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L Jimenez

Publications and source records attributed to L Jimenez.

34 records · Page 2Linked to original sources
PubMed1983

Vi serology in detection of chronic Salmonella typhi carriers in an endemic area.

A passive haemagglutination assay measuring antibody to highly purified Vi antigen, known to be sensitive and specific for the detection of chronic Salmonella typhi carriers in a non-endemic area, was assessed in an endemic area. A reciprocal serum Vi antibody titre of 160 was found to have a sensitivity of 75%, specificity of 92%, and a high predictive value in screening for chronic S typhi carriers in high-risk population group (eg, women over 40 years). This simple assay can screen for chronic S typhi carriers even in areas where typhoid fever is highly endemic.

Adolescent↗
PubMed1983

Community-acquired bacterial pneumonia requiring admission to hospital.

Patients who develop bacterial pneumonia in the community often require admission to acute-care hospitals. Knowledge of the incidence of pneumonia due to different pathogens that are brought into an institution from the community may play a role in determining the patterns of infecting organisms responsible for hospital-acquired pneumonia. For 1 year, we prospectively reviewed the records of patients admitted to our 1000-bed community hospital with community-acquired bacterial pneumonia (CABP). Patients had clinical signs and symptoms, positive radiologic findings, and pure cultures of potential pathogens from sputum, blood, pleural fluid, lung aspirate, lung biopsy, or transtracheal aspirate. Pneumonia due to Legionella pneumophila was diagnosed by serum indirect fluorescent antibody (IFA) titer greater than or equal to 1:256 and clinical signs and symptoms along with response to erythromycin. Of 204 patients with bacterial pneumonia, the following pathogens were implicated: Streptococcus pneumoniae, Haemophilus species, L. pneumophila, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, oral anaerobic bacteria, Psuedomonas aeruginosa, Serratia marcescens, and others. Most patients were more than 50 years of age and many had evidence of underlying pulmonary disease. The etiology of CABP may not be as predictable as in the past. Empiric antimicrobial therapy for CABP should include agents with activity against the pathogens prevalent in the community.

Adult↗
PubMed1983

Prevalence of bancroftian filariasis in the city of Puerto Limón and the province of Limón, Costa Rica.

Examination of blood from randomly selected residents in four subdivisions of Puerto Limón, Costa Rica, demonstrated Wuchereria bancrofti infection in 1.8% of 2,879 persons. Previous studies in four other subdivisions of the city revealed infection in 2.7% of 2,338 persons. In both studies the microfilaremia rate in males was approximately twice that in females. Distribution by race was similar in the two surveys, with microfilaremia in 1% of 1,052 white and 4.1% of 1,286 black residents in the first survey and 0.8% of 2,216 white and 5.4% of 663 black residents in the second. The highest rate of infection was in the 10-to 19-year-old and over 40-year-old age groups. In 13 rural communities near Puerto Limón, infection was found in only three (0.1%) of 3,448 individuals (27% of the population). Dissection revealed filarial larvae in 164 (6%) of 2,714 female Culex pipiens fatigans captured in 137 of 140 urban houses and in none of 936 from rural houses. Precipitin tests on stomach contents of 643 C. p. fatigans showed that 85% had taken human blood. The results indicate that endemic bancroftian filariasis in the Puerto Limón area is restricted to the urban population.

Adolescent↗
PubMed1975

Impairment of mitochondrial respiratory control by activated lymphocytes.

Mitochondria isolated from rat livers were used as a source of antigens capable of producing in vitro activation of lymphocytes that had previously been sensitized in vivo with the same antigen. Such lymphocytes were shown to have an injurious effect on target mitochondria, as was demonstrated by a new biochemical approach based on the study of the inhibition by these cells of mitochondrial respiratory control. A somewhat milder injurious capacity was also observed in normal and sensitized lymphocytes activated in vitro with the mitogen PHA. The lateration of the respiratory control of mitochondria by lymphocytes correlated with an increase in DNA synthesis in these cells.

Adenosine Diphosphate↗
PubMed1971

On the number and nature of antigen-sensitive lymphocytes in the blood of delayed-hypersensitive human donors.

The virus plaque assay has been successfully employed to enumerate antigen-sensitive cells in the peripheral blood lymphocyte populations of tuberculin-hypersensitive human donors. The method is based on the finding that, while resting lymphocytes are unable to produce a variety of viruses upon infection, lymphocytes activated by specific antigens become capable of virus replication. The average number of antigen-sensitive cells detected in cell populations from donors reacting to first test strength or intermediate test strength tuberculin was approximately 3.6/1000 lymphocytes, and the averages for both groups were similar. Studies on the kinetics of appearance of these virus plaque-forming cells and on the effects of the mitotic inhibitor, vinblastine, indicate that the activation of these antigen-sensitive cells is a linear process and that the cells must be nondividing cells during this process. These qualities contrast markedly with those described for the mitogenic response and the antibody-producing cells which require cell division and increase exponentially. On the basis of these experiments it is suggested that the antigen-sensitive cell measured in the virus plaque assay is the effector cell in delayed-type hypersensitivity reactions and, in addition, may be one of the cells critically involved in antibody formation.

Antibody-Producing Cells↗
PubMed1970

A plaque assay for enumerating antigen-sensitive cells in delayed-type hypersensitivity.

