Search PubMed⌕ Search

Biomedical subjects

P M Gamboa

Publications and source records attributed to P M Gamboa.

At least 19 recordsLinked to original sources
PubMed1992

Rapid facile solid-phase immunobead assay for screening ciguatoxic fish in the market place.

The precision of the solid-phase immunobead assay (Ciguatect) to detect toxins associated with ciguatera poisoning have been evaluated through analysis of toxic and non-toxic fish obtained from fishing areas around the Hawaiian Islands. The Ciguatect test kit has been optimized for application to field/marketplace screening of ciguatoxic fish. Twelve parrot, surgeon, and amberjack fish fillet and fish extract test portions containing various concentrations of toxins were distributed to participating laboratories for analysis. The presence or absence of ciguatera-related toxins is determined by binding the toxins to a membrane attached to a plastic strip and exposing the toxin ladened membrane to a monoclonal antibody-colored latex bead complex which has a high specificity for ciguatera-related toxins. The intensity of the color on the membrane denotes the presence of the toxins in the fish or fish extract. Toxic components in the fish were confirmed by extraction, column purification, and toxicity testing using the brine shrimp (Artemia sp.) assay. Okadaic acid was used to standardize both the S-PIA and brine shrimp assays. For determination of ciguatoxin and related polyether toxins in parrot, surgeon, and amberjack fish fillets, the relative standard deviations for repeatability (RSDR) were 13.5, 9.0 and 4.3%, respectively, and the relative standard deviations for reproducibility (RSDR) were 44.4, 29.7 and 14.3%, respectively, for concentrations ranging from 1-4 ng/test strip. For determination of ciguatoxin and related polyether toxins in parrot, surgeon, and amberjack fish extracts, the RSDR were 5.8, 4.8, and 3.7%, respectively, and the RSDR were 11.9, 9.9, and 7.6%, respectively, for concentrations ranging from 3-5 ng/test strip.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Beta-receptor decrease in bronchial asthma.

Sinesterases that intervene in cAMP and oGMP equilibrium in the cytoplasm of mast cells are activated by the adrenergic system through beta-receptors. A study was made on 96 atopic patients with mono sensitization to Dermatophagoides pteronissinus, in 3 groups. Radioligands were used to quantitate the number of beta receptors. In the control group mean no/cell was 541, bronchial symptomatic patients had 327 and nasal symptomatics 348. Asymptomatic patients were similar to controls. The results were similar with pollen-sensitive patients. Beta receptor decrease is a consequence of clinical allergy in atopic patients and is secondary to the immunological events that follow antigen-antibody reactions and cell membrane changes.

Adenylyl Cyclases↗
PubMed1991

Mechanism of ketotifen action in hypersensitivity reactions. Its effect on cellular enzymatic activities.

In this study we observed that asthmatics had less methyltransferase activity and greater phosphodiesterase activity than healthy individuals. These enzymatic activities were nearer to values obtained in healthy individuals when we preincubated cells with ketotifen. The modulator effect of this drug on these two enzymes permits, on the one hand, to re-establish the beta-receptor numbers expressed on the membrane, and on the other hand, to inhibit mediator secretion provoked by antigenic stimulus. With its action on adenylate cyclase and phosphodiesterase activities, it allows cAMP intracellular accumulation and hinders the secretory process. Through its action on methyltransferase activity, it is responsible for the normalization of beta-receptor expression observed in asthmatic patients treated with ketotifen.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

Number of beta-receptors in patients allergic to Dermatophagoides pteronyssinus.

This study was carried out on 96 atopic patients with monosensitization against Dermatophagoides pteronyssinus and 30 control individuals. The patients were divided into 3 subgroups: 27 asymptomatic patients, 27 patients who only presented nasal symptomatology, and 27 patients with marked bronchial symptomatology. Total serum IgE, antigen-specific histamine release, and the number of beta 2-adrenergic receptors in peripheral blood lymphocytes in all patients were determined. The control group presented the highest number of beta-receptors in comparison with the bronchial symptomatic and nasal symptomatic patients. However, asymptomatic patients presented numbers of beta-receptors similar to controls, with no significant differences between both groups. No significant correlation was found between beta-adrenergic receptors and levels of total serum IgE. On the other hand, correlation between beta-receptors and specific histamine release was detected only in symptomatic nasal patients. It can be postulated that the decrease in beta-receptors is a consequence, and not the cause, of atopy.

Adult↗
PubMed1991

Number of beta-receptors in rhinitic pollinic patients.

