE was measured by immunoassay. CD4, CD8, cutaneous-lymphocyte-associated antigen (CLA) and human leucocyte antigen (HLA)-DR expression, and cytokine production (IL-2, IL-13, IFN-gamma, TNF-alpha, IL-10, IL-4) were analysed in mononuclear cells by flow cytometry. RESULTS: In Group B there was a significant increase in eosinophil levels and a non-significant increase in IgE. In Group A we found an increase in CLA(+)CD4(+) cells (8.19+/-1.84) compared with controls (4.83+/-0.53) (P<0.05) and CD4(+)HLA-DR(+) cells in the CLA(+) subpopulation (45.54+/-15.40) compared with controls (30.49+/-6.07) (P<0.05). In the CLA(+)CD4(+) subpopulation, there was a significant increase in IL-4, IL-13 and TNF-alpha production in Group B (12.46+/-7.7, 11.26+/-5.97, 43.92+/-15.55) compared with controls (5.34+/-3.50, 4.54+/-1.78, 19.29+/-9.97) with no differences in Group A. CONCLUSION: Greater immunological differences were detected in peripheral blood from patients with acute compared with chronic lesions, especially in the circulating T cell-subset with skin tropism that preferentially responded to cutaneous allergens. This is the first demonstration of phenotypic changes in circulating CLA(+) T cells between AD patients with acute and chronic lesions.

Acute Disease↗
PubMed2004

Diagnosis of nonimmediate reactions to beta-lactam antibiotics.

Nonimmediate manifestations (i.e. occurring more than 1 h after drug administration), particularly maculopapular and urticarial eruptions, are common during beta-lactam treatment. The mechanisms involved in most nonimmediate reactions seem to be heterogeneous and are not yet completely understood. However, clinical and immunohistological studies, as well as analysis of drug-specific T-cell clones obtained from the circulating blood and the skin, suggest that a type-IV (cell-mediated) pathogenic mechanism may be involved in some nonimmediate reactions such as maculopapular or bullous rashes and acute generalized exanthematous pustulosis. In the diagnostic work-up, the patient's history is fundamental; patch testing is useful, together with delayed-reading intradermal testing. The latter appears to be somewhat more sensitive than patch testing, but also less specific. In case of negative allergologic tests, consideration should be given to provocation tests, and the careful administration of the suspect agents. With regard to in vitro tests, the lymphocyte transformation test may contribute to the identification of the responsible drug. Under the aegis of the European Academy of Allergology and Clinical Immunology (EAACI) interest group on drug hypersensitivity and the European Network for Drug Allergy (ENDA), in this review we describe the general guidelines for evaluating subjects with nonimmediate reactions to beta-lactams.

Adult↗