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Biomedical subjects

J Frías

Publications and source records attributed to J Frías.

At least 19 recordsLinked to original sources
PubMed2001

Influence of diminished susceptibility of Streptococcus pneumoniae to ciprofloxacin on the serum bactericidal activity of gemifloxacin and trovafloxacin after a single dose in healthy volunteers.

The serum bactericidal activity against 2 Streptococcus pneumoniae strains (ciprofloxacin MIC 1 and 4 mg/l) was measured in 12 volunteers who received oral single doses of gemifloxacin 320 mg and trovafloxacin 200 mg in a crossover fashion. The 4-fold increase in ciprofloxacin MIC from the susceptible to the resistant strain resulted in a 2-fold increase in MIC (from 0.015 to 0.03 mg/l), a 2-fold decrease in C(max)/MIC (104 vs 52) and in AUC(0-24 h)/MIC (532 vs 266), but a 5.6-fold decrease in area under the bactericidal curve (AUBC: 168 vs 30) for gemifloxacin. Trovafloxacin showed a 4-fold higher MIC (0.25 vs 0.06 mg/l), a 4-fold lower C(max)/MIC (8.6 vs 36), a 4-fold lower AUC(0-24 h)/MIC (85 vs 356) and a 11-fold lower AUBCs (2 vs 22) against the resistant isolate compared with the susceptible one. Trovafloxacin serum bactericidal titres against the ciprofloxacin-resistant strain were measurable generally only at 1 h after dosing (median titre=2). Gemifloxacin showed similar ex vivo bactericidal activity against the ciprofloxacin-resistant strain to that of trovafloxacin against the ciprofloxacin-susceptible strain.

Adult↗
PubMed2001

Modulation of the biosynthesis of some phenolic compounds in Olea europaea L. fruits: their influence on olive oil quality.

The phenolic composition of olive fruits (Olea europaea L.) (cv. Picual, Villalonga, Alfafarenca, and Cornicabra) grown in different areas of Spain was studied by high performance liquid chromatography-mass spectrometry. Different levels of tyrosol, catechin, p-coumaric acid, rutin, luteolin, and oleuropein were observed in the different varieties analyzed. Treating the fruit with 0.3% Brotomax 50 days after anthesis had a beneficial effect on fruit size, oil content, levels of polyphenolic compounds, and Trolox-equivalent antioxidant activity (TEAC) in all the varieties analyzed.

Antioxidants↗
PubMed2000

Effect of zaleplon on digoxin pharmacokinetics and pharmacodynamics.

The pharmacokinetics and pharmacodynamics of digoxin alone and digoxin plus zaleplon were studied. Healthy, nonsmoking men between 18 and 45 years of age were given a single oral dose of digoxin 0.375 mg daily on days 1 through 9. On days 10 through 14, the subjects received digoxin 0.375 mg plus oral zaleplon 10 mg daily. Blood samples were obtained on days 3, 5, 8, 9, and 14, and serum digoxin concentration data were analyzed by model-independent pharmacokinetic methods. Blood pressure, heart rate, PR interval, and QTc interval were recorded to determine the effect of zaleplon on digoxin pharmacodynamics. A total of 20 men completed the study. Maximum serum digoxin concentration and area under the serum digoxin concentration-versus-time curve from 0 to 24 hours met bioequivalence test criteria. There were no significant differences in QTc or PR interval between days 9 (digoxin alone) and 14 (digoxin plus zaleplon), and there were no clinically important changes from baseline to the study's end in vital signs, physical examination findings, or ECG results for individual subjects. Eighteen percent of the subjects who received digoxin alone and 35% of those who received digoxin plus zaleplon reported one or more adverse effects; all were mild and resolved quickly. Zaleplon had no significant effects on selected pharmacokinetic and pharmacodynamic properties of digoxin.

Acetamides↗
PubMed2000

Cefminox versus metronidazole plus gentamicin intra-abdominal infections: a prospective randomized controlled clinical trial.

BACKGROUND: The aim of this prospective study was to compare the safety and efficacy of a new cephamycin, cefminox 2 g/12 h, to those of the usual regimen combining metronidazole 500 mg/8 h and gentamicin 80 mg/8 h (M+G). PATIENTS AND METHODS: 160 patients with clinically proven intra-abdominal infection were prospectively included in an open parallel randomized comparative multicenter trial. Antibiotics were started preoperatively and discontinued after clinical and laboratory evidence of resolution of the infection. Serum and peritoneal fluid levels and serum bactericidal activities were also studied. RESULTS: 150 patients were clinically evaluable. There was one failure in the cefminox group and three in the M+G group (not significant, RR: 1.07, 95% CI: 1-1.15). No differences were found in the number of wound infections, length of stay or duration of antibiotic therapy. Adverse effects were reported in 11 cases, all of them mild to moderate. Escherichia coli and Bacteroides fragilis were the most frequently found microorganisms. CONCLUSION: Cefminox is as effective and as safe as M+G in the treatment of intra-abdominal infections.

