Sociodemographic Disparities in Tracheostomy Timing and Outcomes.

OBJECTIVE: Tracheostomies are commonly performed in critically ill patients requiring prolonged mechanical ventilation. Although early tracheostomy has been associated with improved outcomes, the reasons for delayed tracheostomy are complex. We examined the impact of sociodemographic factors on tracheostomy timing and outcomes. METHODS: Medical records were retrospectively reviewed of ventilator-dependent adult patients who underwent tracheostomy from 2021 to 2022. Tracheostomy timing was defined as routine (<21 days) versus late (21 days or more). Sociodemographic variables were compared between cohorts using univariate and multivariate models. Secondary outcomes included hospital length of stay (LOS), decannulation, tracheostomy-related complications, and inhospital mortality. RESULTS: One hundred forty-two patients underwent tracheostomy after initial intubation: 74.7% routine (n = 106) and 25.4% late (n = 36). In a multivariate model adjusted for age, race, surgical service, tracheostomy technique, and time between consultation and surgery, non-English speaking patients and women were more likely to receive a late tracheostomy compared with English speaking patients and men, respectively (odds ratio [OR] 3.18, 95% confidence interval [CI] 1.03, 9.81, p < 0.05), (OR 3.15, 95% CI 1.18, 8.41, p < 0.05). Late tracheostomy was associated with longer median hospital LOS (62 vs. 52 days, p < 0.05). Tracheostomy timing did not significantly impact mortality, decannulation or tracheostomy-related complications. CONCLUSION: Despite an association between earlier tracheostomy and shorter LOS, non-English speaking patients and female patients are more likely to receive a late tracheostomy. Standardized protocols for tracheostomy timing may address bias in the referral and execution of tracheostomy and reduce unnecessary hospital days. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:582-587, 2024.

Brucella abortus RNA does not polarize macrophages to a particular profile but interferes with M1 polarization.

Monocytes and macrophages play a central role in chronic brucellosis. Brucella abortus (Ba) is an intracellular pathogen that survives inside these cells. On the other hand, macrophages could be differentiated into classical (M1), alternative (M2) or other less-identified profiles. We have previously shown that Ba RNA (a bacterial viability-associated PAMP or vita-PAMP) is a key molecule by which Ba can evade the host immune response. However, we did not know if macrophages could be polarized by this vita-PAMP. To assess this, we used two different approaches: we evaluated if Ba RNA per se was able to differentiate macrophages to M1 or M2 or, given that Ba survives inside macrophages once a Th1 response is established (i.e., in the presence of IFN-γ), we also analysed if Ba RNA could interfere with M1 polarization. We found that Ba RNA alone does not polarize to M1 or M2 but activates human macrophages instead. However, our results show that Ba RNA does interfere with M1 polarization while they are being differentiated. This vita-PAMP diminished the M1-induced CD64, and MHC-II surface expression on macrophages at 48 h. This phenomenon was not associated with an alternative activation of these cells (M2), as shown by unchanged CD206, DC-SIGN and CD163 surface expression. When evaluating glucose metabolism, we found that Ba RNA did not modify M1 glucose consumption or lactate production. However, production of Nitrogen Reactive Species (NRS) did diminish in Ba RNA-treated M1 macrophages. Overall, our results show that Ba RNA could alter the proper immune response set to counterattack the bacteria that could persist in the host establishing a chronic infection.

Modulation of neutrophil extracellular traps release by Klebsiella pneumoniae.

