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Biomedical subjects

C Lahoz

Publications and source records attributed to C Lahoz.

At least 91 records · Page 5Linked to original sources
PubMed1993

The amino acid sequence of Ole e I, the major allergen from olive tree (Olea europaea) pollen.

The complete primary structure of the major allergen from Olea europaea (olive tree) pollen, Ole e I (IUIS nomenclature), has been determined. The amino acid sequence was established by automated Edman degradation of the reduced and alkylated molecule as well as of selected fragments obtained by proteolytic digestions. Ole e I contains a single polypeptide chain of 145 amino acid residues with a calculated molecular mass of 16331 Da. No free sulfhydryl groups have been detected in the native protein. The molecule contains a putative glycosylation site. A high degree of microheterogeneity has been observed, mainly centered in the first 33% of the molecule. Comparison of Ole e I sequence with protein sequence databases showed no similarity with other known allergens. However, it has a 36% and 38% sequence identity with the putative polypeptide structures, deduced, respectively, from nucleotide sequences of genes isolated from tomato anthers and corn pollen, which have been suggested to be involved in the growing of the pollen tube. Therefore, the olive tree allergen may be a constitutive protein of the pollen involved in reproductive functions.

Allergens↗
PubMed1993

[Effects of n-3 polyunsaturated fatty acids on the cardiovascular system. Should their use be recommended?].

The effects of n-3 polyunsaturated fatty acid (n-3 PFA) intake on lipoprotein metabolism, eicosanoid metabolism, coagulation and the fibrinolytic system, mediators of inflammation, and blood pressure are discussed. The possible role such effects may have on the process of atherogenesis is examined. Laboratory animal studies with n-3 PFA supplements are reviewed. Finally, a review of clinical and epidemiological studies in human subjects is made in order to evaluate whether the experimental findings have clinical relevance. The conclusion is that, at the present time, there is insufficient support for the use of n-3 PFA supplements either in prophylaxis or in treating ischemic cardiopathy.

Animals↗
PubMed1992

Eosinophil as antigen-presenting cell: activation of T cell clones and T cell hybridoma by eosinophils after antigen processing.

We have studied the role of murine eosinophils as antigen-presenting cells (APC). Eosinophils have several characteristics that support the hypothesis of its function as potential APC: they have phagocytic capacity, express adhesion molecules and major histocompatibility complex (MHC) class II antigens and can produce and release interleukin-1 (IL-1). We have obtained several T cell clones specific for Mesocestoides corti antigens and used T cell hybridoma specific for ovalbumin (OVA) to test this hypothesis. Granulocyte-macrophage colony-stimulating factor-activated pure eosinophils (99.9%), express class II antigens and are able to present M. corti antigens to specific T cell clones or OVA to T cell hybridoma 3DO 11.10, inducing the proliferation of T cell clones and IL-2 release by the T cell hybridoma. Proliferation of T cells clones is dependent on the number of eosinophils used as APC. We have compared the efficiency of the same number of macrophages and eosinophils as APC, and have found that macrophages are more efficient than eosinophils. Lysosomotropic agents, such as chloroquine and ammonium chloride, that inhibit antigen processing, impaired eosinophil presentation. This presentation is restricted by MHC class II and inhibited by anti-I-Ad monoclonal antibody. The present study provides clear evidence of APC function for eosinophils. Our investigation points to a new role for eosinophils in the immune response.

Ammonium Chloride↗
PubMed1992

[Regression of coronary arteriosclerosis with hypolipidemic treatment, myth or reality?].

Coronary atherosclerosis regression with hypolipemiant treatment is a well known fact in the animal model since years ago. In humans, during these last years, several clinical trials have been performed to ellucidate the truth to this fact. All of these clinical trials have in common the evolutive study of the coronary lesions with angiographies, in patients following treatment with diet, surgery or drugs, to reduce plasmatic cholesterol. Clinical, analytical and angiographic results of said studies are reviewed. We conclude that the bigger the lowering in plasmatic cholesterol levels, smaller is the progression of these coronary lesions and more probable is finding patients with partial regression of the lesions.

