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L Matas

Publications and source records attributed to L Matas.

68 records · Page 4Linked to original sources
PubMed1996

Evaluation of the disinfectant effect of Solprogel against human immunodeficiency virus type 1 (HIV-1).

The antiviral activities of sodium dichloroisocyanurate (NaDCC) and a commercial product (Solprogel 2%) against human immunodeficiency virus type 1 (HIV-1) were investigated using a quantitative suspension test method. Solprogel is a compound that contains NaDCC and a biodegradable polymer of acrylic acid. Viral suspensions were prepared containing 3.2 x 10(6) tissue culture infective dose 50 (TCID50) in culture media. Syncytium formation in the MT-2 line and HIV antigen p24 on the supernatant of the cultures were used to determine viral titre. Results indicate that satisfactory disinfection (1000-fold reduction in 5 min) can be achieved using NaDCC and Solprogel at concentrations of 100 and 120 ppm available chlorine, respectively.

Antiviral Agents↗
PubMed1996

Comparison of a biphasic non-radiometric system with Lowenstein-Jensen and Bactec-460 system for recovery of mycobacteria from clinical specimens.

SETTING: The resurgence of tuberculosis and the increase of Mycobacterium avium complex infections have renewed interest in developing more efficient systems for isolation of mycobacteria. The Bactec radiometric method enhances the recovery and shortens the detection time of mycobacteria; however, many clinical laboratories are subject to severe restrictions on the utilization of 14C radiolabelled culture media. OBJECTIVE: To compare the biphasic MB-Check system in the recovery of mycobacteria from clinical specimens with the Bactec-460 system and Lowenstein-Jensen (LJ) medium. DESIGN: The MB-Check was evaluated for routine use in a clinical laboratory by comparing the rates and times for isolation of mycobacteria from 1840 clinical specimens with results obtained using the other systems. The isolated organisms were identified by standard procedures and specific deoxyribonucleic acid (DNA) probes. RESULTS: The rate of recovery of all mycobacteria with the MB-Check system was 84.8%, compared to 87.5% for the Bactec-460 system and only 64.2% on LJ. Of the 147 M. tuberculosis isolates recovered by all methods combined, 92.5% were recovered by MB-Check, 87.1% by Bactec and 79.6% on LJ. Of the 109 isolates of nontuberculous mycobacteria (NTM) recovered by all methods combined, 44% were recovered on LJ, 75% by MB-Check and 88% by Bactec (P < 0.001). A combination of the Bactec and MB-Check systems allowed recovery of 99.2% of isolates. The Bactec system showed a faster detection time than the other two methods. CONCLUSION: The MB-Check and Bactec systems were more efficient than LJ medium for the isolation of both M. tuberculosis and NTM. The performance of the MB-Check system and the ease with which processing, inspection, detection, and isolation can be performed, indicated that the biphasic approach for cultivation of mycobacteria is feasible and practical. The MB-Check system is more suitable than Bactec system for laboratories that have a small number of specimens or in situations where the disposal of radioactive waste is a problem.

Bacteriological Techniques↗
PubMed1995

Prospective study of drug-resistant tuberculosis in a Spanish urban population including patients at risk for HIV infection.

From January 1988 to October 1992, the primary resistance to first-line antituberculous drugs in 501 tuberculous patients was evaluated prospectively. Three-hundred and seventeen patients were HIV-negative and 184 were HIV-positive; these patients had several different clinical forms of tuberculosis. Moreover, the acquired resistance to antituberculous drugs was studied in 295 non-AIDS patients and in 42 AIDS patients with evidence of antecedent tuberculosis treatment. The data indicated that during these five years there was no consistent and clear-cut trend toward greater frequency of primary drug resistance to any of the first-line antituberculous drugs. Primary drug resistance in HIV-positive patients (7.1%) did not differ significantly (p > 0.05) from that found in HIV-negative patients (8.2%). Among HIV-positive patients, the acquired drug resistance pattern was similar to that detected in HIV-negative patients although the frequency of resistance in the former (69%) was significantly higher (p < 0.01). During the study, resistance to isoniazid was almost constant in the acquired-resistance cases and was frequently associated with resistance to other drugs. Furthermore, the acquired resistance to isoniazid was often of a higher level (1 to 10 mg/l) than the primary resistance (0.2 mg/l), and those strains were usually catalase and peroxidase negative.

AIDS-Related Opportunistic Infections↗
PubMed1995

Inhibitory effect of sodium dodecyl sulfate in detection of Mycobacterium tuberculosis by amplification of rRNA.

The concentrations of sodium dodecyl (lauryl) sulfate (SDS) found in the sediments of the respiratory samples pretreated with SDS-NaOH varied between 3.36 and 12.42 mg/ml. These concentrations of SDS were higher than the level considered critical (> or = 0.16 mg/ml) to obtain negative results with the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test. Extensive washing, after neutralization of sediment, is sufficient to remove all traces of detergent which interfere with the enzymes used by the Mycobacterium Tuberculosis Direct Test assay.

Bronchoalveolar Lavage Fluid↗
PubMed1994

Role of bronchoalveolar lavage in mechanically ventilated patients with suspected pneumonia.