Abdomen↗
PubMed2000

Digoxin level and clinical manifestations as determinants in the diagnosis of digoxin toxicity.

The aim of this study was to determine the relative importance of different risk factors in the diagnosis of digitalis toxicity. The authors recruited inpatients for whom serum digoxin level was requested and prospectively followed them for a week to ascertain if they showed digitalis toxicity. The predictive value of different factors for the assessment of digoxin toxicity was analyzed by multiple logistic regression. Forty-one toxic and 58 nontoxic patients were included. In the univariant analysis, intoxicated patients were older, most were women, and they had worse renal function and higher digoxin level; but there were no differences in serum electrolytes or other risk factors. In the multivariant analysis, digoxin level was the only independent factor related to digitalis toxicity. A different risk of toxicity for each clinical manifestation was found for a certain digoxin level. Patients with signs of automaticity in the electrocardiogram had a higher likelihood of being intoxicated than patients with gastrointestinal symptoms, atrioventricular block, or bradycardia. Therefore, in the population evaluated in this study, digoxin level is the key independent factor in digoxin intoxication, although the probability of being intoxicated is also a function of the type of clinical manifestations. A graphic approximation of this probability based on these two factors is presented.

Adult↗
PubMed1999

[Patient preference and stereotype about the gender of the family physician].

OBJECTIVE: To study the preferences of patients on the gender of the physician when consulting for particular health problems; and to know the gender stereotypes that patients assign to physicians. DESIGN: Cross-sectional study. SETTING: Five teaching health centres in Granada (Spain). PATIENTS: Randomised sample of patients that consulted 10 female and 20 female physicians during three months (17 patients per physician), for alfa = 5%, beta = 80%, to detect a difference of 12% between male and female physicians. MEASUREMENTS AND MAIN RESULTS: We used a questionnaire adapted from Fennema (Family Medicine Dept., Wisconsin University, 1990) that was administered by interviewers after the consultancy, following a previous pilot study. Preference and stereotype scales comprised 10 items, with five reponses (neutral mid-point). Differences were analysed with chi 2 with correction for continuity. Non-reponders (33%) were replaced, and their age and sex did not bias the study results. Responders were 210 males (40.9%) and 304 women (59.1%). For "flux in penis/vagina" and "haemorrhoids" 50-60% of the patients preferred a physician of the same sex, with the remainder expressing no preference. The women preferred female physicians for family problems (23%) and depression (23%). The male physicians were more often perceived to be unorganised than were the females (24% vs. 5%, p < 0.0005), while the female physicians were more often described as humane (15% vs. 10%, p < 0.0005). Characteristics expressing technical competence were more often attributed to the male physicians than to the females, while those expressing empathy were more often attributed to the female physicians. CONCLUSIONS: Patients prefer physicians of the same gender for some health problems and not for others. Patients assign gender stereotypes to physicians. These findings will permit a better interpretation of doctor-patient relationships.

Cross-Sectional Studies↗
PubMed1998

Effect of polymorphonuclear neutrophils on serum bactericidal activity against Streptococcus pneumoniae after amoxicillin administration.

The effect of phagocytic killing on serum bactericidal activity against Streptococcus pneumoniae was investigated 0, 1.5, 8 and 12 h after a single 875 mg oral dose of amoxicillin in healthy adults. Killing curves were determined with polymorphonuclear neutrophils (PMN), serum or PMN plus serum. Global killing (i. e. intracellular and extracellular killing) over 3 h of incubation was expressed as the area under the killing curve (AUKC; log cfu x h/ml). Amoxicillin did not affect the activity of PMN alone. For serum alone, the AUKC of post-administration samples (with supra-inhibitory amoxicillin concentrations) was significantly lower than in baseline samples. For serum plus PMN, significant bactericidal activity of serum was still found in samples after antibiotic concentrations had reached sub-inhibitory levels.

Adult↗
PubMed1997

Comparison between the evaluation of bacterial regrowth capability in a turbidimeter and biodegradable dissolved organic carbon bioreactor measurements in water.

