Gut microbiota in preterm infants receiving breast milk or mixed feeding.

BACKGROUND: Preterm birth is the leading cause of mortality in newborns, with very-low-birth-weight infants usually experiencing several complications. Breast milk is considered the gold standard of nutrition, especially for preterm infants with delayed gut colonization, because it contains beneficial microorganisms, such as Lactobacilli and Bifidobacteria. AIM: To analyze the gut microbiota of breastfed preterm infants with a birth weight of 1500 g or less. METHODS: An observational study was performed on preterm infants with up to 36.6 wk of gestation and a birth weight of 1500 g or less, born at the University Hospital Dr. José Eleuterio González at Monterrey, Mexico. A total of 40 preterm neonates were classified into breast milk feeding (BM) and mixed feeding (MF) groups (21 in the BM group and 19 in the MF group), from October 2017 to June 2019. Fecal samples were collected before they were introduced to any feeding type. After full enteral feeding was achieved, the composition of the gut microbiota was analyzed using 16S rRNA gene sequencing. Numerical variables were compared using Student's t-test or using the Mann-Whitney U test for nonparametric variables. Dominance, evenness, equitability, Margalef's index, Fisher's alpha, Chao-1 index, and Shannon's diversity index were also calculated. RESULTS: No significant differences were observed at the genus level between the groups. Class comparison indicated higher counts of Alphaproteobacteria and Betaproteobacteria in the initial compared to the final sample of the BM group (P < 0.011). In addition, higher counts of Gammaproteobacteria were detected in the final than in the initial sample (P = 0.040). According to the Margalef index, Fisher's alpha, and Chao-1 index, a decrease in species richness from the initial to the final sample, regardless of the feeding type, was observed (P < 0.050). The four predominant phyla were Bacteroidetes, Actinobacteria, Firmicutes, and Proteobacteria, with Proteobacteria being the most abundant. However, no significant differences were observed between the initial and final samples at the phylum level. CONCLUSION: Breastfeeding is associated with a decrease in Alphaproteobacteria and Betaproteobacteria and an increase of Gammaproteobacteria, contributing to the literature of the gut microbiota structure of very low-birth-weight, preterm.

Factores de riesgo asociados a ingreso a Unidad de Cuidados Intensivos en pacientes con COVID-19 en hospitales colombianos, estudio de cohorte / Risk factors associated with admission in the Intensive Care Unit among patients with COVID-19 in Colombian hospitals, a cohort study

INTRODUCCIÓN: Los pacientes hospitalizados con COVID-19 presentan un espectro clínico variable y su gravedad puede ser predicha por la presencia de factores de riesgo. OBJETIVO: Determinar los factores asociados al ingreso a UCI en pacientes internados por COVID-19 en Colombia. PACIENTES Y MÉTODOS: Estudio de cohorte multicéntrico, retrospectivo, en pacientes adultos hospitalizados por COVID-19 en Colombia, desde marzo de 2020 a enero de 2021. Se describieron las características de los pacientes y se establecieron predictores de ingreso a la UCI mediante un modelo de regresión logística. RESULTADOS: Se incluyeron 1.160 pacientes, edad media de 55 años, 59,7% fueron hombres y 426 pacientes (36,7%) ingresaron a UCI. Los factores asociados al ingreso a UCI fueron edad (OR 1,25; IC 95%: 1,14-1,37), sobrepeso (OR 2,82; IC 95%: 1,98-4,02) y obesidad (OR 2,97; IC 95%: 2,03-4,37), antecedente de cardiopatía valvular (OR 6,46; IC 95%: 1,84-27,48), hipotensión arterial al ingreso (OR 2,35; IC 95%: 1,40-3,97), SIRS (OR 2,03; IC 95%: 1,50-2,74), disnea (OR 1,52; IC 95%: 1,09-2.14), requerimiento de oxígeno (OR 2,64; IC 95%: 1,67-4,30), neutrofilia (OR1,09; IC 95%: 1,05-1,13), elevación de dímero D (OR 1,09; IC 95%: 1,03-1,18), compromiso multilobar (OR 2,19; IC 95%: 1,58-3,07) y consolidación pulmonar (OR1,52; IC 95%: 1,13-2,04). La mortalidad intrahospitalaria fue de 14,4% (166 pacientes), 2,3% entre los que no ingresaron a la UCI y 35,2% entre los que sí lo hicieron. CONCLUSIÓN: El 36,7% de pacientes hospitalizados por COVID-19 ingresó a UCI, identificándose predictores clínicos y de laboratorio asociados con este desenlace. La elaboración de modelos predictores con estos parámetros podría mejorar el pronóstico de los pacientes con COVID-19 que se hospitalizan.