To determine the usefulness of samples obtained by bronchoalveolar lavage (BAL) in establishing the diagnosis of ventilator-associated pneumonia, quantitative cultures of BAL and protected specimen brush (PSB) samples obtained via fiberoptic bronchoscope were compared in 42 patients with suspected ventilator-associated pneumonia. Direct examination of BAL fluid was also used to identify cells with intracellular organisms. Ventilator-associated pneumonia was diagnosed in 18 patients; a total of 39 microorganisms were recovered from BAL fluid and 29 from PSB specimens. Cultures of 21 BAL and 23 PSB specimens were sterile. Quantitative BAL and PSB cultures coincided in 76% of cases. Sterile BAL and PSB cultures agreed in 87% of cases. Cultures were completely discordant in only three cases. The sensitivity of BAL for diagnosis of ventilator-associated pneumonia using bacterial counts of > or = 10(4) cfu/ml was 89%, and specificity was 100%. In 14 of the 18 patients with ventilator-associated pneumonia, the percentage of cells containing intracellular organisms in specimens recovered by BAL was 11.6% versus 0.45% in patients without pneumonia (p < 0.05). In the remaining four patients, all of whom had Pseudomonas aeruginosa pneumonia, no intracellular organisms could be detected. Using a cut-off point of > or = 5% of cells with intracellular organisms, the sensitivity and specificity for the early diagnosis of ventilator-associated pneumonia was 67% and 96%, respectively. The results confirm the usefulness of the quantitative BAL culture (with a cut-off at 10(4) cfu/ml) for the diagnosis of ventilator-associated pneumonia. The identification of intracellular organisms in BAL fluid is a good early indicator of pneumonia, but the sensitivity of this technique may be lower for Pseudomonas aeruginosa infections.

Adult↗
PubMed1975

Infants' reactions to an approaching stranger: description, validation, and functional significance of wariness.

Reliable descriptions of infants' behavioral responses to an approaching stranger were made from video records. Subtle negative responses (wariness) were validated against heart rate acceleration and responses to mother approach and showed significant age changes. Behavioral aspects of wariness appear to serve a "cutoff" (coping) function for the infant, preventing all-or-none responses (crying) and facilitating subsequent reengagement of the stranger. Attention to both positive and negative responses, especially in the milder forms, helps clarify inconsistencies in reported age of onset and frequency of "stranger fear." The role of data on infants' responses to strangers in formulating an integrated picture of development in the second half-year of life is discussed.

Age Factors↗
PubMedDate not supplied

[Bacteremia in 13 general hospitals of the province of Barcelona. Prospective study of 1,674 episodes. Group of Microbiologists of the County Hospitals of Catalonia].

BACKGROUND: Clinical and microbiological description of bacteremias seen in 13 regional hospitals of Barcelona. METHODS: From January to December of 1991 a multicenter prospective study of bacteremia in regional hospitals was performed. The filiation, clinical findings and microbiological results were registered according to a common protocol. RESULTS: We studied 1674 episodes of bacteremia (13.8 per 1000 admissions). Patients were distributed into 3 groups according to age: under 14: 204 patients, between 14 to 65: 759 and over 65: 711 patients. Men account for 55% and women for 45% of episodes. The bacteremia was hospital-acquired in 24.4% of cases. The most common foci of infection were: urinary tract (32%), respiratory tract (14%), intestinal tract (8%), intravascular catheter (7%), biliary tract (7%) and unknown (10%). The most commonly isolated strains were: Escherichia coli 544 cases, Streptococcus pneumoniae 212, Staphylococcus aureus 139, coagulase negative staphylococi 85, Non-typhoid Salmonella 66, Neisseria meningitidis 63, Pseudomonas sp. 59, Enterococcus sp. 59 and Bacteroides sp. 58. Polimicrobial bacteremia was detected in 83 episodes (5%). Related mortality rate was 9.6% (161 patients).

Adolescent↗
PubMedDate not supplied

[Neonatal infection by Streptococcus agalactiae. Multicenter study in the area of Barcelona, Spain].

BACKGROUND: Streptococcus agalactiae or streptococcus group B (SGB) is the main etiologic agent of early neonatal sepsis. A multicenter study was performed with the aim of determining the incidence and characteristics of this disease in our medium and contribute the design of an adequate prevention protocol. METHODS: Ten hospitals and two primary health care centers were implicated in the study; 103 microbiology confirmed episodes of SGB neonatal sepsis (blood and/or LCR positive) were reported from 1994 to 1996. RESULTS: The incidence of early SGB neonatal sepsis was 1.48/1,000 live births with a mortality of 8.7%. The cultures, for detecting the state of the SGB carrier were performed in only 26 (25%) of the patients. At least one of the factors described for risk of perinatal SGB infection was observed in 46% of the mothers, with the most frequent being prolonged amniorrhea (26%), intrapartum fever (17%), and early delivery (14%). At the time of delivery only 10.7% of the mothers received endovenous antibiotherapy. CONCLUSIONS: From these results the following recommendations have been made: a) detection of SGB carriers by the systematic practice of blood cultures in the last weeks of gestation and b) the administration of intrapartum antibiotic prophylaxis in both early births (< 37 weeks) and in all the SGB carriers should be undertaken. With these measures we aim to decrease the neonatal infections by streptococcus group B.

Adult↗