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Biomedical subjects

A Pastor

Publications and source records attributed to A Pastor.

88 records · Page 5Linked to original sources
PubMed1977

[Thrombosis of intracraneal sinuses in homocystinuria (author's transl)].

The case of a child affected with piridoxinresistant homocystinuria who developed early on the disease an aseptic thrombosis of intracraneal sinuses, of chronic evolution is presented. Pathogenesis and therapy of the thrombosis are discussed emphasizing the value of measures directed to avoid the aggregation of platelets.

Aspirin↗
PubMedDate not supplied

Cadmium binding proteins induced in exposed freshwater crayfish Procambarus clarkii.

This work describes results on the characterization of cadmium binding proteins (Cd-BPs) obtained from cadmium exposed freshwater crayfish Procambarus clarkii. After acclimation to laboratory conditions, induction of Cd-BPs was achieved by water exposure at a concentration of 100 micrograms Cd/L during 2, 15, and 30 d. In accordance with the method followed by Engel and Brouwer, in each case two midgut glands were minced and homogenized in Tris-HC1 buffer with PMSF to prevent protease activity and DTT to maintain reducing conditions. The homogenate was centrifuged, heat treated, applied to a column of Sephadex G-75, and eluted with the same buffer (pH 8.6). Absorbances of the fractions collected were measure at 254 and 280 nm. Cadmium concentrations were determined by flame photometry. In midgut glands of two-d treated crayfish, significant levels of cadmium occurred in the void volume, and no cadmium-binding protein peak was resolved. On the contrary, a cadmium peak was clearly resolved in samples of 15 and 30 d. Cadmium was accumulated in the low molecular weight fractions (about 20,000). These fractions had high ultraviolet absorption at 254 nm and a higher 254/280 ratio.

Animals↗
PubMedDate not supplied

A recruitment-based rheological model for mechanical behavior of soft tissues.

When lung tissue is subjected to finite deformations, phenomena appear that can only be described using nonlinear models. This paper considers the lung as a material composed of two elements, a continuous phase that acts uninterruptedly and a second phase composed of fiber elements that are recruited progressively into the mechanical process. Each individual fiber participates in the mechanical response of the set only when the deformation is above a certain value. A nine-parameter model was designed adopting standard viscoelastic elements both for the matrix and for each of the fibers. The mechanical behavior of the lung can be reproduced by a fitting process with standard numerical procedures in both dynamic-mechanical measurements and stress relaxation processes. Mechanical stress relaxation tests and dynamic-mechanical measurements have been carried out on subpleural parenchymal strips from rat lung. The model permits the reproduction of lung behavior in both types of measurements. The results show a recruitment ratio that decreases with deformation and the nonparticipation of the parallel matrix fraction in the lung's mechanical response so that a uniaxial transmission of force in the lung occurs via the recruited elements and the matrix series.

Animals↗
PubMedDate not supplied

Mechanisms of action of quinolones against staphylococci and relationship with their in vitro bactericidal activity.

Ciprofloxacin and norfloxacin exhibited mechanism A (requires cell division as well as bacterial protein and RNA synthesis to kill bacteria) and C (active against nondividing bacteria but requires protein and RNA synthesis) against the reference strain Staphylococcus aureus ATCC 25923, yet only mechanism A was exhibited by these fluoroquinolones when tested against three clinical isolates: S. aureus Sa-215, Staphylococcus epidermidis Se-81 and Staphylococcus haemolyticus Sx-1. On the contrary, fleroxacin exerted mechanism A and C against the three clinical isolates but only mechanism A against the reference strain. Ofloxacin displayed mechanism A against S. epidermidis Se-81, mechanism A and C against S. haemolyticus and mechanism A and B (active against nondividing bacteria and does not require protein and RNA synthesis) against the two S. aureus tested. Sparfloxacin showed mechanism A and C against the four Staphylococcus species studied, and temafloxacin was the only fluoroquinolone tested that exhibited mechanism A and B against the four bacterial strains assayed. No correlation was found between the in vitro bactericidal activity (expressed as minimum inhibitory concentration and optimal bactericidal concentration) and the mechanisms of action exhibited by these fluoroquinolones.

Anti-Bacterial Agents↗
PubMedDate not supplied

Killing of gram-negative bacteria by ciprofloxacin within both healthy human neutrophils and neutrophils with inactivated O2-dependent bactericidal mechanisms.

