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Biomedical subjects

E J Perea

Publications and source records attributed to E J Perea.

At least 109 records · Page 6Linked to original sources
PubMed1990

[Evaluation of an immunoenzyme technique for the diagnosis of syphilis].

A comparative study of an enzyme immunoassay (EIA Captia Syphilis Mercia), FTA-Abs and VDRL to detect anti-Treponema pallidum antibodies was carried out in overall 290 subjects: 113 had a diagnosis of syphilis (40 primary and 73 secondary) and 117 were controls (40 with nonsyphilitic ulcers, 52 with falsely positive VDRL and 85 healthy subjects). The overall correlations between EIA Captia and FTA and with VDRL were 92% and 72%, respectively. The sensitivity of the method was 82%, with 98% specificity.

Antibodies, Bacterial↗
PubMed1989

Effect of amoxycillin and clavulanic acid, alone and in combination, on human polymorphonuclear leukocyte function against Staphylococcus aureus.

The effect of amoxycillin and clavulanic acid on the interaction in vitro of human polymorphonuclear leukocytes with Staphylococcus aureus was examined. The exposure of a non-penicillinase producing Staphylococcus aureus strain to one-fourth the MIC of amoxycillin or clavulanic acid alone significantly increased the uptake of both unopsonized and opsonized bacteria by human polymorphonuclear leukocytes. This effect was also observed when bacteria were exposed to one-fourth the MIC of different proportions of the combination of amoxycillin and clavulanic acid (4/1, 1/1, 1/8 and 1/32). When a penicillinase-producing Staphylococcus aureus strain was used, only clavulanic acid significantly increased the uptake of unopsonized bacteria. The production of superoxide radicals by human polymorphonuclear leukocytes was impaired only by the presence of high concentrations (100 mg/l) of both clavulanic acid or the combination amoxycillin/clavulanic acid (4/1). At this high concentration, however, amoxycillin/clavulanic acid (4/1) significantly increased the intracellular killing of Staphylococcus aureus.

Amoxicillin↗
PubMed1989

Fluorometric measurement of ofloxacin uptake by human polymorphonuclear leukocytes.

A fluorometric assay, based on the natural fluorescence of the quinolone nucleus, was used to determine the uptake of ofloxacin by human polymorphonuclear leukocytes. The ratio of cellular concentration to extracellular concentration (C/E) at 20 min and 37 degrees C was 7.2, using an extracellular concentration of 5 micrograms/ml. Uptake was rapid and was not affected by pH (5 to 9), but required elevated environmental temperature and cell viability. The metabolic inhibitors sodium fluoride and sodium cyanide significantly decreased the uptake of ofloxacin. The penetration of ofloxacin was not affected by the presence of glucose or adenosine, but was decreased by L-amino acids (lysine, leucine, and glycine). These results suggest that ofloxacin could be transported via an amino acid transport system and that the fluorometric assay is a useful method for determining the intracellular penetration of fluoroquinolones, avoiding the use of radiolabeled antimicrobial agents.

Adenosine↗
PubMed1989

Effect of ciprofloxacin and ofloxacin on human polymorphonuclear leukocyte activity against staphylococci.

The interaction of ciprofloxacin and ofloxacin with the bactericidal capability of human polymorphonuclear leukocytes against staphylococci was investigated. Exposure of Staphylococcus aureus and Staphylococcus epidermidis to subinhibitory concentrations of ciprofloxacin and ofloxacin did not significantly affect the uptake and killing by human polymorphonuclear leukocytes. In our assay, ciprofloxacin and ofloxacin in concentrations of one time the minimal inhibitory concentration induced a significant reduction in viable intraphagocytic S. aureus (percentages of survival: 43 and 51%, respectively) compared to the controls without antibiotic (percentage of survival: 65%). In contrast, both antimicrobials failed to produce a reduction in viable intraphagocytic S. epidermidis.

Ciprofloxacin↗
PubMed1989

[Adhesion capacity and surface properties of Staphylococcus epidermidis and Staphylococcus saprophyticus].

We have comparatively studied the adherence of Staphylococcus epidermidis and S. saprophyticus to epithelial cells of a continuous cellular line of urinary origin (MDCK). The adherence of S. saprophyticus was significantly higher than that of S. epidermidis and this phenomenon was not related to the bacterial surface hydrophobicity or the ability of producing slime in vitro. The pre-incubation of the bacteria with sub-inhibitory concentrations of vancomycin, teicoplanin, amikacin, clindamycin, and roxitromycin did not modify the adherence ability of the microorganisms. Of the antimicrobial agents evaluated, only clindamycin significantly agents evaluated, only clindamycin, significantly inhibited the ability of producing slime of S. saprophyticus strains.

Animals↗
PubMed1989

[In situ hybridization with DNA probe for the diagnosis of Neisseria gonorrhoeae infections].