One of the main bactericidal mechanisms of polymorphonuclear neutrophils (PMN) is the release of neutrophil extracellular traps (NETs), which capture and destroy pathogens. Klebsiella pneumoniae (Kpn) producer of carbapenemase (KPC) and belonging to the sequence type 258 (ST258), is a hyper epidemic clone that causes a large number of infections worldwide associated with high persistence and mortality. It is necessary to investigate the interaction of Kpn KPC with the immune system to improve prevention and treatment of infections mediated by this bacterium. Based on the hypothesis that Kpn is able to subvert PMN-mediated death, the aim was to assess whether Kpn KPC ST258 could modulate the bactericidal response of PMN, focusing on NETs formation, compared to another opportunistic pathogen, as Escherichia coli (Eco). The results showed that the release of NETs was absent when PMN were challenged with Kpn KPC, while Eco was a strong inducer of NETosis. Moreover, Kpn KPC was able to inhibit NETosis induced by Eco. The inhibition of Kpn KPC-mediated NETs formation still occurred in spite of exogenous addition of hydrogen peroxide (H2 O2 ), did not involve bacterial-released soluble factors or cell wall components, and was dependent on bacterial viability. Moreover, when degranulation was investigated, we found that Kpn KPC affected only the mobilization of primary granules, which harbor the proteins with more potent bactericidal properties and those related to NETosis. In conclusion, Kpn KPC ST258 effectively managed to evade the PMN response by inhibiting the release of NETs, and primary granule mobilization.

Prognostic value of imaging markers from 18FDG-PET/CT in paediatric patients with Hodgkin lymphoma.

OBJECTIVE: Identification of imaging prognostic parameters for early therapy personalisation to reduce treatment-related morbidity in paediatric Hodgkin lymphoma (HL). Our aim was to evaluate quantitative markers from baseline 2-[18F]fluoro-2-deoxy-d-glucose PET/CT as prognostic factors for treatment outcomes. Another goal was assessing the prognostic value of Deauville score at interim PET/CT. METHODS: Twenty-one patients were prospectively enrolled. Median age was 12 years (range 6-17); 13 were female. Patients underwent PET/CT for disease staging (bPET), at the end of two cycles of chemotherapy (iPET) and after chemotherapy. A total of 173 lesions were segmented from bPET. We calculated 51 texture features for each lesion. Total metabolic tumour volume and total lesion glycolysis from bPET were calculated for response prediction at iPET. Univariate and multivariate analyses were used for optimal cut-off values to separate responders at iPET according to the Deauville score. RESULTS: We identified four texture features as possible independent predictors of treatment outcomes at iPET. The areas under the ROC for univariate analysis were 0.89 (95% CI, 0.75-1), 0.82 (95% CI, 0.64-1), 0.79 (95% CI, 0.59-0.99) and 0.89 (95% CI, 0.75-1). The survival curves for patients assigned Deauville scores 1, 2, 3 and X were different from those assigned a score 4, with 4-year progression free-survival (PFS) rates of 85 versus 29%, respectively (P = 0.05). CONCLUSIONS: We found four textural features as candidates for predicting early response to chemotherapy in paediatric patients with HL. The Deauville score at iPET was useful for differentiating PFS rates.

Effective microencapsulation of Enterococcus faecium in biopolymeric matrices using spray drying.

The objective of this work was to evaluate the potential of whey protein concentrate (WPC), native agave fructans (NAF), and their mixture (WPC-NAF, 1:1 w/w) as wall materials and evaluate the physicochemical properties and stability of encapsulated Enterococcus faecium during the spray drying, storage, and passage through the simulated gastrointestinal tests. The encapsulated microorganisms with WPC-NAF by spray drying showed greater viability (9.26 log CFU/g) and a higher microencapsulation yield (88.43%). They also had a smaller reduction in the cell count (0.61 log cycles), while the microcapsules produced with NAF had the greatest reduction in viability during the simulated gastrointestinal tests. Similarly, probiotics encapsulated with WPC-NAF revealed a higher survival rate (> 8 log CFU/g) when stored at a water activity of 0.328. The thermal analysis showed that the addition of NAF to the WPC produced a slight shift in the Tg towards temperatures higher than that shown by NAF. Therefore, this study provides evidence that the spray drying process was appropriate to encapsulate the probiotic strain Enterococcus faecium and that the mixture WPC-NAF protected it from adverse drying conditions and improved the viability of Enterococcus faecium during storage and simulated gastrointestinal tests, demonstrating that the combination of NAF and WPC as encapsulating material is adequate in the production of more stable microcapsules with potential application in various foods.Key Points• E. faecium was successfully encapsulated in WPC and NAF.• WPC-NAF offered protection to E. faecium in the gastrointestinal tests and during storage.• Aw around 0.328 positively influenced the viability of the microorganism during storage. Graphical abstract.

