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Biomedical subjects

G Prats

Publications and source records attributed to G Prats.

At least 109 records · Page 6Linked to original sources
PubMed1991

Evaluation of different catheter parts for identification of pulmonary artery catheter colonisation.

A prospective study was conducted over 18 months to evaluate the accuracy of the semiquantitative culture technique performed from different catheter parts for detection of catheter colonisation in critically ill patients with pulmonary artery catheters. Semiquantitative culture of the tip catheter segment alone detected 66% of catheter colonisations. Semiquantitative culture of the other intravascular catheter segments (atrial or intradermal) provided similar yield. A combination of intradermal and atrial or tip catheter segment cultures provided the best means of detecting catheter colonisation.

Bacteria↗
PubMed1991

[Detection of pneumococcal capsular polysaccharide antigen in urine by counterimmunoelectrophoresis. Technical features and correlation with serotype].

The effectiveness of CIE in detecting capsular polysaccharide antigen of pneumococci in urine is revised. Using CIE, we studied urine samples from 57 patients with systemic pneumococcal infections, proved bacteriologically by means of isolation of the microorganisms from sterile sites. We compare the usefulness of CIE with the microorganism isolation from organic products. We also determine the sensitivity gain after passive diffusion at 4 degrees C and bright blue Coomasie staining (CBB R-250). We correlate the CIE results with the serotype of isolated pneumococci. CIE was positive in 17 of all 35 pneumonia cases (48.6%), in 2 of all 5 bacteremias (40%), 4 of all 15 meningitis (26.7%) and in none of all two peritonitis. Direct urine examination was positive in 12 out of 23 patients with positive CIE (52.2%) and concentrated urine in 22 patients (95.6%). Passive diffusion at 4 degrees C and CBB R-250 stain increases the positive rate of the test. The correlation of serotype with our results is difficult due to the wide variety of serotypes identified. However, particular serotypes such (3, 4 or 8) had been identified with increased sensitivity. Global sensitivity of CIE in detecting capsular polysaccharide antigen in urine samples is not high enough (40.3%), even under the best circumstances. Antigen detection in urine is more sensitive than blood cultures, and therefore we believe that could be used in clinical microbiology laboratories until a more effective method is available.

Antigens, Bacterial↗
PubMed1991

[Value of studying the extraluminal and intraluminal surfaces in the detection of catheter colonization].

612 catheters have been prospectively investigated. In all of them, both the external and the internal surfaces were cultured, the former with the semiquantitative technique of Maki and the latter with the semiquantitative technique of Liñares. 102 of the 469 central venous catheters (22%), 21 of 70 catheters used for parenteral nutrition (30%), and 19 of the 73 arterial catheters (26%) were positive with one or both techniques. The external surface was positive in 95% of central venous catheters, in 90% of the parenteral nutrition catheters, and in 95% of the arterial catheters, whereas the internal surface was positive in only 59%, 62% and 42%, respectively. The routine study of the internal surface of the catheters does not appear as justified. In our opinion, the microbiological study of catheters should be individualized depending on the relative importance of the skin or the connections in a particular catheter type. The quantitative study of the intraluminal surface should only be carried out in those catheters where connections represent a significant pathogenetical route. These catheters constitute only a small proportion of those that we receive for culture in the Microbiology Laboratory; therefore, this approach represents a considerable simplification of our daily routine.

Bacteria↗
PubMed1990

Risk factors for Staphylococcus aureus nosocomial pneumonia in critically ill patients.

Staphylococcus aureus nosocomial pneumonia has become an important infection not only because of an apparently increasing incidence but also because of its high mortality rate. A total of 50 episodes of nosocomial pneumonia in critically ill patients in which etiologic diagnosis was well established were prospectively followed in a medical-surgical intensive care unit (ICU). S. aureus was isolated in a total of 13 episodes. In the univariate analysis the variables significantly associated with S. aureus nosocomial pneumonia were below 25 yr of age, coma, nonuse of corticosteroids, and antecedent trauma. A step-forward logistic regression analysis defined only coma as significantly influencing the risk of developing S. aureus nosocomial pneumonia. We suggest that antimicrobial drugs active against S. aureus must be included in the initial empirical antimicrobial regimen for treating nosocomial pneumonia in patients with coma. The identification of factors influencing the etiology and the possibility of earlier effective antimicrobial treatment may represent a further step in the control of nosocomial pneumonia in critically ill patients by improving its prognosis.

Adult↗
PubMed1990

[Primary and initial bacterial resistances in tuberculosis patients at a general hospital, 1983-1987].