BACKGROUND: Hospitalized patients with COVID-19 present a variable clinical spectrum and its severity might be predicted by the presence of risk factors. AIM: To determine the factors associated with ICU admission in patients hospitalized for COVID-19 in Colombia. METHOD: Retrospective multicenter cohort study, in adult patients hospitalized for COVID-19 in Colombia, from March 2020 to January 2021. Population characteristics were described and ICU admission predictors were established using a logistic regression model. RESULTS: 1,160 patients were included, mean age 55 years, 59.7% were men and 426 patients (36.7%) were admitted to the ICU. The associated factors were age (OR 1.25, 95% CI: 1.14-1.37), overweight (OR 2.82, 95% CI: 1.98-4.02) and obesity (OR 2.97, 95% CI: 2.03-4.37), valvular heart disease (OR 6.46, 95% CI: 1.84-27.48) hypotension at admission (OR 2.35, 95% CI: 1.40-3, 97), SIRS (OR 2.03, 95% CI: 1.50-2.74), dyspnea (OR 1.52, 95% CI: 1.09-2.14), oxygen requirement (OR 2.64, 95% CI: 1.67-4.30), neutrophilia (OR 1.09, 95% CI: 1.05-1.13), elevated D-dimer (OR 1.09, 95% CI: 1.03-1.18), multilobar lung involvement (OR 2.19, 95% CI: 1.58-3.07) and pulmonary consolidation (OR 1.52, 95% CI: 1.13-2.04). In-hospital mortality was 14.4% (166 patients), 2.3% among those that did not enter to the ICU and 35.2% among those who did. CONCLUSION: 36.7% of patients hospitalized for COVID-19 were admitted to the ICU. We identified clinical predictors associated with this outcome. Predictive models using these parameters could improve the prognostic of those patients with COVID-19 that are hospitalized.

Evidences of the Effect of GO and rGO in PCL Membranes on the Differentiation and Maturation of Human Neural Progenitor Cells.

The effect of doping graphene oxide (GO) and reduced graphene oxide (rGO) into poly(ε-caprolactone) (PCL) membranes prepared by solvent induced phase separation is evaluated in terms of nanomaterial distribution and compatibility with neural stem cell growth and functional differentiation. Raman spectra analyses demonstrate the homogeneous distribution of GO on the membrane surface while rGO concentration increases gradually toward the center of the membrane thickness. This behavior is associated with electrostatic repulsion that PCL exerted toward the polar GO and its affinity for the non-polar rGO. In vitro cell studies using human induced pluripotent cell derived neural progenitor cells (NPCs) show that rGO increases marker expression of NPCs differentiation with respect to GO (significantly to tissue culture plate (TCP)). Moreover, the distinctive nanomaterials distribution defines the cell-to-nanomaterial interaction on the PCL membranes: GO nanomaterials on the membrane surface favor higher number of active matured neurons, while PCL/rGO membranes present cells with significantly higher magnitude of neural activity compared to TCP and PCL/GO despite there being no direct contact of rGO with the cells on the membrane surface. Overall, this work evidences the important role of rGO electrical properties on the stimulation of neural cell electro-activity on PCL membrane scaffolds.

Schwann Cell Precursor Transplant in a Rat Spinal Cord Injury Model.

BACKGROUND: Differentiation of mesenchymal stem cells into Schwann cell precursors could reverse established lesions and sequelae of medullary transection. OBJECTIVE: The objective of this study was to study the clinical response of mesenchymal stem cell transplantation with Schwann precursor cell transplantation in a rat spinal cord injury model, using motor function and histopathologic studies. MATERIALS AND METHODS: A total of 28 Sprague-Dawley rats were randomly divided among four groups (n = 7 in each): sham group, control group, mesenchymal stem cell transplant group, and Schwann cell precursor transplant group. The surgical procedure was a laminectomy with transection of the spinal cord at the T11 level in the transplant groups and the injury control group. After 1 week, the transplant groups received stem cells directly in the injury site. Hind limb motor function was assessed using the locomotive scale of Basso, Beattie, and Bresnahan. 1 month after transplantation, all specimens were sacrificed to make a histopathologic description of sections taken from the site of injury and where stem cells were transplanted. Mean scores of mobility were compared using analysis of variance (ANOVA) of one factor with 95% reliability between groups and ANOVA of repetitive measures to evaluate evolution in the same group. RESULTS: We observed that the control group had statistically greater mobility than the other groups (p < 0.0001) and that the group with spinal injury without treatment had the lowest mean mobility. The mobility score values from the Schwann cell precursor group were statistically higher than the group treated with mesenchymal stem cells (p < 0.0001). CONCLUSION: Schwann precursor cells had a greater effect on locomotive function than mesenchymal stem cells.

Hydrolytic Degradation and Mechanical Stability of Poly(ε-Caprolactone)/Reduced Graphene Oxide Membranes as Scaffolds for In Vitro Neural Tissue Regeneration.

The present work studies the functional behavior of novel poly(ε-caprolactone) (PCL) membranes functionalized with reduced graphene oxide (rGO) nanoplatelets under simulated in vitro culture conditions (phosphate buffer solution (PBS) at 37 °C) during 1 year, in order to elucidate their applicability as scaffolds for in vitro neural regeneration. The morphological, chemical, and DSC results demonstrated that high internal porosity of the membranes facilitated water permeation and procured an accelerated hydrolytic degradation throughout the bulk pathway. Therefore, similar molecular weight reduction, from 80 kDa to 33 kDa for the control PCL, and to 27 kDa for PCL/rGO membranes, at the end of the study, was observed. After 1 year of hydrolytic degradation, though monomers coming from the hydrolytic cleavage of PCL diffused towards the PBS medium, the pH was barely affected, and the rGO nanoplatelets mainly remained in the membranes which envisaged low cytotoxic effect. On the other hand, the presence of rGO nanomaterials accelerated the loss of mechanical stability of the membranes. However, it is envisioned that the gradual degradation of the PCL/rGO membranes could facilitate cells infiltration, interconnectivity, and tissue formation.