Clinical Trials as Topic↗
PubMed1992

Immunology.

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Acute Disease↗
PubMed1991

Phosphoinositide breakdown is associated with Fc-gamma RII-mediated activation of 5'-lipoxygenase in murine eosinophils.

In this report we present data on the ability of murine eosinophils to generate inositol phosphate derivatives, and their relationship with the activation of 5'-lipoxygenase by a Fc-gamma R-dependent mechanism. The addition of anti-IgG F(ab')2 to mouse eosinophils, previously sensitized with IgG, induces inositol phosphate generation after 2 min and after 10 min of stimulation. Maximal generation of inositol tris and inositol tetrakis phosphate has been detected after 15 min of stimulation, and the optimal concentration of anti-IgG F(ab')2 was found to be 25 micrograms. Inositol tris phosphate formation is also observed at 5 min after the addition of the calcium ionophore A23187 (5 microM). We also report that neomycin, an inhibitor of phosphoinositide-phospholipase C, inhibits Fc-gamma R-mediated phosphoinositide breakdown in a dose-dependent manner (88% inhibition at 150 microM of neomycin). The possible involvement of phosphoinositide breakdown in the activation of 5'-lipoxygenase has been investigated. Using streptolysin-O permeabilized cells and different doses of neomycin that inhibit phosphoinositide breakdown, we have demonstrated a parallel decrease in LTC4 released by these cells, using either A23187 (86% inhibition at 200 microM of neomycin) or anti-IgG F(ab')2 (82.4% inhibition at 100 microM of neomycin). [Ca2+]i elevation has been observed by loading the cells with the fluorescent calcium indicator Fura-2 penta-acetoxy methyl ester and after stimulating with the anti-Fc-gamma RII mAb (2.4G2). It is likely that the activation of murine eosinophils by a Fc-gamma R mechanism stimulates phosphoinositide breakdown as a primary step that leads to the activation of murine 5'-lipoxygenase, producing the formation of leukotriene C4.

Animals↗
PubMed1990

Isolation of three allergenic fractions of the major allergen from Olea europea pollen and N-terminal amino acid sequence.

A method to isolate the major allergen from olive pollen (Ole e I) in high yield is described. The allergenic fraction has been separated into 3 subfractions by reverse-phase HPLC. All these fractions were reactive to allergic sera from olive-sensitized patients, giving similar responses. No significant differences were observed between the amino acid compositions of these three proteins. The amino acid sequence of the first 27 amino acid residues from the N-terminal end is given. No homologies have been detected between Ole e I and other known allergens obtained from pollen.

Allergens↗
PubMed1990

[Importance of risk factors in the extension of pulmonary thromboembolism].

The cases of pulmonary thromboembolism (PTE) diagnosed in the clinical autopsies performed in our hospital during a 15-year period were reviewed. The incidence was 2.7% (63 cases). The most common disease associated with thromboembolism was cancer (41%). In 30 cases, thromboembolism involved more than 60% of the pulmonary circulation (group I), between 40% and 60% in 18 cases (group II), and less than 40% in 15 cases (group III). 30% of the embolisms were recurrent. A statistically significant correlation between the extension of the involved pulmonary circulation and the condition associated with thromboembolism was found. Whereas in patients with neoplasia the extension of pulmonary circulation involved by PTE was quite variable, the patients with cardiovascular disease or thrombophlebitis had PTE with invariably severe compromise of pulmonary vasculature (groups I and II).

Acute Disease↗
PubMed1990

Murine eosinophils and IL-1: alpha IL-1 mRNA detection by in situ hybridization. Production and release of IL-1 from peritoneal eosinophils.

