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Joaquín Zúñiga,
Martha Torres,
Javier Romo,
Diana Torres,
Luis Jiménez,
Gustavo Ramírez,
Alfredo Cruz,
Enrique Espinosa,
Teresa Herrera,
Ivette Buendía, [......],
Fernando Hernández,
Jorge García, Francisco Quiñones-Falconi,
Eduardo Sada,
María E Manjarrez,
Carlos Cabello,
Simón Kawa,
Albert Zlotnik,
Annie Pardo,
Moisés Selman
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ABSTRACT: The immune mechanisms underlying the pathogenesis of severe pneumonia associated with the A/H1N1 virus are not well known. The objective of this study was to determine whether severe A/H1N1-associated pneumonia can be explained by the emergence of particular T-cell subsets and the cytokines/chemokines they produced, as well as distinct responses to infection. T-cell subset distribution and cytokine/chemokine levels in peripheral blood and bronchoalveolar lavage (BAL) were determined in patients with severe A/H1N1 infection, asymptomatic household contacts, and healthy controls. Cytokine and chemokine production was also evaluated after in vitro infection with seasonal H1N1 and pandemic A/H1N1 strains. We found an increase in the frequency of peripheral Th2 and Tc2 cells in A/H1N1 patients. A trend toward increased Tc1 cells was observed in household contacts. Elevated serum levels of IL-6, CXCL8, and CCL2 were found in patients and a similar cytokine/chemokine profile was observed in BAL, in which CCL5 was also increased. Infection assays revealed that both strains induce the production of several cytokines/chemokines at 24 and 72 h, however, IL-6, CCL3, and CXCL8 were strongly up-regulated in 72-h cultures in presence of the A/H1N1 virus. Several inflammatory mediators are up-regulated in peripheral and lung samples from A/H1N1-infected patients who developed severe pneumonia. In addition, the A/H1N1 strain induces higher levels of pro-inflammatory cytokines and chemokines than the seasonal H1N1 strain. These findings suggest that it is possible to identify biomarkers of severe pneumonia and also suggest the therapeutic use of immunomodulatory drugs in patients with severe pneumonia associated with A/H1N1 infection.
Autoimmunity 08/2011; 44(7):562-70. · 2.47 Impact Factor
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ABSTRACT: Laboratory services for the detection of tuberculosis form an essential component of the DOTS strategy. Our objective was to evaluate the recovery rate and mean time to detection (TTD) of mycobacteria of 2 culture media: the VersaTREK system and the Löwenstein-Jensen medium (LJ). Clinical specimens were processed using the standard N-acetyl-L-cysteine (NALC)-NaOH method, and then inoculated onto VersaTREK system and LJ slants. Of 1510 specimens cultured, a total of 200 mycobacterial isolates (159 Mycobacterium tuberculosis and 41 no M. tuberculosis mycobacteria) were detected. The recovery rates were 84.8% (168/198) for the VersaTREK system and 89.4% (168/188) for LJ (p=0.2); while the contamination rates were 4.2% for the VersaSATREK system and 7.4% for LJ (p<0.001). The TTDs for mycobacteria spp. were 18.2 (+/-11.4) d for the VersaTREK system and 27.9 (+/-10.9) d for LJ (p<0.001). The TTDs for M. tuberculosis were 19.8 (+/-11.2) d for the VersaTREK system and 27.3 (+/-10.2) d for LJ (p<0.001). The difference in TTD between smear-positive and smear-negative specimens for Mycobacterium spp. was 15.9 (+/-10.0) vs 23.0 (+/-12.5) d, and for M. tuberculosis 16.7 (+/-9.5) vs 28.4 (+/-11.1) d for the VersaTREK system. The VersaTREK system significantly reduces the TTDs of mycobacteria detection, which is clinically relevant.
Scandinavian Journal of Infectious Diseases 02/2008; 40(1):49-53. · 1.72 Impact Factor
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ABSTRACT: Recycled treated or untreated wastewater represents an important health challenge in developing countries due to potential water related microbiological exposure. Our aim was to assess water quality and health implications in a Mexico City periurban agricultural area.