From july 1982 to december 1987 we prospectively evaluated the primary resistance (PR) of 248 strains of M. tuberculosis isolated from patients with several clinical forms of tuberculosis. The results were compared with those of a similar study carried out between 1978-1982. PR persisted relatively stable with time, although it showed a trend towards reduction. Isoniazide resistance (4.8%) still has a leading epidemiological interest. The 89% of strains showed isolated resistance to a single drug. Only two strains had associated resistance to INH and SM. Strains with PR to RIF, ETB or PZA were not detected. Of the 248 evaluated strains, 32 were isolated from intravenous drug abusers with AIDS. Only one of these strains had a low level (0.2 mg/l) PR to INH. At last two of these drug abusers developed acquired resistance to INH and ETB-RIF, respectively. Considering the difficulty to control chemotherapy in this group of patients, our finding has a considerable epidemiological interest.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Detection of early cytomegalovirus antigen in cell culture].

The reference technique for the diagnosis of active cytomegalovirus infection is the isolation in cellular culture. Its major drawback is the interval between the inoculation of the sample and the development of the characteristic cytopathic effect. Occasionally, this delay may be longer than four weeks. The centrifugation of the sample on the cell monolayer at the time of inoculation and the use of a fluorescein-labeled monoclonal antibody for the detection of the early antigen in cells may considerable reduce the time required for the diagnosis of cytomegalovirus infection. In the present study the technique of detection of the early antigen by immunofluorescence was compared with conventional cell culture in 258 clinical samples referred to the laboratory for study. Fifty-one of them were positive: 28 with both techniques, 12 only with cell culture and 11 only with immunofluorescence. The mean time to obtain positive results was 25 hours for immunofluorescence and 13 days for culture.

Antigens, Viral↗
PubMed1989

A serological survey of toxocariasis in patients and healthy donors in Barcelona (Spain).

The ELISA test, using excretory-secretory antigen from larvae II of Toxocara canis, was applied on 1018 sera (793 from adults and 225 from pediatrics) distributed in: A) patients with an hypereosinophilia where the ethiological agent was undetermined (99); B) patients with ocular complaints compatible with an ocular toxocariasis (116); C) patients with hidatidosis (97); D) patient with other non-toxocaral helminthiasis (34); E) patients with other clinical features (468) and F) healthy donors (204). Over 3,6% of sera showed elevated levels of antibodies reacting with T. canis antigen. The prevalence of seropositivity was statistically higher in patients with eosinophilia (14,1%) (a less than 0,001) and ocular complaints (6%) (0,025 greater than alpha greater than 0,01) than in the control group (1%). In the overall seropositivity from pediatrics did not differ from that of the adults.

Animals↗
PubMed1989

[Characterization of immunogenic proteins from Echinococcus granulosus with the immunoblot technique].

The serological response to Echinococcus granulosus was evaluated by immunoblotting in 20 patients with hydatid disease. In non-reducing conditions, the highest reactivity corresponded to 80, 66 and 56 kd proteins, while in reducing conditions only one 36 kd protein was detected. A low molecular weight component which moved with the migration front of gels was also detected. In reducing conditions the activity was less marked. Immunoblotting permits the identification of specific immunogenic proteins and the improvement of the serologic diagnosis of hydatid disease, as it eliminates the problem of low titer nonspecific reactions with serological tests using complex antigens.

Animals↗
PubMed1988

Prospective study on the etiology of community-acquired pneumonia in children and adults in Spain.

The cause of primary pneumonia was diagnosed in 157 of 198 children and 165 of 207 adults seen as inpatients or outpatients in a 12-month period. In children Mycoplasma pneumoniae and pneumococcus were identified in 79 and 29 cases respectively. Twenty-nine of 53 cases of viral infection in children were caused by respiratory syncytial virus, two-thirds of the cases occurring in children under three years of age. No children died of pneumonia. In adults pneumococcus was the most common pathogen, accounting for 81 cases. The overall mortality in adults was 7.7%. A high mortality was found in patients with Haemophilus influenzae and other gram-negative bacilli infections, and in elderly patients with pneumococcal pneumonia. Coagglutination was more sensitive than counterimmunoelectrophoresis for the detection of pneumococcal antigen in respiratory samples (p less than 0.001). Counterimmunoelectrophoresis was the only useful technique for detection of pneumococcal antigen in urine specimens, concentration, overnight storage at 4 degrees C and specific staining significantly increasing positivity (p less than 0.001).

Adult↗