In recent years, two different approaches to the study of biodegradable organic matter in distribution systems have been followed. The assimilable organic carbon (AOC) indicates the portion of the dissolved organic matter used by bacteria and converted to biomass, which is directly measured as total bacteria, active bacteria or colony-forming units and indirectly as ATP or increase in turbidity. In contrast, the biodegradable dissolved organic carbon (BDOC) is the portion of the dissolved organic carbon that can be mineralized by heterotrophic microorganisms, and it is measured as the difference between the inflow and the outflow of a bioreactor. In this study, at different steps in a water treatment plant, the bacterial regrowth capability was determined by the AOC method that measures the maximum growth rate by using a computerized Monitek turbidimeter. The BDOC was determined using a plug flow bioreactor. Measurements of colony-forming units and total organic carbon (TOC) evolution in a turbidimeter and of colony-forming units at the inflow/outflow of the bioreactor were also performed, calculating at all sampling points the coefficient yield (Y = cfu/delta TOC) in both systems. The correlations between the results from the bioreactor and turbidimeter have been calculated; a high correlation level was observed between BDOC values and all the other parameters, except for Y calculated from bacterial suspension measured in the turbidimeter.

Bacteria↗
PubMed1997

Pharmacodynamic effects of amoxicillin versus cefotaxime against penicillin-susceptible and penicillin-resistant pneumococcal strains: a phase I study.

Serum bactericidal activity against a penicillin-susceptible strain and a penicillin-resistant strain of Streptococcus pneumoniae (amoxicillin and cefotaxime MICs, 0.001 and 1 microg/ml, respectively, and MBCs, 0.01 and 2 microg/ml, respectively) was measured in 12 healthy volunteers who each received an oral 875-mg dose of amoxicillin and an intramuscular 1-g dose of cefotaxime in a crossover fashion. The areas under the bactericidal activity-time curves for the two strains were found to be similar for both antibiotics despite the significantly higher (P < 0.002) AUC/MIC and peak level/MIC values for cefotaxime.

Adult↗
PubMed1997

Dual transduction signaling by a Xenopus muscarinic receptor: adenylyl cyclase inhibition and MAP kinase activation.

Using transient transfection of COS-7 and human embryonic kidney 293 cells, we studied the functional properties of a previously cloned muscarinic Xenopus receptor [Herrera et al. (1994): FEBS Lett 352:175-179] and its coupling to adenylyl cyclase (AC) and mitogen-activated protein kinase (MAPK) pathways. Expression of the Xenopus muscarinic receptor results in the inhibition of AC activity and activation of the MAPK pathway through a mechanism that involves a Pertussis-toxin-sensitive G-protein and the G beta gamma subunits. The signal transduction properties of this receptor are similar to the mammalian m2 and m4 muscarinic receptors. These results strongly support the idea that inhibition of AC and MAPK activation, signaled out from the muscarinic oocyte receptor, are involved in the oocyte maturation process.

Adenylate Cyclase Toxin↗
PubMed1997

Pharmacokinetic study of ebrotidine administered in multiple doses to healthy volunteers for 4 days.

The safety of ebrotidine (N-[(E)-[[2-[[[2-[(diaminomethylene)amino]-4- thiazolyl]methyl]thio]ethyl]amino] methylene]-4-bromo-benzenesulfonamide, CAS 100981-43-9, FI-3542), a new H2-receptor antagonist with gastroprotective activity, was assessed and its main pharmacokinetic parameters were determined in order to establish the dose linearity after the repeated administration of three different dose levels. The study was carried out in a group of 8 healthy volunteers of either sex, aged between 20 to 29 years. Oral doses of ebrotidine were administered in a randomized, single-blind design. Volunteers remained in the Unit for two days at each of the three study phases with washout intervals of 2 weeks and received seven doses of ebrotidine (150, 300 and 500 mg b.i.d). Pharmacological evaluation included vital signs, laboratory tests, adverse events and blood and urine samplings for pharmacokinetic analysis. Ebrotidine was determined by high performance liquid chromatography (HPLC) with UV detection. The results showed a good tolerability of ebrotidine after the administration of seven doses for 4 days, with no changes in the vital signs or laboratory parameters. No clinically significant dose-related adverse events were reported during the study. The absorption of ebrotidine was relatively rapid (tmax approximately 2 h) and linear within the dose range from 150 to 500 mg. Drug biotransformation was linear with doses tested, and no metabolic saturation occurred. The terminal elimination half-life of ebrotidine was between 7 and 11 h or even longer. There was no accumulation of ebrotidine and the steady state was reached, regardless of the dose administered, within the first 24-48 h.

Adult↗