UNVEILING THE SIGNIFICANCE OF DYNAMIC ARTERIAL ELASTANCE: AN INSIGHTFUL APPROACH TO ASSESSING ARTERIAL LOAD IN AN ENDOTOXIN SHOCK MODEL.

ABSTRACT: Background: The aim of this study was to investigate the relationship between dynamic arterial elastance (EaDyn) and the pulsatile and steady components of arterial load in an endotoxin shock model using a two-element Windkessel model and to describe the behavior of EaDyn in this model. Methods : Ten female Yorkshire pigs were administered lipopolysaccharide intravenously to induce endotoxin shock, while three female pigs served as the control group. Measurements of EaDyn (ratio between pulse pressure variation and stroke volume variation), effective arterial elastance, arterial compliance (Cart), and systemic vascular resistance were taken every 30 min in the endotoxin group until shock was induced. In the control group, these variables were measured every 30 min for 3 h. Subsequently, a fluid load was administered to both groups, and measurements were repeated every 30 min. After 1 hour of shock induction, the endotoxin group was divided into two subgroups: one receiving norepinephrine (END-NE) and the other not receiving it (END-F). Results: EaDyn showed an association with Cart, while pulse pressure variation was connected to both pulsatile and steady components, and stroke volume variation was solely associated with steady components. In addition, EaDyn exhibited higher values in the END groups than in the control group when shock was achieved. Furthermore, after the administration of norepinephrine, EaDyn displayed higher values in END-F than in END-NE. Conclusions: The EaDyn variable helps identify changes in the pulsatile component of arterial load, providing valuable guidance for management strategies aimed at improving cardiac performance.

Bacillus licheniformis and Bacillus subtilis, Probiotics That Induce the Formation of Macrophage Extracellular Traps.

Probiotics are considered living microorganisms that help preserve the health of the host who uses them. Bacillus are a genus of Gram-positive bacteria used as probiotics for animal and human consumption. They are currently distributed in various commercial forms. Two of the species used as probiotics are B. licheniformis and B. subtilis. Macrophages are central cells in the immune response, being fundamental in the elimination of microbial pathogens, for which they use various mechanisms, including the formation of extracellular traps (METs). There have been very few studies carried out on the participation of macrophages in response to the interaction of probiotics of the genus Bacillus with the host. In this work, we used macrophages from the J774A mouse cell line.1, and we found that they are susceptible to infection by the two Bacillus species. However, both species were eliminated as the infection progressed. Using confocal microscopy, we identified the formation of METs from the first hours of infection, which were characterized by the presence of myeloperoxidase (MPO) and citrullinated histone (Hit3Cit). Quantitative data on extracellular DNA release were also obtained; release was observed starting in the first hour of infection. The induction of METs by B. licheniformis caused a significant decrease in the colony-forming units (CFU) of Staphylococcus aureus. The induction of METS by bacteria of the Bacillus genus is a mechanism that participates in controlling the probiotic and potentially pathogenic bacteria such as S. aureus. The induction of METs to control pathogens may be a novel mechanism that could explain the beneficial effects of probiotics of the genus Bacillus.

Expression of Antimicrobial Peptides in Human Monocytic Cells and Neutrophils in Response to Dengue Virus Type 2.

BACKGROUND/AIMS: The innate immune response is remarkably important for controlling infections. Information about the participation of antimicrobial peptides (AMPs) in response to dengue virus (DENV) is scarce. The aim of this study was to examine the AMP response to DENV-2 in human THP-1 cells and neutrophils. METHODS: Protein and mRNA levels of two AMPs - hBD-1 and cathelicidin LL-37 - were assessed in DENV-infected macrophage-like THP-1 cells using qRT-PCR and indirect immunofluorescence. Also, mRNA levels of α-defensins (hDEFAs) and LL-37 were examined by qRT-PCR in human neutrophils taken from peripheral blood and treated with DENV-2. RESULTS: mRNA expression of hBD-1 rose in THP-1 cells at 24-72 h, while protein expression increased later, from 48 to 72 h after infection. Cathelicidin LL-37 mRNA expression of DENV-infected THP-1 cells was observed at 6-48 h after infection, while protein levels increased importantly up to 72 h after infection. Regarding neutrophils, the mRNA expression of hDEFAs and LL-37 increased slightly at 2 and 5 h after the contact with DENV-2. CONCLUSION: THP-1 cells and human neutrophils strongly respond to DENV by producing AMPs: hBD-1 and LL-37 for the THP-1 cells and hDEFAs and LL-37 for neutrophils. However, the direct effect of these molecules on DENV particles remains unclear.