A comparative study of a DNA probe for the detection of Neisseria gonorrhoeae with Gram stain and modified Thayer-Martin medium was performed. The probe was the 2.6 megadaltons (Mda) cryptic plasmid of N. gonorrhoeae, labeled with a nonradioactive system combining sulphonation of DNA with the antibody detection of sulphonated groups (Organics Chemiprobe). Overall 101 samples were evaluated: 39 urethral exudates, 3 rectal exudates, and 59 cervical exudates, from 42 males and 54 females in whom gonococcal infection was suspected. Simultaneously, Gram stain and culture of the several exudates were carried out. The in vitro sensitivity of the method was evaluated with different dilutions of N. gonorrhoeae, from 1 to 1000 cfu/ml, and a minimum of 50 cfu/ml were detected. In the detection of N. gonorrhoeae in clinical samples, there was a 100% sensitivity and a specificity of 83% (males) and 79% (females), with positive predictive value of 97% in males and 53% in females. The negative predictive value was 100% both for males and females.

DNA Probes↗
PubMed1989

[Healthy carriers of enteropathogenic micro-organisms among the child population of Seville].

We have studied for 1-year period a group of 144 children (31 newborn infants, 62 aged 1 year and 51 aged 2 years) who were randomly selected from the registrar's office of Sevilla with the purpose of determining the incidence of diarrhoea and the prevalence of enteropathogenic microorganisms. Two samples of faeces (one at the beginning and the second by the second semester of the 1-year period) were obtained from all children which were processed for culture and parasite and rotavirus examination. We found a prevalence rate of enteropathogenic Escherichia coli carriers (EPEC) of 7%, of Giardia lamblia of 4% and of rotavirus of 14%. The state of EPEC was more frequent among children from high social-economic status. The state of G. lamblia carrier was six-fold higher in children with body weight alterations and in non-vaccinated or incompletely vaccinated children.

Animals↗
PubMed1989

[Genital herpes of mixed etiology].

The relevance of mixed genital infections in our area was evaluated, and we report their clinical and epidemiological features for both viral types. We evaluated overall 54 Herpes simplex virus (HSV) isolates from 44 patients seen at the clinic of sexually transmitted diseases (STD) of the Sevilla School of Medicine during 1986 and 1987. The identification of the isolated strains was made by direct immunofluorescence with type-specific monoclonal antibodies. In those isolates where we detected both viral types confirmation was obtained with the endonuclease analysis: Hind III and Xho I. Four mixed infections were diagnosed, representing 7% of all HVS isolates of genital origin. Two were classified as initial nonprimary infections, and the remaining two were asymptomatic infections. Two patients showed simultaneous infections by other organisms.

Adult↗
PubMed1988

Interaction of aminoglycosides and cephalosporins against Pseudomonas aeruginosa. Correlation between interaction index and killing curve.

Three multiresistant clinical isolates of Pseudomonas aeruginosa were evaluated, by the chequerboard and the killing curve methods, for in-vitro synergy between cephalosporins and aminoglycosides. The killing-curve method was standardized to give results comparable with those obtained with the chequerboard test (FIC index). This was achieved with combinations showing synergy by chequerboard (FIC less than or equal to 0.75) by using in the killing curves subinhibitory concentrations: half the MIC in single antibiotic assay and one eighth the MIC in the combinations. For combinations that showed indifference by chequerboard (FIC = 1) half the MIC was used for antibiotics alone and in combination. For the antagonistic combinations by chequerboard (FIC greater than 2) concentrations equal to the MIC were used with single antibiotics and combinations in the killing curve experiments. Prediction of killing curve results could then be obtained with the FIC index. The killing curve results could not be explained by pH changes or inactivation of the antibiotics.

Amikacin↗
PubMed1988

Penetration of cefuroxime and ceftazidime into human lungs.

We have studied the penetration of cefuroxime and ceftazidime into lung tissue of 40 patients subjected to pulmonary surgery. Samples of blood and lung tissue were taken 1 and 2 h after antibiotic administration. Patients were randomly assigned to four dosage schedule groups: group A received a single intravenous injection of 750 mg cefuroxime; the lung tissue levels at 1 and 2 h were 9.6 +/- 3.1 and 4.54 +/- 2.64 micrograms/g of cefuroxime; the percentage penetration from serum into the lung tissue was 33.7 and 34.6%, respectively. Group B patients received three doses of 750 mg cefuroxime; lung tissue levels were 17.1 +/- 7.7 and 14.7 +/- 5.4 micrograms/g, the percentage of penetration being 89.1 and 102.8% at 1 and 2 h. Group C received a single intravenous injection of 1 g ceftazidime; the lung tissue levels were 16.3 +/- 10.1 and 10 +/- 5.04 micrograms/g; the percentage of penetration from serum was 38.3 and 35.3%. Group D received three doses of 1 g ceftazidime; the lung tissue concentrations were 11.98 +/- 7.5 and 8.5 +/- 7.3 micrograms/g and the percentage of penetration 35.1 and 32.2% at 1 and 2 h after last dose.