Brucella abortus-infected platelets modulate the activation of neutrophils.

Brucellosis is a contagious disease caused by bacteria of the genus Brucella. Platelets (PLTs) have been widely involved in the modulation of the immune response. We have previously reported the modulation of Brucella abortus-mediated infection of monocytes. As a result, PLTs cooperate with monocytes and increase their inflammatory capacity, promoting the resolution of the infection. Extending these results, in this study we demonstrate that patients with brucellosis present slightly elevated levels of complexes between PLTs and both monocytes and neutrophils. We then assessed whether PLTs were capable of modulating functional aspects of neutrophils. The presence of PLTs throughout neutrophil infection increased the production of interleukin-8, CD11b surface expression and reactive oxygen species formation, whereas it decreased the expression of CD62L, indicating an activated status of these cells. We next analyzed whether this modulation was mediated by released factors. To discriminate between these options, neutrophils were treated with supernatants collected from B. abortus-infected PLTs. Our results show that CD11b expression was induced by soluble factors of PLTs but direct contact between cell populations was needed to enhance the respiratory burst. Additionally, B. abortus-infected PLTs recruit polymorphonuclear (PMN) cells to the site of infection. Finally, the presence of PLTs did not modify the initial invasion of PMN cells by B. abortus but improved the control of the infection at extended times. Altogether, our results demonstrate that PLTs interact with neutrophils and promote a proinflammatory phenotype which could also contribute to the resolution of the infection.

Prokaryotic RNA activates endothelial cells promoting neutrophil transmigration.

Endothelial cell (EC)-neutrophil (PMN) interactions are crucial in the resolution of bacterial infections. Prokaryotic RNA (pRNA) has been reported as a pathogen-associated molecular pattern that is released from bacteria upon death and is able to activate PMN. In this work, we studied the effects of pRNA on EC and investigated whether these effects could modulate EC-PMN interaction. For this purpose, we purified total pRNA from Escherichia coli and used it as a stimulus for Human Umbilical Vein Endothelial Cells (HUVEC). We found that the incubation of pRNA with HUVEC caused the increase of surface intercellular adhesion molecule 1 (ICAM-1 or CD54) expression on HUVEC, and the secretion of IL-8 and von Willebrand factor, characteristics consistent with HUVEC activation, without causing toxic effects. Moreover, pRNA-treated HUVEC also induced PMN adhesion and the conditioned medium obtained from treated-HUVEC was chemotactic for PMN and caused their activation, as determined by CD11b upregulation. As reported previously, the degradation products of pRNA induced similar biological effects. The treatment of HUVEC with endocytosis inhibitors revealed that the entry of pRNA partially relied on a clathrin-dependent mechanism, whereas the effects of degradation products could not be inhibited by any of the inhibitors tested. Using a transwell system, we found that pRNA or degraded pRNA were also able to stimulate HUVEC when recognized from the basolateral side. Our results indicate that pRNA activates EC, resulting in the modulation of EC-PMN interaction by inducing PMN chemotaxis, adhesion and activation. In the context of infection, pRNA sensed by EC and PMN could favor bacterial clearance.

Klebsiella pneumoniae ST258 Negatively Regulates the Oxidative Burst in Human Neutrophils.

