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Biomedical subjects

F Antón

Publications and source records attributed to F Antón.

11 recordsLinked to original sources

Anticholinergic effects of desloratadine, the major metabolite of loratadine, in rabbit and guinea-pig iris smooth muscle.

Allergic conjunctivitis is the most common ocular allergic disease. Although very symptomatic it does not endanger vision, and topical antihistamines or chromones are the first choice treatment in clinical practice. Recently, equivalent nanomolar affinities for histamine H and muscarinic M 1 and M3 cloned human receptors have been reported for desloratadine, the active metabolite of loratadine, a widely prescribed antihistamine. This property might enhance its utility in the treatment of asthma, but could induce adverse anticholinergic effects after topical administration. In the present study, we compare the anticholinergic activity of desloratadine with other known muscarinic antagonists and antihistamines on rabbit and guinea-pig iris smooth muscle. Desloratadine was found to be a competitive antagonist (pA2 = 6.67+/-0.09) of carbachol-induced contractions in isolated rabbit iris smooth muscle. Atropine (pA2 = 9.44+/-0.02) and NPC-14695 (pA2 = 9.18+/-0.03) also behaved as competitive antagonists, whereas tiotropium bromide (pD'2 = 9.06+/-0.02) exhibited a non-competitive behaviour in this tissue. Carebastine (pA2 = 5.64+/-0.04) and fexofenadine (pA2 < 4.0) were also studied. After topical administration on the guinea-pig eye conjunctiva, desloratadine produced a potent (ED50 = 2.3 mg/ml) and long lasting mydriasis (> 120 min at the ED50) in conscious animals. Fexofenadine and carebastine were inactive even at the highest concentration tested (10 mg/ml). Atropine (ED50 = 30 microg/ml) and tiotropium bromide (ED50 = 10 microg/ml) were much more potent than desloratadine or pirenzepine (ED50 = 3 mg/ml) in this model. The competitive muscarinic antagonism of desloratadine in vitro, and its potency and duration of action in vivo, suggest that topical treatment of allergic conjunctivitis and rhinitis with desloratadine could produce undesirable peripheral anticholinergic side effects such as mydriasis and xerostomia.

Animals↗

Pharmacological activity of PF-904 in guinea pig in vivo, and on human bronchus and neutrophils in vitro.

The effects of PF-904 (4-amino-1-ethyl-6-methylpyrazino[2,3-c][1,2,6]thiadiazine 2,2-dioxide), a pyrazinothiadiazine derivative, were examined in guinea-pig airways in vivo, in human isolated bronchus and human polymorphonuclear leukocytes. PF-904 (12.5-200 mg/kg, intraduodenal) reduced bronchoconstriction in response to histamine, arachidonic acid, platelet-activating factor (PAF) and methacholine. PF-904 (50-200 mg/kg) prevented PAF-induced airways hyperreactivity and inhibited antigen-induced bronchoconstriction, airway microvascular leakage and eosinophil lung accumulation, but antigen-induced airways hyperresponsiveness was not reduced. PF-904 (1 microM-1 mM) produced complete inhibition of spontaneous (-logEC50 = 3.57+/-0.04; n = 10) and histamine-stimulated tone (-logEC50 = 3.66+/-0.07; n = 10) of human isolated bronchus. Glibenclamide (10 microM) or precontraction with KCl (80 mM) did not impede PF-904-induced bronchial relaxation. PF-904 inhibited cyclic AMP (-logIC50 = 2.83+/-0.25; n = 8) and cyclic GMP (-logIC50 = 2.90+/-0.21; n = 8) phosphodiesterase activity in human bronchus. The activity of type IV phosphodiesterase was inhibited by PF-904 (-logIC50 = 3.43+/-0.11; n= 3). PF-904 also inhibited superoxide release by N-formylmethionyl-leucyl-phenylalanine-stimulated human polymorphonuclear leukocytes, but the maximal effect was approx. 50% of that produced by rolipram (10 microM). This profile of activities of PF-904 suggests that this compound has potential therapeutic value as an anti-asthma drug.

Animals↗

Testicular serotonin is related to mast cells but not to Leydig cells in the rat.

Testicular serotonin (5HT) concentrations were determined by HPLC in the testes of rats treated neonatally with oestradiol benzoate (EB) and in adult rats treated with the Leydig cell cytotoxic ethylene dimethane sulphonate (EDS). 5HT concentrations were related to mast cell numbers. EB-treated rats showed an accumulation of mast cells in the testes at 35 and 70 days of age and increased 5HT concentrations in both the interstitial fluid and the testicular capsule, whereas no increases in 5HT concentrations or in the number of mast cells were found for the ventral prostate of these animals. On the contrary, 5HT concentrations were not related to the number of Leydig cells. In EB-treated rats, in which Leydig cells were nearly absent at 35 days of age, 5HT concentrations were significantly increased. Furthermore, EDS-treated rats did not show significant changes in 5HT concentrations, in spite of the elimination of Leydig cells. These data suggest that mast cells are a major source of serotonin in the rat testis.