The study was carried out on venous blood from 67 patients with seasonal rhinoconjunctivitis caused by sensitization to grass pollen and 30 control individuals. Total IgE determination, antigen-specific histamine release test against two concentrations of Phleum pratense, and quantification of beta 2-adrenergic receptor numbers in lymphocyte membrane of peripheral blood were done on all patients. Those pollinic patients who were asymptomatic at the time of the study had 500.07 +/- 237.27 receptors/cell; no significant differences were established with the control group, with 541.53 +/- 123.63 receptors/cell. However, both the control group and asymptomatic patients had receptor numbers which were significantly higher than those of symptomatic pollinic patients, with 376.81 +/- 158.65 receptors/cell (p < 0.01 and p < 0.05, respectively). The average decrease in number of receptors in symptomatic pollinic patients was 30.42% in relation to controls and 24.65% in relation to asymptomatic patients. Within the subgroup of pollinic patients, studied both in and out of season, the number of beta 2-adrenergic receptors had an average decrease of 13.22% during pollination, with 363.7 receptors/cell. Once the pollination season was over, this figure increased to 419.1 receptors/cell, establishing significant differences with p < 0.025. The number of beta 2-adrenergic receptors did not correlate with total seric IgE figures or with antigen-specific histamine release. These data indicate that the decrease of these receptors does not constitute the causal factor of atopic diseases; it seems more likely to be a consequence of the same.

Adolescent↗
PubMed1990

Seasonal influence on serum and receptor-bound IgE in pollinosis.

Analysis of the correlation between bound and free IgE in 32 patients with pollinosis before and during the pollen season disclosed no correlation between bound and free IgE in rhinitic patients before the pollen season, while there was correlation during the season. In the asthmatic patients there was good correlation before the pollen season rather than during it.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

Results of the in vitro follow-up of immunotherapy.

With the advances made in allergological diagnosis, thanks to the application of various in vitro immunological techniques, we have also learnt more about the immunological modifications produced during the course of the immunotherapy. Among the techniques which will detect immunological changes is the histamine release test, which will show a decrease in antigen-specific histamine release. On the other hand, both total IgE and IgG4 are modified in the course of this immunotherapeutic treatment.

Follow-Up Studies↗
PubMed1987

The viral factor in childhood asthma.

Independently of the important role the infections bacterial factor plays in childhood asthma, many authors have considered the virus the primary triggering factor of bronchospasm. This latter factor has been so exaggerated that some authors have even conceded it the maximum importance. In studies carried out with a more numerous population than in those works presented so far, controlling the presence of antibodies during the crisis and a week later in serum from asthmatic children, the authors found that only 13.5% presented specific antibodies against one or two of the sixteen viral antigens studied. These children at the same time developed a bacterial infection which remitted with antibiotic therapy, with the consequent disappearance of the asthma. In etiopathological studies realized in 700 children it was equally confirmed that the bacterial factor was involved in 90% of the cases, in the sense of a sinopulmonary syndrome. More profound studies are needed to clarify this point which is held in little consideration by many clinicians.

Antibodies, Viral↗
PubMedDate not supplied

Effect of ketotifen on phosphodiesterase activity from asthmatic individuals.

It was demonstrated, in this study, that phosphodiesterase activity was elevated in asthmatic patients compared to healthy individuals. This may be reason why various authors found higher intracellular cAMP levels in healthy individuals than in asthmatic patients. We also demonstrated that the efficacy of ketotifen in inhibiting antigen-specific histamine release is due to the potent inhibitor effect of ketotifen on cellular phosphodiesterase activity which then allowed intracellular cAMP accumulation, and as a consequence prevented mediators release.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

Membrane IgE and adenyl cyclase activity in the dynamics of bronchospasm. Ketotifen as a blocker of antigen action.

A continuous exposition to antigen provokes an increase of IgE synthesis in individuals sensitized to that antigen. This increase in the synthesis is hardly seen to be reflected in seric levels; however, it is clearly seen in the quantity of IgE associated with membranes as this value increases considerably. This fact is due to the characteristic of IgE which tends to fix itself to basophil membrane. On the other hand, although no difference exists in basal adenyl cyclase activity of asthmatic and healthy individuals, the sensitivity of this enzyme to isoproterenol (beta-agonist) is greater in healthy than in asthmatic individuals. The antigenic stimulus makes adenyl cyclase activity descend in these individuals; this does not happen when the cells are treated with ketotifen before stimulating them with the antigen.

Adenylyl Cyclase Inhibitors↗
PubMedDate not supplied

Effect of ketotifen on the methyltransferase activity of asthmatic patients.

The results of this study have revealed that asthmatic individuals have less methyltransferase activity, compared to healthy individuals. This is reflected in a less fluidity of the plasmatic membrane and thus, presents with less beta-receptors compared to healthy subjects. Ketotifen is capable of partially reversing this situation where it stimulates methyltransferase activity of asthmatic individuals approaching the enzyme activity to healthy individuals.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

Extrinsic allergic alveolitis caused by esparto (Stipa tenacissima).

