5 research outputs found
Arsénico edáfico y su distribución en el distrito de riego 017: uso métodos de interpolación
Los constituyentes del suelo (arcillas, carbonatos, materia orgánica y óxidos e hidróxidos), intervienen en la movilidad del arsénico (As) y determinan su variación espacial; por lo cual, su cartografía puede contribuir al entendimiento de la presencia de este metaloide en el suelo. Los objetivos de esta investigación fueron determinar la concentración de As en los suelos del Distrito de Riego 017 (DR017) de México y establecer su distribución espacial, utilizando dos métodos de interpolación. Cuatro etapas fueron realizadas; la primera consistió en trabajo de gabinete y campo, en la que 33 sitios de muestreo fueron localizados en un polígono del DR017, posteriormente en cada sitio, muestras simples de suelo (0-30 cm de profundidad) fueron colectadas. La segunda y tercera se llevaron a cabo en laboratorio, en las cuales, a cada muestra se determinó la concentración de As disponible, contenidos de arcilla, carbonatos de calcio y fósforo disponible y su regresión. La cuarta etapa tuvo dos partes, la elaboración de dos mapas con dos métodos de interpolación (Interpolador Ponderación Inversa de la Distancia, IDW en sus siglas en inglés y Kriging ordinario, KO), así como la verificación de la precisión de cada mapa. Los resultados mostraron que, la distribución del As en el DR017 no es uniforme y está asociada con el contenido de arcilla y CaCO3. De tal manera que, las concentraciones de As fluctuaron de 0.07 a 1.89 mg kg-1, donde las mayores concentraciones de este metaloide (1.39-1.89 mg kg‑1) se relacionaron positivamente (R2 = 0.9058) con altos contenidos de arcilla (39.44 a 43.44%). El mapa de distribución espacial de As obtenido con KO, tuvo la mayor precisión (75.7%), en el cual se muestra que la concentración aumenta en un sentido sur-norte, donde el área de mayor concentración está en la parte norte del distrito
Ependymal damage in a Plasmodium yoelii yoelii lethal murine malaria model
Malaria continues to be a major global health
problem, and over 40% of the world’s population is at
risk. Severe or complicated malaria is defined by clinical
or laboratory evidence of vital organ dysfunction,
including dysfunction of the central nervous system
(CNS). The pathogenesis of complicated malaria has not
been completely elucidated; however, the development
of the multiorgan affection seems to play an important
role in the disruption of the blood brain barrier (BBB)
that protects the CNS against chemical insults.
Historically, the BBB has received more attention in the
pathogenesis of malaria than have the cerebrospinal
fluid-brain barrier (CSFBB) and ependymal cells. This
perspective may be misguided because, in the context of
disease or toxicity, the CSFBB is more vulnerable to
many foreign invaders than are the capillaries. Given the
lack on studies of the damage to the CSFBB and
ependymal epithelium in experimental murine malaria,
the present study evaluated morphological changes in
the ependymal cells of CD-1 male mice infected with
lethal Plasmodium yoelii yoelii (Pyy) via histopathology
and scanning electron microscopy (SEM). Samples were
taken two, four and six days post-infection (PI). No
lesions were observed upon the initial infection. By the
fourth day PI, fourth ventricle ependymal samples
exhibited disruptions and roughened epithelia. More
severe injuries were observed at six days PI and included
thickened cilia and deep separations between the
ependymal intercellular spaces. In some of the analyzed
areas, the absence of microvilli and cell layer
detachment were observed, and some areas exhibited
blebbing surfaces. The ependymal cell lesions observed
in the CD1 male mice infected with lethal Pyy seemed to
facilitate the paracellular permeability of the CSFBB and
consequently promote the access of inflammatory
mediators and toxic molecules through the barrier, which
resulted in damage to the brain tissue. Understanding the
mechanism of ependymal disruption during lethal
murine malaria could help to elucidate the local and
systemic factors that are involved in the pathogenesis of
the disease and may provide essential clues for the
prevention and treatment of complicated human malaria
Evolution over Time of Ventilatory Management and Outcome of Patients with Neurologic Disease∗
OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease
Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries
Background
Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.
Methods
The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.
Results
A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).
Conclusion
Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)