Animals↗

Cost-effectiveness analysis of hepatitis B vaccination strategies in Catalonia, Spain.

Hepatitis B virus (HBV) infection is an important public health problem all over the world. Vaccination is one way to prevent it, and several strategies can be used depending on endemicity, the main pattern of HBV transmission and the demographic structure of the population. In this study, an economic comparison of 3 vaccination strategies (mass adolescent vaccination, mass infant vaccination and mass combined vaccination) was performed in Catalonia, Spain. Screening pregnant women for HBV infection in combination with these strategies was also evaluated. Epidemiological models to analyse patterns of HBV infection with and without vaccination and to calculate HBV-associated costs were designed. Comparison between strategies was done using cost-effectiveness analysis from the perspective of the healthcare system. Epidemiological model results indicate that implementation of HBV vaccination could prevent as many as 104,778 new acute infections, and avoid up to 5239 chronic infections, 2096 cases of cirrhosis and 419 cases of hepatocarcinoma over a 20-year period in Catalonia. Cost-effectiveness analysis shows that mass adolescent vaccination is the most efficient strategy, with lower costs per avoided case than the other 2 strategies. When any of these strategies is complemented by screening for HBV in pregnant women, the number of avoided cases is always higher and the cost per avoided case decreases or remains unchanged.

Adolescent↗

[Clinico-epidemiological study of botulism poisoning in La Rioja (1979-1990)].

BACKGROUND: The aim of the present study was to evaluate botulinic poisoning requiring hospital admission in La Rioja (Spain) during one decade from a clinical-epidemiologic point of view. METHODS: Chart records from patients admitted to the departments of Internal Medicine, Neurology, the ICU, and the Neurophysiology and Preventive Medicine files of the reference hospital between 1979 and 1990 were retrospectively reviewed. RESULTS: Fifteen cases were identified. Home preserves of vegetables were most frequently the foods responsible for the poisoning. The presentation as a sole case constituted half of this series. The most frequent symptomatology was neuro-ophthalmologic and digestive. All the cases were type B. Neurophysiologic studies were compatible with the diagnosis in all the cases in which they were performed. Two cases (13.3%) required intensive care and death occurred in one (6.6%). CONCLUSIONS: a) The habit of home preserves was responsible for the presentation of botulism in this environment. b) Early diagnosis was based on complementary clinical tests together with the neurophysiologic study. c) The mild forms were most frequent. Death in this series was 6.6%.

Adolescent↗

[Economic evaluation of prophylaxis with recombinant granulopoiesis stimulating factor].

BACKGROUND: The aim of the study was to economically evaluate the prophylactic use of the recombinant factor of the stimulation of granulocyte colonies (rG-CSF) for the prevention of episodes of febrile neutropenia (EFN) following antineoplasic chemotherapy. METHODS: The methods of economic evaluation used were those of cost analysis and cost-effectivity analysis. The probability of occurence of EFN was estimated by the application of the Delphi method and the costs were calculated. RESULTS: The costs of EFN for the patients with solid tumors is situated between 236,000-377,000 pesetas according to hospitalary centers. For patients with acute leukemia the value was estimated as between 391,000-667,000 pesetas. The results of the cost analysis indicate that the net cost per patient prophylactically treated is between 4,000-64,000 pesetas. The results of the cost-effectivity analysis indicate that the cost per case of no incidence of EFN is between 20,000-320,000 pesetas. CONCLUSIONS: Episodes of febrile neutropenia carry expansive hospital and antibiotic clinical treatment. The prophylactic use of new medication for patients between the first and second cycle of chemotherapy, in agreement with the estimates calculated, does not save health care costs but may improve the quality of life in these patients and permit the continuation of a therapeutic schedule without interruption which may improve the life expectancy of the patient.

Antineoplastic Agents↗

[Health care resources utilization in HIV-infected patients: creation of a data base and cost results].