Defensin production by human limbo-corneal fibroblasts infected with mycobacteria.

Epithelial cells of the cornea and the conjunctiva constitutively produce antimicrobial peptides; however, the production of defensins by other cell types located around the eye has not been investigated. We analyzed the production of beta-defensins (hBD) and cathelicidin LL-37 during the infection of primary limbo-corneal fibroblasts with M. tuberculosis (MTB), M. abscessus (MAB), and M. smegmatis (MSM). The intracellular survival of each mycobacterium, the production of cytokines and the changes on the distribution of the actin filaments during the infection were also analyzed. Fibroblasts produce basal levels of hBD1 and LL-37 and under PMA stimulation they produce hBD2, hBD3 and overexpress hBD1 and LL-37. MAB induced the highest levels of hBD1 and LL-37 and intermediate levels of IL-6; however, MAB was not eliminated. In addition, MAB induced the greatest change to the distribution of the actin filaments. MTB also produced changes in the structure of the cytoskeleton and induced low levels of hBD1 and IL-6, and intermediate levels of LL-37. The balance of these molecules induced by MTB appeared to contribute to the non-replicative state observed in the limbo-corneal cells. MSM induced the lowest levels of hBD1 and LL-37 but the highest levels of IL-6; MSM was eliminated. The results suggest that mycobacterial infections regulate the production of antimicrobial peptides and cytokines, which in conjunction can contribute to the control of the bacilli.

Innate response of human endothelial cells infected with mycobacteria.

Endothelial cells are susceptible to infection by several pathogens, but little is known about mycobacterial infection. We analyzed some features of mycobacteria-endothelial cell interactions and the innate response to the infection. Intracellular growth in human umbilical vein endothelial cells (HUVECs) of three Mycobacterium species: M. tuberculosis (MTB), M. abscessus (MAB) and M. smegmatis (MSM) was analyzed. M. smegmatis was eliminated; M. abscessus had an accelerate intracellular replication and M. tuberculosis did not replicate or was eliminated. M. abscessus infection induced profound cytoskeleton rearrangements, with M. tuberculosis infection changes were less marked, and with MSM were slight. Nitric oxide (NO) production was induced differentially: M. abscessus induced the highest levels followed by M. tuberculosis and M. smegmatis; the contrary was true for reactive oxygen species (ROS) production. Only M. tuberculosis infection caused beta-1 defensin over-expression. As a whole, our results describe some aspects of the innate response of HUVEC infected by mycobacteria with different virulence and suggest that a strong cytoskeleton mobilization triggers a high NO production in these cells.

Peptidic sequence "HSEAETGPP" is recognized by the sera of pars planitis patients.

PURPOSE: HLA class II, p-36 protein, heat shock protein and retinal antigens have been associated with pars planitis (PP), but their participation in the development of the disease are unknown. A search for new molecules related to PP is necessary. This work focused on the identification of peptides recognized by PP patient sera using the phage display method. METHODS: Sera of PP patients were used to isolate peptides fused to M13-phage pIII protein. The response of PP and healthy sera to peptides was determined by ELISA. PCR amplification and sequencing of peptide-encoding fragments from clones with high recognition by PP sera were used to characterize displayed peptides. RESULTS: One hundred clones were randomly selected from a phage display library after three panning rounds using serum proteins from a PP patient. The immunologic response level of 100 clones selected were determined with a major number of patients, it was found that one clone was recognized stronger in PP patients sera than in healthy sera (PP vs. healthy; P < 0.05). The peptide-encoding region of this clone was sequenced and translated. The peptide sequence corresponded to HSEAETGPP. An identical amino acid sequence to HSEAETGPP is found in the human proline-rich transmembrane protein 2 which has not been related with eye diseases. CONCLUSION: These results suggest that the peptide HSEAETGPP is associated with PP.