The intraphagocytic killing of Escherichia coli, Serratia marcescens, Pseudomonas aeruginosa, and Salmonella typhi by ciprofloxacin (0.1, 1 and 5 microg/ml) within human neutrophils with intact and impaired (by phenylbutazone treatment) O2-dependent killing mechanisms was studied and compared with the extracellular killing in the same medium of the intraphagocytic killing, but omitting neutrophils. The MIC/MBC of ciprofloxacin in vitro (assays performed according to NCCLS specifications) were: 0.015/0.06 for E. coli, 0.12/32 for S. marcescens, 1/16 for P. aeruginosa, and 0.007/0.06 for S. typhi. Ciprofloxacin showed bactericidal activity both extracellular and within phenylbutazone-treated and untreated neutrophils. The minimum concentration of ciprofloxacin to kill 90% of phagocytosed bacteria within neutrophils with normal O2-dependent killing power after 30 min was: 0.1 microg/ml for E. coli, and S. typhi, 1 microg/ml for P. aeruginosa, and 5 microg/ml for S. marcescens. In contrast, exposure for 60 min was required to reach this percentage within phenylbutazone treated neutrophils. The minimum concentration to kill 90% of extracellular bacteria after 30 min was: 0.1 microg/ml for E. coli, P. aeruginosa and S. typhi, and 5 microg/ml, for S. marcescens. A positive interaction between ciprofloxacin and the O2-dependent mechanisms of phagocytes was found. The reactive oxygen metabolites produced in the respiratory burst did not affect the intraphagocytic activity of ciprofloxacin. Phenylbutazone treatment of phagocytes would be a good experimental model to study the intraphagocytic killing of drugs in situations such as AIDS and chronic granulomatous disease where inefficient oxidative mechanisms of neutrophils exist.

Anti-Infective Agents↗
PubMedDate not supplied

Clinical utility of the single point method for theophylline maintenance dose prediction.

In this work, we tried to correlate the usefulness of the Koup nomogram for dosage prediction of continuous theophylline Dm therapy as compared with the usual method of dosification. To do this, a first group of 20 patients (5 with chronic bronchitis and 15 with bronchial asthma) without clinical or biochemical evidence of hepatic or heart disease (3 with smoking habit), were chosen. They were given a loading dose of theophylline 5 mg/kg over 30 min (as aminophylline). A blood sample was then taken after six hours. The result of this value and in accordance with the nomogram determines the individual oral dose of theophylline administered to attain a serum concentration of 10 mg/ml. The oral dose of theophylline, based according to Hendeles was given to another group of 16 asthmatic patients without smoking habit and clinical or biochemical signs of hepatic or heart disease. Two commercial preparations of theophylline were chosen (Theolair or Theodur). We concluded that: 1) Koup's nomogram is useful in estimating the dose requirement of oral theophylline to reach 10 mcg/ml (Css) at steady state, although it could not be useful in greater Css. 2) Among the patients given the dose according to Hendeles, 37.5% showed toxic serum concentrations. 3) Therapeutic serum concentrations could be obtained in the greater number of patients with twice daily doses, independently of the commercial product. 4) A great number of subjects showed the side effects (discomfort of the stomach, irritability, headache) which appeared to have little direct relationship to serum concentration.

Administration, Oral↗
PubMedDate not supplied

[Rhinitis with intolerance to non-steroidal anti-inflammatory agents. Report of 3 cases].

Lumry described 6 patients who presented hypertrophic rhinosinusitis, positive nasal eosinophilia and intolerance to nonsteroidal antiinflammatory drugs, manifested exclusively with naso-ocular symptomatology. We present three patients with clinical manifestations of chronic rhinitis who had noticed before their first visit that several nonsteroidal antiinflammatory drugs precipitated their nasal symptomatology. None of them had ever presented with asthma symptoms. All of them had nasal polyps. The nasal smear showed eosinophilia of 20 to 45%. All three had sinusitis radiologically. The spirometric values were within normal limits (V.C., FEV1, MMEF25-75%). Skin tests with different inhalants antigens using the prick test technique as well as skin tests with pyrazolones (Phenyldimetrylpyrazolone: 25 and 250 mg./ml.; dipyrone: 4 and 44 mg./ml.; amidopyrine: 2.2 and 22 mg./ml.) using the intradermal technique were negative. Serum IgE (Phadezym IgE-Pharmacia) showed values of 23.9, 17.1 and 25.8 IU/ml. respectively. The bronchial inhalation challenge test with methacholine was positive with PD20FVE1 of 14 and 4.8 mg./ml. in two of our patients. Different nonsteroidal antiinflammatory drugs were administered to each patient in different days orally, with intervals of 7 and 25 days (aspirin 500 mg., dipyrone 575 mg., indomethacin 25 mg., naproxen 500 mg.) as well as tartrazine (50 mg.), paracetamol (500 mg.) and lactose as placebo. With 30 minutes intervals and up to three hours after drug administration, the symptoms were observed and spirometry was carried out. Steroids and antihistamines were suspended at least 48 hours before the test. Acetyl-salicylic acid, dipyrone, indomethacin and naproxen produced naso-ocular symptomatology without any objective reduction of FEV1; but paracetamol and tartrazine were well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Cervicofacial actinomycosis in a patient treated by surgery of the lymph node due to laryngeal cancer: case report].

An actinomycotic cervical abscess was excised in a 55-year-old man who had undergone partial laryngectomy and ipsilateral cervical lymph node dissection 6 years earlier. This rare case is described in detail. We conclude that postoperative structural changes producing the loss of physical and immunologic barriers may be determinant factors in the development of this late actinomycotic infection.

Abscess↗
PubMedDate not supplied

[Graphic recording of the maxillary ostium permeability].

Currently we practise salpingography for evaluating Eustachian tube permeability. In a similar mode, we describe a technique of graphic search, with impedianciometry, of patency in the osteomeatal complex, after puncture and placing Foley's catheter in the maxillary sinus. In several cases without opening, we make topical treatment though catheter. For this technique, we propose the term of infundibulography.

Adolescent↗