Extrinsic allergic alveolitis (EAA) are clinical entities of growing importance. The discovered etiological agents which can induce them, organic and inorganic substances of low molecular weight which are frequently found in the laboral environment, are every day more numerous. In the group of substances which are rarely implied in EAA etiology, we must mention esparto (Stipa tenacissima), a grass of the graminea family widely used in Spain. The EAA caused by Stipa tenacissima inhalation in known as stipatosis, a disease with poorly systematized clinical manifestations because of the few cases described in the literature so far. Our purpose in this report is to show the second case, in world literature, of EAA correctly characterized.

Adult↗
PubMedDate not supplied

Decrease of beta-receptors after the antigen-specific bronchial provocation test in bronchial asthma.

Airway hyperreactivity to different stimuli is a characteristic feature of bronchial asthma. The beta-adrenergic theory, as proposed by Szentivanyi in 1968, tried to explain with beta-adrenergic dysfunction, the cause not only of bronchial hyperreactivity but of all atopic diseases. In a previous work, we found that asymptomatic asthmatic patients presented a number of beta-receptors similar to that of a normal control group, while symptomatic asthmatic patients presented a significantly decreased number when compared to both groups (40% decrease). In view of these results, we proposed to study the possible changes in the number of beta-receptors in asymptomatic asthmatic patients after a bronchial provocation test. Fifteen patients, diagnosed of bronchial asthma and sensitive to the house dust mite, D. pteronyssinus, were studied. All were free of medication and asymptomatic at least 90 days before the study. A test of specific bronchial provocation was performed on 10 patients, determining the number of beta-receptors in basal conditions, after 30 minutes and 24 hours. The other five patients underwent an unspecific provocation test with methacholine, with determination of the beta-receptor number at basal conditions, and 24 hours later. Only a significant decrease (30.4%) was found in the beta-receptor numbers, 24 hours after specific bronchial provocation with p less than 0.025 with the Student test for paired data. With regards the beta-adrenergic theory of atopy, in our opinion our results show that the detected decrease of beta-receptors would be the consequence and not the cause of atopic diseases.

Allergens↗
PubMedDate not supplied

Study of various immunological parameters in the diagnosis of allergy to penicillin G and its derivatives.

The objective of this paper was to draw up an efficient and safe study protocol to diagnose allergy to beta-lactam antibiotics. Seven hundred and fifty patients with clinical histories suggesting penicillin allergy were studied. RAST to penicilloyl G/V, skin tests with PPL, MDM, penicillin G and ampicillin, epicutaneous tests with differed type reactions and a provocation test (in case of the negative results of the other tests) were performed on the patients. The incidence of this pathology is very low (6.5%) and atopic patients do not present greater predisposition to suffer from it than the general population. By carrying out RAST and skin tests with PPL, MDM, penicillin G and ampicillin we arrived at the diagnosis, in the anaphylactic type charts, in 97.5% of the cases. In reactions of a differed type, by performing patch tests we arrived at the diagnosis in 50% of the cases.

Amoxicillin↗
PubMedDate not supplied

Adverse reactions produced by iodinated contrast media.

Given the wide utilization of iodide contrast media for the visualization of the different apparatus of the human being and in the view of the presence of adverse reactions in 50% of the explored patients, we thought it interesting to write this review. In it we intend to show, in a clear and concise way, the different mechanisms implicated in the type of reactions. We also comment on the various actual and future methods that could be useful at the time of detecting and preventing such reactions.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Late asthmatic reaction in a hairdresser, due to the inhalation of ammonium persulphate salts.

Persulphate salts are among the various chemical substances that can cause occupational diseases in hairdressers. We present the case of a 21 year-old female who worked in a hairdressing salon for five and a half years. Five years prior to consultation, she presented with rhinitic symptoms and wheezing dyspnea which were related with her working environment. The routine laboratory examinations carried out on the patient were found to be normal. Among the various allergic exams performed there was an elevated total IgE. The provocation test with histamine was positive at the concentration of 10 mg/ml, demonstrating mild bronchial hyperreactivity. The test of bronchial exposure to ammonium persulphate was positive with bronchospasm 3-4 hours after this test. With a prior inhalation of betamethasone we were able to block this reaction, but with disodium cromoglycate we were able to block it only partially. We conclude that the patient presented with late onset bronchial asthma due to sensitivity to ammonium persulphate. It has to be pointed out that this patient was a rare case as generally persulphate salts choose to invade and affect the skin. The rarity of this pathology is reflected by the scarce bibliography on this subject.

Adult↗