The presence of IL-1 mRNA in eosinophils from mice infected with larvae of the parasite Mesocestoides corti was investigated by in situ hybridization technique. S35 labeled cDNA probe for alpha IL-1, hybridized with mRNA in murine eosinophils and macrophages. After 6 h of LPS stimulation eosinophils were able to express mRNA in their cytoplasm. This expression was highly increased by the addition of indomethacine. The IL-1 mRNA expression in murine macrophages was higher than in eosinophils in LPS-stimulated cells. This difference was statistically significant, p less than 0.001. To test if eosinophils may produce and release IL-1 in the culture medium, we isolated these cells in a Percoll gradient. Cell preparations with a purity exceeding 94% were cultured with various stimuli and their supernatants were tested for IL-1 activity. Eosinophils produced 169.65 +/- 73 U/ml when stimulated with LPS (n = 14). A dose-dependent response was obtained when the eosinophils were in the presence of the calcium ionophore A23187. Controls were performed to rule out the contribution of the contaminating population on the thymocyte proliferating activity. They were also used to detect other possible causes of interference in the assay, such as leukotrienes or TNF. IL-1 in supernatants was also detected using a conversion assay such as EL-4 thymoma cells. IL-1 activity was first detected in culture supernatants 18 h later, maximal production being in the first 24 h. In accordance with our hybridization results, an increase in IL-1 activity was obtained when eosinophils were stimulated with LPS and treated with indomethacine. The factor had a molecular mass between 16 to 20 kDa that corresponded to the described for murine IL-1. Inasmuch as IL-1 is an important mediator of inflammatory reactions this IL may enhance the proinflammatory action of eosinophils.

Animals↗
PubMed1990

[What factors make the diagnosis of pulmonary thromboembolism difficult?].

A series of 63 cases of fatal acute pulmonary thromboembolism (PTE) with available necropsy study was evaluated The diagnosis was established ante mortem in 20 cases (predictive index 31%). The diagnosis was only suspected in 2 of the 16 patients in whom PTE was associated with pneumonia (predictive index 12.5%, p less than 0.01), in 3 of the 26 cases if PTE associated with neoplasia (predictive index 11.5% p less than 0.01) and in 8 of the 41 cases with terminal disease (predictive index 19.5%, p less than 0.01). On the contrary, thrombophlebitis and relapsing PTE had a significative facilitation effect on the diagnosis (predictive indexes 53.3% and 52.6%, respectively; p less than 0.01). It was concluded that the presence of neoplasia, pneumonia or terminal illness make the diagnosis of pulmonary thromboembolism difficult.

Adult↗
PubMed1990

Members of the alpha-amylase inhibitors family from wheat endosperm are major allergens associated with baker's asthma.

We have identified the major antigens or IgE binding components from wheat flour. Thirty-five sera from patients with baker's asthma were used to analyze the reaction with wheat salt-soluble proteins. We found a 15 kDa SDS-PAGE band which reacted with all sera tested. Purified members of the alpha-amylase inhibitor family, which are the main components of the 15 kDa band, were recognized by specific IgE when tested with a pool of reactive sera. Immunodetection after two-dimensional electrophoretic fractionation of crude inhibitor preparations from wheat endosperms also detected several inhibitor subunits as major low-molecular-weight allergens.

Allergens↗
PubMed1990

Release of O2- and LTC4 by murine eosinophils: role of intra- and extracellular calcium.

Using an experimental model of mouse peritoneal eosinophilia, we investigated the role of Ca2+ in the in vitro activation of these cells challenged with specific Mesocestoides corti antigen. We have detected LTC4, a metabolite derived from arachidonic acid by way of 5'lipo-oxygenase and superoxide anion from the oxidative burst, as inflammatory mediators produced by activated eosinophils. Preincubation with hyperimmune mice serum increases the amount of LTC4 and superoxide anion in response to the antigenic extract. Release of O2- is inhibited by Verapamil (a voltage-gated calcium channel) and Quin 2 (an intracellular trapped chelator of calcium). Also, LTC4 produced by preincubated eosinophils challenged with M. corti is dramatically inhibited by Quin 2. Our results suggest an intact mechanism for calcium control for the release of these inflammatory mediators by eosinophils, after specific antigenic stimulation.

Animals↗
PubMed1989

[Pulmonary thromboembolism: clinical characteristics and diagnostic and therapeutic approaches].