The epidemic clone of Klebsiella pneumoniae (Kpn), sequence type 258 (ST258), carbapenamase producer (KPC), commonly infects hospitalized patients that are left with scarce therapeutic option since carbapenems are last resort antibiotics for life-threatening bacterial infections. To improve prevention and treatment, we should better understand the biology of Kpn KPC ST258 infections. Our hypothesis was that Kpn KPC ST258 evade the first line of defense of innate immunity, the polymorphonuclear neutrophil (PMN), by decreasing its functional response. Therefore, our aim was to evaluate how the ST258 Kpn clone affects PMN responses, focusing on the respiratory burst, compared to another opportunistic pathogen, Escherichia coli (Eco). We found that Kpn KPC ST258 was unable to trigger bactericidal responses as reactive oxygen species (ROS) generation and NETosis, compared to the high induction observed with Eco, but both bacterial strains were similarly phagocytized and cause increases in cell size and CD11b expression. The absence of ROS induction was also observed with other Kpn ST258 strains negative for KPC. These results reflect certain selectivity in terms of the functions that are triggered in PMN by Kpn, which seems to evade specifically those responses critical for bacterial survival. In this sense, bactericidal mechanisms evasion was associated with a higher survival of Kpn KPC ST258 compared to Eco. To investigate the mechanisms and molecules involved in ROS inhibition, we used bacterial extracts (BE) and found that BE were able to inhibit ROS generation triggered by the well-known ROS inducer, fMLP. A sequence of experiments led us to elucidate that the polysaccharide part of LPS was responsible for this inhibition, whereas lipid A mediated the other responses that were not affected by bacteria, such as cell size increase and CD11b up-regulation. In conclusion, we unraveled a mechanism of immune evasion of Kpn KPC ST258, which may contribute to design more effective strategies for the treatment of these multi-resistant bacterial infections.

Synthesis of colloidal silver nanoparticle clusters and their application in ascorbic acid detection by SERS.

Ascorbic acid (vitamin C) has an essential role in the human body mainly due to its antioxidant function. In this work, metallic silver nanoparticle (AgNP) colloids were used in SERS experiments to detect ascorbic acid in aqueous solution. The AgNPs were synthesized by a green method using potato starch as reducing and stabilizing agent, and water as the solvent. The optical properties of the yellowish as-synthesized silver colloids were characterized by UV-vis spectroscopy, in which besides a typical band at 410 nm related to the localized surface plasmon resonance of the silver nanoparticles, a shoulder band around 500 nm, due to silver nanoparticle cluster formation, is presented when relatively higher concentrations of starch are used in the synthesis. These starch-capped silver nanoparticles show an intrinsic Raman peak at 1386 cm-1 assigned to deformation modes of the starch structure. The increase of the intensity of the SERS peak at 1386 cm-1 with an increase in the concentration of the ascorbic acid is related to a decrease of the gap between dimers and trimers of the silver nanoparticle clusters produced by the presence of ascorbic acid in the colloid. The limit of detection of this technique for ascorbic acid is 0.02 mM with a measurement concentration range of 0.02-10 mM, which is relevant for the application of this method for detecting ascorbic acid in biological specimen.

Prokaryotic RNA Associated to Bacterial Viability Induces Polymorphonuclear Neutrophil Activation.

Polymorphonuclear neutrophils (PMN) are the first cellular line of antibacterial host defense. They sense pathogens through recognition of pathogen-associated molecular patterns (PAMPs) by innate pattern recognition receptors, such as Toll-like receptors (TLR). The aim of this study was to investigate whether PMN sense bacterial viability and explore which viability factor could be involved in this phenomenon. For this purpose, different functions were evaluated in isolated human PMN using live Escherichia coli (Ec) and heat-killed Ec (HK-Ec). We found that bacterial viability was indispensable to induce PMN activation, as measured by forward-scatter (FSC) increase, CD11b surface expression, chemotaxis, reactive oxygen species (ROS) generation and neutrophil extracellular trap (NET) formation. As uncapped non-polyadenylated prokaryotic mRNA has been recognized as a PAMP associated to bacterial viability by macrophages and dendritic cells, total prokaryotic RNA (pRNA) from live Ec was purified and used as a stimulus for PMN. pRNA triggered similar responses to those observed with live bacteria. No RNA could be isolated from HK-Ec, explaining the lack of effect of dead bacteria. Moreover, the supernatant of dead bacteria was able to induce PMN activation, and this was associated with the presence of pRNA in this supernatant, which is released in the killing process. The induction of bactericidal functions (ROS and NETosis) by pRNA were abolished when the supernatant of dead bacteria or isolated pRNA were treated with RNAse. Moreover, endocytosis was necessary for pRNA-induced ROS generation and NETosis, and priming was required for the induction of pRNA-induced ROS in whole blood. However, responses related to movement and degranulation (FSC increase, CD11b up-regulation, and chemotaxis) were still triggered when pRNA was digested with RNase, and were not dependent on pRNA endocytosis or PMN priming. In conclusion, our results indicate that PMN sense live bacteria through recognition of pRNA, and this sensing triggers potent bactericidal mechanisms.