Adult↗
PubMed1987

Prevalence of anti-Legionella pneumophila antibodies in various groups with different risk factors in Seville (Spain).

A study was undertaken to establish the background prevalence of antibodies to L. pneumophila in 324 persons from the area of Seville, Spain. The serum specimens were obtained from healthy volunteers divided into groups with different risk factors. The results were as follows: a prevalence of 1.96% in 51 persons working in a cooling-tower air conditioned building (group A), a prevalence of 25% in 36 persons working in a dry-heat air conditioned building (group B), a prevalence of 16% in 87 underground construction workers (group C) and a prevalence of 1.2% in 150 healthy blood donors with none of the above risk factors (group D). There is statistical significance between D and B and C.

Adolescent↗
PubMed1987

Single doses of ofloxacin in uncomplicated gonorrhoea.

The clinical efficacies of 2 different single-dose oral treatments of ofloxacin were evaluated in a double-blind, randomised study of 60 males with gonococcal urethritis. 30 patients received a single dose of ofloxacin 100mg and 30 received a single dose of ofloxacin 200mg. The minimal inhibitory concentrations of ofloxacin against all isolates were less than or equal to 0.25 mg/L. Neisseria gonorrhoeae was eradicated from all 50 patients evaluated and clinical cure was achieved in 84%. In total, 8 patients developed post-gonococcal urethritis, although there was a significantly (p less than 0.05) lower rate of post-gonococcal urethritis in the group treated with ofloxacin 200mg. In conclusion, a single oral dose of ofloxacin 100mg could be an alternative treatment for uncomplicated gonorrhoea.

Adolescent↗
PubMed1987

Effect of subinhibitory concentrations of ampicillin on the R plasmid transfer in Escherichia coli.

The effects of subinhibitory concentrations (sub-MICs) of ampicillin on R plasmid transfer in Escherichia coli were studied. Each donor strain culture was separated into two parts; one was mixed with a recipient strain culture for mating, the other was treated with the sub-MIC of ampicillin and then mixed with the recipient strain culture. In both cases the R plasmid transfer frequency was determined at 30, 60, 90 and 120 min of mating. Results showed that there exists a general decrease in the transfer frequencies under sub-MIC treatment (two plasmids did not transfer at all). The proportion of aggregates and the number of cells that compose them were not affected by the sub-MIC of ampicillin. Our study supports the idea that the changes induced in E. coli by sub-MICs of ampicillin did not affect the function of the surface structures responsible for aggregation but did affect the proteins implicated in DNA transfer, situated on the cell surface.

Ampicillin↗
PubMed1986

Efficacy of ofloxacin (HOE 280) in a model of subcutaneous abscess: penetration and prevention of abscess formation.

A mouse model of subcutaneous abscess was used to determine the penetration into the abscess and the preventive value of ofloxacin (Hoe 280). Sterile cecal contents were injected subcutaneously combined with three different types of inoculum: Bacteroides fragilis, Escherichia coli and E. coli plus B. fragilis. For penetration studies three doses of 20 mg/kg of ofloxacin were administered intraperitoneally 8 hourly after abscesses had formed. Serum levels at 10, 20, 30, 60 and 90 min after the last dose showed mean values of: 6.9, 4.7, 3.8, 2.35 and 1.08 mg/l respectively. Simultaneously assessed ofloxacin abscess levels were 3.6, 4.1, 2.4, 1.91 and 1.98 mg/kg. In order to evaluate its preventive value, ofloxacin was given intraperitoneally at doses of 20 mg/kg in four regimens. Regimen A: one dose immediately before injection of the inoculum; regimen B: one dose 4 h after the injection of the inoculum; regimen C: one dose immediately before and two doses 8 h and 16 h after injection of the inoculum and regimen D: one dose 4 h, 12 h and 20 h after injection of the inoculum. The results are expressed as the percentage of the reduction in the number of abscesses formed in the survivors versus the control groups: regimens A) 30 to 70%; B) 0 to 40%; C) 50 to 60%, and D) 10 to 60%. The viable bacterial counts in the abscess contents were also assessed.

Abscess↗
PubMed1986

Effect of medium, pH, and inoculum size on activity of ceftizoxime and Sch-34343 against anaerobic bacteria.

The effect of two media, three pH values, and three inoculum densities on the activity of ceftizoxime and Sch-34343 against anaerobic bacteria was evaluated. The activities of both antimicrobial agents were affected by medium composition, especially against Bacteroides fragilis. Changes in pH and inoculum size affected only the activity of ceftizoxime against anaerobic bacteria.

Anti-Bacterial Agents↗