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M Llano

Publications and source records attributed to M Llano.

25 records · Page 2Linked to original sources
PubMed1994

Enhanced ELISA sensitivity using TCA for efficient coating of biologically active lipopolysaccharides or lipid A to the solid phase.

A new simple, reproducible and sensitive ELISA that uses trichloroacetic acid (TCA) for the coating of lipooligosaccharide (LOS), smooth lipopolysaccharide (LPS) or lipid A to the solid phase has been developed. The experimental parameters (temperature of coating, time of coating, antigen concentration and TCA concentration) were evaluated by a complete factorial design (2(4)). As a result of the evaluation, two main coating procedures were developed. In one, LOS was shown to coat efficiently in 0.2% TCA, at 37 degrees C, when incubated for only 30 min. In the other procedure, LOS in 0.2% TCA was coated at 37 degrees C for 16 h. The slower procedure proved, as expected, to be even more efficient than the former. The new ELISA was compared to three previously reported ELISAs, and showed the greatest sensitivity, probably, as a consequence of the higher coating efficiency of LOS to plates. The biologic activity of LOS was not modified by the low TCA concentration used, as proven by retention of its biological activity in the induction of procoagulant activity in blood mononuclear cells. We conclude that small amounts of biologically active LOS/LPS or lipid A can be coated on solid surfaces by this approach to achieve a rapid and economical assay procedure.

Animals↗
PubMed1992

Human monoclonal antibodies against an epitope on the class 5c outer membrane protein common to many pathogenic strains of Neisseria meningitidis.

Neisseria meningitidis is a causative agent of meningitis. Despite vaccination programs, it still causes a large number of deaths in young children. Early diagnosis followed by passive immunization with human monoclonal antibodies could be an approach to effective therapy. Peripheral blood lymphocytes from normal, healthy blood donors and from vaccinated individuals were immunized in vitro, using outer membrane proteins purified from N. meningitidis B:4:P1.15. The immunized human B cells were Epstein-Barr virus transformed and fused to a heteromyeloma. Several stable human hybridoma cell lines were established and two, secreting antibodies against the 31-kDa class 5c outer membrane protein, were characterized further. The human antibodies were of IgG1 and IgG3 isotypes, with kappa light chains. The recognized epitope was commonly found among pathogenic strains of N. meningitidis; thus, these human monoclonal antibodies may be important in the evaluation of N. meningitidis infections.

Animals↗
PubMed1990

Effect on urogenital flora of antibiotic therapy for urinary tract infection.

Specimens were examined from 70 female presenting with urinary tract infection. 50 patients were randomly treated with 7 days amoxicillin or bacampicillin and another 20 randomly received amoxicillin or enoxacin. Effective clearance of the infections was achieved with each antibiotic, and only minor side effects occurred. Bacteriological analyses of the urogenital flora demonstrated a relationship between urethral carriage and bladder infection, with Escherichia coli being the most common pathogen. Antibiotic resistant E. coli were isolated more frequently from the bladder, urethra, introitus and rectum following amoxicillin treatment compared to bacampicillin and enoxacin. An examination of the urogenital flora post therapy showed that an indigenous lactobacillus population had not been restored in the majority of patients. Rather, uropathogenic bacteria were found to dominate the urethra and introitus. The effects of antibiotics on urogenital flora is clearly a matter of importance. Future clinical trials should address this. It may be that artificial supplementation of indigenous bacteria is necessary to restore the flora back to normality.

Adolescent↗
PubMed1989

Aggregation by fragilis and non-fragilis Bacteroides strains in vitro.

Bacteroides fragilis is associated with the formation of intra-abdominal abscesses, whereas other Bacteroides species are rarely involved. Since bacterial clumping may contribute to the survival of bacteria in the face of host defence mechanisms, the hypothesis has been put forward that differences in aggregation between fragilis and non-fragilis strains of Bacteroides may account for their differences in survival in vivo. All seven B. fragilis strains tested formed aggregates within 4 h, but strains not associated with intra-abdominal sepsis--B. vulgatus, B. thetaiotaomicron and B. distasonis--did not form aggregates in vitro. Aggregation occurred at 37 degrees C, but not at 4 degrees C or 20 degrees C. Treatment with pronase partially inhibited aggregation. Periodate treatment killed the cells and caused them to form clumps which were distinguishable from the control aggregates. Heat-killed B. fragilis cells formed similar distinct clumps, but cells killed by glutaraldehyde and formaldehyde did so to a lesser degree. No inhibition was found upon addition of carbohydrates, ethylenediaminetetraacetic acid or after treatment with trypsin. These results demonstrate that aggregate formation occurs with B. fragilis strains alone, and that surface proteins probably mediate this interaction.

Bacteroides↗