A general method is described for enumerating antigen-sensitive lymphocytes obtained from individuals having delayed hypersensitivity, in this case from highly tuberculin-sensitive guinea pigs. The method is based on the observation that resting lymphocytes are generally unable to support replication of RNA viruses, whereas antigen-"activated" lymphocytes can. Lymph node lymphocytes from individual animals were cultured in the presence or absence of tuberculin purified protein derivatives (PPD). After various periods of time, the cells were infected either with Newcastle disease virus or vesicular stomatitis virus, and plated in agar over a monolayer of cells susceptible to the virus. Wherever a lymphocyte yielded infectious virus, a discrete plaque in the monolayer could be seen. The increase in plaques of the antigen-stimulated cells over the background of the control sample was taken as the number of antigen-sensitive cells in the population. When lymphocytes from normal guinea pigs or from guinea pigs immunized to produce only circulating antibody to PPD were similarly tested, no increase in plaque-forming units (PFU) was observed. The average increase in PFU due to antigenic stimulation varied from 1 per 1000 lymphocytes at 24 hr to 16 per 1000 lymphocytes at 96 hr. By employing inhibitors of mitosis (colchicine, vinblastine, and thymidine) it was evident that the increase in PFU at least up to 48 hr was primarily due to initial antigen-reactive cells and not their progeny.

Animals↗
PubMedDate not supplied

Molecular detection of Burkholderia cepacia in toiletry, cosmetic, and pharmaceutical raw materials and finished products.

A polymerase chain reaction (PCR) assay was developed and compared with standard methods for rapid detection of Burkholderia cepacia, a major industrial contaminant, in cosmetic and pharmaceutical raw materials and finished products. Artificially contaminated samples were incubated for 24 h in trypticase soy broth containing 4% Tween 20 and 0.5% soy lecithin. DNA was extracted from each sample using a proteinase K-tris-EDTA-Tween 20 treatment at 35 degrees C. The extracted DNA was added to Ready-To-Go PCR beads and specific DNA primers for B. cepacia. The B. cepacia DNA primers coded for a 209-base pair (bp) fragment of the 16S rRNA ribosomal gene. No DNA amplification was observed in samples that were not spiked with B. cepacia. However, all contaminated samples showed the specific 209-bp fragment for B. cepacia. There was a 100% correlation between standard methods and the PCR assay. Standard microbiological methods required 5-6 days for isolation and identification of spiked microorganisms, whereas PCR detection and identification was completed in 27 h. PCR detection of B. cepacia allows for rapid quality evaluation of cosmetic and pharmaceutical raw materials and finished products.

Burkholderia cepacia↗
PubMedDate not supplied

Molecular diagnosis of microbial contamination in cosmetic and pharmaceutical products: a review.

Molecular methodologies such as adenosine triphosphate (ATP) bioluminescence and polymerase chain reaction (PCR)-based assays provide rapid quality control analysis of cosmetic and pharmaceutical finished products and raw materials. Using a single enrichment broth for bacteria, yeast, and mold, ATP bioluminescence detected microbial contamination within 27 h. Samples were automatically lysed to release microbial ATP and light production was quantitated using the Celsis Optocomp. However, to maintain the detection time to within 27 h, different enrichment broths were required for neutralization of antimicrobial ingredients in finished products and to provide specific nutrients for growth optimization. To perform the PCR reaction, bacterial DNA was extracted using a Tris-EDTA-Tween 20-proteinase K buffer at 35 degrees C while yeast and mold DNA were extracted using a Tris-EDTA-SDS buffer at 95 degrees C. Extracted microbial DNA was added to Ready-To-Go PCR beads and specific DNA primers. The primers were targeted to amplify specific regions within Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhimurium, Burkholderia cepacia, Candida albicans, and Aspergillus niger. Furthermore, conserved bacterial ribosomal DNA sequences have also been used for sterility testing of samples. The results from these studies indicate that both ATP bioluminescence and PCR assays provide rapid, reliable, and cost effective methods for quality evaluation. This will ultimately result in faster product release and production optimization.

Adenosine Triphosphate↗
PubMedDate not supplied

Rapid methods for the microbiological surveillance of pharmaceuticals.

The use of rapid microbiological methods in pharmaceutical laboratories has improved the quality control analysis of water, products, raw materials, and enhanced the antimicrobial effectiveness testing of pharmaceutical finished products. Rapid release of samples has resulted in the optimization of manufacturing, product testing, and release allowing high throughput and simultaneous analysis of pharmaceutical formulations. ATP Bioluminescence, Impedance, Direct Viable Counts, and Flow Cytometry determine the total microbial content in a given pharmaceutical sample while PCR and Immunoassays detect the presence or absence of specific microbial species. Rapid methods provide reliable and cost effective analysis for the microbiological evaluation of pharmaceutical environments. The dramatic reduction in detection times and analysis, e.g., from 30 hours to 90 minutes, by using rapid methods will ultimately lead the pharmaceutical industry closer to real time monitoring of processes and samples.

Colony Count, Microbial↗
PubMedDate not supplied

PCR detection of Salmonella typhimurium in pharmaceutical raw materials and products contaminated with a mixed bacterial culture using the BAX system.

The BAX system, a PCR-based assay, was evaluated for detecting Salmonella typhimurium in pharmaceutical raw materials and products contaminated with mixed bacterial cultures of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhimurium. Artificially contaminated samples were preenriched in lactose broth with and without Tween 20. After preenrichment, samples were analyzed by PCR and standard methods. Ten of 25 samples did not show presence of the specific Salmonella spp. 740-base pair DNA fragment. However, S. typhimurium was isolated and identified by standard methods from all 25 samples. To optimize S. typhimurium detection in PCR negative samples, lactose broth was replaced by buffered peptone water (BPW) as the preenrichment broth. When BPW was used, all 10 samples were PCR positive. BPW enrichments increased S. typhimurium growth resulting in rapid PCR detection. The presence of non-Salmonella bacteria influenced the performance of the PCR-based assay. Optimization of S. typhimurium PCR detection in mixed culture required the use of different preenrichment broths. However, the BAX system detected S. typhimurium within 27 hours while standard methods required 5-7 days.

Culture Media↗