Novel Use of All-Trans-Retinoic Acid in A Model of Lipopolysaccharide-Immunosuppression to Decrease the Generation of Myeloid-Derived Suppressor Cells by Reducing the Proliferation of CD34+ Precursor Cells.

All-trans-retinoic acid (ATRA) is a derivative of vitamin A with antiproliferative properties. Endotoxin shock and subsequent immunosuppression (IS) by lipopolysaccharide (LPS) stimulates myelopoiesis with expansion of myeloid-derived suppressor cells (MDSC). Since we have previously shown that ATRA reverses the IS state by decreasing functional MDSC, our aim was to investigate if ATRA was able to modulate MDSC generation by regulating myelopoiesis in murine hematopoietic organs. We found that ATRA administration in vivo and in vitro decreased the number of CD34+ precursor cells that were increased in IS mice. When we studied the cellular mechanisms involved, we did not find any differences in apoptosis of CD34+ precursors or in the differentiation of these cells to their mature counterparts. Surprisingly, ATRA decreased precursor proliferation, in vitro and in vivo, as assessed by a reduction in the size and number of colony forming units generated from CD34+ cells and by a decreased incorporation of H-thymidine. Moreover, ATRA administration to IS mice decreased the number of MDSC in the spleen, with a restoration of T lymphocyte proliferation and a restitution of the histological architecture. Our results indicate, for the first time, a new use of ATRA to abolish LPS-induced myelopoiesis, affecting the proliferation of precursor cells, and in consequence, decreasing MDSC generation, having a direct impact on the improvement of immune competence. Administration of ATRA could overcome the immunosuppressive state generated by sepsis that often leads to opportunistic life-threatening infections. Therefore, ATRA could be considered a complementary treatment to enhance immune responses.

Carboplatin in the treatment of Ewing sarcoma: Results of the first Brazilian collaborative study group for Ewing sarcoma family tumors-EWING1.

BACKGROUND: Large cooperative group studies have shown the efficacy of risk-adapted treatment for Ewing sarcoma. However, validation and local adaptation by National cooperative groups is needed. A multicenter protocol to determine the efficacy and safety of a risk-adapted intensive regimen was developed by the Brazilian cooperative group. PROCEDURE: Patients <30 years old with Ewing sarcoma were eligible. Induction chemotherapy consisted of two cycles of ICE (ifosfamide, carboplatin, and etoposide) followed by two cycles of VDC (vincristine, doxorubicin, and cyclophosphamide), followed by local control. Patients with low risk (LR) disease (localized resectable with normal LDH) received 10 additional alternating courses of IE with VDC. For patients with high-risk (HR) disease (unresectable, pelvic, metastatic, or high LDH), two additional cycles of ICE were given. RESULTS: One-hundred seventy five patients (39% metastatic) were enrolled. Fifty-two patients (29.7%) were LR and 123 (70.3%) were HR. Overall response rate at end of induction was 27.4%. Five-year event-free survival (EFS) and overall survival (OS) estimates were 51.4% and 54.4%, respectively. Patients with localized disease had better outcomes than patients with metastases (5-year EFS 67.9% vs. 25.5%, and 5-year OS 70.3% vs. 29.1%, respectively). On multivariate analysis, the presence of metastatic disease was the only prognostic factor (P < 0.01). CONCLUSION: The VDC/ICE protocol was feasible, and considering the high tumor burden in our population, resulted in comparable results to those reported by cooperative groups in high-income countries. Further adaptation to maximize efficacy and minimize toxicity will be required.

