Serum amino acid levels after permanent middle cerebral artery occlusion in the rat

BACKGROUND AND PURPOSE: High levels of glutamate in plasma and cerebrospinal fluid (CSF) have been demonstrated in patients with acute ischemic stroke. Whereas this glutamate increase in CSF is only evidenced during the first 6 h in stable ischemic stroke, it is sustained for 24 h in progressing stroke. The aim of this investigation was to study the evolution of serum glutamate levels after stroke in a rat model of permanent cerebral artery occlusion. METHODS: Glutamate, glycine, aspartate, taurine and tryptophan were measured by high-performance liquid chromatography from serum samples taken before and at different times after permanent middle cerebral artery occlusion (MCAO) and from sham-operated rats. RESULTS: After MCAO, a 3-fold increase in glutamate and a 2-fold increase in glycine and aspartate were observed in rat serum. The onset of this amino acid increase began 4-6 h after ischemic induction, reached peak values at 8-24 h and returned to preischemic values by 48-72 h. Serum concentrations of taurine and tryptophan were not modified after MCAO. Sham-operated rats did not exhibit changes of basal amino acid concentrations in serum. CONCLUSIONS: The serum excitatory amino acid profile in this experimental model confirms that the early detection of increased concentrations of glutamate and glycine at systemic circulation observed in patients with acute stroke is a consequence of the cerebral ischemic process.     

Spontaneous rupture of the membranes, functional dystocia, oxytocin treatment, and the route of delivery

The details of clinical management were examined in 96 nulliparous patients with functional dystocia who had spontaneous rupture of the membranes before admission and were treated with oxytocin in the first stage of labor. It was our hypothesis that if the allegedly "high" rate of cesarean sections was the result of mediocre or flawed practices, these should be most evident in patients delivered abdominally. A group of 59 patients delivered vaginally were compared with 37 patients delivered by cesarean section. The means of many variables were not statistically different. The cesarean section group was characterized by smaller stature, a lesser cervical dilatation rate both before and after oxytocin administration, a larger maximum oxytocin dose, a longer period of oxytocin administration, more frequent cessation of oxytocin administration or dose reduction because of hypercontractility or an abnormal fetal heart rate or both, and a higher incidence of intra-amniotic infection. We conclude that the decision to perform cesarean section in nulliparous women with functional dystocia arises from disabilities of the patient and not from differences in the application of our management principles, services, or treatments.     

Gestational malaria: HELLP syndrome mistaken diagnosis

Malaria is one of the most important parasitic infections in Mexico and Latin America. Here we report a case of a 21 year-old female with 38.4 weeks of pregnancy and previous hospitalization due to malaria. Showing a thick drop negative test she was referred to Mexico City Hospital de la Mujer with presumptive diagnosis of preeclampsia and HELLP syndrome. During her stay in ICU she developed malarial paroxysm and Plasmodium vivax was identified, conducting to specific therapy.     

An approach for evaluating the effects of dietary fiber polysaccharides on the human gut microbiome and plasma proteome

Increases in snack consumption associated with Westernized lifestyles provide an opportunity to introduce nutritious foods into poor diets. We describe two 10-wk-long open label, single group assignment human studies that measured the effects of two snack prototypes containing fiber preparations from two sustainable and scalable sources; the byproducts remaining after isolation of protein from the endosperm of peas and the vesicular pulp remaining after processing oranges for the manufacture of juices. The normal diets of study participants were supplemented with either a pea- or orange fiber-containing snack. We focused our analysis on quantifying the abundances of genes encoding carbohydrate-active enzymes (CAZymes) (glycoside hydrolases and polysaccharide lyases) in the fecal microbiome, mass spectrometric measurements of glycan structures (glycosidic linkages) in feces, plus aptamer-based assessment of levels of 1,300 plasma proteins reflecting a broad range of physiological functions. Computational methods for feature selection identified treatment-discriminatory changes in CAZyme genes that correlated with alterations in levels of fiber-associated glycosidic linkages; these changes in turn correlated with levels of plasma proteins representing diverse biological functions, including transforming growth factor type β/bone morphogenetic protein-mediated fibrosis, vascular endothelial growth factor-related angiogenesis, P38/MAPK-associated immune cell signaling, and obesity-associated hormonal regulators. The approach used represents a way to connect changes in consumer microbiomes produced by specific fiber types with host responses in the context of varying background diets.