In the present study the variability and diagnostic meaning of clinical features and common laboratory investigations were evaluated in a series of 220 patients with pulmonary thromboembolism (PTE) diagnosed by clinical means. The patients were classified into the two following groups: group I consisted of 102 critical patients admitted to an intensive care unit; group II consisted of 118 less-severely ill patients admitted to an ordinary hospital ward. Although clinical and laboratory features were nonspecific, the association of thrombotic risk factors in 88% of the patients permitted us to suspect the diagnosis of PTE within the initial three days in 71%. Chest radiogram was normal in 48%, ECG was normal in 32%, and contrast phlebography did not demonstrate phlebothrombosis in 16.4% of cases. The presumptive diagnosis was earlier (4 +/- 2 days) in group I than in group II patients (8 +/- 5 days) (p less than 0.01), and there was a significantly higher frequency of thoracic symptoms, hypoxemia, hypocapnia and radiologic and electrocardiographic abnormalities in group I patients. Chest radiogram and ECG were normal in only a small minority of these patients (9 and 7%, respectively). Overall mortality rate was 9.4% (20 patients, 14 from group I and 6 from group II). In 10 patients, all from group I, death took place within the first 72 hours after the diagnosis.

Adult↗
PubMed1989

Polyarteritis nodosa and necrotizing glomerulonephritis associated with long-standing silicosis.

A 55-year-old white male, with silicosis diagnosed 10 years earlier, presented massive proteinuria with microscopic hematuria, moderate renal failure and distal polyneuropathy. Bilateral renal angiography showed multiple intraparenchymal saccular aneurysms. Renal biopsy disclosed a focal segmental necrotizing glomerulonephritis and arteriolitis. After combined corticosteroid and immunosuppressive treatment, renal function improved and remained stable 6 months later.

Glomerulonephritis↗
PubMed1988

Olive (Olea europea) pollen allergens--I. Immunochemical characterization by immunoblotting, CRIE and immunodetection by a monoclonal antibody.

The pattern of reactivity of the Olea europea crude extract antigens was analysed after electroblotting to nitrocellulose from SDS-PAGE. The antigens contained in the 17, 19 and 42 K bands were most reactive with specific IgE from individual sera. Following immunization with a crude extract, one monoclonal antibody (OL-1) was raised against components which exhibited IgE binding capacity in electroblotting and crossed radioimmunoelectrophoresis (CRIE). Monoclonal antibody OL-1 reacted with the 17 and 19 K antigens and with three arcs of crossed immunoelectrophoresis (CIE), one of which is considered to contain a major allergen by CRIE.

Allergens↗
PubMed1988

Olive (Olea europea) pollen allergens--II. Isolation and characterization of two major antigens.

A dialyzed extract of olive (Olea europea) pollen was fractionated by anion exchange chromatography on DEAE-Sepharose CL-6B using a discontinuous gradient of ammonium bicarbonate. The most important protein allergen was obtained from the 0.3 M fraction after gel filtration on Sephadex G-100 and separation by lentil-lectin Sepharose-4B. The major allergen of olive pollen was contained in the effluent and was designated Olea Antigen I. This material inhibited the RAST activity of 15 patients' sera that were tested. Analytical IEF demonstrated a major band at pH 5.3 and two minor ones at pH 5.6 and 5.0. When these were run into SDS-polyacrylamide gel electrophoresis in a second dimension, all were separated into two bands of mol. wt 17 and 19 K. A second protein, which is the next most important allergen, Olea Antigen II, was obtained from the 0.5 M fraction by chromatofocusing in a 4-7 pH range followed by filtration on Bio-gel P-30. Olea Antigen II had a mol. wt of 8 K as assessed by SDS-PAGE. IEF analysis displayed one main band at pH 3.6 and two minor bands at pH 3.8 and 4.0, respectively. OL-1, an anti-Olea europea monoclonal antibody (MAb) previously reported by us Lauzurica et al. (1988) reacted with the 17 and 19 K antigens from the crude extract and with Olea Antigen I but not with Olea Antigen II.

Allergens↗