Mycobacterium tuberculosis and M. smegmatis form drug-tolerant biofilms through dedicated genetic programs. In support of a stepwise process regulating biofilm production in mycobacteria, it was ...shown elsewhere that lsr2 participates in intercellular aggregation, while groEL1 was required for biofilm maturation in M. smegmatis. Here, by means of RNA-Seq, we monitored the early steps of biofilm production in M. bovis BCG, to distinguish intercellular aggregation from attachment to a surface. Genes encoding for the transcriptional regulators dosR and BCG0114 (Rv0081) were significantly regulated and responded differently to intercellular aggregation and surface attachment. Moreover, a M. tuberculosis H37Rv deletion mutant in the Rv3134c-dosS-dosR regulon, formed less biofilm than wild type M. tuberculosis, a phenotype reverted upon reintroduction of this operon into the mutant. Combining RT-qPCR with microbiological assays (colony and surface pellicle morphologies, biofilm quantification, Ziehl-Neelsen staining, growth curve and replication of planktonic cells), we found that BCG0642c affected biofilm production and replication of planktonic BCG, whereas ethR affected only phenotypes linked to planktonic cells despite its downregulation at the intercellular aggregation step. Our results provide evidence for a stage-dependent expression of genes that contribute to biofilm production in slow-growing mycobacteria.
Abstract
A single intradermal vaccination with an antibiotic-less version of BCGΔBCG1419c given to guinea pigs conferred a significant improvement in outcome following a low dose aerosol exposure to
...M. tuberculosis
compared to that provided by a single dose of BCG Pasteur. BCGΔBCG1419c was more attenuated than BCG in murine macrophages, athymic, BALB/c, and C57BL/6 mice. In guinea pigs, BCGΔBCG1419c was at least as attenuated as BCG and induced similar dermal reactivity to that of BCG. Vaccination of guinea pigs with BCGΔBCG1419c resulted in increased anti-PPD IgG compared with those receiving BCG. Guinea pigs vaccinated with BCGΔBCG1419c showed a significant reduction of
M. tuberculosis
replication in lungs and spleens compared with BCG, as well as a significant reduction of pulmonary and extrapulmonary tuberculosis (TB) pathology measured using pathology scores recorded at necropsy. Evaluation of cytokines produced in lungs of infected guinea pigs showed that BCGΔBCG1419c significantly reduced TNF-α and IL-17 compared with BCG-vaccinated animals, with no changes in IL-10. This work demonstrates a significantly improved protection against pulmonary and extrapulmonary TB provided by BCGΔBCG1419c in susceptible guinea pigs together with an increased safety compared with BCG in several models. These results support the continued development of BCGΔBCG1419c as an effective vaccine for TB.
Development of rigid toughened photocurable epoxy foams Acosta Ortiz, Ricardo; Garcia Valdez, Aida Esmeralda; Rodriguez Ramos, Zirahuen Xokoyotzin ...
Journal of polymer research,
07/2017, Letnik:
24, Številka:
7
Journal Article
Recenzirano
This study present a fast and efficient method for preparing photocurable rigid epoxy foams. A system based on the anionic photopolymerization of diglycidyl ether of bisphenol A (DGEBA) combined with ...a thiol-ene photopolymerization, was used. A tertiary diamine curing agent functionalized with four allyl groups was used in conjunction with a multifunctional thiol. The presence of several basic species, like tertiary amines, thiolates, polythioethers and alkoxide groups induced the anionic ring opening polymerization of the epoxy groups. At the same time the double bonds of the curing agent reacted with the multifunctional thiol generating polythioethers. The flexibility of the polythioethers modified the properties of the epoxy polymers, improving their toughness. Benzenesulfonyl hydrazide as foaming agent and zinc oxide as activator were added to DGEBA to produce the epoxy foams. The photopolymerization kinetics showed that conversion of the epoxide groups reached 80% in 600 s. Thermal curing studies performed by DSC showed that the main curing exotherm were determined at 84–89 °C, which match the temperature at which the photocuring was carried out in the UV light chamber (85 °C). It was found that the viscosity of the formulations plays a key role in the pore size of the foamed polymer, the higher the viscosity the larger the pore sizes. It was also determined that the impact resistance of the produced foams increased with increasing concentration of the thiol-ene system, as a consequence of a greater amount of polythioethers present in the co-network.