Trasplante alogénico haploidéntico de progenitores hematopoyéticos en pediatría en Uruguay / Haploidentical allogeneic hematopoietic transplant of hematopoietic parents in pediatrics in Uruguay

Introducción: el trasplante alogénico de progenitores hematopoyéticos (TPH) es actualmente la única opción de tratamiento curativo disponible para un número de neoplasias hematológicas de alto riesgo, así como para algunas enfermedades no malignas hereditarias o adquiridas. El TPH haploidéntico (HI) es una opción válida para pacientes que no tienen un hermano HLA-idéntico. Objetivo: describir los resultados obtenidos con TPH HI en pediatría. Material y método: en el año 2005 se inició en el Centro Hemato-Oncológico Pediátrico del Centro Hospitalario Pereira Rossell un programa de TPH HI para aquellos pacientes sin donante relacionado HLA-idéntico. Resultados: se trasplantaron 32 pacientes, 24 con neoplasias hematológicas y 8 con enfermedades no malignas. Se utilizaron dos estrategias de prevención de la enfermedad injerto contra huésped (EICH), depleción de linfocitos T (DLT) in vitro (28 pacientes) y DLT alorreactivos in vivo con altas dosis de ciclofosfamida postrasplante (4 pacientes). Veintisiete pacientes (84%) tuvieron un implante con quimerismo total del donante. La incidencia de EICH agudo y crónico fue de 26,9% y 11,8%, respectivamente. La muerte no relacionada a recaída al año del trasplante fue de 21,9%. Con una mediana de seguimiento de 32 meses, la sobrevida global a dos años fue de 52,4%. Conclusiones: el TPH HI ha demostrado ser una opción factible en nuestro medio para aquellos pacientes sin donante HLA-idéntico. Los resultados son comparables a los obtenidos con otros donantes alternativos y con costos más accesibles. Uruguay está hoy día mejor posicionado para ofrecer un TPH a los pacientes que así lo requieran...

Una exitosa empres estatal boliviana: :Las Plantas Industriliadoras de Leche -PIL y el Plan Nacional de Desarrollo Lecheto Integral; creación de la lecheria industrial nacional (1955-1980)

El libro se deja tentar por lo atractivo de su contenido, en cuanto a que toca una temática distinta a la conocidaa.Su mérito también radica en que si bien logra recobrar la memoria institucional de un laboral gerencial, describe también el modo se puede concretar la ralización de un proyecto la realización de un proyecto estrealla que concitó el interés de las agencias de coooperación internacional, y que logró, con su ejecutoría, exaltar y poner en evidencia la labor del Estado,que bien puede terminar con reconocidos logros cuando éste actúa como empresario El documento narra la ejecución del Plan Nacional de Desarrollo Lechero Integral, PNDLI, que llevo adelante exitosamente la Empresa de Industria Lácteas de la Cooperación Boliviana de Fomento EIL-CBF

Solución a un problema estático en un área con topografía abrupta usando una velocidad de reemplazamiento variable

Uno de los problemas encontrados en la sísmica de reflexión es la determinación de las correcciones estáticas que han sido aplicados a los datos de reflexión para poder eliminar los efectos de la capa meteorizada y de la superficie. Esas correcciones son calculadas con ayuda de estudios de refracción, con costos adicionales y también pueden ser insuficientes con respecto a las necesidades del método de reflexión sísmica. Las ondas refractadas en la capa meteorizada están presentes en los datos de reflexión (sismogramas) y constituyen parte de lo que se conoce como "primeros arribos", las cuales pueden ser definidas como ondas donde, la trayectoria del par fuente-receptor, son localizadas parcialmente dentro de la capa meteorizada y parcialmente a lo largo de su base. Los arribos de esas ondas refractadas también llevan información necesaria de los tiempos de viaje vertical a través de la capa meteorizada, para calcular las correcciones estáticas de campo. En este método se utiliza un calculo de estáticas, donde las consideraciones hechas son: a) una topografía abrupta b) Una velocidad de reemplazamiento variable. Teniendo en cuenta que para poder obtener una buena imagen del subsuelo, es necesario que las soluciones estáticas sean lo mas acertadas posible en la etapa inicial del procesamiento, y no gastar tiempo en ensayos con procesos mas sofisticados, sin tener resuelto el problema estático, se propone implementar un método de procesamiento, usando un modelo de velocidad de reemplazamiento variable en el calculo de la solución estática. Se pretende explicar como el valor de la velocidad de reemplazamiento influye notoriamente en la imagen de la estructura, la cual puede verse deformada en gran magnitud. (AU)