Advances in our understanding of the role of the gut microbiome in regulating many aspects of human physiology hold the promise of evolving our view of human nutrition by establishing mechanistic connections between the foods we consume and how they affect health status. One manifestation of this effort is a series of studies, performed on well-phenotyped cohorts, that seek to relate features of gut microbial community composition (organisms, genes), dietary practices, and pre- and postprandial cardiometabolic responses to test meals (1–4). A key question raised by these initiatives relates to the nature of the “bioactive” components of foods. Specifically, what are the nutrients utilized by various gut community members or microbiome-encoded metabolic pathways? What products are produced by biotransformation of these nutrients? How are these products linked to specific host physiologic (or pathophysiologic) processes?Plant-derived dietary fibers represent a “poster child” for these efforts and illustrate the formidable challenges faced. The health benefits of dietary fibers are widely known, as is their inadequate representation in Western diets. However, natural fibers are structurally complex and highly diverse. They contain numerous, typically undefined polysaccharide structures and largely unspecified protein, lipid, and small molecule constituents. Their composition varies as a function of their origin (food staple and cultivar), the different methods employed to recover them from these sources, as well as the different techniques used to incorporate them into processed foods with acceptable organoleptic properties (5). Moreover, analyzing the host effects of metabolism of different fibers is confounded by the fact that there is substantial intra- and interpersonal variation in microbiome configuration (6, 7).Snacking is becoming an ever more dominant feature of daily life worldwide and thus provides an opportunity to introduce nutritious ingredients, such as fibers, into diets. However, obtaining structure-activity relationships for specific fiber types and their corresponding targets in the gut community is foundational for designing snack foods that evoke and/or reinforce microbiome responses that are beneficial to the host.Degradation of dietary polysaccharides is a function primarily performed by bacterial carbohydrate-active enzymes (CAZymes). The gut microbiome harbors tens of thousands of CAZyme genes belonging to at least 136 glycoside hydrolase (GH) and 29 polysaccharide lyase (PL) families [extrapolated and updated from El Kaoutari et al. (8)]. In contrast, the human genome only contains 98 GH and no PL genes (9), of which <20% contribute to the processing of dietary glycans.In the current study, we test the effects of dietary supplementation with two snack food prototypes, one containing pea fiber and the other orange fiber, in two pilot studies of overweight and obese individuals consuming their normal, unrestricted diets. Our strategy was to focus on fiber-associated changes in the abundances of microbial GH and PL genes to determine whether responses to the pea or orange fiber prototypes in the gut microbiome and host are decipherable against a background of varying dietary practices and starting microbiome configurations. Higher order singular value decomposition (10) was utilized as a feature selection tool to identify treatment-discriminating changes in GH and PL gene representation. Mass spectrometric assays of the levels of fecal glycan structures (glycosidic linkages) were subsequently performed and the results were correlated with changes in the abundances of treatment-discriminating GH and PL genes with known or predicted substrate specificities. Our analysis concluded by measuring changes in levels of 1,305 plasma proteins in each study participant as a function of fiber treatment and applying computational tools to identify links between these microbiome and plasma proteome changes in response to fiber consumption. Our results provide an approach, using pilot human studies, for selecting specific fiber preparations, plus informative microbiome and host biomarkers, that can be advanced to proof-of-concept clinical trials which assess their capacity for precise manipulation of microbiome and host features.     

Nuevos modelos predictivos de bacteriemia en el servicio de urgencias: un paso adelante

La atención de pacientes con sospecha de un proceso infeccioso en los servicios de urgencias hospitalarios(SUH) se ha incrementado en la última década hasta suponer alrededor del 15-20% de todas las atenciones diarias. En la valoración inicial de estos enfermos se toman muestras para los distintos estudios microbiológicos en un 45% de los casos, donde predomina la obtención de hemocultivos (HC), en el 14,6% de todos ellos. La rentabilidad diagnóstica de estos HC es muy variable (2-20%). Los focos o procesos infecciosos más frecuentes sospechados o confirmados de las bacteriemias verdaderas(BV) en los SUH son la infección del tracto urinario (45%) y la infección respiratoria (25%). Por todo ello, la sospecha y confirmación de la BV tiene un relevante significado diagnóstico, pronóstico y obliga a cambiar algunas de las decisiones más importantes a tomar en el SUH. Entre otras, indicar el alta o ingreso, extraer HC y administrar el antimicrobiano adecuado y precoz. La intención de esta revisión es poner de manifiesto las evidencias científicas publicadas en los últimos cinco años, aclarar las controversias existentes actuales y comparar la capacidad para predecir bacteriemia de los últimos modelos predictivos publicados desde el año 2017 con los ya existentes en esa fecha, año en el que se publicó una revisión que dejaba abierta la propuesta de seguir buscando un modelo con un rendimiento adecuado para los SUH. Y así, a partir de ella, generar distintas recomendaciones que ayuden a definir el papel que pueden tener estos modelos o escalas en la mejora de la indicación de obtención de los HC, así como en la toma inmediata de otras decisiones diagnóstico-terapéuticas (administración precoz y adecuada del tratamiento antibiótico, solicitud de estudios complementarios y otras muestras microbiológicas, intensidad del soporte hemodinámico, necesidad de ingreso, etc.)