Se reporta por primera vez la presencia de la cotorra argentina (Myiopsitta monachus) en áreas urbanas y en la periferia de la ciudad de Durango, México. Se observaron seis sitios de nidada en cinco ...especies de plantas diferentes; un sitio se localizaba cerca de la vegetación natural.
Rheumatoid arthritis (RA) associates with cardiovascular risk factors (CVRF) such as dyslipidemias and systemic inflammation. Cardiovascular Disease (CVD) is the leading cause of mortality. The ...hypertriglyceridemic waist phenotype (HTWP) identifies increased CVRF; however, information about HTWP on RA is scarce.
To evaluate the association of HTWP with CVRF in RA.
Cross-sectional study. Women (125) with RA were included (ACR, 1987). Anthropometry, bioimpedance, body mass index (BMI), disease activity score 28 (DAS28), and health assessment questionnaire disability index (HAQ-Di) were determined. The lipid profile determination includes the atherogenic index (AI) (TC/HDL) and Framingham Risk Score. HTWP is defined as a waist circumference ≥88 cm and triglycerides ≥ 150 mg/dL. Chi-squared and Student's
-tests were applied for comparisons.
HTWP was found in 38 (30.4%) patients. The subgroup with HTWP had a greater frequency of arterial hypertension (AHT) (57.9 vs. 37.9,
= 0.04), Type 2 DM (23.7 vs. 8.0,
= 0.02), BMI (29.7 ± 3.2, vs. 26.8 ± 4.3,
< 0.001), fat mass (39.3 ± 4.8 vs. 34.7 ± 6.8,
< 0.001), and AI (4.7 ± 1.2 vs. 3.7 ± 1.0,
< 0.001). No differences between DAS28 and HAQ-Di were found. HTWP was associated with the presence of MetS and CVR (
< 0.001 and
= 0.012, respectively).
The HTWP in RA is associated with CVRF, and its potential predictive role should be evaluated in longitudinal studies.
Severe ischemia-reperfusion injury (SIRI) seems to be the key factor that can significantly affect the function of both native kidneys and renal allografts. Therefore, the development of a successful ...strategy is of a paramount importance in both basic and clinical research.
To determine the effects of SIRI on the native kidney function, a murine model was planned as follows: group 1 (n = 6) mice underwent to nephrectomy plus ischemia-reperfusion injury for 30 minutes; group 2 (n = 6) mice underwent to nephrectomy without ischemia-reperfusion injury and thus served as sham controls for SIRI. The results of serum creatinine (SCr) were analyzed using Mann-Whitney U tests to calculate the significance between mean values. Survival between groups was measured by Kaplan-Meier test.
To reliably achieve an elevation of SCr levels animals were exposed to a SIRI. The values of SCr increased from 0.35 (SD, 0.09) mg/dL to about 2-fold within 2 days and 3-fold within the following 5 days. Under these given conditions the mice displayed signs and histologic findings of severe kidney damage. The survival rate was about 83% of the animals within a week, and they showed no capacity of complete spontaneous self-regeneration.
In this study, we aim to establish a murine model with extensive structural kidney damage and significant elevation of SCr levels, which could be used in basic and translational research of transplantation and regenerative therapies.
Comparison of routine hospital indicators (consults at the Emergency Room (ER) and hospital admissions) during the 2009 pandemic of the influenza AH1N1 virus at the national referral hospital for ...respiratory diseases in Mexico City.
The outbreak was from April to mid-May 2009 and two control periods were used:2009 (before and after the outbreak),and during April-May from 2007 and 2008.
During the outbreak total consultation at the ER increased six times compared with the 2007-2008 control period and 11 times compared with the 2009 control period. Pneumonia- or influenza-related ER consultations increased 23.2 and 15.3%, respectively. The rate of nosocomial infection during the outbreak was 13.6 and that of nosocomial pneumonia was 6 per/100 hospital discharges, a two-fold and three-fold increase compared to the control periods respectively.
During the outbreak,mean severity of admitted patients increased,with a rise in in-hospital mortality and nosocomial infections rate, including nosocomial pneumonia.
PDF