A longitudinal study in the Xochimilco wetland area was conducted, and 42 sites were randomly selected from 211, including irrigation water canals and effluents of treatment plants. Sample collection took place during rainy and dry seasons (2000-2001). Microbiological parameters (total coliforms, fecal coliforms, streptococci/enterococci, and bacteria other than Vibrio grown on TCBS), Helicobacter pylori, and physicochemical parameters including trihalomethanes (THM) were determined. Fecal coliforms and fecal streptococci are appropriate indicators of human or animal fecal contamination. Fecal coliform counts surpass Mexican and World Health Organization irrigation water guidelines. Identified microorganisms associated with various pathologies in humans and domestic animals comprise Escherichia coli, Klebsiella spp., Salmonella spp., Enterobacter spp., Enterococcus spp., and Pseudomonas spp; H. pylori was also present in the water. An environmental characteristic of the canal system showed high Total Organic Carbon content and relatively low dissolved oxygen concentration; residual chlorine as a disinfection control is not efficient, but THMs do not represent a problem. During the rainy season, temperature and conductivity were higher; in contrast, pH, dissolved oxygen, ammonia, and residual chlorine were lower. This is related with the continuous load of feces from human and animal sources, and to the aquatic systems, which vary seasonally and exhibit evidence of lower water quality in effluents from treatment plants.
There is a need for improvement of wastewater treatment systems, as well as more efficient monitoring, regulation, and enforcement procedures for wastewater disposal into bodies of water.
PLoS ONE 02/2008; 3(5):e2305. · 4.09 Impact Factor
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ABSTRACT: The susceptibility to 14 beta-lactam and non-beta-lactam antimicrobial agents was evaluated for Streptococcus pneumoniae from patients with community-acquired respiratory infections in a Mexican medical center. Three hundred fifteen pneumococcal isolates obtained from patients between 1995 and 2001 were tested by the broth microdilution test. Fifty-two percent of the isolates were nonsusceptible to penicillin (minimal inhibitory concentration, >0.06 microg/mL). Penicillin-nonsusceptible isolates were more likely to exhibit resistance to cephalosporins, macrolides, ciprofloxacin, trimethoprim/sulfamethoxazole, chloramphenicol, and tetracycline when compared to penicillin-susceptible isolates. Ninety-three percent of the penicillin-nonsusceptible isolates were resistant to at least one other class of antimicrobials, in contrast to only 47% of the penicillin-susceptible strains (p < 0.0001). More than 90% of the tested isolates were susceptible to amoxicillin/clavulanate, ceftriaxone, levofloxacin, and gatifloxacin. Reduced susceptibility to penicillin was considered to be a reliable marker for the higher probability of multidrug resistance, thus requiring in vitro tests to guide chemotherapy or the choices of parenteral extended spectrum cephalosporins or newer respiratory quinolones.
Diagnostic Microbiology and Infectious Disease 06/2004; 49(1):53-8. · 2.53 Impact Factor
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ABSTRACT: It has been described an increase of the frequency of Directly Observed Therapy Short-course (DOTS) failure in countries with high rates of mycobacterial drug resistance. This increase could be due to the standardized doses of DOTS results in low or insufficient dosage of drugs in plasma. Several members of cytochrome P450 enzymes superfamily could explain the variations on acetylation velocity and in drug disposition. A population with slow acetylation has a higher risk of toxicity, as that potent inhibition of cytochrome P450 (CYP450) isoforms by isoniazid (CYP2C19 y CYP3A) are dependent of INH plasmatic concentration. This inhibitory effect has been described also for CYP12, CYP2C9 and CYP2E1. INH is metabolized by N-acetyltransferase 2 (NAT2). The wide variability interethnic and intraethnic in acetylation velocity is associated with the polymorphisms of NAT2. Patients with rapid acetylation have plasmatic concentration of INH low or insufficient which induces treatment failure. The study of genotypes of P450 and NAT2 allow us to predict therapeutic and individualized dosages.
Revista de investigacion clinica; organo del Hospital de Enfermedades de la Nutricion 60(1):47-57. · 0.42 Impact Factor
