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Biomedical subjects

F Pineda

Publications and source records attributed to F Pineda.

17 recordsLinked to original sources
PubMed2006

Mitochondrial factors with dual roles in death and survival.

At least in mammals, we have some understanding of how caspases facilitate mitochondria-mediated cell death, but the biochemical mechanisms by which other factors promote or inhibit programmed cell death are not understood. Moreover, most of these factors are only studied after treating cells with a death stimulus. A growing body of new evidence suggests that cell death regulators also have 'day jobs' in healthy cells. Even caspases, mitochondrial fission proteins and pro-death Bcl-2 family proteins appear to have normal cellular functions that promote cell survival. Here, we review some of the supporting evidence and stretch beyond the evidence to seek an understanding of the remaining questions.

Animals↗
PubMed2006

Exotic pets are new allergenic sources: allergy to iguana.

Although furry animals are known sources of respiratory allergy, scaly animals are assumed not to be allergenic. Exotic animals such as iguanas are becoming increasingly common pets. Nevertheless, these animals are not suspected to be allergenic. We present the case of a 42-year-old woman suffering from allergic rhinoconjunctivitis and asthma caused by a pet iguana. Clear IgE-sensitization and respiratory allergy to iguana scales is demonstrated, suggesting that scaly pets should be taken into account as possible allergenic sources.

Adult↗
PubMed2006

Occupational rhinitis and asthma due to cedroarana (Cedrelinga catenaeformis Ducke) wood dust allergy.

We describe a case of occupational rhinitis and asthma in a 46-year-old carpenter who presented nasal and bronchial symptoms after cedrorana (Cedrelinga catenaeformis Ducke) wood dust exposure. Skin prick tests (SPT) with a battery of common allergens and different kinds of wood, were positive to cedrorana and grass pollen and negative to the other wood extracts. Nasal provocation and exposure challenge tests with Cedrorana wood dust also gave a positive reaction. IgE-immunoblotting showed two bands of 45 and 78 kDa respectively. This is the first reported case of occupational rhinitis and asthma due to Cedrorana wood dust where an IgE mediated mechanism has been found.

Air Pollutants↗
PubMed2000

Structure activity relationships for bradykinin antagonists on the inhibition of cytokine release and the release of histamine.

Highly potent bradykinin antagonists were found to inhibit bradykinin-induced release of cytokines but to stimulate histamine release. Both actions show structural requirements completely different from those for bradykinin B1 and B2 receptors, indicating that the release of some cytokines from spleen mononuclear cells and of histamine from rat mast cells is not mediated by these receptors. Most potent bradykinin antagonists release histamine at lower concentrations than does bradykinin itself. Dimers of bradykinin antagonists are the most potent compounds for histamine release. In contrast to enhanced histamine release, potent inhibition of cytokine release enhances the applicability of these compounds as anti-inflammatory drugs. Many of the peptides designed for high B2-receptor antagonism were found to be compared by their concentrations far more potent for inhibition of cytokine release than for smooth muscle contraction. Thus, for some antagonists inhibition of cytokine release was detected at concentrations as low as 10(-15) M. The rational design of peptide and nonpeptide bradykinin antagonists for therapeutic use requires not only knowledge about the potency but also knowledge about the structure-activity relationships of such important side effects as cytokine and histamine release.

Amino Acid Substitution↗
PubMed2000

New bivalent thrombin inhibitors with N(alpha)(methyl)arginine at the P1-position.

A series of bivalent thrombin inhibitors was synthesized, consisting of a d-phenylalanyl-prolyl-N(alpha)(methyl)arginyl active site blocking segment, a fibrinogen recognition exosite inhibitor part, and a peptidic linker connecting these fragments. The methylation of the P1 amino acid led to a moderate decrease in affinity compared with the unmethylated analog. In addition, it prevented the thrombin catalyzed proteolysis, independent of the P1' amino acid used. This is a significant advantage compared to the original hirulogs, which strictly require a proline as P1' amino acid to reduce the cleavage C-terminal to the arginyl residue. Several analogs were prepared by incorporation of different P1' amino acids found in natural thrombin substrates. The most potent inhibitor was I-11 [dCha-Pro-N(Me)Arg-Thr-(Gly)5-DYEPIPEEA-Cha-dGlu] with a Ki of 37 pM. I-11 is highly selective and no inhibition of the related serine proteases trypsin, factor Xa and plasmin was observed. The stability of I-11 in human plasma in vitro was strongly improved compared to hirulog-1. In addition, a significantly reduced plasma clearance of I-11 was observed after intravenous injection in rats. Results from molecular modeling suggest that a strong reorganization of the hydrogen bonds in the active site of thrombin may result in the proteolytic stability found in this inhibitor series.

Amino Acid Sequence↗
PubMed1996

[Subacute thyroiditis and concurrent suppurative thyroiditis in one case].

We report a 41 years old man admitted with a tender goiter, fever, thyrotoxic manifestations and atrial fibrillation. Laboratory confirmed the diagnosis of subacute thyroiditis and treatment with aspirin and propranolol was started, obtaining a rapid relief of symptoms and normalization of heart rate. On the tenth day after admission, severe dysphagia, dysphonia, irritative cough and further enlargement of the neck mass developed. Fine needle aspiration of the mass and thyroid ultrasound lead to the diagnosis of a thyroidal abscess, which was surgically excised, draining 250 ml of purulent material. Cultures were positive for Staphylococcus aureus. Patient was treated during 21 with cloxacilyn and discharged with normal thyroid function. Long term follow up has been uneventful.

Adult↗
PubMedDate not supplied

Occupational asthma due to carrot in a cook.

BACKGROUND: Few previous reports of carrot-induced asthma have been confirmed by objective tests. Hypersensitivity to carrot is frequently associated with allergy to Apiaceae spices and sensitization to birch and mugwort pollens. CLINICAL CASE: A 40-year-old cook woman was seen with sneezing, rhinorrhea, contact urticaria and wheezing within few minutes of handling or cutting raw carrots. She needed to leave out of the kitchen while the other cooks cut raw carrots. METHODS AND RESULTS: Skin tests were positive to carrot, celery, aniseed and fennel. Rubbing test with fresh carrot was positive. Specific IgE to carrot was 4.44 kU/L. Determinations of specific IgE to mugwort, grass and birch pollens were negative. Inhalative provocation test, performed as a handling test, was positive. The IgE-immunoblotting showed two bands in carrot extract: a band with apparent molecular weight of 30 kd and other band of 18 kd. This band of 18 kd was Dau c 1. The band of 30 kd could correspond a phenylcoumaran benzylic ether reductase. Dau c 1 did not appear to be the unique allergen in this case. Additional allergens may induce the sensitization. Primary sensitization due to airborne allergens of foods and the lack of pollen allergy in this patient are notorious events.

Adult↗