OBJECTIVES: To make and validate a data base that allows to collect information about clinical characteristics and use of health care services by HIV-infected patients. An additional purpose is to obtain some data about costs of health care services utilization. METHODS: We have designed an informatic data base that includes: demographic data, clinical data and health care services utilization during the follow up. One hundred and nine patients were selected from 5 different hospitals in Spain and they were followed for 6 months (from January to June 1997). Analytic accounting of one hospital and official tariffs were used to calculate costs of the health care services. RESULTS: The informatic data base designed is useful and appropriate to collect the information of these patients. The annual average cost is 2.5 millions dollars, ranging from 1 million dollars for asymptomatic patients to 3.8 millions for AIDS patients. The comparison of our results with previous studies shows an increased cost of asymptomatic patients. CONCLUSIONS: These results give a preliminary information about health care services utilization by HIV-infected patients and confirm the possibility of using the designed instrument in the future. Since HIV-infection presents an uncertain evolution and a variable prognosis, to implant a tracking system is a necessary requirement in order to obtain a fast and accurate information system about the evolution of clinical variables and their economic repercussions.

Acquired Immunodeficiency Syndrome↗

[HIV infection in an autonomous Spanish community (La Rioja). Features, trends and conclusions applicable to other regions].

BACKGROUND: The epidemiologic characteristics of HIV infection in La Rioja (Spain) were studied and the future tendencies of the same analyzed. METHODS: The data from official Health sources were collected and analyzed. RESULTS: In La Rioja, the 5th region in Spain regarding to AIDS incidence, the duplication time of the number of cases continues to shorten. The number in December 1991 was 81. The heterosexual route of infection was 5% of the cases of AIDS up to December 1990 and in 1991 it was 15%, while, with regards to the total number of seropositive subjects, the number rose from 0.3% in December 1990 to 10% in 1991. One thousand one hundred fifty-one seropositive patients were detected in December 1991 representing seroprevalence of 0.34% which reaches 1.14% in the age range between 18-32 years. Mean hospital stay was 23.6 days with 3,032 hospital stays calculated for 1991 representing 8.3 occupied beds/day. There are presently 92 patients undergoing antiviral treatment. Between 43-69 new cases of AIDS have been calculated for 1992. CONCLUSIONS: 1) Medical care should be provided to a greater number of seropositive people to avoid early deterioration. 2) The increase in heterosexual infection is alarming. 3) The need for rehabilitation centers for drug abusers and social alternatives to prostitution is clear. 4) Organized campaigns pointing out and returning the dignity and value of life and therewith the role of human sexuality are needed. 5) Alternative means to conventional hospitalization is required.

Acquired Immunodeficiency Syndrome↗

[Results of health examination by age and sex groups].

The present study describes the results achieved 6 months after the establishment of a health examination, with different features depending on age and sex groups, which was progressively applied to the population of the C.A.P. "Virgen de la Fuensanta" (Valencia). The preventive activities included: vaccination (rubella, tetanus and influenza), tuberculin skin testing, determination of body weight and mass (BMI), measurement of blood pressure and heart rate, cervical cytology, breast examination and search for occult blood in feces. Among the 388 evaluated individuals (69.4% females and 30.6% males), 10 cases of hypertension, 2 of diabetes, 65 of obesity, 20 of hypercholesterolemia, 23 women with benign breast abnormalities and 8 instances of occult blood in feces were detected. In the age group of 15-26 years, 7 positive tuberculin reactions were detected. In 175 cytological studies no case of malignant disease was discovered. The degree of acceptance of the program by the users was satisfactory, as assessed by the compliance with both the appointments (85%) and the individual interventions (88-100%).

Adolescent↗

[Lymphocyte subpopulations, neopterin, and beta-2-microglobulin: relationship with clinical stage, risk of progression to AIDS and presence of active infection in HIV infection].

BACKGROUND: The aim of the present study was to evaluate the relation between the number of CD4 lymphocytes, the CD4/CD8 ratio and the plasma levels of neopterin and beta-2 microglobulin, and the clinical status, risk of progression without of active opportunistic infections, among HIV-infected patients. METHODS: Seventy-two patients infected by HIV in different clinical groups were evaluated upon entering the study and following a mean follow up of 6 months for the parameters studied. RESULTS: The values of CD4 lymphocytes and neopterin were related with the clinical status according to the CDC's classification, with no significant differences existing in the beta-2 microglobulin level. The CD4 count as well as the neopterin and the beta-2 microglobulin levels differed significantly when classified to the patients with regard to the risk of progression to AIDS throughout the study. The presence of active opportunistic infections was related with significantly higher concentrations of neopterin without differences recorded for the remaining parameters. CONCLUSIONS: The parameters studied are good markers or both clinical status and/or the risk of short-term progression to AIDS. Neopterin levels are high during acute infections. Therefore, its prognostic value should be cautiously evaluated in this situation.

Acquired Immunodeficiency Syndrome↗