Monitoring poly(3-hydroxybutyrate) production in cupriavidus necator DSM 428 (H16) with raman spectroscopy.

This study explored the potential of Raman spectroscopy for the analysis of poly(3-hydroxybutyrate) (PHB) in bacteria. PHB can be formed in large amounts by certain bacteria as a storage material and is of high importance for industrial biodegradable plastic production. Raman spectra were collected from Cupriavidus necator DSM 428 (H16), from its non-PHB-producing mutant strain C. necator DSM 541, and from pure PHB, in order to determine at which Raman shifts a contribution of PHB in bacterial spectra can be expected. The Raman band intensity at ca. 1734 cm(-1) appeared to be suitable for the monitoring of PHB production and consumption. These intensities were linearly related to the PHB concentration (mg L(-1) culture) determined by parallel HPLC analysis. Therefore, Raman spectroscopy is considered as a fast and noninvasive technique for the determination and monitoring of the PHB content in bacteria.

Application of reverse transcriptase PCR-based T-RFLP to perform semi-quantitative analysis of metabolically active bacteria in dairy fermentations.

A method consisting of reverse transcriptase (RT)-PCR amplification of 16S rRNA from the total microbial community, coupled with T-RFLP, was optimized for semi-quantitative characterization of the metabolically active population in defined strain cultures of Lactococcus lactis ssp. lactis and Leuconostoc citreum, two mesophilic lactic acid bacteria (LAB) species routinely used in cheese manufacture. The set of PCR primers selected efficiently amplified the 16S rRNA from both bacterial species. The digestion of the PCR products with DdeI yielded different terminal restriction fragments (T-RFs) for each species. Nevertheless, additional T-RFs due to formation of chimeric molecules and pseudo-T-RFs derived from partly single-stranded 16S rRNA amplicons were observed in both species, although in minor amounts. Twenty PCR cycles were determined as the optimum to minimize the presence of artifactual fragments and to avoid underestimation of populations due to the saturation effect on DNA quantification caused by a PCR product excess. T-RFLP analysis showed a good repeatability when applied to mixed dairy cultures. Dynamics of two defined mixed starters consisting of a L. lactis ssp. lactis strain and a L. citreum strain were studied by this method and results compared to those obtained by a culture-dependent technique. The data indicated the suitability of T-RFLP to perform semi-quantitative analyses of microbial populations. Some slight differences could be explained by the presence of metabolically active cells that could not be detected by colony counting. RT-PCR-based T-RFLP can be an alternative to classical methods in order to study dynamics of metabolically active populations in relatively simple microbial ecosystems, such as defined dairy starter cultures.

Frecuencia de diferentes tipos de Parkinsonismo en Medellin / Frequency of different Parkinsonismïs types in Medellin, Colombia

El objetivo fue determinar la frecuencia de los diversos tipos de Parkinsonismo, mediante la aplicación sistemática de criterios preestablecidos de inclusión y exclusión en una población de Medellín. Se seleccionaron 302 pacientes de algunos servicios de neurología de Medellín a quienes se aplicó un protocolo estructurado y cuantitativo. Se atendieron 147 mujeres (48.7/100) y 155 hombres (51.3/100) con edad promedio de 66.8 años y rango entre 13 y 90; con una escolaridad promedio de 7.5 y rango entre 0-20. El síndrome más frecuente fue la enfermedad de Parkinson idiopática definida (EPID) en 132 sujetos, la enfermedad de Parkinson probable se halló en 60 casos, el Parkinson posible en 8 casos, Parkinson idiopático precoz (20 a 39 años) en 10, Parkinson idiopático juvenil (menores de 19 años) en uno Parkinson familiar en cinco, Parkinson con demencia 216 casos. Otras afecciones como la parálisis supranuclear progresiva, la atrofia multisistémica y la neurolúes y el parkinsonismo por medicamentos fueron menos frecuentes